text: 
  /*
   * Copyright (C) Igor Sysoev
   * Copyright (C) Nginx, Inc.
   * Copyright (C) Intel, Inc.
   */
  
  
  #include <ngx_config.h>
  #include <ngx_core.h>
  #include <ngx_event.h>
  #include <ngx_ssl_engine.h>
  
  
  #define NGX_SSL_PASSWORD_BUFFER_SIZE  4096
  
  
  static X509 *ngx_ssl_load_certificate(ngx_pool_t *pool, char **err,
      ngx_str_t *cert, STACK_OF(X509) **chain);
  static EVP_PKEY *ngx_ssl_load_certificate_key(ngx_pool_t *pool, char **err,
      ngx_str_t *key, ngx_array_t *passwords);
  static int ngx_ssl_password_callback(char *buf, int size, int rwflag,
      void *userdata);
  static int ngx_ssl_verify_callback(int ok, X509_STORE_CTX *x509_store);
  static void ngx_ssl_info_callback(const ngx_ssl_conn_t *ssl_conn, int where,
      int ret);
  static void ngx_ssl_passwords_cleanup(void *data);
  static int ngx_ssl_new_client_session(ngx_ssl_conn_t *ssl_conn,
      ngx_ssl_session_t *sess);
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
  static ngx_int_t ngx_ssl_try_early_data(ngx_connection_t *c);
  #endif
  #if (NGX_DEBUG)
  static void ngx_ssl_handshake_log(ngx_connection_t *c);
  #endif
  static void ngx_ssl_handshake_handler(ngx_event_t *ev);
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
  static ssize_t ngx_ssl_recv_early(ngx_connection_t *c, u_char *buf,
      size_t size);
  #endif
  static ngx_int_t ngx_ssl_handle_recv(ngx_connection_t *c, int n);
  static void ngx_ssl_write_handler(ngx_event_t *wev);
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
  static ssize_t ngx_ssl_write_early(ngx_connection_t *c, u_char *data,
      size_t size);
  #endif
  static void ngx_ssl_read_handler(ngx_event_t *rev);
  static void ngx_ssl_shutdown_handler(ngx_event_t *ev);
  static void ngx_ssl_connection_error(ngx_connection_t *c, int sslerr,
      ngx_err_t err, char *text);
  static void ngx_ssl_clear_error(ngx_log_t *log);
  
  static ngx_int_t ngx_ssl_session_id_context(ngx_ssl_t *ssl,
      ngx_str_t *sess_ctx, ngx_array_t *certificates);
  static int ngx_ssl_new_session(ngx_ssl_conn_t *ssl_conn,
      ngx_ssl_session_t *sess);
  static ngx_ssl_session_t *ngx_ssl_get_cached_session(ngx_ssl_conn_t *ssl_conn,
  #if OPENSSL_VERSION_NUMBER >= 0x10100003L
      const
  #endif
      u_char *id, int len, int *copy);
  static void ngx_ssl_remove_session(SSL_CTX *ssl, ngx_ssl_session_t *sess);
  static void ngx_ssl_expire_sessions(ngx_ssl_session_cache_t *cache,
      ngx_slab_pool_t *shpool, ngx_uint_t n);
  static void ngx_ssl_session_rbtree_insert_value(ngx_rbtree_node_t *temp,
      ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
  
  #ifdef SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB
  static int ngx_ssl_session_ticket_key_callback(ngx_ssl_conn_t *ssl_conn,
      unsigned char *name, unsigned char *iv, EVP_CIPHER_CTX *ectx,
      HMAC_CTX *hctx, int enc);
  static void ngx_ssl_session_ticket_keys_cleanup(void *data);
  #endif
  
  #ifndef X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT
  static ngx_int_t ngx_ssl_check_name(ngx_str_t *name, ASN1_STRING *str);
  #endif
  
  static time_t ngx_ssl_parse_time(
  #if OPENSSL_VERSION_NUMBER > 0x10100000L
      const
  #endif
      ASN1_TIME *asn1time, ngx_log_t *log);
  
  static void ngx_ssl_handshake_async_handler(ngx_event_t * aev);
  static void ngx_ssl_read_async_handler(ngx_event_t * aev);
  static void ngx_ssl_write_async_handler(ngx_event_t * aev);
  static void ngx_ssl_shutdown_async_handler(ngx_event_t *aev);
  
  
  #define NGX_ASYNC_EVENT_TIMEOUT 10000
  
  
  int  ngx_ssl_connection_index;
  int  ngx_ssl_server_conf_index;
  int  ngx_ssl_session_cache_index;
  int  ngx_ssl_session_ticket_keys_index;
  int  ngx_ssl_ocsp_index;
  int  ngx_ssl_certificate_index;
  int  ngx_ssl_next_certificate_index;
  int  ngx_ssl_certificate_name_index;
  int  ngx_ssl_stapling_index;
  
  
  static void
  ngx_ssl_empty_handler(ngx_event_t *ev)
  {
      ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ev->log, 0, "ssl empty handler");
  
      if(ev->timedout &&
         ev->saved_handler &&
         ev->saved_handler != ngx_ssl_empty_handler ) {
          ev->saved_handler(ev);
      }
  
      return;
  }
  
  
  ngx_int_t
  ngx_ssl_init(ngx_log_t *log)
  {
  #if OPENSSL_VERSION_NUMBER >= 0x10100003L
  
      if (OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL) == 0) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0, "OPENSSL_init_ssl() failed");
          return NGX_ERROR;
      }
  
      /*
       * OPENSSL_init_ssl() may leave errors in the error queue
       * while returning success
       */
  
      ERR_clear_error();
  
      ENGINE_load_builtin_engines();
      ENGINE_load_dynamic();
  #else
  
      OPENSSL_config(NULL);
  
      SSL_library_init();
      SSL_load_error_strings();
  
      OpenSSL_add_all_algorithms();
  
  #endif
  
  #ifndef SSL_OP_NO_COMPRESSION
      {
      /*
       * Disable gzip compression in OpenSSL prior to 1.0.0 version,
       * this saves about 522K per connection.
       */
      int                  n;
      STACK_OF(SSL_COMP)  *ssl_comp_methods;
  
      ssl_comp_methods = SSL_COMP_get_compression_methods();
      n = sk_SSL_COMP_num(ssl_comp_methods);
  
      while (n--) {
          (void) sk_SSL_COMP_pop(ssl_comp_methods);
      }
      }
  #endif
  
      ngx_ssl_connection_index = SSL_get_ex_new_index(0, NULL, NULL, NULL, NULL);
  
      if (ngx_ssl_connection_index == -1) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0, "SSL_get_ex_new_index() failed");
          return NGX_ERROR;
      }
  
      ngx_ssl_server_conf_index = SSL_CTX_get_ex_new_index(0, NULL, NULL, NULL,
                                                           NULL);
      if (ngx_ssl_server_conf_index == -1) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0,
                        "SSL_CTX_get_ex_new_index() failed");
          return NGX_ERROR;
      }
  
      ngx_ssl_session_cache_index = SSL_CTX_get_ex_new_index(0, NULL, NULL, NULL,
                                                             NULL);
      if (ngx_ssl_session_cache_index == -1) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0,
                        "SSL_CTX_get_ex_new_index() failed");
          return NGX_ERROR;
      }
  
      ngx_ssl_session_ticket_keys_index = SSL_CTX_get_ex_new_index(0, NULL, NULL,
                                                                   NULL, NULL);
      if (ngx_ssl_session_ticket_keys_index == -1) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0,
                        "SSL_CTX_get_ex_new_index() failed");
          return NGX_ERROR;
      }
  
      ngx_ssl_ocsp_index = SSL_CTX_get_ex_new_index(0, NULL, NULL, NULL, NULL);
      if (ngx_ssl_ocsp_index == -1) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0,
                        "SSL_CTX_get_ex_new_index() failed");
          return NGX_ERROR;
      }
  
      ngx_ssl_certificate_index = SSL_CTX_get_ex_new_index(0, NULL, NULL, NULL,
                                                           NULL);
      if (ngx_ssl_certificate_index == -1) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0,
                        "SSL_CTX_get_ex_new_index() failed");
          return NGX_ERROR;
      }
  
      ngx_ssl_next_certificate_index = X509_get_ex_new_index(0, NULL, NULL, NULL,
                                                             NULL);
      if (ngx_ssl_next_certificate_index == -1) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0, "X509_get_ex_new_index() failed");
          return NGX_ERROR;
      }
  
      ngx_ssl_certificate_name_index = X509_get_ex_new_index(0, NULL, NULL, NULL,
                                                             NULL);
  
      if (ngx_ssl_certificate_name_index == -1) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0, "X509_get_ex_new_index() failed");
          return NGX_ERROR;
      }
  
      ngx_ssl_stapling_index = X509_get_ex_new_index(0, NULL, NULL, NULL, NULL);
  
      if (ngx_ssl_stapling_index == -1) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0, "X509_get_ex_new_index() failed");
          return NGX_ERROR;
      }
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_create(ngx_ssl_t *ssl, ngx_uint_t protocols, void *data)
  {
      ssl->ctx = SSL_CTX_new(SSLv23_method());
  
      if (ssl->ctx == NULL) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "SSL_CTX_new() failed");
          return NGX_ERROR;
      }
  
      if (SSL_CTX_set_ex_data(ssl->ctx, ngx_ssl_server_conf_index, data) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_set_ex_data() failed");
          return NGX_ERROR;
      }
  
      if (SSL_CTX_set_ex_data(ssl->ctx, ngx_ssl_certificate_index, NULL) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_set_ex_data() failed");
          return NGX_ERROR;
      }
  
      ssl->buffer_size = NGX_SSL_BUFSIZE;
  
      /* client side options */
  
  #ifdef SSL_OP_MICROSOFT_SESS_ID_BUG
      SSL_CTX_set_options(ssl->ctx, SSL_OP_MICROSOFT_SESS_ID_BUG);
  #endif
  
  #ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG
      SSL_CTX_set_options(ssl->ctx, SSL_OP_NETSCAPE_CHALLENGE_BUG);
  #endif
  
      /* server side options */
  
  #ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG
      SSL_CTX_set_options(ssl->ctx, SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG);
  #endif
  
  #ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER
      SSL_CTX_set_options(ssl->ctx, SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER);
  #endif
  
  #ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING
      /* this option allow a potential SSL 2.0 rollback (CAN-2005-2969) */
      SSL_CTX_set_options(ssl->ctx, SSL_OP_MSIE_SSLV2_RSA_PADDING);
  #endif
  
  #ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG
      SSL_CTX_set_options(ssl->ctx, SSL_OP_SSLEAY_080_CLIENT_DH_BUG);
  #endif
  
  #ifdef SSL_OP_TLS_D5_BUG
      SSL_CTX_set_options(ssl->ctx, SSL_OP_TLS_D5_BUG);
  #endif
  
  #ifdef SSL_OP_TLS_BLOCK_PADDING_BUG
      SSL_CTX_set_options(ssl->ctx, SSL_OP_TLS_BLOCK_PADDING_BUG);
  #endif
  
  #ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
      SSL_CTX_set_options(ssl->ctx, SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS);
  #endif
  
      SSL_CTX_set_options(ssl->ctx, SSL_OP_SINGLE_DH_USE);
  
  #if OPENSSL_VERSION_NUMBER >= 0x009080dfL
      /* only in 0.9.8m+ */
      SSL_CTX_clear_options(ssl->ctx,
                            SSL_OP_NO_SSLv2|SSL_OP_NO_SSLv3|SSL_OP_NO_TLSv1);
  #endif
  
      if (!(protocols & NGX_SSL_SSLv2)) {
          SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_SSLv2);
      }
      if (!(protocols & NGX_SSL_SSLv3)) {
          SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_SSLv3);
      }
      if (!(protocols & NGX_SSL_TLSv1)) {
          SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_TLSv1);
      }
  #ifdef SSL_OP_NO_TLSv1_1
      SSL_CTX_clear_options(ssl->ctx, SSL_OP_NO_TLSv1_1);
      if (!(protocols & NGX_SSL_TLSv1_1)) {
          SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_TLSv1_1);
      }
  #endif
  #ifdef SSL_OP_NO_TLSv1_2
      SSL_CTX_clear_options(ssl->ctx, SSL_OP_NO_TLSv1_2);
      if (!(protocols & NGX_SSL_TLSv1_2)) {
          SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_TLSv1_2);
      }
  #endif
  #ifdef SSL_OP_NO_TLSv1_3
      SSL_CTX_clear_options(ssl->ctx, SSL_OP_NO_TLSv1_3);
      if (!(protocols & NGX_SSL_TLSv1_3)) {
          SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_TLSv1_3);
      }
  #endif
  
  #ifdef SSL_CTX_set_min_proto_version
      SSL_CTX_set_min_proto_version(ssl->ctx, 0);
      SSL_CTX_set_max_proto_version(ssl->ctx, TLS1_2_VERSION);
  #endif
  
  #ifdef TLS1_3_VERSION
      SSL_CTX_set_min_proto_version(ssl->ctx, 0);
      SSL_CTX_set_max_proto_version(ssl->ctx, TLS1_3_VERSION);
  #endif
  
  #ifdef SSL_OP_NO_COMPRESSION
      SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_COMPRESSION);
  #endif
  
  #ifdef SSL_OP_NO_ANTI_REPLAY
      SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_ANTI_REPLAY);
  #endif
  
  #ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
      SSL_CTX_set_options(ssl->ctx, SSL_OP_NO_CLIENT_RENEGOTIATION);
  #endif
  
  #ifdef SSL_MODE_RELEASE_BUFFERS
      SSL_CTX_set_mode(ssl->ctx, SSL_MODE_RELEASE_BUFFERS);
  #endif
  
  #ifdef SSL_MODE_NO_AUTO_CHAIN
      SSL_CTX_set_mode(ssl->ctx, SSL_MODE_NO_AUTO_CHAIN);
  #endif
  
      if(ssl->asynch) {
          SSL_CTX_set_mode(ssl->ctx, SSL_MODE_ASYNC);
      }
  
      SSL_CTX_set_read_ahead(ssl->ctx, 1);
  
      SSL_CTX_set_info_callback(ssl->ctx, ngx_ssl_info_callback);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_certificates(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_array_t *certs,
      ngx_array_t *keys, ngx_array_t *passwords)
  {
      ngx_str_t   *cert, *key;
      ngx_uint_t   i;
  
      cert = certs->elts;
      key = keys->elts;
  
      for (i = 0; i < certs->nelts; i++) {
  
          if (ngx_ssl_certificate(cf, ssl, &cert[i], &key[i], passwords)
              != NGX_OK)
          {
              return NGX_ERROR;
          }
      }
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *cert,
      ngx_str_t *key, ngx_array_t *passwords)
  {
      char            *err;
      X509            *x509;
      EVP_PKEY        *pkey;
      STACK_OF(X509)  *chain;
  
      ngx_ssl_engine_unload_check(cf->cycle);
  
      x509 = ngx_ssl_load_certificate(cf->pool, &err, cert, &chain);
      if (x509 == NULL) {
          if (err != NULL) {
              ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                            "cannot load certificate \"%s\": %s",
                            cert->data, err);
          }
  
          return NGX_ERROR;
      }
  
      if (SSL_CTX_use_certificate(ssl->ctx, x509) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_use_certificate(\"%s\") failed", cert->data);
          X509_free(x509);
          sk_X509_pop_free(chain, X509_free);
          return NGX_ERROR;
      }
  
      if (X509_set_ex_data(x509, ngx_ssl_certificate_name_index, cert->data)
          == 0)
      {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "X509_set_ex_data() failed");
          X509_free(x509);
          sk_X509_pop_free(chain, X509_free);
          return NGX_ERROR;
      }
  
      if (X509_set_ex_data(x509, ngx_ssl_next_certificate_index,
                        SSL_CTX_get_ex_data(ssl->ctx, ngx_ssl_certificate_index))
          == 0)
      {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "X509_set_ex_data() failed");
          X509_free(x509);
          sk_X509_pop_free(chain, X509_free);
          return NGX_ERROR;
      }
  
      if (SSL_CTX_set_ex_data(ssl->ctx, ngx_ssl_certificate_index, x509) == 0) {
  
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_set_ex_data() failed");
          X509_free(x509);
          sk_X509_pop_free(chain, X509_free);
          return NGX_ERROR;
      }
  
      /*
       * Note that x509 is not freed here, but will be instead freed in
       * ngx_ssl_cleanup_ctx().  This is because we need to preserve all
       * certificates to be able to iterate all of them through exdata
       * (ngx_ssl_certificate_index, ngx_ssl_next_certificate_index),
       * while OpenSSL can free a certificate if it is replaced with another
       * certificate of the same type.
       */
  
  #ifdef SSL_CTX_set0_chain
  
      if (SSL_CTX_set0_chain(ssl->ctx, chain) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_set0_chain(\"%s\") failed", cert->data);
          sk_X509_pop_free(chain, X509_free);
          return NGX_ERROR;
      }
  
  #else
      {
      int  n;
  
      /* SSL_CTX_set0_chain() is only available in OpenSSL 1.0.2+ */
  
      n = sk_X509_num(chain);
  
      while (n--) {
          x509 = sk_X509_shift(chain);
  
          if (SSL_CTX_add_extra_chain_cert(ssl->ctx, x509) == 0) {
              ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                            "SSL_CTX_add_extra_chain_cert(\"%s\") failed",
                            cert->data);
              sk_X509_pop_free(chain, X509_free);
              return NGX_ERROR;
          }
      }
  
      sk_X509_free(chain);
      }
  #endif
  
      pkey = ngx_ssl_load_certificate_key(cf->pool, &err, key, passwords);
      if (pkey == NULL) {
          if (err != NULL) {
              ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                            "cannot load certificate key \"%s\": %s",
                            key->data, err);
          }
  
          return NGX_ERROR;
      }
  
      if (SSL_CTX_use_PrivateKey(ssl->ctx, pkey) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_use_PrivateKey(\"%s\") failed", key->data);
          EVP_PKEY_free(pkey);
          return NGX_ERROR;
      }
  
      EVP_PKEY_free(pkey);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_connection_certificate(ngx_connection_t *c, ngx_pool_t *pool,
      ngx_str_t *cert, ngx_str_t *key, ngx_array_t *passwords)
  {
      char            *err;
      X509            *x509;
      EVP_PKEY        *pkey;
      STACK_OF(X509)  *chain;
  
      x509 = ngx_ssl_load_certificate(pool, &err, cert, &chain);
      if (x509 == NULL) {
          if (err != NULL) {
              ngx_ssl_error(NGX_LOG_ERR, c->log, 0,
                            "cannot load certificate \"%s\": %s",
                            cert->data, err);
          }
  
          return NGX_ERROR;
      }
  
      if (SSL_use_certificate(c->ssl->connection, x509) == 0) {
          ngx_ssl_error(NGX_LOG_ERR, c->log, 0,
                        "SSL_use_certificate(\"%s\") failed", cert->data);
          X509_free(x509);
          sk_X509_pop_free(chain, X509_free);
          return NGX_ERROR;
      }
  
      X509_free(x509);
  
  #ifdef SSL_set0_chain
  
      /*
       * SSL_set0_chain() is only available in OpenSSL 1.0.2+,
       * but this function is only called via certificate callback,
       * which is only available in OpenSSL 1.0.2+ as well
       */
  
      if (SSL_set0_chain(c->ssl->connection, chain) == 0) {
          ngx_ssl_error(NGX_LOG_ERR, c->log, 0,
                        "SSL_set0_chain(\"%s\") failed", cert->data);
          sk_X509_pop_free(chain, X509_free);
          return NGX_ERROR;
      }
  
  #endif
  
      pkey = ngx_ssl_load_certificate_key(pool, &err, key, passwords);
      if (pkey == NULL) {
          if (err != NULL) {
              ngx_ssl_error(NGX_LOG_ERR, c->log, 0,
                            "cannot load certificate key \"%s\": %s",
                            key->data, err);
          }
  
          return NGX_ERROR;
      }
  
      if (SSL_use_PrivateKey(c->ssl->connection, pkey) == 0) {
          ngx_ssl_error(NGX_LOG_ERR, c->log, 0,
                        "SSL_use_PrivateKey(\"%s\") failed", key->data);
          EVP_PKEY_free(pkey);
          return NGX_ERROR;
      }
  
      EVP_PKEY_free(pkey);
  
      return NGX_OK;
  }
  
  
  static X509 *
  ngx_ssl_load_certificate(ngx_pool_t *pool, char **err, ngx_str_t *cert,
      STACK_OF(X509) **chain)
  {
      BIO     *bio;
      X509    *x509, *temp;
      u_long   n;
  
      if (ngx_strncmp(cert->data, "data:", sizeof("data:") - 1) == 0) {
  
          bio = BIO_new_mem_buf(cert->data + sizeof("data:") - 1,
                                cert->len - (sizeof("data:") - 1));
          if (bio == NULL) {
              *err = "BIO_new_mem_buf() failed";
              return NULL;
          }
  
      } else {
  
          if (ngx_get_full_name(pool, (ngx_str_t *) &ngx_cycle->conf_prefix, cert)
              != NGX_OK)
          {
              *err = NULL;
              return NULL;
          }
  
          bio = BIO_new_file((char *) cert->data, "r");
          if (bio == NULL) {
              *err = "BIO_new_file() failed";
              return NULL;
          }
      }
  
      /* certificate itself */
  
      x509 = PEM_read_bio_X509_AUX(bio, NULL, NULL, NULL);
      if (x509 == NULL) {
          *err = "PEM_read_bio_X509_AUX() failed";
          BIO_free(bio);
          return NULL;
      }
  
      /* rest of the chain */
  
      *chain = sk_X509_new_null();
      if (*chain == NULL) {
          *err = "sk_X509_new_null() failed";
          BIO_free(bio);
          X509_free(x509);
          return NULL;
      }
  
      for ( ;; ) {
  
          temp = PEM_read_bio_X509(bio, NULL, NULL, NULL);
          if (temp == NULL) {
              n = ERR_peek_last_error();
  
              if (ERR_GET_LIB(n) == ERR_LIB_PEM
                  && ERR_GET_REASON(n) == PEM_R_NO_START_LINE)
              {
                  /* end of file */
                  ERR_clear_error();
                  break;
              }
  
              /* some real error */
  
              *err = "PEM_read_bio_X509() failed";
              BIO_free(bio);
              X509_free(x509);
              sk_X509_pop_free(*chain, X509_free);
              return NULL;
          }
  
          if (sk_X509_push(*chain, temp) == 0) {
              *err = "sk_X509_push() failed";
              BIO_free(bio);
              X509_free(x509);
              sk_X509_pop_free(*chain, X509_free);
              return NULL;
          }
      }
  
      BIO_free(bio);
  
      return x509;
  }
  
  
  static EVP_PKEY *
  ngx_ssl_load_certificate_key(ngx_pool_t *pool, char **err,
      ngx_str_t *key, ngx_array_t *passwords)
  {
      BIO              *bio;
      EVP_PKEY         *pkey;
      ngx_str_t        *pwd;
      ngx_uint_t        tries;
      pem_password_cb  *cb;
  
      if (ngx_strncmp(key->data, "engine:", sizeof("engine:") - 1) == 0) {
  
  #ifndef OPENSSL_NO_ENGINE
  
          u_char  *p, *last;
          ENGINE  *engine;
  
          p = key->data + sizeof("engine:") - 1;
          last = (u_char *) ngx_strchr(p, ':');
  
          if (last == NULL) {
              *err = "invalid syntax";
              return NULL;
          }
  
          *last = '\0';
  
          engine = ENGINE_by_id((char *) p);
  
          if (engine == NULL) {
              *err = "ENGINE_by_id() failed";
              return NULL;
          }
  
          *last++ = ':';
  
          pkey = ENGINE_load_private_key(engine, (char *) last, 0, 0);
  
          if (pkey == NULL) {
              *err = "ENGINE_load_private_key() failed";
              ENGINE_free(engine);
              return NULL;
          }
  
          ENGINE_free(engine);
  
          return pkey;
  
  #else
  
          *err = "loading \"engine:...\" certificate keys is not supported";
          return NULL;
  
  #endif
      }
  
      if (ngx_strncmp(key->data, "data:", sizeof("data:") - 1) == 0) {
  
          bio = BIO_new_mem_buf(key->data + sizeof("data:") - 1,
                                key->len - (sizeof("data:") - 1));
          if (bio == NULL) {
              *err = "BIO_new_mem_buf() failed";
              return NULL;
          }
  
      } else {
  
          if (ngx_get_full_name(pool, (ngx_str_t *) &ngx_cycle->conf_prefix, key)
              != NGX_OK)
          {
              *err = NULL;
              return NULL;
          }
  
          bio = BIO_new_file((char *) key->data, "r");
          if (bio == NULL) {
              *err = "BIO_new_file() failed";
              return NULL;
          }
      }
  
      if (passwords) {
          tries = passwords->nelts;
          pwd = passwords->elts;
          cb = ngx_ssl_password_callback;
  
      } else {
          tries = 1;
          pwd = NULL;
          cb = NULL;
      }
  
      for ( ;; ) {
  
          pkey = PEM_read_bio_PrivateKey(bio, NULL, cb, pwd);
          if (pkey != NULL) {
              break;
          }
  
          if (tries-- > 1) {
              ERR_clear_error();
              (void) BIO_reset(bio);
              pwd++;
              continue;
          }
  
          *err = "PEM_read_bio_PrivateKey() failed";
          BIO_free(bio);
          return NULL;
      }
  
      BIO_free(bio);
  
      return pkey;
  }
  
  
  static int
  ngx_ssl_password_callback(char *buf, int size, int rwflag, void *userdata)
  {
      ngx_str_t *pwd = userdata;
  
      if (rwflag) {
          ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
                        "ngx_ssl_password_callback() is called for encryption");
          return 0;
      }
  
      if (pwd == NULL) {
          return 0;
      }
  
      if (pwd->len > (size_t) size) {
          ngx_log_error(NGX_LOG_ERR, ngx_cycle->log, 0,
                        "password is truncated to %d bytes", size);
      } else {
          size = pwd->len;
      }
  
      ngx_memcpy(buf, pwd->data, size);
  
      return size;
  }
  
  
  ngx_int_t
  ngx_ssl_ciphers(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *ciphers,
      ngx_uint_t prefer_server_ciphers)
  {
      if (SSL_CTX_set_cipher_list(ssl->ctx, (char *) ciphers->data) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_set_cipher_list(\"%V\") failed",
                        ciphers);
          return NGX_ERROR;
      }
  
      if (prefer_server_ciphers) {
          SSL_CTX_set_options(ssl->ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
      }
  
  #if (OPENSSL_VERSION_NUMBER < 0x10100001L && !defined LIBRESSL_VERSION_NUMBER)
      /* a temporary 512-bit RSA key is required for export versions of MSIE */
      SSL_CTX_set_tmp_rsa_callback(ssl->ctx, ngx_ssl_rsa512_key_callback);
  #endif
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_client_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *cert,
      ngx_int_t depth)
  {
      STACK_OF(X509_NAME)  *list;
  
      SSL_CTX_set_verify(ssl->ctx, SSL_VERIFY_PEER, ngx_ssl_verify_callback);
  
      SSL_CTX_set_verify_depth(ssl->ctx, depth);
  
      if (cert->len == 0) {
          return NGX_OK;
      }
  
      if (ngx_conf_full_name(cf->cycle, cert, 1) != NGX_OK) {
          return NGX_ERROR;
      }
  
      if (SSL_CTX_load_verify_locations(ssl->ctx, (char *) cert->data, NULL)
          == 0)
      {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_load_verify_locations(\"%s\") failed",
                        cert->data);
          return NGX_ERROR;
      }
  
      /*
       * SSL_CTX_load_verify_locations() may leave errors in the error queue
       * while returning success
       */
  
      ERR_clear_error();
  
      list = SSL_load_client_CA_file((char *) cert->data);
  
      if (list == NULL) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_load_client_CA_file(\"%s\") failed", cert->data);
          return NGX_ERROR;
      }
  
      SSL_CTX_set_client_CA_list(ssl->ctx, list);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_trusted_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *cert,
      ngx_int_t depth)
  {
      SSL_CTX_set_verify(ssl->ctx, SSL_CTX_get_verify_mode(ssl->ctx),
                         ngx_ssl_verify_callback);
  
      SSL_CTX_set_verify_depth(ssl->ctx, depth);
  
      if (cert->len == 0) {
          return NGX_OK;
      }
  
      if (ngx_conf_full_name(cf->cycle, cert, 1) != NGX_OK) {
          return NGX_ERROR;
      }
  
      if (SSL_CTX_load_verify_locations(ssl->ctx, (char *) cert->data, NULL)
          == 0)
      {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_load_verify_locations(\"%s\") failed",
                        cert->data);
          return NGX_ERROR;
      }
  
      /*
       * SSL_CTX_load_verify_locations() may leave errors in the error queue
       * while returning success
       */
  
      ERR_clear_error();
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_crl(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *crl)
  {
      X509_STORE   *store;
      X509_LOOKUP  *lookup;
  
      if (crl->len == 0) {
          return NGX_OK;
      }
  
      if (ngx_conf_full_name(cf->cycle, crl, 1) != NGX_OK) {
          return NGX_ERROR;
      }
  
      store = SSL_CTX_get_cert_store(ssl->ctx);
  
      if (store == NULL) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_get_cert_store() failed");
          return NGX_ERROR;
      }
  
      lookup = X509_STORE_add_lookup(store, X509_LOOKUP_file());
  
      if (lookup == NULL) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "X509_STORE_add_lookup() failed");
          return NGX_ERROR;
      }
  
      if (X509_LOOKUP_load_file(lookup, (char *) crl->data, X509_FILETYPE_PEM)
          == 0)
      {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "X509_LOOKUP_load_file(\"%s\") failed", crl->data);
          return NGX_ERROR;
      }
  
      X509_STORE_set_flags(store,
                           X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL);
  
      return NGX_OK;
  }
  
  
  static int
  ngx_ssl_verify_callback(int ok, X509_STORE_CTX *x509_store)
  {
  #if (NGX_DEBUG)
      char              *subject, *issuer;
      int                err, depth;
      X509              *cert;
      X509_NAME         *sname, *iname;
      ngx_connection_t  *c;
      ngx_ssl_conn_t    *ssl_conn;
  
      ssl_conn = X509_STORE_CTX_get_ex_data(x509_store,
                                            SSL_get_ex_data_X509_STORE_CTX_idx());
  
      c = ngx_ssl_get_connection(ssl_conn);
  
      if (!(c->log->log_level & NGX_LOG_DEBUG_EVENT)) {
          return 1;
      }
  
      cert = X509_STORE_CTX_get_current_cert(x509_store);
      err = X509_STORE_CTX_get_error(x509_store);
      depth = X509_STORE_CTX_get_error_depth(x509_store);
  
      sname = X509_get_subject_name(cert);
  
      if (sname) {
          subject = X509_NAME_oneline(sname, NULL, 0);
          if (subject == NULL) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0,
                            "X509_NAME_oneline() failed");
          }
  
      } else {
          subject = NULL;
      }
  
      iname = X509_get_issuer_name(cert);
  
      if (iname) {
          issuer = X509_NAME_oneline(iname, NULL, 0);
          if (issuer == NULL) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0,
                            "X509_NAME_oneline() failed");
          }
  
      } else {
          issuer = NULL;
      }
  
      ngx_log_debug5(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "verify:%d, error:%d, depth:%d, "
                     "subject:\"%s\", issuer:\"%s\"",
                     ok, err, depth,
                     subject ? subject : "(none)",
                     issuer ? issuer : "(none)");
  
      if (subject) {
          OPENSSL_free(subject);
      }
  
      if (issuer) {
          OPENSSL_free(issuer);
      }
  #endif
  
      return 1;
  }
  
  
  static void
  ngx_ssl_info_callback(const ngx_ssl_conn_t *ssl_conn, int where, int ret)
  {
      BIO               *rbio, *wbio;
      ngx_connection_t  *c;
  
  #ifndef SSL_OP_NO_RENEGOTIATION
  
      if ((where & SSL_CB_HANDSHAKE_START)
          && SSL_is_server((ngx_ssl_conn_t *) ssl_conn))
      {
          c = ngx_ssl_get_connection((ngx_ssl_conn_t *) ssl_conn);
  
          if (c->ssl->handshaked) {
              c->ssl->renegotiation = 1;
              ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL renegotiation");
          }
      }
  
  #endif
  
      if ((where & SSL_CB_ACCEPT_LOOP) == SSL_CB_ACCEPT_LOOP) {
          c = ngx_ssl_get_connection((ngx_ssl_conn_t *) ssl_conn);
  
          if (!c->ssl->handshake_buffer_set) {
              /*
               * By default OpenSSL uses 4k buffer during a handshake,
               * which is too low for long certificate chains and might
               * result in extra round-trips.
               *
               * To adjust a buffer size we detect that buffering was added
               * to write side of the connection by comparing rbio and wbio.
               * If they are different, we assume that it's due to buffering
               * added to wbio, and set buffer size.
               */
  
              rbio = SSL_get_rbio(ssl_conn);
              wbio = SSL_get_wbio(ssl_conn);
  
              if (rbio != wbio) {
                  (void) BIO_set_write_buffer_size(wbio, NGX_SSL_BUFSIZE);
                  c->ssl->handshake_buffer_set = 1;
              }
          }
      }
  }
  
  
  RSA *
  ngx_ssl_rsa512_key_callback(ngx_ssl_conn_t *ssl_conn, int is_export,
      int key_length)
  {
      static RSA  *key;
  
      if (key_length != 512) {
          return NULL;
      }
  
  #if (OPENSSL_VERSION_NUMBER < 0x10100003L && !defined OPENSSL_NO_DEPRECATED)
  
      if (key == NULL) {
          key = RSA_generate_key(512, RSA_F4, NULL, NULL);
      }
  
  #endif
  
      return key;
  }
  
  
  ngx_array_t *
  ngx_ssl_read_password_file(ngx_conf_t *cf, ngx_str_t *file)
  {
      u_char              *p, *last, *end;
      size_t               len;
      ssize_t              n;
      ngx_fd_t             fd;
      ngx_str_t           *pwd;
      ngx_array_t         *passwords;
      ngx_pool_cleanup_t  *cln;
      u_char               buf[NGX_SSL_PASSWORD_BUFFER_SIZE];
  
      if (ngx_conf_full_name(cf->cycle, file, 1) != NGX_OK) {
          return NULL;
      }
  
      passwords = ngx_array_create(cf->temp_pool, 4, sizeof(ngx_str_t));
      if (passwords == NULL) {
          return NULL;
      }
  
      cln = ngx_pool_cleanup_add(cf->temp_pool, 0);
      if (cln == NULL) {
          return NULL;
      }
  
      cln->handler = ngx_ssl_passwords_cleanup;
      cln->data = passwords;
  
      fd = ngx_open_file(file->data, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0);
  
      if (fd == NGX_INVALID_FILE) {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
                             ngx_open_file_n " \"%s\" failed", file->data);
          return NULL;
      }
  
      len = 0;
      last = buf;
  
      do {
          n = ngx_read_fd(fd, last, NGX_SSL_PASSWORD_BUFFER_SIZE - len);
  
          if (n == -1) {
              ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
                                 ngx_read_fd_n " \"%s\" failed", file->data);
              passwords = NULL;
              goto cleanup;
          }
  
          end = last + n;
  
          if (len && n == 0) {
              *end++ = LF;
          }
  
          p = buf;
  
          for ( ;; ) {
              last = ngx_strlchr(last, end, LF);
  
              if (last == NULL) {
                  break;
              }
  
              len = last++ - p;
  
              if (len && p[len - 1] == CR) {
                  len--;
              }
  
              if (len) {
                  pwd = ngx_array_push(passwords);
                  if (pwd == NULL) {
                      passwords = NULL;
                      goto cleanup;
                  }
  
                  pwd->len = len;
                  pwd->data = ngx_pnalloc(cf->temp_pool, len);
  
                  if (pwd->data == NULL) {
                      passwords->nelts--;
                      passwords = NULL;
                      goto cleanup;
                  }
  
                  ngx_memcpy(pwd->data, p, len);
              }
  
              p = last;
          }
  
          len = end - p;
  
          if (len == NGX_SSL_PASSWORD_BUFFER_SIZE) {
              ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                 "too long line in \"%s\"", file->data);
              passwords = NULL;
              goto cleanup;
          }
  
          ngx_memmove(buf, p, len);
          last = buf + len;
  
      } while (n != 0);
  
      if (passwords->nelts == 0) {
          pwd = ngx_array_push(passwords);
          if (pwd == NULL) {
              passwords = NULL;
              goto cleanup;
          }
  
          ngx_memzero(pwd, sizeof(ngx_str_t));
      }
  
  cleanup:
  
      if (ngx_close_file(fd) == NGX_FILE_ERROR) {
          ngx_conf_log_error(NGX_LOG_ALERT, cf, ngx_errno,
                             ngx_close_file_n " \"%s\" failed", file->data);
      }
  
      ngx_explicit_memzero(buf, NGX_SSL_PASSWORD_BUFFER_SIZE);
  
      return passwords;
  }
  
  
  ngx_array_t *
  ngx_ssl_preserve_passwords(ngx_conf_t *cf, ngx_array_t *passwords)
  {
      ngx_str_t           *opwd, *pwd;
      ngx_uint_t           i;
      ngx_array_t         *pwds;
      ngx_pool_cleanup_t  *cln;
      static ngx_array_t   empty_passwords;
  
      if (passwords == NULL) {
  
          /*
           * If there are no passwords, an empty array is used
           * to make sure OpenSSL's default password callback
           * won't block on reading from stdin.
           */
  
          return &empty_passwords;
      }
  
      /*
       * Passwords are normally allocated from the temporary pool
       * and cleared after parsing configuration.  To be used at
       * runtime they have to be copied to the configuration pool.
       */
  
      pwds = ngx_array_create(cf->pool, passwords->nelts, sizeof(ngx_str_t));
      if (pwds == NULL) {
          return NULL;
      }
  
      cln = ngx_pool_cleanup_add(cf->pool, 0);
      if (cln == NULL) {
          return NULL;
      }
  
      cln->handler = ngx_ssl_passwords_cleanup;
      cln->data = pwds;
  
      opwd = passwords->elts;
  
      for (i = 0; i < passwords->nelts; i++) {
  
          pwd = ngx_array_push(pwds);
          if (pwd == NULL) {
              return NULL;
          }
  
          pwd->len = opwd[i].len;
          pwd->data = ngx_pnalloc(cf->pool, pwd->len);
  
          if (pwd->data == NULL) {
              pwds->nelts--;
              return NULL;
          }
  
          ngx_memcpy(pwd->data, opwd[i].data, opwd[i].len);
      }
  
      return pwds;
  }
  
  
  static void
  ngx_ssl_passwords_cleanup(void *data)
  {
      ngx_array_t *passwords = data;
  
      ngx_str_t   *pwd;
      ngx_uint_t   i;
  
      pwd = passwords->elts;
  
      for (i = 0; i < passwords->nelts; i++) {
          ngx_explicit_memzero(pwd[i].data, pwd[i].len);
      }
  }
  
  
  ngx_int_t
  ngx_ssl_dhparam(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *file)
  {
      DH   *dh;
      BIO  *bio;
  
      if (file->len == 0) {
          return NGX_OK;
      }
  
      if (ngx_conf_full_name(cf->cycle, file, 1) != NGX_OK) {
          return NGX_ERROR;
      }
  
      bio = BIO_new_file((char *) file->data, "r");
      if (bio == NULL) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "BIO_new_file(\"%s\") failed", file->data);
          return NGX_ERROR;
      }
  
      dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
      if (dh == NULL) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "PEM_read_bio_DHparams(\"%s\") failed", file->data);
          BIO_free(bio);
          return NGX_ERROR;
      }
  
      SSL_CTX_set_tmp_dh(ssl->ctx, dh);
  
      DH_free(dh);
      BIO_free(bio);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_ecdh_curve(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *name)
  {
  #ifndef OPENSSL_NO_ECDH
  
      /*
       * Elliptic-Curve Diffie-Hellman parameters are either "named curves"
       * from RFC 4492 section 5.1.1, or explicitly described curves over
       * binary fields.  OpenSSL only supports the "named curves", which provide
       * maximum interoperability.
       */
  
  #if (defined SSL_CTX_set1_curves_list || defined SSL_CTRL_SET_CURVES_LIST)
  
      /*
       * OpenSSL 1.0.2+ allows configuring a curve list instead of a single
       * curve previously supported.  By default an internal list is used,
       * with prime256v1 being preferred by server in OpenSSL 1.0.2b+
       * and X25519 in OpenSSL 1.1.0+.
       *
       * By default a curve preferred by the client will be used for
       * key exchange.  The SSL_OP_CIPHER_SERVER_PREFERENCE option can
       * be used to prefer server curves instead, similar to what it
       * does for ciphers.
       */
  
      SSL_CTX_set_options(ssl->ctx, SSL_OP_SINGLE_ECDH_USE);
  
  #if SSL_CTRL_SET_ECDH_AUTO
      /* not needed in OpenSSL 1.1.0+ */
      SSL_CTX_set_ecdh_auto(ssl->ctx, 1);
  #endif
  
      if (ngx_strcmp(name->data, "auto") == 0) {
          return NGX_OK;
      }
  
      if (SSL_CTX_set1_curves_list(ssl->ctx, (char *) name->data) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_set1_curves_list(\"%s\") failed", name->data);
          return NGX_ERROR;
      }
  
  #else
  
      int      nid;
      char    *curve;
      EC_KEY  *ecdh;
  
      if (ngx_strcmp(name->data, "auto") == 0) {
          curve = "prime256v1";
  
      } else {
          curve = (char *) name->data;
      }
  
      nid = OBJ_sn2nid(curve);
      if (nid == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "OBJ_sn2nid(\"%s\") failed: unknown curve", curve);
          return NGX_ERROR;
      }
  
      ecdh = EC_KEY_new_by_curve_name(nid);
      if (ecdh == NULL) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "EC_KEY_new_by_curve_name(\"%s\") failed", curve);
          return NGX_ERROR;
      }
  
      SSL_CTX_set_options(ssl->ctx, SSL_OP_SINGLE_ECDH_USE);
  
      SSL_CTX_set_tmp_ecdh(ssl->ctx, ecdh);
  
      EC_KEY_free(ecdh);
  #endif
  #endif
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_early_data(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_uint_t enable)
  {
      if (!enable) {
          return NGX_OK;
      }
  
  #ifdef SSL_ERROR_EARLY_DATA_REJECTED
  
      /* BoringSSL */
  
      SSL_CTX_set_early_data_enabled(ssl->ctx, 1);
  
  #elif defined SSL_READ_EARLY_DATA_SUCCESS
  
      /* OpenSSL */
  
      SSL_CTX_set_max_early_data(ssl->ctx, NGX_SSL_BUFSIZE);
  
  #else
      ngx_log_error(NGX_LOG_WARN, ssl->log, 0,
                    "\"ssl_early_data\" is not supported on this platform, "
                    "ignored");
  #endif
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_conf_commands(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_array_t *commands)
  {
      if (commands == NULL) {
          return NGX_OK;
      }
  
  #ifdef SSL_CONF_FLAG_FILE
      {
      int            type;
      u_char        *key, *value;
      ngx_uint_t     i;
      ngx_keyval_t  *cmd;
      SSL_CONF_CTX  *cctx;
  
      cctx = SSL_CONF_CTX_new();
      if (cctx == NULL) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CONF_CTX_new() failed");
          return NGX_ERROR;
      }
  
      SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_FILE);
      SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SERVER);
      SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CLIENT);
      SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CERTIFICATE);
      SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SHOW_ERRORS);
  
      SSL_CONF_CTX_set_ssl_ctx(cctx, ssl->ctx);
  
      cmd = commands->elts;
      for (i = 0; i < commands->nelts; i++) {
  
          key = cmd[i].key.data;
          type = SSL_CONF_cmd_value_type(cctx, (char *) key);
  
          if (type == SSL_CONF_TYPE_FILE || type == SSL_CONF_TYPE_DIR) {
              if (ngx_conf_full_name(cf->cycle, &cmd[i].value, 1) != NGX_OK) {
                  SSL_CONF_CTX_free(cctx);
                  return NGX_ERROR;
              }
          }
  
          value = cmd[i].value.data;
  
          if (SSL_CONF_cmd(cctx, (char *) key, (char *) value) <= 0) {
              ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                            "SSL_CONF_cmd(\"%s\", \"%s\") failed", key, value);
              SSL_CONF_CTX_free(cctx);
              return NGX_ERROR;
          }
      }
  
      if (SSL_CONF_CTX_finish(cctx) != 1) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CONF_finish() failed");
          SSL_CONF_CTX_free(cctx);
          return NGX_ERROR;
      }
  
      SSL_CONF_CTX_free(cctx);
  
      return NGX_OK;
      }
  #else
      ngx_log_error(NGX_LOG_EMERG, ssl->log, 0,
                    "SSL_CONF_cmd() is not available on this platform");
      return NGX_ERROR;
  #endif
  }
  
  
  ngx_int_t
  ngx_ssl_client_session_cache(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_uint_t enable)
  {
      if (!enable) {
          return NGX_OK;
      }
  
      SSL_CTX_set_session_cache_mode(ssl->ctx,
                                     SSL_SESS_CACHE_CLIENT
                                     |SSL_SESS_CACHE_NO_INTERNAL);
  
      SSL_CTX_sess_set_new_cb(ssl->ctx, ngx_ssl_new_client_session);
  
      return NGX_OK;
  }
  
  
  static int
  ngx_ssl_new_client_session(ngx_ssl_conn_t *ssl_conn, ngx_ssl_session_t *sess)
  {
      ngx_connection_t  *c;
  
      c = ngx_ssl_get_connection(ssl_conn);
  
      if (c->ssl->save_session) {
          c->ssl->session = sess;
  
          c->ssl->save_session(c);
  
          c->ssl->session = NULL;
      }
  
      return 0;
  }
  
  
  ngx_int_t
  ngx_ssl_create_connection(ngx_ssl_t *ssl, ngx_connection_t *c, ngx_uint_t flags)
  {
      ngx_ssl_connection_t  *sc;
  
      sc = ngx_pcalloc(c->pool, sizeof(ngx_ssl_connection_t));
      if (sc == NULL) {
          return NGX_ERROR;
      }
  
      sc->buffer = ((flags & NGX_SSL_BUFFER) != 0);
      sc->buffer_size = ssl->buffer_size;
  
      sc->session_ctx = ssl->ctx;
  
      if (ssl->max_pipelines > 0) {
          SSL_CTX_set_max_pipelines(ssl->ctx, ssl->max_pipelines);
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ssl->log, 0,
                  "Set max_pipelines = %d", ssl->max_pipelines);
      }
  
      if (ssl->split_send_fragment > 0) {
          SSL_CTX_set_split_send_fragment(ssl->ctx, ssl->split_send_fragment);
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ssl->log, 0,
                  "Set split_send_fragment = %d", ssl->split_send_fragment);
      }
  
      if (ssl->max_send_fragment > 0) {
          SSL_CTX_set_max_send_fragment(ssl->ctx, ssl->max_send_fragment);
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ssl->log, 0,
                  "Set max_send_fragment = %d", ssl->max_send_fragment);
      }
  
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
      if (SSL_CTX_get_max_early_data(ssl->ctx)) {
          sc->try_early_data = 1;
      }
  #endif
  
      sc->connection = SSL_new(ssl->ctx);
  
      if (sc->connection == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "SSL_new() failed");
          return NGX_ERROR;
      }
  
      if (SSL_set_fd(sc->connection, c->fd) == 0) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "SSL_set_fd() failed");
          return NGX_ERROR;
      }
  
      if (flags & NGX_SSL_CLIENT) {
          SSL_set_connect_state(sc->connection);
  
      } else {
          SSL_set_accept_state(sc->connection);
  
  #ifdef SSL_OP_NO_RENEGOTIATION
          SSL_set_options(sc->connection, SSL_OP_NO_RENEGOTIATION);
  #endif
      }
  
      if (SSL_set_ex_data(sc->connection, ngx_ssl_connection_index, c) == 0) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "SSL_set_ex_data() failed");
          return NGX_ERROR;
      }
  
      c->ssl = sc;
  
      if(ssl->asynch && !c->asynch) {
          c->asynch = ssl->asynch;
      } else if (c->asynch) {
          SSL_set_mode(sc->connection,SSL_MODE_ASYNC);
      }
  
      return NGX_OK;
  }
  
  
  ngx_ssl_session_t *
  ngx_ssl_get_session(ngx_connection_t *c)
  {
  #ifdef TLS1_3_VERSION
      if (c->ssl->session) {
          SSL_SESSION_up_ref(c->ssl->session);
          return c->ssl->session;
      }
  #endif
  
      return SSL_get1_session(c->ssl->connection);
  }
  
  
  ngx_ssl_session_t *
  ngx_ssl_get0_session(ngx_connection_t *c)
  {
      if (c->ssl->session) {
          return c->ssl->session;
      }
  
      return SSL_get0_session(c->ssl->connection);
  }
  
  
  ngx_int_t
  ngx_ssl_set_session(ngx_connection_t *c, ngx_ssl_session_t *session)
  {
      if (session) {
          if (SSL_set_session(c->ssl->connection, session) == 0) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "SSL_set_session() failed");
              return NGX_ERROR;
          }
      }
  
      return NGX_OK;
  }
  
  ngx_int_t
  ngx_ssl_async_process_fds(ngx_connection_t *c)
  {
      OSSL_ASYNC_FD *add_fds = NULL;
      OSSL_ASYNC_FD *del_fds = NULL;
      size_t        num_add_fds = 0;
      size_t        num_del_fds = 0;
      unsigned      loop = 0;
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "ngx_ssl_async_process_fds called");
  
      if (!ngx_del_async_conn || !ngx_add_async_conn) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0,
                        "Async notifications not supported");
          return 0;
      }
  
      SSL_get_changed_async_fds(c->ssl->connection, NULL, &num_add_fds,
                                NULL, &num_del_fds);
  
      if (num_add_fds) {
          add_fds = ngx_alloc(num_add_fds * sizeof(OSSL_ASYNC_FD), c->log);
          if (add_fds == NULL) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0,
                            "Memory Allocation Error");
              return 0;
          }
      }
  
      if (num_del_fds) {
          del_fds = ngx_alloc(num_del_fds * sizeof(OSSL_ASYNC_FD), c->log);
          if (del_fds == NULL) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0,
                            "Memory Allocation Error");
              if (add_fds)
                  ngx_free(add_fds);
              return 0;
          }
      }
  
      SSL_get_changed_async_fds(c->ssl->connection, add_fds, &num_add_fds,
                                del_fds, &num_del_fds);
  
      if (num_del_fds) {
          for (loop = 0; loop < num_del_fds; loop++) {
              c->async_fd = del_fds[loop];
              if (c->num_async_fds) {
                  ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "%s: deleting fd = %d", __func__, c->async_fd);
                  ngx_del_async_conn(c, NGX_DISABLE_EVENT);
                  c->num_async_fds--;
              }
          }
      }
      if (num_add_fds) {
          for (loop = 0; loop < num_add_fds; loop++) {
              if (c->num_async_fds == 0) {
                  c->num_async_fds++;
                  c->async_fd = add_fds[loop];
                  ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "%s: adding fd = %d", __func__, c->async_fd);
                  ngx_add_async_conn(c);
              }
          }
      }
  
      if (add_fds)
          ngx_free(add_fds);
      if (del_fds)
          ngx_free(del_fds);
  
      if (ngx_ssl_engine_enable_heuristic_polling) {
          ngx_ssl_engine_heuristic_poll(c->log);
      }
  
      return 1;
  }
  
  ngx_int_t
  ngx_ssl_handshake(ngx_connection_t *c)
  {
      int        n, sslerr;
      ngx_err_t  err;
      ngx_int_t  rc;
  
      if (c->asynch && !c->async->handler) {
          c->async->handler = ngx_ssl_empty_handler;
      }
  
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
      if (c->ssl->try_early_data) {
          return ngx_ssl_try_early_data(c);
      }
  #endif
  
      if (c->ssl->in_ocsp) {
          return ngx_ssl_ocsp_validate(c);
      }
  
      ngx_ssl_clear_error(c->log);
  
      n = SSL_do_handshake(c->ssl->connection);
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_do_handshake: %d", n);
  
      if (n == 1) {
  
          if(c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
  #if (NGX_DEBUG)
          ngx_ssl_handshake_log(c);
  #endif
  
          c->recv = ngx_ssl_recv;
          c->send = ngx_ssl_write;
          c->recv_chain = ngx_ssl_recv_chain;
          c->send_chain = ngx_ssl_send_chain;
  
  #ifndef SSL_OP_NO_RENEGOTIATION
  #if OPENSSL_VERSION_NUMBER < 0x10100000L
  #ifdef SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS
  
          /* initial handshake done, disable renegotiation (CVE-2009-3555) */
          if (c->ssl->connection->s3 && SSL_is_server(c->ssl->connection)) {
              c->ssl->connection->s3->flags |= SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS;
          }
  
  #endif
  #endif
  #endif
  
          rc = ngx_ssl_ocsp_validate(c);
  
          if (rc == NGX_ERROR) {
              return NGX_ERROR;
          }
  
          if (rc == NGX_AGAIN) {
              c->read->handler = ngx_ssl_handshake_handler;
              c->write->handler = ngx_ssl_handshake_handler;
              if (c->asynch) {
                  c->async->handler = ngx_ssl_handshake_async_handler;
              }
              return NGX_AGAIN;
          }
  
          c->ssl->handshaked = 1;
  
          return NGX_OK;
      }
  
      sslerr = SSL_get_error(c->ssl->connection, n);
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_get_error: %d", sslerr);
  
      if (sslerr == SSL_ERROR_WANT_READ) {
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
          c->read->ready = 0;
          c->read->handler = ngx_ssl_handshake_handler;
          c->write->handler = ngx_ssl_handshake_handler;
  
          if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          return NGX_AGAIN;
      }
  
      if (sslerr == SSL_ERROR_WANT_WRITE) {
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
          c->write->ready = 0;
          c->read->handler = ngx_ssl_handshake_handler;
          c->write->handler = ngx_ssl_handshake_handler;
  
          if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          return NGX_AGAIN;
      }
  
      if (c->asynch && sslerr == SSL_ERROR_WANT_ASYNC)
      {
          c->async->ready = 0;
          c->async->handler = ngx_ssl_handshake_async_handler;
          if (c->read->handler != ngx_ssl_empty_handler) {
              c->read->saved_handler = c->read->handler;
              c->read->handler = ngx_ssl_empty_handler;
          }
  
          if (c->write->handler != ngx_ssl_empty_handler) {
              c->write->saved_handler = c->write->handler;
              c->write->handler = ngx_ssl_empty_handler;
          }
  
          ngx_add_timer(c->async, NGX_ASYNC_EVENT_TIMEOUT);
  
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL ASYNC WANT recieved: \"%s\"", __func__);
  
          if (ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          return NGX_AGAIN;
      }
  
      err = (sslerr == SSL_ERROR_SYSCALL) ? ngx_errno : 0;
  
      c->ssl->no_wait_shutdown = 1;
      c->ssl->no_send_shutdown = 1;
      c->read->eof = 1;
  
      if (sslerr == SSL_ERROR_ZERO_RETURN || ERR_peek_error() == 0) {
          ngx_connection_error(c, err,
                               "peer closed connection in SSL handshake");
  
          return NGX_ERROR;
      }
  
      if (c->ssl->handshake_rejected) {
          ngx_connection_error(c, err, "handshake rejected");
          ERR_clear_error();
  
          return NGX_ERROR;
      }
  
      c->read->error = 1;
  
      ngx_ssl_connection_error(c, sslerr, err, "SSL_do_handshake() failed");
  
      return NGX_ERROR;
  }
  
  
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
  
  static ngx_int_t
  ngx_ssl_try_early_data(ngx_connection_t *c)
  {
      int        n, sslerr;
      u_char     buf;
      size_t     readbytes;
      ngx_err_t  err;
      ngx_int_t  rc;
  
      ngx_ssl_clear_error(c->log);
  
      readbytes = 0;
  
      n = SSL_read_early_data(c->ssl->connection, &buf, 1, &readbytes);
  
      ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "SSL_read_early_data: %d, %uz", n, readbytes);
  
      if (n == SSL_READ_EARLY_DATA_FINISH) {
          c->ssl->try_early_data = 0;
          return ngx_ssl_handshake(c);
      }
  
      if (n == SSL_READ_EARLY_DATA_SUCCESS) {
          if(c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
  #if (NGX_DEBUG)
          ngx_ssl_handshake_log(c);
  #endif
  
          c->ssl->try_early_data = 0;
  
          c->ssl->early_buf = buf;
          c->ssl->early_preread = 1;
  
          c->ssl->in_early = 1;
  
          c->recv = ngx_ssl_recv;
          c->send = ngx_ssl_write;
          c->recv_chain = ngx_ssl_recv_chain;
          c->send_chain = ngx_ssl_send_chain;
  
          rc = ngx_ssl_ocsp_validate(c);
  
          if (rc == NGX_ERROR) {
              return NGX_ERROR;
          }
  
          if (rc == NGX_AGAIN) {
              c->read->handler = ngx_ssl_handshake_handler;
              c->write->handler = ngx_ssl_handshake_handler;
              if (c->asynch) {
                  c->async->handler = ngx_ssl_handshake_async_handler;
              }
              return NGX_AGAIN;
          }
  
          c->ssl->handshaked = 1;
  
          return NGX_OK;
      }
  
      /* SSL_READ_EARLY_DATA_ERROR */
  
      sslerr = SSL_get_error(c->ssl->connection, n);
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_get_error: %d", sslerr);
  
      if (sslerr == SSL_ERROR_WANT_READ) {
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
          c->read->ready = 0;
          c->read->handler = ngx_ssl_handshake_handler;
          c->write->handler = ngx_ssl_handshake_handler;
  
          if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          return NGX_AGAIN;
      }
  
      if (sslerr == SSL_ERROR_WANT_WRITE) {
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
          c->write->ready = 0;
          c->read->handler = ngx_ssl_handshake_handler;
          c->write->handler = ngx_ssl_handshake_handler;
  
          if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          return NGX_AGAIN;
      }
      if (c->asynch && sslerr == SSL_ERROR_WANT_ASYNC)
      {
          c->async->ready = 0;
          c->async->handler = ngx_ssl_handshake_async_handler;
          if (c->read->handler != ngx_ssl_empty_handler) {
              c->read->saved_handler = c->read->handler;
              c->read->handler = ngx_ssl_empty_handler;
          }
  
          if (c->write->handler != ngx_ssl_empty_handler) {
              c->write->saved_handler = c->write->handler;
              c->write->handler = ngx_ssl_empty_handler;
          }
  
          ngx_add_timer(c->async, NGX_ASYNC_EVENT_TIMEOUT);
  
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL ASYNC WANT recieved: \"%s\"", __func__);
  
          if (ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
  
          return NGX_AGAIN;
      }
  
      err = (sslerr == SSL_ERROR_SYSCALL) ? ngx_errno : 0;
  
      c->ssl->no_wait_shutdown = 1;
      c->ssl->no_send_shutdown = 1;
      c->read->eof = 1;
  
      if (sslerr == SSL_ERROR_ZERO_RETURN || ERR_peek_error() == 0) {
          ngx_connection_error(c, err,
                               "peer closed connection in SSL handshake");
  
          return NGX_ERROR;
      }
  
      c->read->error = 1;
  
      ngx_ssl_connection_error(c, sslerr, err, "SSL_read_early_data() failed");
  
      return NGX_ERROR;
  }
  
  #endif
  
  
  #if (NGX_DEBUG)
  
  static void
  ngx_ssl_handshake_log(ngx_connection_t *c)
  {
      char         buf[129], *s, *d;
  #if OPENSSL_VERSION_NUMBER >= 0x10000000L
      const
  #endif
      SSL_CIPHER  *cipher;
  
      if (!(c->log->log_level & NGX_LOG_DEBUG_EVENT)) {
          return;
      }
  
      cipher = SSL_get_current_cipher(c->ssl->connection);
  
      if (cipher) {
          SSL_CIPHER_description(cipher, &buf[1], 128);
  
          for (s = &buf[1], d = buf; *s; s++) {
              if (*s == ' ' && *d == ' ') {
                  continue;
              }
  
              if (*s == LF || *s == CR) {
                  continue;
              }
  
              *++d = *s;
          }
  
          if (*d != ' ') {
              d++;
          }
  
          *d = '\0';
  
          ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL: %s, cipher: \"%s\"",
                         SSL_get_version(c->ssl->connection), &buf[1]);
  
          if (SSL_session_reused(c->ssl->connection)) {
              ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                             "SSL reused session");
          }
  
      } else {
          ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL no shared ciphers");
      }
  }
  
  #endif
  
  
  static void
  ngx_ssl_handshake_async_handler(ngx_event_t *aev)
  {
      ngx_connection_t  *c;
  
      c = aev->data;
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "SSL handshake async handler");
  
      if (!aev->ready && aev->timedout) {
          c->ssl->handler(c);
          return;
      }
  
      aev->ready = 0;
      aev->handler = ngx_ssl_empty_handler;
      if (c->read->saved_handler != ngx_ssl_empty_handler) {
          c->read->handler = c->read->saved_handler;
          c->read->saved_handler = ngx_ssl_empty_handler;
      }
  
      if (c->write->saved_handler != ngx_ssl_empty_handler) {
          c->write->handler = c->write->saved_handler;
          c->write->saved_handler = ngx_ssl_empty_handler;
      }
  
      if (ngx_ssl_handshake(c) == NGX_AGAIN) {
          return;
      }
  
      c->ssl->handler(c);
  }
  
  
  static void
  ngx_ssl_handshake_handler(ngx_event_t *ev)
  {
      ngx_connection_t  *c;
  
      c = ev->data;
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "SSL handshake handler: %d", ev->write);
  
      if (ev->timedout) {
          c->ssl->handler(c);
          return;
      }
  
      if (ngx_ssl_handshake(c) == NGX_AGAIN) {
          return;
      }
  
      c->ssl->handler(c);
  }
  
  
  ssize_t
  ngx_ssl_recv_chain(ngx_connection_t *c, ngx_chain_t *cl, off_t limit)
  {
      u_char     *last;
      ssize_t     n, bytes, size;
      ngx_buf_t  *b;
  
      bytes = 0;
  
      b = cl->buf;
      last = b->last;
  
      for ( ;; ) {
          size = b->end - last;
  
          if (limit) {
              if (bytes >= limit) {
                  return bytes;
              }
  
              if (bytes + size > limit) {
                  size = (ssize_t) (limit - bytes);
              }
          }
  
          n = ngx_ssl_recv(c, last, size);
  
          if (n > 0) {
              last += n;
              bytes += n;
  
              if (!c->read->ready) {
                  return bytes;
              }
  
              if (last == b->end) {
                  cl = cl->next;
  
                  if (cl == NULL) {
                      return bytes;
                  }
  
                  b = cl->buf;
                  last = b->last;
              }
  
              continue;
          }
  
          if (bytes) {
  
              if (n == 0 || n == NGX_ERROR) {
                  c->read->ready = 1;
              }
  
              return bytes;
          }
  
          return n;
      }
  }
  
  
  ssize_t
  ngx_ssl_recv(ngx_connection_t *c, u_char *buf, size_t size)
  {
      int  n, bytes;
  
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
      if (c->ssl->in_early) {
          return ngx_ssl_recv_early(c, buf, size);
      }
  #endif
  
      if (c->ssl->last == NGX_ERROR) {
          c->read->error = 1;
          return NGX_ERROR;
      }
  
      if (c->ssl->last == NGX_DONE) {
          c->read->ready = 0;
          c->read->eof = 1;
          return 0;
      }
  
      bytes = 0;
  
      ngx_ssl_clear_error(c->log);
  
      /*
       * SSL_read() may return data in parts, so try to read
       * until SSL_read() would return no data
       */
  
      for ( ;; ) {
  
          n = SSL_read(c->ssl->connection, buf, size);
  
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_read: %d", n);
  
          if (n > 0) {
              bytes += n;
          }
  
          c->ssl->last = ngx_ssl_handle_recv(c, n);
  
          if (c->ssl->last == NGX_OK) {
  
              size -= n;
  
              if (size == 0) {
                  c->read->ready = 1;
  
                  if (c->read->available >= 0) {
                      c->read->available -= bytes;
  
                      /*
                       * there can be data buffered at SSL layer,
                       * so we post an event to continue reading on the next
                       * iteration of the event loop
                       */
  
                      if (c->read->available < 0) {
                          c->read->available = 0;
                          c->read->ready = 0;
  
                          if (c->read->posted) {
                              ngx_delete_posted_event(c->read);
                          }
  
                          ngx_post_event(c->read, &ngx_posted_next_events);
                      }
  
                      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                                     "SSL_read: avail:%d", c->read->available);
  
                  } else {
  
  #if (NGX_HAVE_FIONREAD)
  
                      if (ngx_socket_nread(c->fd, &c->read->available) == -1) {
                          c->read->error = 1;
                          ngx_connection_error(c, ngx_socket_errno,
                                               ngx_socket_nread_n " failed");
                          return NGX_ERROR;
                      }
  
                      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                                     "SSL_read: avail:%d", c->read->available);
  
  #endif
                  }
  
                  return bytes;
              }
  
              buf += n;
  
              continue;
          }
  
          if (bytes) {
              if (c->ssl->last != NGX_AGAIN) {
                  c->read->ready = 1;
              }
  
              return bytes;
          }
  
          switch (c->ssl->last) {
  
          case NGX_DONE:
              c->read->ready = 0;
              c->read->eof = 1;
              return 0;
  
          case NGX_ERROR:
              c->read->error = 1;
  
              /* fall through */
  
          case NGX_AGAIN:
              return c->ssl->last;
          }
      }
  }
  
  
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
  
  static ssize_t
  ngx_ssl_recv_early(ngx_connection_t *c, u_char *buf, size_t size)
  {
      int        n, bytes;
      size_t     readbytes;
  
      if (c->ssl->last == NGX_ERROR) {
          c->read->error = 1;
          return NGX_ERROR;
      }
  
      if (c->ssl->last == NGX_DONE) {
          c->read->ready = 0;
          c->read->eof = 1;
          return 0;
      }
  
      bytes = 0;
  
      ngx_ssl_clear_error(c->log);
  
      if (c->ssl->early_preread) {
  
          if (size == 0) {
              c->read->ready = 0;
              c->read->eof = 1;
              return 0;
          }
  
          *buf = c->ssl->early_buf;
  
          c->ssl->early_preread = 0;
  
          bytes = 1;
          size -= 1;
          buf += 1;
      }
  
      if (c->ssl->write_blocked) {
          return NGX_AGAIN;
      }
  
      /*
       * SSL_read_early_data() may return data in parts, so try to read
       * until SSL_read_early_data() would return no data
       */
  
      for ( ;; ) {
  
          readbytes = 0;
  
          n = SSL_read_early_data(c->ssl->connection, buf, size, &readbytes);
  
          ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL_read_early_data: %d, %uz", n, readbytes);
  
          if (n == SSL_READ_EARLY_DATA_SUCCESS) {
  
              c->ssl->last = ngx_ssl_handle_recv(c, 1);
  
              bytes += readbytes;
              size -= readbytes;
  
              if (size == 0) {
                  c->read->ready = 1;
                  return bytes;
              }
  
              buf += readbytes;
  
              continue;
          }
  
          if (n == SSL_READ_EARLY_DATA_FINISH) {
  
              c->ssl->last = ngx_ssl_handle_recv(c, 1);
              c->ssl->in_early = 0;
  
              if (bytes) {
                  c->read->ready = 1;
                  return bytes;
              }
  
              return ngx_ssl_recv(c, buf, size);
          }
  
          /* SSL_READ_EARLY_DATA_ERROR */
  
          c->ssl->last = ngx_ssl_handle_recv(c, 0);
  
          if (bytes) {
              if (c->ssl->last != NGX_AGAIN) {
                  c->read->ready = 1;
              }
  
              return bytes;
          }
  
          switch (c->ssl->last) {
  
          case NGX_DONE:
              c->read->ready = 0;
              c->read->eof = 1;
              return 0;
  
          case NGX_ERROR:
              c->read->error = 1;
  
              /* fall through */
  
          case NGX_AGAIN:
              return c->ssl->last;
          }
      }
  }
  
  #endif
  
  
  static ngx_int_t
  ngx_ssl_handle_recv(ngx_connection_t *c, int n)
  {
      int        sslerr;
      ngx_err_t  err;
  
  #ifndef SSL_OP_NO_RENEGOTIATION
  
      if (c->ssl->renegotiation) {
          /*
           * disable renegotiation (CVE-2009-3555):
           * OpenSSL (at least up to 0.9.8l) does not handle disabled
           * renegotiation gracefully, so drop connection here
           */
  
          ngx_log_error(NGX_LOG_NOTICE, c->log, 0, "SSL renegotiation disabled");
  
          if (c->asynch \
              && SSL_get_error(c->ssl->connection, n) == SSL_ERROR_WANT_ASYNC) {
              c->async->ready = 0;
              c->async->handler = ngx_ssl_read_async_handler;
              if (c->read->handler != ngx_ssl_empty_handler) {
                  c->read->saved_handler = c->read->handler;
                  c->read->handler = ngx_ssl_empty_handler;
              }
              ngx_add_timer(c->async, NGX_ASYNC_EVENT_TIMEOUT);
  
              if (ngx_ssl_async_process_fds(c) == 0) {
                  return NGX_ERROR;
              }
  
              return NGX_AGAIN;
          }
  
          while (ERR_peek_error()) {
              ngx_ssl_error(NGX_LOG_DEBUG, c->log, 0,
                            "ignoring stale global SSL error");
          }
  
          ERR_clear_error();
  
          c->ssl->no_wait_shutdown = 1;
          c->ssl->no_send_shutdown = 1;
  
          return NGX_ERROR;
      }
  
  #endif
  
      if (n > 0) {
  
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          if (c->ssl->saved_write_handler) {
  
              c->write->handler = c->ssl->saved_write_handler;
              c->ssl->saved_write_handler = NULL;
              c->write->ready = 1;
  
              if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
                  return NGX_ERROR;
              }
  
              ngx_post_event(c->write, &ngx_posted_events);
          }
  
          return NGX_OK;
      }
  
      sslerr = SSL_get_error(c->ssl->connection, n);
      err = (sslerr == SSL_ERROR_SYSCALL) ? ngx_errno : 0;
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_get_error: %d", sslerr);
  
      if (sslerr == SSL_ERROR_WANT_READ) {
  
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          if (c->ssl->saved_write_handler) {
  
              c->write->handler = c->ssl->saved_write_handler;
              c->ssl->saved_write_handler = NULL;
              c->write->ready = 1;
  
              if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
                  return NGX_ERROR;
              }
  
              ngx_post_event(c->write, &ngx_posted_events);
          }
  
          c->read->ready = 0;
          return NGX_AGAIN;
      }
  
      if (sslerr == SSL_ERROR_WANT_WRITE) {
  
          ngx_log_error(NGX_LOG_INFO, c->log, 0,
                        "peer started SSL renegotiation");
  
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          c->write->ready = 0;
  
          if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          /*
           * we do not set the timer because there is already the read event timer
           */
  
          if (c->ssl->saved_write_handler == NULL) {
              c->ssl->saved_write_handler = c->write->handler;
              c->write->handler = ngx_ssl_write_handler;
          }
  
          return NGX_AGAIN;
      }
  
      if (c->asynch && sslerr == SSL_ERROR_WANT_ASYNC) {
          c->async->ready = 0;
          c->async->handler = ngx_ssl_read_async_handler;
          if (c->read->handler != ngx_ssl_empty_handler) {
              c->read->saved_handler = c->read->handler;
              c->read->handler = ngx_ssl_empty_handler;
          }
  
          ngx_add_timer(c->async, NGX_ASYNC_EVENT_TIMEOUT);
  
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL ASYNC WANT recieved: \"%s\"", __func__);
  
          if (ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          return NGX_AGAIN;
      }
  
      c->ssl->no_wait_shutdown = 1;
      c->ssl->no_send_shutdown = 1;
  
      if (sslerr == SSL_ERROR_ZERO_RETURN || ERR_peek_error() == 0) {
          ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "peer shutdown SSL cleanly");
          return NGX_DONE;
      }
  
      ngx_ssl_connection_error(c, sslerr, err, "SSL_read() failed");
  
      return NGX_ERROR;
  }
  
  
  static void
  ngx_ssl_read_async_handler(ngx_event_t *aev)
  {
      ngx_connection_t  *c;
  
      c = aev->data;
  
      if (c->destroyed) {
          return;
      }
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "SSL read async handler");
  
      aev->ready = 0;
      aev->handler = ngx_ssl_empty_handler;
      if (c->read->saved_handler != ngx_ssl_empty_handler) {
          c->read->handler = c->read->saved_handler;
          c->read->saved_handler = ngx_ssl_empty_handler;
      }
  
      c->read->ready = 1;
      c->read->handler(c->read);
  }
  
  
  static void
  ngx_ssl_write_handler(ngx_event_t *wev)
  {
      ngx_connection_t  *c;
  
      c = wev->data;
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL write handler");
  
      c->read->handler(c->read);
  }
  
  
  /*
   * OpenSSL has no SSL_writev() so we copy several bufs into our 16K buffer
   * before the SSL_write() call to decrease a SSL overhead.
   *
   * Besides for protocols such as HTTP it is possible to always buffer
   * the output to decrease a SSL overhead some more.
   */
  
  ngx_chain_t *
  ngx_ssl_send_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
  {
      int          n;
      ngx_uint_t   flush;
      ssize_t      send, size;
      ngx_buf_t   *buf;
  
      if (!c->ssl->buffer) {
  
          while (in) {
              if (ngx_buf_special(in->buf)) {
                  in = in->next;
                  continue;
              }
  
              n = ngx_ssl_write(c, in->buf->pos, in->buf->last - in->buf->pos);
  
              if (n == NGX_ERROR) {
                  return NGX_CHAIN_ERROR;
              }
  
              if (n == NGX_AGAIN) {
                  return in;
              }
  
              in->buf->pos += n;
  
              if (in->buf->pos == in->buf->last) {
                  in = in->next;
              }
          }
  
          return in;
      }
  
  
      /* the maximum limit size is the maximum int32_t value - the page size */
  
      if (limit == 0 || limit > (off_t) (NGX_MAX_INT32_VALUE - ngx_pagesize)) {
          limit = NGX_MAX_INT32_VALUE - ngx_pagesize;
      }
  
      buf = c->ssl->buf;
  
      if (buf == NULL) {
          buf = ngx_create_temp_buf(c->pool, c->ssl->buffer_size);
          if (buf == NULL) {
              return NGX_CHAIN_ERROR;
          }
  
          c->ssl->buf = buf;
      }
  
      if (buf->start == NULL) {
          buf->start = ngx_palloc(c->pool, c->ssl->buffer_size);
          if (buf->start == NULL) {
              return NGX_CHAIN_ERROR;
          }
  
          buf->pos = buf->start;
          buf->last = buf->start;
          buf->end = buf->start + c->ssl->buffer_size;
      }
  
      send = buf->last - buf->pos;
      flush = (in == NULL) ? 1 : buf->flush;
  
      for ( ;; ) {
  
          while (in && buf->last < buf->end && send < limit) {
              if (in->buf->last_buf || in->buf->flush) {
                  flush = 1;
              }
  
              if (ngx_buf_special(in->buf)) {
                  in = in->next;
                  continue;
              }
  
              size = in->buf->last - in->buf->pos;
  
              if (size > buf->end - buf->last) {
                  size = buf->end - buf->last;
              }
  
              if (send + size > limit) {
                  size = (ssize_t) (limit - send);
              }
  
              ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                             "SSL buf copy: %z", size);
  
              ngx_memcpy(buf->last, in->buf->pos, size);
  
              buf->last += size;
              in->buf->pos += size;
              send += size;
  
              if (in->buf->pos == in->buf->last) {
                  in = in->next;
              }
          }
  
          if (!flush && send < limit && buf->last < buf->end) {
              break;
          }
  
          size = buf->last - buf->pos;
  
          if (size == 0) {
              buf->flush = 0;
              c->buffered &= ~NGX_SSL_BUFFERED;
              return in;
          }
  
          n = ngx_ssl_write(c, buf->pos, size);
  
          if (n == NGX_ERROR) {
              return NGX_CHAIN_ERROR;
          }
  
          if (n == NGX_AGAIN) {
              break;
          }
  
          buf->pos += n;
  
          if (n < size) {
              break;
          }
  
          flush = 0;
  
          buf->pos = buf->start;
          buf->last = buf->start;
  
          if (in == NULL || send == limit) {
              break;
          }
      }
  
      buf->flush = flush;
  
      if (buf->pos < buf->last) {
          c->buffered |= NGX_SSL_BUFFERED;
  
      } else {
          c->buffered &= ~NGX_SSL_BUFFERED;
      }
  
      return in;
  }
  
  
  ssize_t
  ngx_ssl_write(ngx_connection_t *c, u_char *data, size_t size)
  {
      int        n, sslerr;
      ngx_err_t  err;
  
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
      if (c->ssl->in_early) {
          return ngx_ssl_write_early(c, data, size);
      }
  #endif
  
      ngx_ssl_clear_error(c->log);
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL to write: %uz", size);
  
      n = SSL_write(c->ssl->connection, data, size);
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_write: %d", n);
  
      if (n > 0) {
  
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          if (c->ssl->saved_read_handler) {
  
              c->read->handler = c->ssl->saved_read_handler;
              c->ssl->saved_read_handler = NULL;
              c->read->ready = 1;
  
              if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
                  return NGX_ERROR;
              }
  
              ngx_post_event(c->read, &ngx_posted_events);
          }
  
          c->sent += n;
  
          return n;
      }
  
      sslerr = SSL_get_error(c->ssl->connection, n);
  
      if (sslerr == SSL_ERROR_ZERO_RETURN) {
  
          /*
           * OpenSSL 1.1.1 fails to return SSL_ERROR_SYSCALL if an error
           * happens during SSL_write() after close_notify alert from the
           * peer, and returns SSL_ERROR_ZERO_RETURN instead,
           * https://git.openssl.org/?p=openssl.git;a=commitdiff;h=8051ab2
           */
  
          sslerr = SSL_ERROR_SYSCALL;
      }
  
      err = (sslerr == SSL_ERROR_SYSCALL) ? ngx_errno : 0;
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_get_error: %d", sslerr);
  
      if (sslerr == SSL_ERROR_WANT_WRITE) {
  
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          if (c->ssl->saved_read_handler) {
  
              c->read->handler = c->ssl->saved_read_handler;
              c->ssl->saved_read_handler = NULL;
              c->read->ready = 1;
  
              if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
                  return NGX_ERROR;
              }
  
              ngx_post_event(c->read, &ngx_posted_events);
          }
  
          c->write->ready = 0;
          return NGX_AGAIN;
      }
  
      if (sslerr == SSL_ERROR_WANT_READ) {
  
          ngx_log_error(NGX_LOG_INFO, c->log, 0,
                        "peer started SSL renegotiation");
  
          if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
          c->read->ready = 0;
  
          if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          /*
           * we do not set the timer because there is already
           * the write event timer
           */
  
          if (c->ssl->saved_read_handler == NULL) {
              c->ssl->saved_read_handler = c->read->handler;
              c->read->handler = ngx_ssl_read_handler;
          }
  
          return NGX_AGAIN;
      }
  
      if(c->asynch && sslerr == SSL_ERROR_WANT_ASYNC) {
          c->async->ready = 0;
          c->async->handler = ngx_ssl_write_async_handler;
          if (c->read->handler != ngx_ssl_empty_handler) {
              c->read->saved_handler = c->read->handler;
              c->read->handler = ngx_ssl_empty_handler;
          }
  
          ngx_add_timer(c->async, NGX_ASYNC_EVENT_TIMEOUT);
  
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL ASYNC WANT recieved: \"%s\"", __func__);
  
          if (ngx_ssl_async_process_fds(c) == 0) {
              return NGX_ERROR;
          }
  
          return NGX_AGAIN;
      }
  
      c->ssl->no_wait_shutdown = 1;
      c->ssl->no_send_shutdown = 1;
      c->write->error = 1;
  
      ngx_ssl_connection_error(c, sslerr, err, "SSL_write() failed");
  
      return NGX_ERROR;
  }
  
  
  static void
  ngx_ssl_write_async_handler(ngx_event_t *aev)
  {
      ngx_connection_t  *c;
  
      c = aev->data;
  
      if (c->destroyed) {
          return;
      }
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "SSL write async handler");
  
      aev->ready = 0;
      aev->handler = ngx_ssl_empty_handler;
      if (c->read->saved_handler != ngx_ssl_empty_handler) {
          c->read->handler = c->read->saved_handler;
          c->read->saved_handler = ngx_ssl_empty_handler;
      }
  
      c->write->handler(c->write);
  }
  
  
  #ifdef SSL_READ_EARLY_DATA_SUCCESS
  
  ssize_t
  ngx_ssl_write_early(ngx_connection_t *c, u_char *data, size_t size)
  {
      int        n, sslerr;
      size_t     written;
      ngx_err_t  err;
  
      ngx_ssl_clear_error(c->log);
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL to write: %uz", size);
  
      written = 0;
  
      n = SSL_write_early_data(c->ssl->connection, data, size, &written);
  
      ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "SSL_write_early_data: %d, %uz", n, written);
  
      if (n > 0) {
  
          if (c->ssl->saved_read_handler) {
  
              c->read->handler = c->ssl->saved_read_handler;
              c->ssl->saved_read_handler = NULL;
              c->read->ready = 1;
  
              if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
                  return NGX_ERROR;
              }
  
              ngx_post_event(c->read, &ngx_posted_events);
          }
  
          if (c->ssl->write_blocked) {
              c->ssl->write_blocked = 0;
              ngx_post_event(c->read, &ngx_posted_events);
          }
  
          c->sent += written;
  
          return written;
      }
  
      sslerr = SSL_get_error(c->ssl->connection, n);
  
      err = (sslerr == SSL_ERROR_SYSCALL) ? ngx_errno : 0;
  
      ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_get_error: %d", sslerr);
  
      if (sslerr == SSL_ERROR_WANT_WRITE) {
  
          ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL_write_early_data: want write");
  
          if (c->ssl->saved_read_handler) {
  
              c->read->handler = c->ssl->saved_read_handler;
              c->ssl->saved_read_handler = NULL;
              c->read->ready = 1;
  
              if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
                  return NGX_ERROR;
              }
  
              ngx_post_event(c->read, &ngx_posted_events);
          }
  
          /*
           * OpenSSL 1.1.1a fails to handle SSL_read_early_data()
           * if an SSL_write_early_data() call blocked on writing,
           * see https://github.com/openssl/openssl/issues/7757
           */
  
          c->ssl->write_blocked = 1;
  
          c->write->ready = 0;
          return NGX_AGAIN;
      }
  
      if (sslerr == SSL_ERROR_WANT_READ) {
  
          ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL_write_early_data: want read");
  
          c->read->ready = 0;
  
          if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
              return NGX_ERROR;
          }
  
          /*
           * we do not set the timer because there is already
           * the write event timer
           */
  
          if (c->ssl->saved_read_handler == NULL) {
              c->ssl->saved_read_handler = c->read->handler;
              c->read->handler = ngx_ssl_read_handler;
          }
  
          return NGX_AGAIN;
      }
  
      c->ssl->no_wait_shutdown = 1;
      c->ssl->no_send_shutdown = 1;
      c->write->error = 1;
  
      ngx_ssl_connection_error(c, sslerr, err, "SSL_write_early_data() failed");
  
      return NGX_ERROR;
  }
  
  #endif
  
  
  static void
  ngx_ssl_read_handler(ngx_event_t *rev)
  {
      ngx_connection_t  *c;
  
      c = rev->data;
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL read handler");
  
      c->write->handler(c->write);
  }
  
  
  void
  ngx_ssl_free_buffer(ngx_connection_t *c)
  {
      if (c->ssl->buf && c->ssl->buf->start) {
          if (ngx_pfree(c->pool, c->ssl->buf->start) == NGX_OK) {
              c->ssl->buf->start = NULL;
          }
      }
  }
  
  
  ngx_int_t
  ngx_ssl_shutdown(ngx_connection_t *c)
  {
      int         n, sslerr, mode;
      ngx_err_t   err;
      ngx_uint_t  tries;
  
      ngx_ssl_ocsp_cleanup(c);
  
      if(!c->ssl) {
          return NGX_OK;
      }
  
      if (SSL_in_init(c->ssl->connection)) {
          /*
           * OpenSSL 1.0.2f complains if SSL_shutdown() is called during
           * an SSL handshake, while previous versions always return 0.
           * Avoid calling SSL_shutdown() if handshake wasn't completed.
           */
  
          if(c->asynch) {
              /* Check if there is inflight request.
               * Wait till async job becomes finished.
               */
              if (SSL_want_async(c->ssl->connection)) {
                  ngx_ssl_async_process_fds(c);
                  if(!c->async->timer_set)
                      ngx_add_timer(c->async, NGX_ASYNC_EVENT_TIMEOUT);
                  return NGX_AGAIN;
              }
  
              /* Ignore errors from ngx_ssl_async_process_fds as
                 we want to carry on and close the SSL connection
                 anyway. */
              ngx_ssl_async_process_fds(c);
              if (ngx_del_async_conn) {
                  if (c->num_async_fds) {
                      ngx_del_async_conn(c, NGX_DISABLE_EVENT);
                      c->num_async_fds--;
                  }
              }
              if(ngx_del_conn && c->read->active) {
                  ngx_del_conn(c, NGX_DISABLE_EVENT);
              }
          }
  
          SSL_free(c->ssl->connection);
          c->ssl = NULL;
          c->recv = ngx_recv;
  
          return NGX_OK;
      }
  
      if (c->timedout || c->error || c->buffered) {
          mode = SSL_RECEIVED_SHUTDOWN|SSL_SENT_SHUTDOWN;
          SSL_set_quiet_shutdown(c->ssl->connection, 1);
  
      } else {
          mode = SSL_get_shutdown(c->ssl->connection);
  
          if (c->ssl->no_wait_shutdown) {
              mode |= SSL_RECEIVED_SHUTDOWN;
          }
  
          if (c->ssl->no_send_shutdown) {
              mode |= SSL_SENT_SHUTDOWN;
          }
  
          if (c->ssl->no_wait_shutdown && c->ssl->no_send_shutdown) {
              SSL_set_quiet_shutdown(c->ssl->connection, 1);
          }
      }
  
      SSL_set_shutdown(c->ssl->connection, mode);
  
      ngx_ssl_clear_error(c->log);
  
      tries = 2;
  
      for ( ;; ) {
  
          /*
           * For bidirectional shutdown, SSL_shutdown() needs to be called
           * twice: first call sends the "close notify" alert and returns 0,
           * second call waits for the peer's "close notify" alert.
           */
  
          n = SSL_shutdown(c->ssl->connection);
  
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_shutdown: %d", n);
  
          if (n == 1) {
              if(c->asynch) {
                  /* Ignore errors from ngx_ssl_async_process_fds as
                     we want to carry on and close the SSL connection
                     anyway. */
                  ngx_ssl_async_process_fds(c);
                  if (ngx_del_async_conn) {
                      if (c->num_async_fds) {
                          ngx_del_async_conn(c, NGX_DISABLE_EVENT);
                          c->num_async_fds--;
                      }
                  }
                  if(ngx_del_conn && c->read->active) {
                      ngx_del_conn(c, NGX_DISABLE_EVENT);
                  }
              }
  
              SSL_free(c->ssl->connection);
              c->ssl = NULL;
              c->recv = ngx_recv;
  
              return NGX_OK;
          }
  
          if (n == 0 && tries-- > 1) {
              if(c->asynch) {
                  /* Ignore errors from ngx_ssl_async_process_fds as
                     we want to carry on and close the SSL connection
                     anyway. */
                  ngx_ssl_async_process_fds(c);
                  if (ngx_del_async_conn) {
                      if (c->num_async_fds) {
                          ngx_del_async_conn(c, NGX_DISABLE_EVENT);
                          c->num_async_fds--;
                      }
                  }
                  if(ngx_del_conn && c->read->active) {
                      ngx_del_conn(c, NGX_DISABLE_EVENT);
                  }
              }
              continue;
          }
  
          /* before 0.9.8m SSL_shutdown() returned 0 instead of -1 on errors */
  
          sslerr = SSL_get_error(c->ssl->connection, n);
  
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL_get_error: %d", sslerr);
          if(c->asynch && n == -1) {
              if (sslerr == SSL_ERROR_WANT_ASYNC) {
                  c->async->ready = 0;
                  c->async->handler = ngx_ssl_shutdown_async_handler;
                  c->read->saved_handler = ngx_ssl_shutdown_handler;
                  if (c->read->handler != ngx_ssl_empty_handler)
                      c->read->handler = ngx_ssl_empty_handler;
                  c->write->handler = ngx_ssl_shutdown_handler;
  
                  ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                             "SSL ASYNC WANT recieved: \"%s\"", __func__);
  
                  ngx_add_timer(c->async, NGX_ASYNC_EVENT_TIMEOUT);
                  /* Ignore errors from ngx_ssl_async_process_fds as
                     we want to carry on anyway */
                  ngx_ssl_async_process_fds(c);
                  return NGX_AGAIN;
              }
  
              /* Ignore errors from ngx_ssl_async_process_fds as
                 we want to carry on and close the SSL connection
                 anyway. */
              ngx_ssl_async_process_fds(c);
              if (ngx_del_async_conn) {
                  if (c->num_async_fds) {
                      ngx_del_async_conn(c, NGX_DISABLE_EVENT);
                      c->num_async_fds--;
                  }
              }
              if(ngx_del_conn && c->read->active) {
                  ngx_del_conn(c, NGX_DISABLE_EVENT);
              }
          }
  
          if (sslerr == SSL_ERROR_WANT_READ || sslerr == SSL_ERROR_WANT_WRITE) {
              c->read->handler = ngx_ssl_shutdown_handler;
              c->write->handler = ngx_ssl_shutdown_handler;
              if (c->asynch && ngx_ssl_async_process_fds(c) == 0) {
                  return NGX_ERROR;
              }
  
              //Work around: Readd write event on shutdown;
              c->write->ready = 0;
              c->write->active = 0;
  
              if (sslerr == SSL_ERROR_WANT_READ) {
                  c->read->ready = 0;
  
              } else {
                  c->write->ready = 0;
              }
  
              if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
                  return NGX_ERROR;
              }
  
              if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
                  return NGX_ERROR;
              }
  
              ngx_add_timer(c->read, 3000);
  
              if (sslerr == SSL_ERROR_WANT_WRITE) {
                  ngx_add_timer(c->write, 10000);
              }
  
              return NGX_AGAIN;
          }
  
          if (sslerr == SSL_ERROR_ZERO_RETURN || ERR_peek_error() == 0) {
              if(c->asynch) {
                  /* Ignore errors from ngx_ssl_async_process_fds as
                     we want to carry on and close the SSL connection
                     anyway. */
                  ngx_ssl_async_process_fds(c);
                  if (ngx_del_async_conn) {
                      if (c->num_async_fds) {
                          ngx_del_async_conn(c, NGX_DISABLE_EVENT);
                          c->num_async_fds--;
                      }
                  }
                  if(ngx_del_conn && c->read->active) {
                      ngx_del_conn(c, NGX_DISABLE_EVENT);
                  }
              }
              SSL_free(c->ssl->connection);
              c->ssl = NULL;
              c->recv = ngx_recv;
  
              return NGX_OK;
          }
  
          err = (sslerr == SSL_ERROR_SYSCALL) ? ngx_errno : 0;
  
          ngx_ssl_connection_error(c, sslerr, err, "SSL_shutdown() failed");
  
          SSL_free(c->ssl->connection);
          c->ssl = NULL;
          c->recv = ngx_recv;
  
          return NGX_ERROR;
      }
  }
  
  
  static void
  ngx_ssl_shutdown_async_handler(ngx_event_t *aev)
  {
      ngx_connection_t           *c;
      ngx_connection_handler_pt   handler;
  
      c = aev->data;
      handler = c->ssl->handler;
  
      if (!aev->ready && aev->timedout) {
          c->timedout = 1;
      }
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, aev->log, 0,
                     "SSL shutdown async handler");
  
      aev->ready = 0;
      aev->handler = ngx_ssl_empty_handler;
      if (c->read->saved_handler != ngx_ssl_empty_handler) {
          c->read->handler = c->read->saved_handler;
          c->read->saved_handler = ngx_ssl_empty_handler;
      }
  
      if (ngx_ssl_shutdown(c) == NGX_AGAIN) {
          return;
      }
  
      handler(c);
  }
  
  
  static void
  ngx_ssl_shutdown_handler(ngx_event_t *ev)
  {
      ngx_connection_t           *c;
      ngx_connection_handler_pt   handler;
  
      c = ev->data;
      handler = c->ssl->handler;
  
      if (ev->timedout) {
          c->timedout = 1;
      }
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, 0, "SSL shutdown handler");
  
      if (ngx_ssl_shutdown(c) == NGX_AGAIN) {
          return;
      }
  
      handler(c);
  }
  
  
  static void
  ngx_ssl_connection_error(ngx_connection_t *c, int sslerr, ngx_err_t err,
      char *text)
  {
      int         n;
      ngx_uint_t  level;
  
      level = NGX_LOG_CRIT;
  
      if (sslerr == SSL_ERROR_SYSCALL) {
  
          if (err == NGX_ECONNRESET
  #if (NGX_WIN32)
              || err == NGX_ECONNABORTED
  #endif
              || err == NGX_EPIPE
              || err == NGX_ENOTCONN
              || err == NGX_ETIMEDOUT
              || err == NGX_ECONNREFUSED
              || err == NGX_ENETDOWN
              || err == NGX_ENETUNREACH
              || err == NGX_EHOSTDOWN
              || err == NGX_EHOSTUNREACH)
          {
              switch (c->log_error) {
  
              case NGX_ERROR_IGNORE_ECONNRESET:
              case NGX_ERROR_INFO:
                  level = NGX_LOG_INFO;
                  break;
  
              case NGX_ERROR_ERR:
                  level = NGX_LOG_ERR;
                  break;
  
              default:
                  break;
              }
          }
  
      } else if (sslerr == SSL_ERROR_SSL) {
  
          n = ERR_GET_REASON(ERR_peek_error());
  
              /* handshake failures */
          if (n == SSL_R_BAD_CHANGE_CIPHER_SPEC                        /*  103 */
  #ifdef SSL_R_NO_SUITABLE_KEY_SHARE
              || n == SSL_R_NO_SUITABLE_KEY_SHARE                      /*  101 */
  #endif
  #ifdef SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM
              || n == SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM            /*  118 */
  #endif
              || n == SSL_R_BLOCK_CIPHER_PAD_IS_WRONG                  /*  129 */
              || n == SSL_R_DIGEST_CHECK_FAILED                        /*  149 */
              || n == SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST              /*  151 */
              || n == SSL_R_EXCESSIVE_MESSAGE_SIZE                     /*  152 */
              || n == SSL_R_HTTPS_PROXY_REQUEST                        /*  155 */
              || n == SSL_R_HTTP_REQUEST                               /*  156 */
              || n == SSL_R_LENGTH_MISMATCH                            /*  159 */
  #ifdef SSL_R_NO_CIPHERS_PASSED
              || n == SSL_R_NO_CIPHERS_PASSED                          /*  182 */
  #endif
              || n == SSL_R_NO_CIPHERS_SPECIFIED                       /*  183 */
              || n == SSL_R_NO_COMPRESSION_SPECIFIED                   /*  187 */
              || n == SSL_R_NO_SHARED_CIPHER                           /*  193 */
              || n == SSL_R_RECORD_LENGTH_MISMATCH                     /*  213 */
  #ifdef SSL_R_CLIENTHELLO_TLSEXT
              || n == SSL_R_CLIENTHELLO_TLSEXT                         /*  226 */
  #endif
  #ifdef SSL_R_PARSE_TLSEXT
              || n == SSL_R_PARSE_TLSEXT                               /*  227 */
  #endif
  #ifdef SSL_R_CALLBACK_FAILED
              || n == SSL_R_CALLBACK_FAILED                            /*  234 */
  #endif
              || n == SSL_R_UNEXPECTED_MESSAGE                         /*  244 */
              || n == SSL_R_UNEXPECTED_RECORD                          /*  245 */
              || n == SSL_R_UNKNOWN_ALERT_TYPE                         /*  246 */
              || n == SSL_R_UNKNOWN_PROTOCOL                           /*  252 */
  #ifdef SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS
              || n == SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS             /*  253 */
  #endif
              || n == SSL_R_UNSUPPORTED_PROTOCOL                       /*  258 */
  #ifdef SSL_R_NO_SHARED_GROUP
              || n == SSL_R_NO_SHARED_GROUP                            /*  266 */
  #endif
              || n == SSL_R_WRONG_VERSION_NUMBER                       /*  267 */
              || n == SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC        /*  281 */
  #ifdef SSL_R_RENEGOTIATE_EXT_TOO_LONG
              || n == SSL_R_RENEGOTIATE_EXT_TOO_LONG                   /*  335 */
              || n == SSL_R_RENEGOTIATION_ENCODING_ERR                 /*  336 */
              || n == SSL_R_RENEGOTIATION_MISMATCH                     /*  337 */
  #endif
  #ifdef SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED
              || n == SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED       /*  338 */
  #endif
  #ifdef SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING
              || n == SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING           /*  345 */
  #endif
  #ifdef SSL_R_INAPPROPRIATE_FALLBACK
              || n == SSL_R_INAPPROPRIATE_FALLBACK                     /*  373 */
  #endif
  #ifdef SSL_R_CERT_CB_ERROR
              || n == SSL_R_CERT_CB_ERROR                              /*  377 */
  #endif
  #ifdef SSL_R_VERSION_TOO_LOW
              || n == SSL_R_VERSION_TOO_LOW                            /*  396 */
  #endif
              || n == 1000 /* SSL_R_SSLV3_ALERT_CLOSE_NOTIFY */
  #ifdef SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE
              || n == SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE             /* 1010 */
              || n == SSL_R_SSLV3_ALERT_BAD_RECORD_MAC                 /* 1020 */
              || n == SSL_R_TLSV1_ALERT_DECRYPTION_FAILED              /* 1021 */
              || n == SSL_R_TLSV1_ALERT_RECORD_OVERFLOW                /* 1022 */
              || n == SSL_R_SSLV3_ALERT_DECOMPRESSION_FAILURE          /* 1030 */
              || n == SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE              /* 1040 */
              || n == SSL_R_SSLV3_ALERT_NO_CERTIFICATE                 /* 1041 */
              || n == SSL_R_SSLV3_ALERT_BAD_CERTIFICATE                /* 1042 */
              || n == SSL_R_SSLV3_ALERT_UNSUPPORTED_CERTIFICATE        /* 1043 */
              || n == SSL_R_SSLV3_ALERT_CERTIFICATE_REVOKED            /* 1044 */
              || n == SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED            /* 1045 */
              || n == SSL_R_SSLV3_ALERT_CERTIFICATE_UNKNOWN            /* 1046 */
              || n == SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER              /* 1047 */
              || n == SSL_R_TLSV1_ALERT_UNKNOWN_CA                     /* 1048 */
              || n == SSL_R_TLSV1_ALERT_ACCESS_DENIED                  /* 1049 */
              || n == SSL_R_TLSV1_ALERT_DECODE_ERROR                   /* 1050 */
              || n == SSL_R_TLSV1_ALERT_DECRYPT_ERROR                  /* 1051 */
              || n == SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION             /* 1060 */
              || n == SSL_R_TLSV1_ALERT_PROTOCOL_VERSION               /* 1070 */
              || n == SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY          /* 1071 */
              || n == SSL_R_TLSV1_ALERT_INTERNAL_ERROR                 /* 1080 */
              || n == SSL_R_TLSV1_ALERT_USER_CANCELLED                 /* 1090 */
              || n == SSL_R_TLSV1_ALERT_NO_RENEGOTIATION               /* 1100 */
  #endif
              )
          {
              switch (c->log_error) {
  
              case NGX_ERROR_IGNORE_ECONNRESET:
              case NGX_ERROR_INFO:
                  level = NGX_LOG_INFO;
                  break;
  
              case NGX_ERROR_ERR:
                  level = NGX_LOG_ERR;
                  break;
  
              default:
                  break;
              }
          }
      }
  
      ngx_ssl_error(level, c->log, err, text);
  }
  
  
  static void
  ngx_ssl_clear_error(ngx_log_t *log)
  {
      while (ERR_peek_error()) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0, "ignoring stale global SSL error");
      }
  
      ERR_clear_error();
  }
  
  
  void ngx_cdecl
  ngx_ssl_error(ngx_uint_t level, ngx_log_t *log, ngx_err_t err, char *fmt, ...)
  {
      int          flags;
      u_long       n;
      va_list      args;
      u_char      *p, *last;
      u_char       errstr[NGX_MAX_CONF_ERRSTR];
      const char  *data;
  
      last = errstr + NGX_MAX_CONF_ERRSTR;
  
      va_start(args, fmt);
      p = ngx_vslprintf(errstr, last - 1, fmt, args);
      va_end(args);
  
      if (ERR_peek_error()) {
          p = ngx_cpystrn(p, (u_char *) " (SSL:", last - p);
  
          for ( ;; ) {
  
              n = ERR_peek_error_line_data(NULL, NULL, &data, &flags);
  
              if (n == 0) {
                  break;
              }
  
              /* ERR_error_string_n() requires at least one byte */
  
              if (p >= last - 1) {
                  goto next;
              }
  
              *p++ = ' ';
  
              ERR_error_string_n(n, (char *) p, last - p);
  
              while (p < last && *p) {
                  p++;
              }
  
              if (p < last && *data && (flags & ERR_TXT_STRING)) {
                  *p++ = ':';
                  p = ngx_cpystrn(p, (u_char *) data, last - p);
              }
  
          next:
  
              (void) ERR_get_error();
          }
  
          if (p < last) {
              *p++ = ')';
          }
      }
  
      ngx_log_error(level, log, err, "%*s", p - errstr, errstr);
  }
  
  
  ngx_int_t
  ngx_ssl_session_cache(ngx_ssl_t *ssl, ngx_str_t *sess_ctx,
      ngx_array_t *certificates, ssize_t builtin_session_cache,
      ngx_shm_zone_t *shm_zone, time_t timeout)
  {
      long  cache_mode;
  
      SSL_CTX_set_timeout(ssl->ctx, (long) timeout);
  
      if (ngx_ssl_session_id_context(ssl, sess_ctx, certificates) != NGX_OK) {
          return NGX_ERROR;
      }
  
      if (builtin_session_cache == NGX_SSL_NO_SCACHE) {
          SSL_CTX_set_session_cache_mode(ssl->ctx, SSL_SESS_CACHE_OFF);
          return NGX_OK;
      }
  
      if (builtin_session_cache == NGX_SSL_NONE_SCACHE) {
  
          /*
           * If the server explicitly says that it does not support
           * session reuse (see SSL_SESS_CACHE_OFF above), then
           * Outlook Express fails to upload a sent email to
           * the Sent Items folder on the IMAP server via a separate IMAP
           * connection in the background.  Therefore we have a special
           * mode (SSL_SESS_CACHE_SERVER|SSL_SESS_CACHE_NO_INTERNAL_STORE)
           * where the server pretends that it supports session reuse,
           * but it does not actually store any session.
           */
  
          SSL_CTX_set_session_cache_mode(ssl->ctx,
                                         SSL_SESS_CACHE_SERVER
                                         |SSL_SESS_CACHE_NO_AUTO_CLEAR
                                         |SSL_SESS_CACHE_NO_INTERNAL_STORE);
  
          SSL_CTX_sess_set_cache_size(ssl->ctx, 1);
  
          return NGX_OK;
      }
  
      cache_mode = SSL_SESS_CACHE_SERVER;
  
      if (shm_zone && builtin_session_cache == NGX_SSL_NO_BUILTIN_SCACHE) {
          cache_mode |= SSL_SESS_CACHE_NO_INTERNAL;
      }
  
      SSL_CTX_set_session_cache_mode(ssl->ctx, cache_mode);
  
      if (builtin_session_cache != NGX_SSL_NO_BUILTIN_SCACHE) {
  
          if (builtin_session_cache != NGX_SSL_DFLT_BUILTIN_SCACHE) {
              SSL_CTX_sess_set_cache_size(ssl->ctx, builtin_session_cache);
          }
      }
  
      if (shm_zone) {
          SSL_CTX_sess_set_new_cb(ssl->ctx, ngx_ssl_new_session);
          SSL_CTX_sess_set_get_cb(ssl->ctx, ngx_ssl_get_cached_session);
          SSL_CTX_sess_set_remove_cb(ssl->ctx, ngx_ssl_remove_session);
  
          if (SSL_CTX_set_ex_data(ssl->ctx, ngx_ssl_session_cache_index, shm_zone)
              == 0)
          {
              ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                            "SSL_CTX_set_ex_data() failed");
              return NGX_ERROR;
          }
      }
  
      return NGX_OK;
  }
  
  
  static ngx_int_t
  ngx_ssl_session_id_context(ngx_ssl_t *ssl, ngx_str_t *sess_ctx,
      ngx_array_t *certificates)
  {
      int                   n, i;
      X509                 *cert;
      X509_NAME            *name;
      ngx_str_t            *certs;
      ngx_uint_t            k;
      EVP_MD_CTX           *md;
      unsigned int          len;
      STACK_OF(X509_NAME)  *list;
      u_char                buf[EVP_MAX_MD_SIZE];
  
      /*
       * Session ID context is set based on the string provided,
       * the server certificates, and the client CA list.
       */
  
      md = EVP_MD_CTX_create();
      if (md == NULL) {
          return NGX_ERROR;
      }
  
      if (EVP_DigestInit_ex(md, EVP_sha1(), NULL) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "EVP_DigestInit_ex() failed");
          goto failed;
      }
  
      if (EVP_DigestUpdate(md, sess_ctx->data, sess_ctx->len) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "EVP_DigestUpdate() failed");
          goto failed;
      }
  
      for (cert = SSL_CTX_get_ex_data(ssl->ctx, ngx_ssl_certificate_index);
           cert;
           cert = X509_get_ex_data(cert, ngx_ssl_next_certificate_index))
      {
          if (X509_digest(cert, EVP_sha1(), buf, &len) == 0) {
              ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                            "X509_digest() failed");
              goto failed;
          }
  
          if (EVP_DigestUpdate(md, buf, len) == 0) {
              ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                            "EVP_DigestUpdate() failed");
              goto failed;
          }
      }
  
      if (SSL_CTX_get_ex_data(ssl->ctx, ngx_ssl_certificate_index) == NULL
          && certificates != NULL)
      {
          /*
           * If certificates are loaded dynamically, we use certificate
           * names as specified in the configuration (with variables).
           */
  
          certs = certificates->elts;
          for (k = 0; k < certificates->nelts; k++) {
  
              if (EVP_DigestUpdate(md, certs[k].data, certs[k].len) == 0) {
                  ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                                "EVP_DigestUpdate() failed");
                  goto failed;
              }
          }
      }
  
      list = SSL_CTX_get_client_CA_list(ssl->ctx);
  
      if (list != NULL) {
          n = sk_X509_NAME_num(list);
  
          for (i = 0; i < n; i++) {
              name = sk_X509_NAME_value(list, i);
  
              if (X509_NAME_digest(name, EVP_sha1(), buf, &len) == 0) {
                  ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                                "X509_NAME_digest() failed");
                  goto failed;
              }
  
              if (EVP_DigestUpdate(md, buf, len) == 0) {
                  ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                                "EVP_DigestUpdate() failed");
                  goto failed;
              }
          }
      }
  
      if (EVP_DigestFinal_ex(md, buf, &len) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "EVP_DigestFinal_ex() failed");
          goto failed;
      }
  
      EVP_MD_CTX_destroy(md);
  
      if (SSL_CTX_set_session_id_context(ssl->ctx, buf, len) == 0) {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_set_session_id_context() failed");
          return NGX_ERROR;
      }
  
      return NGX_OK;
  
  failed:
  
      EVP_MD_CTX_destroy(md);
  
      return NGX_ERROR;
  }
  
  
  ngx_int_t
  ngx_ssl_session_cache_init(ngx_shm_zone_t *shm_zone, void *data)
  {
      size_t                    len;
      ngx_slab_pool_t          *shpool;
      ngx_ssl_session_cache_t  *cache;
  
      if (data) {
          shm_zone->data = data;
          return NGX_OK;
      }
  
      shpool = (ngx_slab_pool_t *) shm_zone->shm.addr;
  
      if (shm_zone->shm.exists) {
          shm_zone->data = shpool->data;
          return NGX_OK;
      }
  
      cache = ngx_slab_alloc(shpool, sizeof(ngx_ssl_session_cache_t));
      if (cache == NULL) {
          return NGX_ERROR;
      }
  
      shpool->data = cache;
      shm_zone->data = cache;
  
      ngx_rbtree_init(&cache->session_rbtree, &cache->sentinel,
                      ngx_ssl_session_rbtree_insert_value);
  
      ngx_queue_init(&cache->expire_queue);
  
      len = sizeof(" in SSL session shared cache \"\"") + shm_zone->shm.name.len;
  
      shpool->log_ctx = ngx_slab_alloc(shpool, len);
      if (shpool->log_ctx == NULL) {
          return NGX_ERROR;
      }
  
      ngx_sprintf(shpool->log_ctx, " in SSL session shared cache \"%V\"%Z",
                  &shm_zone->shm.name);
  
      shpool->log_nomem = 0;
  
      return NGX_OK;
  }
  
  
  /*
   * The length of the session id is 16 bytes for SSLv2 sessions and
   * between 1 and 32 bytes for SSLv3/TLSv1, typically 32 bytes.
   * It seems that the typical length of the external ASN1 representation
   * of a session is 118 or 119 bytes for SSLv3/TSLv1.
   *
   * Thus on 32-bit platforms we allocate separately an rbtree node,
   * a session id, and an ASN1 representation, they take accordingly
   * 64, 32, and 128 bytes.
   *
   * On 64-bit platforms we allocate separately an rbtree node + session_id,
   * and an ASN1 representation, they take accordingly 128 and 128 bytes.
   *
   * OpenSSL's i2d_SSL_SESSION() and d2i_SSL_SESSION are slow,
   * so they are outside the code locked by shared pool mutex
   */
  
  static int
  ngx_ssl_new_session(ngx_ssl_conn_t *ssl_conn, ngx_ssl_session_t *sess)
  {
      int                       len;
      u_char                   *p, *id, *cached_sess, *session_id;
      uint32_t                  hash;
      SSL_CTX                  *ssl_ctx;
      unsigned int              session_id_length;
      ngx_shm_zone_t           *shm_zone;
      ngx_connection_t         *c;
      ngx_slab_pool_t          *shpool;
      ngx_ssl_sess_id_t        *sess_id;
      ngx_ssl_session_cache_t  *cache;
      u_char                    buf[NGX_SSL_MAX_SESSION_SIZE];
  
      len = i2d_SSL_SESSION(sess, NULL);
  
      /* do not cache too big session */
  
      if (len > (int) NGX_SSL_MAX_SESSION_SIZE) {
          return 0;
      }
  
      p = buf;
      i2d_SSL_SESSION(sess, &p);
  
      c = ngx_ssl_get_connection(ssl_conn);
  
      ssl_ctx = c->ssl->session_ctx;
      shm_zone = SSL_CTX_get_ex_data(ssl_ctx, ngx_ssl_session_cache_index);
  
      cache = shm_zone->data;
      shpool = (ngx_slab_pool_t *) shm_zone->shm.addr;
  
      ngx_shmtx_lock(&shpool->mutex);
  
      /* drop one or two expired sessions */
      ngx_ssl_expire_sessions(cache, shpool, 1);
  
      cached_sess = ngx_slab_alloc_locked(shpool, len);
  
      if (cached_sess == NULL) {
  
          /* drop the oldest non-expired session and try once more */
  
          ngx_ssl_expire_sessions(cache, shpool, 0);
  
          cached_sess = ngx_slab_alloc_locked(shpool, len);
  
          if (cached_sess == NULL) {
              sess_id = NULL;
              goto failed;
          }
      }
  
      sess_id = ngx_slab_alloc_locked(shpool, sizeof(ngx_ssl_sess_id_t));
  
      if (sess_id == NULL) {
  
          /* drop the oldest non-expired session and try once more */
  
          ngx_ssl_expire_sessions(cache, shpool, 0);
  
          sess_id = ngx_slab_alloc_locked(shpool, sizeof(ngx_ssl_sess_id_t));
  
          if (sess_id == NULL) {
              goto failed;
          }
      }
  
      session_id = (u_char *) SSL_SESSION_get_id(sess, &session_id_length);
  
  #if (NGX_PTR_SIZE == 8)
  
      id = sess_id->sess_id;
  
  #else
  
      id = ngx_slab_alloc_locked(shpool, session_id_length);
  
      if (id == NULL) {
  
          /* drop the oldest non-expired session and try once more */
  
          ngx_ssl_expire_sessions(cache, shpool, 0);
  
          id = ngx_slab_alloc_locked(shpool, session_id_length);
  
          if (id == NULL) {
              goto failed;
          }
      }
  
  #endif
  
      ngx_memcpy(cached_sess, buf, len);
  
      ngx_memcpy(id, session_id, session_id_length);
  
      hash = ngx_crc32_short(session_id, session_id_length);
  
      ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "ssl new session: %08XD:%ud:%d",
                     hash, session_id_length, len);
  
      sess_id->node.key = hash;
      sess_id->node.data = (u_char) session_id_length;
      sess_id->id = id;
      sess_id->len = len;
      sess_id->session = cached_sess;
  
      sess_id->expire = ngx_time() + SSL_CTX_get_timeout(ssl_ctx);
  
      ngx_queue_insert_head(&cache->expire_queue, &sess_id->queue);
  
      ngx_rbtree_insert(&cache->session_rbtree, &sess_id->node);
  
      ngx_shmtx_unlock(&shpool->mutex);
  
      return 0;
  
  failed:
  
      if (cached_sess) {
          ngx_slab_free_locked(shpool, cached_sess);
      }
  
      if (sess_id) {
          ngx_slab_free_locked(shpool, sess_id);
      }
  
      ngx_shmtx_unlock(&shpool->mutex);
  
      ngx_log_error(NGX_LOG_ALERT, c->log, 0,
                    "could not allocate new session%s", shpool->log_ctx);
  
      return 0;
  }
  
  
  static ngx_ssl_session_t *
  ngx_ssl_get_cached_session(ngx_ssl_conn_t *ssl_conn,
  #if OPENSSL_VERSION_NUMBER >= 0x10100003L
      const
  #endif
      u_char *id, int len, int *copy)
  {
      size_t                    slen;
      uint32_t                  hash;
      ngx_int_t                 rc;
      const u_char             *p;
      ngx_shm_zone_t           *shm_zone;
      ngx_slab_pool_t          *shpool;
      ngx_rbtree_node_t        *node, *sentinel;
      ngx_ssl_session_t        *sess;
      ngx_ssl_sess_id_t        *sess_id;
      ngx_ssl_session_cache_t  *cache;
      u_char                    buf[NGX_SSL_MAX_SESSION_SIZE];
      ngx_connection_t         *c;
  
      hash = ngx_crc32_short((u_char *) (uintptr_t) id, (size_t) len);
      *copy = 0;
  
      c = ngx_ssl_get_connection(ssl_conn);
  
      ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "ssl get session: %08XD:%d", hash, len);
  
      shm_zone = SSL_CTX_get_ex_data(c->ssl->session_ctx,
                                     ngx_ssl_session_cache_index);
  
      cache = shm_zone->data;
  
      sess = NULL;
  
      shpool = (ngx_slab_pool_t *) shm_zone->shm.addr;
  
      ngx_shmtx_lock(&shpool->mutex);
  
      node = cache->session_rbtree.root;
      sentinel = cache->session_rbtree.sentinel;
  
      while (node != sentinel) {
  
          if (hash < node->key) {
              node = node->left;
              continue;
          }
  
          if (hash > node->key) {
              node = node->right;
              continue;
          }
  
          /* hash == node->key */
  
          sess_id = (ngx_ssl_sess_id_t *) node;
  
          rc = ngx_memn2cmp((u_char *) (uintptr_t) id, sess_id->id,
                            (size_t) len, (size_t) node->data);
  
          if (rc == 0) {
  
              if (sess_id->expire > ngx_time()) {
                  slen = sess_id->len;
  
                  ngx_memcpy(buf, sess_id->session, slen);
  
                  ngx_shmtx_unlock(&shpool->mutex);
  
                  p = buf;
                  sess = d2i_SSL_SESSION(NULL, &p, slen);
  
                  return sess;
              }
  
              ngx_queue_remove(&sess_id->queue);
  
              ngx_rbtree_delete(&cache->session_rbtree, node);
  
              ngx_slab_free_locked(shpool, sess_id->session);
  #if (NGX_PTR_SIZE == 4)
              ngx_slab_free_locked(shpool, sess_id->id);
  #endif
              ngx_slab_free_locked(shpool, sess_id);
  
              sess = NULL;
  
              goto done;
          }
  
          node = (rc < 0) ? node->left : node->right;
      }
  
  done:
  
      ngx_shmtx_unlock(&shpool->mutex);
  
      return sess;
  }
  
  
  void
  ngx_ssl_remove_cached_session(SSL_CTX *ssl, ngx_ssl_session_t *sess)
  {
      SSL_CTX_remove_session(ssl, sess);
  
      ngx_ssl_remove_session(ssl, sess);
  }
  
  
  static void
  ngx_ssl_remove_session(SSL_CTX *ssl, ngx_ssl_session_t *sess)
  {
      u_char                   *id;
      uint32_t                  hash;
      ngx_int_t                 rc;
      unsigned int              len;
      ngx_shm_zone_t           *shm_zone;
      ngx_slab_pool_t          *shpool;
      ngx_rbtree_node_t        *node, *sentinel;
      ngx_ssl_sess_id_t        *sess_id;
      ngx_ssl_session_cache_t  *cache;
  
      shm_zone = SSL_CTX_get_ex_data(ssl, ngx_ssl_session_cache_index);
  
      if (shm_zone == NULL) {
          return;
      }
  
      cache = shm_zone->data;
  
      id = (u_char *) SSL_SESSION_get_id(sess, &len);
  
      hash = ngx_crc32_short(id, len);
  
      ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ngx_cycle->log, 0,
                     "ssl remove session: %08XD:%ud", hash, len);
  
      shpool = (ngx_slab_pool_t *) shm_zone->shm.addr;
  
      ngx_shmtx_lock(&shpool->mutex);
  
      node = cache->session_rbtree.root;
      sentinel = cache->session_rbtree.sentinel;
  
      while (node != sentinel) {
  
          if (hash < node->key) {
              node = node->left;
              continue;
          }
  
          if (hash > node->key) {
              node = node->right;
              continue;
          }
  
          /* hash == node->key */
  
          sess_id = (ngx_ssl_sess_id_t *) node;
  
          rc = ngx_memn2cmp(id, sess_id->id, len, (size_t) node->data);
  
          if (rc == 0) {
  
              ngx_queue_remove(&sess_id->queue);
  
              ngx_rbtree_delete(&cache->session_rbtree, node);
  
              ngx_slab_free_locked(shpool, sess_id->session);
  #if (NGX_PTR_SIZE == 4)
              ngx_slab_free_locked(shpool, sess_id->id);
  #endif
              ngx_slab_free_locked(shpool, sess_id);
  
              goto done;
          }
  
          node = (rc < 0) ? node->left : node->right;
      }
  
  done:
  
      ngx_shmtx_unlock(&shpool->mutex);
  }
  
  
  static void
  ngx_ssl_expire_sessions(ngx_ssl_session_cache_t *cache,
      ngx_slab_pool_t *shpool, ngx_uint_t n)
  {
      time_t              now;
      ngx_queue_t        *q;
      ngx_ssl_sess_id_t  *sess_id;
  
      now = ngx_time();
  
      while (n < 3) {
  
          if (ngx_queue_empty(&cache->expire_queue)) {
              return;
          }
  
          q = ngx_queue_last(&cache->expire_queue);
  
          sess_id = ngx_queue_data(q, ngx_ssl_sess_id_t, queue);
  
          if (n++ != 0 && sess_id->expire > now) {
              return;
          }
  
          ngx_queue_remove(q);
  
          ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ngx_cycle->log, 0,
                         "expire session: %08Xi", sess_id->node.key);
  
          ngx_rbtree_delete(&cache->session_rbtree, &sess_id->node);
  
          ngx_slab_free_locked(shpool, sess_id->session);
  #if (NGX_PTR_SIZE == 4)
          ngx_slab_free_locked(shpool, sess_id->id);
  #endif
          ngx_slab_free_locked(shpool, sess_id);
      }
  }
  
  
  static void
  ngx_ssl_session_rbtree_insert_value(ngx_rbtree_node_t *temp,
      ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel)
  {
      ngx_rbtree_node_t  **p;
      ngx_ssl_sess_id_t   *sess_id, *sess_id_temp;
  
      for ( ;; ) {
  
          if (node->key < temp->key) {
  
              p = &temp->left;
  
          } else if (node->key > temp->key) {
  
              p = &temp->right;
  
          } else { /* node->key == temp->key */
  
              sess_id = (ngx_ssl_sess_id_t *) node;
              sess_id_temp = (ngx_ssl_sess_id_t *) temp;
  
              p = (ngx_memn2cmp(sess_id->id, sess_id_temp->id,
                                (size_t) node->data, (size_t) temp->data)
                   < 0) ? &temp->left : &temp->right;
          }
  
          if (*p == sentinel) {
              break;
          }
  
          temp = *p;
      }
  
      *p = node;
      node->parent = temp;
      node->left = sentinel;
      node->right = sentinel;
      ngx_rbt_red(node);
  }
  
  
  #ifdef SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB
  
  ngx_int_t
  ngx_ssl_session_ticket_keys(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_array_t *paths)
  {
      u_char                         buf[80];
      size_t                         size;
      ssize_t                        n;
      ngx_str_t                     *path;
      ngx_file_t                     file;
      ngx_uint_t                     i;
      ngx_array_t                   *keys;
      ngx_file_info_t                fi;
      ngx_pool_cleanup_t            *cln;
      ngx_ssl_session_ticket_key_t  *key;
  
      if (paths == NULL) {
          return NGX_OK;
      }
  
      keys = ngx_array_create(cf->pool, paths->nelts,
                              sizeof(ngx_ssl_session_ticket_key_t));
      if (keys == NULL) {
          return NGX_ERROR;
      }
  
      cln = ngx_pool_cleanup_add(cf->pool, 0);
      if (cln == NULL) {
          return NGX_ERROR;
      }
  
      cln->handler = ngx_ssl_session_ticket_keys_cleanup;
      cln->data = keys;
  
      path = paths->elts;
      for (i = 0; i < paths->nelts; i++) {
  
          if (ngx_conf_full_name(cf->cycle, &path[i], 1) != NGX_OK) {
              return NGX_ERROR;
          }
  
          ngx_memzero(&file, sizeof(ngx_file_t));
          file.name = path[i];
          file.log = cf->log;
  
          file.fd = ngx_open_file(file.name.data, NGX_FILE_RDONLY,
                                  NGX_FILE_OPEN, 0);
  
          if (file.fd == NGX_INVALID_FILE) {
              ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
                                 ngx_open_file_n " \"%V\" failed", &file.name);
              return NGX_ERROR;
          }
  
          if (ngx_fd_info(file.fd, &fi) == NGX_FILE_ERROR) {
              ngx_conf_log_error(NGX_LOG_CRIT, cf, ngx_errno,
                                 ngx_fd_info_n " \"%V\" failed", &file.name);
              goto failed;
          }
  
          size = ngx_file_size(&fi);
  
          if (size != 48 && size != 80) {
              ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                 "\"%V\" must be 48 or 80 bytes", &file.name);
              goto failed;
          }
  
          n = ngx_read_file(&file, buf, size, 0);
  
          if (n == NGX_ERROR) {
              ngx_conf_log_error(NGX_LOG_CRIT, cf, ngx_errno,
                                 ngx_read_file_n " \"%V\" failed", &file.name);
              goto failed;
          }
  
          if ((size_t) n != size) {
              ngx_conf_log_error(NGX_LOG_CRIT, cf, 0,
                                 ngx_read_file_n " \"%V\" returned only "
                                 "%z bytes instead of %uz", &file.name, n, size);
              goto failed;
          }
  
          key = ngx_array_push(keys);
          if (key == NULL) {
              goto failed;
          }
  
          if (size == 48) {
              key->size = 48;
              ngx_memcpy(key->name, buf, 16);
              ngx_memcpy(key->aes_key, buf + 16, 16);
              ngx_memcpy(key->hmac_key, buf + 32, 16);
  
          } else {
              key->size = 80;
              ngx_memcpy(key->name, buf, 16);
              ngx_memcpy(key->hmac_key, buf + 16, 32);
              ngx_memcpy(key->aes_key, buf + 48, 32);
          }
  
          if (ngx_close_file(file.fd) == NGX_FILE_ERROR) {
              ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
                            ngx_close_file_n " \"%V\" failed", &file.name);
          }
  
          ngx_explicit_memzero(&buf, 80);
      }
  
      if (SSL_CTX_set_ex_data(ssl->ctx, ngx_ssl_session_ticket_keys_index, keys)
          == 0)
      {
          ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                        "SSL_CTX_set_ex_data() failed");
          return NGX_ERROR;
      }
  
      if (SSL_CTX_set_tlsext_ticket_key_cb(ssl->ctx,
                                           ngx_ssl_session_ticket_key_callback)
          == 0)
      {
          ngx_log_error(NGX_LOG_WARN, cf->log, 0,
                        "nginx was built with Session Tickets support, however, "
                        "now it is linked dynamically to an OpenSSL library "
                        "which has no tlsext support, therefore Session Tickets "
                        "are not available");
      }
  
      return NGX_OK;
  
  failed:
  
      if (ngx_close_file(file.fd) == NGX_FILE_ERROR) {
          ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
                        ngx_close_file_n " \"%V\" failed", &file.name);
      }
  
      ngx_explicit_memzero(&buf, 80);
  
      return NGX_ERROR;
  }
  
  
  static int
  ngx_ssl_session_ticket_key_callback(ngx_ssl_conn_t *ssl_conn,
      unsigned char *name, unsigned char *iv, EVP_CIPHER_CTX *ectx,
      HMAC_CTX *hctx, int enc)
  {
      size_t                         size;
      SSL_CTX                       *ssl_ctx;
      ngx_uint_t                     i;
      ngx_array_t                   *keys;
      ngx_connection_t              *c;
      ngx_ssl_session_ticket_key_t  *key;
      const EVP_MD                  *digest;
      const EVP_CIPHER              *cipher;
  
      c = ngx_ssl_get_connection(ssl_conn);
      ssl_ctx = c->ssl->session_ctx;
  
  #ifdef OPENSSL_NO_SHA256
      digest = EVP_sha1();
  #else
      digest = EVP_sha256();
  #endif
  
      keys = SSL_CTX_get_ex_data(ssl_ctx, ngx_ssl_session_ticket_keys_index);
      if (keys == NULL) {
          return -1;
      }
  
      key = keys->elts;
  
      if (enc == 1) {
          /* encrypt session ticket */
  
          ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "ssl session ticket encrypt, key: \"%*xs\" (%s session)",
                         (size_t) 16, key[0].name,
                         SSL_session_reused(ssl_conn) ? "reused" : "new");
  
          if (key[0].size == 48) {
              cipher = EVP_aes_128_cbc();
              size = 16;
  
          } else {
              cipher = EVP_aes_256_cbc();
              size = 32;
          }
  
          if (RAND_bytes(iv, EVP_CIPHER_iv_length(cipher)) != 1) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "RAND_bytes() failed");
              return -1;
          }
  
          if (EVP_EncryptInit_ex(ectx, cipher, NULL, key[0].aes_key, iv) != 1) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0,
                            "EVP_EncryptInit_ex() failed");
              return -1;
          }
  
  #if OPENSSL_VERSION_NUMBER >= 0x10000000L
          if (HMAC_Init_ex(hctx, key[0].hmac_key, size, digest, NULL) != 1) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "HMAC_Init_ex() failed");
              return -1;
          }
  #else
          HMAC_Init_ex(hctx, key[0].hmac_key, size, digest, NULL);
  #endif
  
          ngx_memcpy(name, key[0].name, 16);
  
          return 1;
  
      } else {
          /* decrypt session ticket */
  
          for (i = 0; i < keys->nelts; i++) {
              if (ngx_memcmp(name, key[i].name, 16) == 0) {
                  goto found;
              }
          }
  
          ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "ssl session ticket decrypt, key: \"%*xs\" not found",
                         (size_t) 16, name);
  
          return 0;
  
      found:
  
          ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "ssl session ticket decrypt, key: \"%*xs\"%s",
                         (size_t) 16, key[i].name, (i == 0) ? " (default)" : "");
  
          if (key[i].size == 48) {
              cipher = EVP_aes_128_cbc();
              size = 16;
  
          } else {
              cipher = EVP_aes_256_cbc();
              size = 32;
          }
  
  #if OPENSSL_VERSION_NUMBER >= 0x10000000L
          if (HMAC_Init_ex(hctx, key[i].hmac_key, size, digest, NULL) != 1) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "HMAC_Init_ex() failed");
              return -1;
          }
  #else
          HMAC_Init_ex(hctx, key[i].hmac_key, size, digest, NULL);
  #endif
  
          if (EVP_DecryptInit_ex(ectx, cipher, NULL, key[i].aes_key, iv) != 1) {
              ngx_ssl_error(NGX_LOG_ALERT, c->log, 0,
                            "EVP_DecryptInit_ex() failed");
              return -1;
          }
  
          return (i == 0) ? 1 : 2 /* renew */;
      }
  }
  
  
  static void
  ngx_ssl_session_ticket_keys_cleanup(void *data)
  {
      ngx_array_t  *keys = data;
  
      ngx_explicit_memzero(keys->elts,
                           keys->nelts * sizeof(ngx_ssl_session_ticket_key_t));
  }
  
  #else
  
  ngx_int_t
  ngx_ssl_session_ticket_keys(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_array_t *paths)
  {
      if (paths) {
          ngx_log_error(NGX_LOG_WARN, ssl->log, 0,
                        "\"ssl_session_ticket_key\" ignored, not supported");
      }
  
      return NGX_OK;
  }
  
  #endif
  
  
  void
  ngx_ssl_cleanup_ctx(void *data)
  {
      ngx_ssl_t  *ssl = data;
  
      X509  *cert, *next;
  
      cert = SSL_CTX_get_ex_data(ssl->ctx, ngx_ssl_certificate_index);
  
      while (cert) {
          next = X509_get_ex_data(cert, ngx_ssl_next_certificate_index);
          X509_free(cert);
          cert = next;
      }
  
      SSL_CTX_free(ssl->ctx);
  }
  
  
  ngx_int_t
  ngx_ssl_check_host(ngx_connection_t *c, ngx_str_t *name)
  {
      X509   *cert;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_ERROR;
      }
  
  #ifdef X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT
  
      /* X509_check_host() is only available in OpenSSL 1.0.2+ */
  
      if (name->len == 0) {
          goto failed;
      }
  
      if (X509_check_host(cert, (char *) name->data, name->len, 0, NULL) != 1) {
          ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "X509_check_host(): no match");
          goto failed;
      }
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "X509_check_host(): match");
  
      goto found;
  
  #else
      {
      int                      n, i;
      X509_NAME               *sname;
      ASN1_STRING             *str;
      X509_NAME_ENTRY         *entry;
      GENERAL_NAME            *altname;
      STACK_OF(GENERAL_NAME)  *altnames;
  
      /*
       * As per RFC6125 and RFC2818, we check subjectAltName extension,
       * and if it's not present - commonName in Subject is checked.
       */
  
      altnames = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL);
  
      if (altnames) {
          n = sk_GENERAL_NAME_num(altnames);
  
          for (i = 0; i < n; i++) {
              altname = sk_GENERAL_NAME_value(altnames, i);
  
              if (altname->type != GEN_DNS) {
                  continue;
              }
  
              str = altname->d.dNSName;
  
              ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                             "SSL subjectAltName: \"%*s\"",
                             ASN1_STRING_length(str), ASN1_STRING_data(str));
  
              if (ngx_ssl_check_name(name, str) == NGX_OK) {
                  ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                                 "SSL subjectAltName: match");
                  GENERAL_NAMES_free(altnames);
                  goto found;
              }
          }
  
          ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL subjectAltName: no match");
  
          GENERAL_NAMES_free(altnames);
          goto failed;
      }
  
      /*
       * If there is no subjectAltName extension, check commonName
       * in Subject.  While RFC2818 requires to only check "most specific"
       * CN, both Apache and OpenSSL check all CNs, and so do we.
       */
  
      sname = X509_get_subject_name(cert);
  
      if (sname == NULL) {
          goto failed;
      }
  
      i = -1;
      for ( ;; ) {
          i = X509_NAME_get_index_by_NID(sname, NID_commonName, i);
  
          if (i < 0) {
              break;
          }
  
          entry = X509_NAME_get_entry(sname, i);
          str = X509_NAME_ENTRY_get_data(entry);
  
          ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                         "SSL commonName: \"%*s\"",
                         ASN1_STRING_length(str), ASN1_STRING_data(str));
  
          if (ngx_ssl_check_name(name, str) == NGX_OK) {
              ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                             "SSL commonName: match");
              goto found;
          }
      }
  
      ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                     "SSL commonName: no match");
      }
  #endif
  
  failed:
  
      X509_free(cert);
      return NGX_ERROR;
  
  found:
  
      X509_free(cert);
      return NGX_OK;
  }
  
  
  #ifndef X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT
  
  static ngx_int_t
  ngx_ssl_check_name(ngx_str_t *name, ASN1_STRING *pattern)
  {
      u_char  *s, *p, *end;
      size_t   slen, plen;
  
      s = name->data;
      slen = name->len;
  
      p = ASN1_STRING_data(pattern);
      plen = ASN1_STRING_length(pattern);
  
      if (slen == plen && ngx_strncasecmp(s, p, plen) == 0) {
          return NGX_OK;
      }
  
      if (plen > 2 && p[0] == '*' && p[1] == '.') {
          plen -= 1;
          p += 1;
  
          end = s + slen;
          s = ngx_strlchr(s, end, '.');
  
          if (s == NULL) {
              return NGX_ERROR;
          }
  
          slen = end - s;
  
          if (plen == slen && ngx_strncasecmp(s, p, plen) == 0) {
              return NGX_OK;
          }
      }
  
      return NGX_ERROR;
  }
  
  #endif
  
  
  ngx_int_t
  ngx_ssl_get_protocol(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      s->data = (u_char *) SSL_get_version(c->ssl->connection);
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_cipher_name(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      s->data = (u_char *) SSL_get_cipher_name(c->ssl->connection);
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_ciphers(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
  #ifdef SSL_CTRL_GET_RAW_CIPHERLIST
  
      int                n, i, bytes;
      size_t             len;
      u_char            *ciphers, *p;
      const SSL_CIPHER  *cipher;
  
      bytes = SSL_get0_raw_cipherlist(c->ssl->connection, NULL);
      n = SSL_get0_raw_cipherlist(c->ssl->connection, &ciphers);
  
      if (n <= 0) {
          s->len = 0;
          return NGX_OK;
      }
  
      len = 0;
      n /= bytes;
  
      for (i = 0; i < n; i++) {
          cipher = SSL_CIPHER_find(c->ssl->connection, ciphers + i * bytes);
  
          if (cipher) {
              len += ngx_strlen(SSL_CIPHER_get_name(cipher));
  
          } else {
              len += sizeof("0x") - 1 + bytes * (sizeof("00") - 1);
          }
  
          len += sizeof(":") - 1;
      }
  
      s->data = ngx_pnalloc(pool, len);
      if (s->data == NULL) {
          return NGX_ERROR;
      }
  
      p = s->data;
  
      for (i = 0; i < n; i++) {
          cipher = SSL_CIPHER_find(c->ssl->connection, ciphers + i * bytes);
  
          if (cipher) {
              p = ngx_sprintf(p, "%s", SSL_CIPHER_get_name(cipher));
  
          } else {
              p = ngx_sprintf(p, "0x");
              p = ngx_hex_dump(p, ciphers + i * bytes, bytes);
          }
  
          *p++ = ':';
      }
  
      p--;
  
      s->len = p - s->data;
  
  #else
  
      u_char  buf[4096];
  
      if (SSL_get_shared_ciphers(c->ssl->connection, (char *) buf, 4096)
          == NULL)
      {
          s->len = 0;
          return NGX_OK;
      }
  
      s->len = ngx_strlen(buf);
      s->data = ngx_pnalloc(pool, s->len);
      if (s->data == NULL) {
          return NGX_ERROR;
      }
  
      ngx_memcpy(s->data, buf, s->len);
  
  #endif
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_curves(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
  #ifdef SSL_CTRL_GET_CURVES
  
      int         *curves, n, i, nid;
      u_char      *p;
      size_t       len;
  
      n = SSL_get1_curves(c->ssl->connection, NULL);
  
      if (n <= 0) {
          s->len = 0;
          return NGX_OK;
      }
  
      curves = ngx_palloc(pool, n * sizeof(int));
  
      n = SSL_get1_curves(c->ssl->connection, curves);
      len = 0;
  
      for (i = 0; i < n; i++) {
          nid = curves[i];
  
          if (nid & TLSEXT_nid_unknown) {
              len += sizeof("0x0000") - 1;
  
          } else {
              len += ngx_strlen(OBJ_nid2sn(nid));
          }
  
          len += sizeof(":") - 1;
      }
  
      s->data = ngx_pnalloc(pool, len);
      if (s->data == NULL) {
          return NGX_ERROR;
      }
  
      p = s->data;
  
      for (i = 0; i < n; i++) {
          nid = curves[i];
  
          if (nid & TLSEXT_nid_unknown) {
              p = ngx_sprintf(p, "0x%04xd", nid & 0xffff);
  
          } else {
              p = ngx_sprintf(p, "%s", OBJ_nid2sn(nid));
          }
  
          *p++ = ':';
      }
  
      p--;
  
      s->len = p - s->data;
  
  #else
  
      s->len = 0;
  
  #endif
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_session_id(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      u_char        *buf;
      SSL_SESSION   *sess;
      unsigned int   len;
  
      sess = SSL_get0_session(c->ssl->connection);
      if (sess == NULL) {
          s->len = 0;
          return NGX_OK;
      }
  
      buf = (u_char *) SSL_SESSION_get_id(sess, &len);
  
      s->len = 2 * len;
      s->data = ngx_pnalloc(pool, 2 * len);
      if (s->data == NULL) {
          return NGX_ERROR;
      }
  
      ngx_hex_dump(s->data, buf, len);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_session_reused(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      if (SSL_session_reused(c->ssl->connection)) {
          ngx_str_set(s, "r");
  
      } else {
          ngx_str_set(s, ".");
      }
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_early_data(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      s->len = 0;
  
  #ifdef SSL_ERROR_EARLY_DATA_REJECTED
  
      /* BoringSSL */
  
      if (SSL_in_early_data(c->ssl->connection)) {
          ngx_str_set(s, "1");
      }
  
  #elif defined SSL_READ_EARLY_DATA_SUCCESS
  
      /* OpenSSL */
  
      if (!SSL_is_init_finished(c->ssl->connection)) {
          ngx_str_set(s, "1");
      }
  
  #endif
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_server_name(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
  #ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
  
      size_t       len;
      const char  *name;
  
      name = SSL_get_servername(c->ssl->connection, TLSEXT_NAMETYPE_host_name);
  
      if (name) {
          len = ngx_strlen(name);
  
          s->len = len;
          s->data = ngx_pnalloc(pool, len);
          if (s->data == NULL) {
              return NGX_ERROR;
          }
  
          ngx_memcpy(s->data, name, len);
  
          return NGX_OK;
      }
  
  #endif
  
      s->len = 0;
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_raw_certificate(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      size_t   len;
      BIO     *bio;
      X509    *cert;
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
      bio = BIO_new(BIO_s_mem());
      if (bio == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "BIO_new() failed");
          X509_free(cert);
          return NGX_ERROR;
      }
  
      if (PEM_write_bio_X509(bio, cert) == 0) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "PEM_write_bio_X509() failed");
          goto failed;
      }
  
      len = BIO_pending(bio);
      s->len = len;
  
      s->data = ngx_pnalloc(pool, len);
      if (s->data == NULL) {
          goto failed;
      }
  
      BIO_read(bio, s->data, len);
  
      BIO_free(bio);
      X509_free(cert);
  
      return NGX_OK;
  
  failed:
  
      BIO_free(bio);
      X509_free(cert);
  
      return NGX_ERROR;
  }
  
  
  ngx_int_t
  ngx_ssl_get_certificate(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      u_char      *p;
      size_t       len;
      ngx_uint_t   i;
      ngx_str_t    cert;
  
      if (ngx_ssl_get_raw_certificate(c, pool, &cert) != NGX_OK) {
          return NGX_ERROR;
      }
  
      if (cert.len == 0) {
          s->len = 0;
          return NGX_OK;
      }
  
      len = cert.len - 1;
  
      for (i = 0; i < cert.len - 1; i++) {
          if (cert.data[i] == LF) {
              len++;
          }
      }
  
      s->len = len;
      s->data = ngx_pnalloc(pool, len);
      if (s->data == NULL) {
          return NGX_ERROR;
      }
  
      p = s->data;
  
      for (i = 0; i < cert.len - 1; i++) {
          *p++ = cert.data[i];
          if (cert.data[i] == LF) {
              *p++ = '\t';
          }
      }
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_escaped_certificate(ngx_connection_t *c, ngx_pool_t *pool,
      ngx_str_t *s)
  {
      ngx_str_t  cert;
      uintptr_t  n;
  
      if (ngx_ssl_get_raw_certificate(c, pool, &cert) != NGX_OK) {
          return NGX_ERROR;
      }
  
      if (cert.len == 0) {
          s->len = 0;
          return NGX_OK;
      }
  
      n = ngx_escape_uri(NULL, cert.data, cert.len, NGX_ESCAPE_URI_COMPONENT);
  
      s->len = cert.len + n * 2;
      s->data = ngx_pnalloc(pool, s->len);
      if (s->data == NULL) {
          return NGX_ERROR;
      }
  
      ngx_escape_uri(s->data, cert.data, cert.len, NGX_ESCAPE_URI_COMPONENT);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_subject_dn(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      BIO        *bio;
      X509       *cert;
      X509_NAME  *name;
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
      name = X509_get_subject_name(cert);
      if (name == NULL) {
          X509_free(cert);
          return NGX_ERROR;
      }
  
      bio = BIO_new(BIO_s_mem());
      if (bio == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "BIO_new() failed");
          X509_free(cert);
          return NGX_ERROR;
      }
  
      if (X509_NAME_print_ex(bio, name, 0, XN_FLAG_RFC2253) < 0) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "X509_NAME_print_ex() failed");
          goto failed;
      }
  
      s->len = BIO_pending(bio);
      s->data = ngx_pnalloc(pool, s->len);
      if (s->data == NULL) {
          goto failed;
      }
  
      BIO_read(bio, s->data, s->len);
  
      BIO_free(bio);
      X509_free(cert);
  
      return NGX_OK;
  
  failed:
  
      BIO_free(bio);
      X509_free(cert);
  
      return NGX_ERROR;
  }
  
  
  ngx_int_t
  ngx_ssl_get_issuer_dn(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      BIO        *bio;
      X509       *cert;
      X509_NAME  *name;
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
      name = X509_get_issuer_name(cert);
      if (name == NULL) {
          X509_free(cert);
          return NGX_ERROR;
      }
  
      bio = BIO_new(BIO_s_mem());
      if (bio == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "BIO_new() failed");
          X509_free(cert);
          return NGX_ERROR;
      }
  
      if (X509_NAME_print_ex(bio, name, 0, XN_FLAG_RFC2253) < 0) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "X509_NAME_print_ex() failed");
          goto failed;
      }
  
      s->len = BIO_pending(bio);
      s->data = ngx_pnalloc(pool, s->len);
      if (s->data == NULL) {
          goto failed;
      }
  
      BIO_read(bio, s->data, s->len);
  
      BIO_free(bio);
      X509_free(cert);
  
      return NGX_OK;
  
  failed:
  
      BIO_free(bio);
      X509_free(cert);
  
      return NGX_ERROR;
  }
  
  
  ngx_int_t
  ngx_ssl_get_subject_dn_legacy(ngx_connection_t *c, ngx_pool_t *pool,
      ngx_str_t *s)
  {
      char       *p;
      size_t      len;
      X509       *cert;
      X509_NAME  *name;
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
      name = X509_get_subject_name(cert);
      if (name == NULL) {
          X509_free(cert);
          return NGX_ERROR;
      }
  
      p = X509_NAME_oneline(name, NULL, 0);
      if (p == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "X509_NAME_oneline() failed");
          X509_free(cert);
          return NGX_ERROR;
      }
  
      for (len = 0; p[len]; len++) { /* void */ }
  
      s->len = len;
      s->data = ngx_pnalloc(pool, len);
      if (s->data == NULL) {
          OPENSSL_free(p);
          X509_free(cert);
          return NGX_ERROR;
      }
  
      ngx_memcpy(s->data, p, len);
  
      OPENSSL_free(p);
      X509_free(cert);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_issuer_dn_legacy(ngx_connection_t *c, ngx_pool_t *pool,
      ngx_str_t *s)
  {
      char       *p;
      size_t      len;
      X509       *cert;
      X509_NAME  *name;
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
      name = X509_get_issuer_name(cert);
      if (name == NULL) {
          X509_free(cert);
          return NGX_ERROR;
      }
  
      p = X509_NAME_oneline(name, NULL, 0);
      if (p == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "X509_NAME_oneline() failed");
          X509_free(cert);
          return NGX_ERROR;
      }
  
      for (len = 0; p[len]; len++) { /* void */ }
  
      s->len = len;
      s->data = ngx_pnalloc(pool, len);
      if (s->data == NULL) {
          OPENSSL_free(p);
          X509_free(cert);
          return NGX_ERROR;
      }
  
      ngx_memcpy(s->data, p, len);
  
      OPENSSL_free(p);
      X509_free(cert);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_serial_number(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      size_t   len;
      X509    *cert;
      BIO     *bio;
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
      bio = BIO_new(BIO_s_mem());
      if (bio == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "BIO_new() failed");
          X509_free(cert);
          return NGX_ERROR;
      }
  
      i2a_ASN1_INTEGER(bio, X509_get_serialNumber(cert));
      len = BIO_pending(bio);
  
      s->len = len;
      s->data = ngx_pnalloc(pool, len);
      if (s->data == NULL) {
          BIO_free(bio);
          X509_free(cert);
          return NGX_ERROR;
      }
  
      BIO_read(bio, s->data, len);
      BIO_free(bio);
      X509_free(cert);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_fingerprint(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      X509          *cert;
      unsigned int   len;
      u_char         buf[EVP_MAX_MD_SIZE];
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
      if (!X509_digest(cert, EVP_sha1(), buf, &len)) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "X509_digest() failed");
          X509_free(cert);
          return NGX_ERROR;
      }
  
      s->len = 2 * len;
      s->data = ngx_pnalloc(pool, 2 * len);
      if (s->data == NULL) {
          X509_free(cert);
          return NGX_ERROR;
      }
  
      ngx_hex_dump(s->data, buf, len);
  
      X509_free(cert);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_client_verify(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      X509        *cert;
      long         rc;
      const char  *str;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          ngx_str_set(s, "NONE");
          return NGX_OK;
      }
  
      X509_free(cert);
  
      rc = SSL_get_verify_result(c->ssl->connection);
  
      if (rc == X509_V_OK) {
          if (ngx_ssl_ocsp_get_status(c, &str) == NGX_OK) {
              ngx_str_set(s, "SUCCESS");
              return NGX_OK;
          }
  
      } else {
          str = X509_verify_cert_error_string(rc);
      }
  
      s->data = ngx_pnalloc(pool, sizeof("FAILED:") - 1 + ngx_strlen(str));
      if (s->data == NULL) {
          return NGX_ERROR;
      }
  
      s->len = ngx_sprintf(s->data, "FAILED:%s", str) - s->data;
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_client_v_start(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      BIO     *bio;
      X509    *cert;
      size_t   len;
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
      bio = BIO_new(BIO_s_mem());
      if (bio == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "BIO_new() failed");
          X509_free(cert);
          return NGX_ERROR;
      }
  
  #if OPENSSL_VERSION_NUMBER > 0x10100000L
      ASN1_TIME_print(bio, X509_get0_notBefore(cert));
  #else
      ASN1_TIME_print(bio, X509_get_notBefore(cert));
  #endif
  
      len = BIO_pending(bio);
  
      s->len = len;
      s->data = ngx_pnalloc(pool, len);
      if (s->data == NULL) {
          BIO_free(bio);
          X509_free(cert);
          return NGX_ERROR;
      }
  
      BIO_read(bio, s->data, len);
      BIO_free(bio);
      X509_free(cert);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_client_v_end(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      BIO     *bio;
      X509    *cert;
      size_t   len;
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
      bio = BIO_new(BIO_s_mem());
      if (bio == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "BIO_new() failed");
          X509_free(cert);
          return NGX_ERROR;
      }
  
  #if OPENSSL_VERSION_NUMBER > 0x10100000L
      ASN1_TIME_print(bio, X509_get0_notAfter(cert));
  #else
      ASN1_TIME_print(bio, X509_get_notAfter(cert));
  #endif
  
      len = BIO_pending(bio);
  
      s->len = len;
      s->data = ngx_pnalloc(pool, len);
      if (s->data == NULL) {
          BIO_free(bio);
          X509_free(cert);
          return NGX_ERROR;
      }
  
      BIO_read(bio, s->data, len);
      BIO_free(bio);
      X509_free(cert);
  
      return NGX_OK;
  }
  
  
  ngx_int_t
  ngx_ssl_get_client_v_remain(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
  {
      X509    *cert;
      time_t   now, end;
  
      s->len = 0;
  
      cert = SSL_get_peer_certificate(c->ssl->connection);
      if (cert == NULL) {
          return NGX_OK;
      }
  
  #if OPENSSL_VERSION_NUMBER > 0x10100000L
      end = ngx_ssl_parse_time(X509_get0_notAfter(cert), c->log);
  #else
      end = ngx_ssl_parse_time(X509_get_notAfter(cert), c->log);
  #endif
  
      if (end == (time_t) NGX_ERROR) {
          X509_free(cert);
          return NGX_OK;
      }
  
      now = ngx_time();
  
      if (end < now + 86400) {
          ngx_str_set(s, "0");
          X509_free(cert);
          return NGX_OK;
      }
  
      s->data = ngx_pnalloc(pool, NGX_TIME_T_LEN);
      if (s->data == NULL) {
          X509_free(cert);
          return NGX_ERROR;
      }
  
      s->len = ngx_sprintf(s->data, "%T", (end - now) / 86400) - s->data;
  
      X509_free(cert);
  
      return NGX_OK;
  }
  
  static time_t
  ngx_ssl_parse_time(
  #if OPENSSL_VERSION_NUMBER > 0x10100000L
      const
  #endif
      ASN1_TIME *asn1time, ngx_log_t *log)
  {
      BIO     *bio;
      char    *value;
      size_t   len;
      time_t   time;
  
      /*
       * OpenSSL doesn't provide a way to convert ASN1_TIME
       * into time_t.  To do this, we use ASN1_TIME_print(),
       * which uses the "MMM DD HH:MM:SS YYYY [GMT]" format (e.g.,
       * "Feb  3 00:55:52 2015 GMT"), and parse the result.
       */
  
      bio = BIO_new(BIO_s_mem());
      if (bio == NULL) {
          ngx_ssl_error(NGX_LOG_ALERT, log, 0, "BIO_new() failed");
          return NGX_ERROR;
      }
  
      /* fake weekday prepended to match C asctime() format */
  
      BIO_write(bio, "Tue ", sizeof("Tue ") - 1);
      ASN1_TIME_print(bio, asn1time);
      len = BIO_get_mem_data(bio, &value);
  
      time = ngx_parse_http_time((u_char *) value, len);
  
      BIO_free(bio);
  
      return time;
  }
  