text: /*
   * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <errno.h>
  #include <openssl/crypto.h>
  #include "internal/bio.h"
  #include <openssl/err.h>
  #include "ssl_locl.h"
  
  static int ssl_write(BIO *h, const char *buf, size_t size, size_t *written);
  static int ssl_read(BIO *b, char *buf, size_t size, size_t *readbytes);
  static int ssl_puts(BIO *h, const char *str);
  static long ssl_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  static int ssl_new(BIO *h);
  static int ssl_free(BIO *data);
  static long ssl_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
  typedef struct bio_ssl_st {
      SSL *ssl;                   /* The ssl handle :-) */
      /* re-negotiate every time the total number of bytes is this size */
      int num_renegotiates;
      unsigned long renegotiate_count;
      size_t byte_count;
      unsigned long renegotiate_timeout;
      unsigned long last_time;
  } BIO_SSL;
  
  static const BIO_METHOD methods_sslp = {
      BIO_TYPE_SSL,
      "ssl",
      ssl_write,
      NULL,                       /* ssl_write_old, */
      ssl_read,
      NULL,                       /* ssl_read_old,  */
      ssl_puts,
      NULL,                       /* ssl_gets,      */
      ssl_ctrl,
      ssl_new,
      ssl_free,
      ssl_callback_ctrl,
  };
  
  const BIO_METHOD *BIO_f_ssl(void)
  {
      return &methods_sslp;
  }
  
  static int ssl_new(BIO *bi)
  {
      BIO_SSL *bs = OPENSSL_zalloc(sizeof(*bs));
  
      if (bs == NULL) {
          BIOerr(BIO_F_SSL_NEW, ERR_R_MALLOC_FAILURE);
          return 0;
      }
      BIO_set_init(bi, 0);
      BIO_set_data(bi, bs);
      /* Clear all flags */
      BIO_clear_flags(bi, ~0);
  
      return 1;
  }
  
  static int ssl_free(BIO *a)
  {
      BIO_SSL *bs;
  
      if (a == NULL)
          return 0;
      bs = BIO_get_data(a);
      if (bs->ssl != NULL)
          SSL_shutdown(bs->ssl);
      if (BIO_get_shutdown(a)) {
          if (BIO_get_init(a))
              SSL_free(bs->ssl);
          /* Clear all flags */
          BIO_clear_flags(a, ~0);
          BIO_set_init(a, 0);
      }
      OPENSSL_free(bs);
      return 1;
  }
  
  static int ssl_read(BIO *b, char *buf, size_t size, size_t *readbytes)
  {
      int ret = 1;
      BIO_SSL *sb;
      SSL *ssl;
      int retry_reason = 0;
      int r = 0;
  
      if (buf == NULL)
          return 0;
      sb = BIO_get_data(b);
      ssl = sb->ssl;
  
      BIO_clear_retry_flags(b);
  
      ret = ssl_read_internal(ssl, buf, size, readbytes);
  
      switch (SSL_get_error(ssl, ret)) {
      case SSL_ERROR_NONE:
          if (sb->renegotiate_count > 0) {
              sb->byte_count += *readbytes;
              if (sb->byte_count > sb->renegotiate_count) {
                  sb->byte_count = 0;
                  sb->num_renegotiates++;
                  SSL_renegotiate(ssl);
                  r = 1;
              }
          }
          if ((sb->renegotiate_timeout > 0) && (!r)) {
              unsigned long tm;
  
              tm = (unsigned long)time(NULL);
              if (tm > sb->last_time + sb->renegotiate_timeout) {
                  sb->last_time = tm;
                  sb->num_renegotiates++;
                  SSL_renegotiate(ssl);
              }
          }
  
          break;
      case SSL_ERROR_WANT_READ:
          BIO_set_retry_read(b);
          break;
      case SSL_ERROR_WANT_WRITE:
          BIO_set_retry_write(b);
          break;
      case SSL_ERROR_WANT_X509_LOOKUP:
          BIO_set_retry_special(b);
          retry_reason = BIO_RR_SSL_X509_LOOKUP;
          break;
      case SSL_ERROR_WANT_ACCEPT:
          BIO_set_retry_special(b);
          retry_reason = BIO_RR_ACCEPT;
          break;
      case SSL_ERROR_WANT_CONNECT:
          BIO_set_retry_special(b);
          retry_reason = BIO_RR_CONNECT;
          break;
      case SSL_ERROR_SYSCALL:
      case SSL_ERROR_SSL:
      case SSL_ERROR_ZERO_RETURN:
      default:
          break;
      }
  
      BIO_set_retry_reason(b, retry_reason);
  
      return ret;
  }
  
  static int ssl_write(BIO *b, const char *buf, size_t size, size_t *written)
  {
      int ret, r = 0;
      int retry_reason = 0;
      SSL *ssl;
      BIO_SSL *bs;
  
      if (buf == NULL)
          return 0;
      bs = BIO_get_data(b);
      ssl = bs->ssl;
  
      BIO_clear_retry_flags(b);
  
      ret = ssl_write_internal(ssl, buf, size, written);
  
      switch (SSL_get_error(ssl, ret)) {
      case SSL_ERROR_NONE:
          if (bs->renegotiate_count > 0) {
              bs->byte_count += *written;
              if (bs->byte_count > bs->renegotiate_count) {
                  bs->byte_count = 0;
                  bs->num_renegotiates++;
                  SSL_renegotiate(ssl);
                  r = 1;
              }
          }
          if ((bs->renegotiate_timeout > 0) && (!r)) {
              unsigned long tm;
  
              tm = (unsigned long)time(NULL);
              if (tm > bs->last_time + bs->renegotiate_timeout) {
                  bs->last_time = tm;
                  bs->num_renegotiates++;
                  SSL_renegotiate(ssl);
              }
          }
          break;
      case SSL_ERROR_WANT_WRITE:
          BIO_set_retry_write(b);
          break;
      case SSL_ERROR_WANT_READ:
          BIO_set_retry_read(b);
          break;
      case SSL_ERROR_WANT_X509_LOOKUP:
          BIO_set_retry_special(b);
          retry_reason = BIO_RR_SSL_X509_LOOKUP;
          break;
      case SSL_ERROR_WANT_CONNECT:
          BIO_set_retry_special(b);
          retry_reason = BIO_RR_CONNECT;
      case SSL_ERROR_SYSCALL:
      case SSL_ERROR_SSL:
      default:
          break;
      }
  
      BIO_set_retry_reason(b, retry_reason);
  
      return ret;
  }
  
  static long ssl_ctrl(BIO *b, int cmd, long num, void *ptr)
  {
      SSL **sslp, *ssl;
      BIO_SSL *bs, *dbs;
      BIO *dbio, *bio;
      long ret = 1;
      BIO *next;
  
      bs = BIO_get_data(b);
      next = BIO_next(b);
      ssl = bs->ssl;
      if ((ssl == NULL) && (cmd != BIO_C_SET_SSL))
          return 0;
      switch (cmd) {
      case BIO_CTRL_RESET:
          SSL_shutdown(ssl);
  
          if (ssl->handshake_func == ssl->method->ssl_connect)
              SSL_set_connect_state(ssl);
          else if (ssl->handshake_func == ssl->method->ssl_accept)
              SSL_set_accept_state(ssl);
  
          if (!SSL_clear(ssl)) {
              ret = 0;
              break;
          }
  
          if (next != NULL)
              ret = BIO_ctrl(next, cmd, num, ptr);
          else if (ssl->rbio != NULL)
              ret = BIO_ctrl(ssl->rbio, cmd, num, ptr);
          else
              ret = 1;
          break;
      case BIO_CTRL_INFO:
          ret = 0;
          break;
      case BIO_C_SSL_MODE:
          if (num)                /* client mode */
              SSL_set_connect_state(ssl);
          else
              SSL_set_accept_state(ssl);
          break;
      case BIO_C_SET_SSL_RENEGOTIATE_TIMEOUT:
          ret = bs->renegotiate_timeout;
          if (num < 60)
              num = 5;
          bs->renegotiate_timeout = (unsigned long)num;
          bs->last_time = (unsigned long)time(NULL);
          break;
      case BIO_C_SET_SSL_RENEGOTIATE_BYTES:
          ret = bs->renegotiate_count;
          if ((long)num >= 512)
              bs->renegotiate_count = (unsigned long)num;
          break;
      case BIO_C_GET_SSL_NUM_RENEGOTIATES:
          ret = bs->num_renegotiates;
          break;
      case BIO_C_SET_SSL:
          if (ssl != NULL) {
              ssl_free(b);
              if (!ssl_new(b))
                  return 0;
          }
          BIO_set_shutdown(b, num);
          ssl = (SSL *)ptr;
          bs->ssl = ssl;
          bio = SSL_get_rbio(ssl);
          if (bio != NULL) {
              if (next != NULL)
                  BIO_push(bio, next);
              BIO_set_next(b, bio);
              BIO_up_ref(bio);
          }
          BIO_set_init(b, 1);
          break;
      case BIO_C_GET_SSL:
          if (ptr != NULL) {
              sslp = (SSL **)ptr;
              *sslp = ssl;
          } else
              ret = 0;
          break;
      case BIO_CTRL_GET_CLOSE:
          ret = BIO_get_shutdown(b);
          break;
      case BIO_CTRL_SET_CLOSE:
          BIO_set_shutdown(b, (int)num);
          break;
      case BIO_CTRL_WPENDING:
          ret = BIO_ctrl(ssl->wbio, cmd, num, ptr);
          break;
      case BIO_CTRL_PENDING:
          ret = SSL_pending(ssl);
          if (ret == 0)
              ret = BIO_pending(ssl->rbio);
          break;
      case BIO_CTRL_FLUSH:
          BIO_clear_retry_flags(b);
          ret = BIO_ctrl(ssl->wbio, cmd, num, ptr);
          BIO_copy_next_retry(b);
          break;
      case BIO_CTRL_PUSH:
          if ((next != NULL) && (next != ssl->rbio)) {
              /*
               * We are going to pass ownership of next to the SSL object...but
               * we don't own a reference to pass yet - so up ref
               */
              BIO_up_ref(next);
              SSL_set_bio(ssl, next, next);
          }
          break;
      case BIO_CTRL_POP:
          /* Only detach if we are the BIO explicitly being popped */
          if (b == ptr) {
              /* This will clear the reference we obtained during push */
              SSL_set_bio(ssl, NULL, NULL);
          }
          break;
      case BIO_C_DO_STATE_MACHINE:
          BIO_clear_retry_flags(b);
  
          BIO_set_retry_reason(b, 0);
          ret = (int)SSL_do_handshake(ssl);
  
          switch (SSL_get_error(ssl, (int)ret)) {
          case SSL_ERROR_WANT_READ:
              BIO_set_flags(b, BIO_FLAGS_READ | BIO_FLAGS_SHOULD_RETRY);
              break;
          case SSL_ERROR_WANT_WRITE:
              BIO_set_flags(b, BIO_FLAGS_WRITE | BIO_FLAGS_SHOULD_RETRY);
              break;
          case SSL_ERROR_WANT_CONNECT:
              BIO_set_flags(b, BIO_FLAGS_IO_SPECIAL | BIO_FLAGS_SHOULD_RETRY);
              BIO_set_retry_reason(b, BIO_get_retry_reason(next));
              break;
          case SSL_ERROR_WANT_X509_LOOKUP:
              BIO_set_retry_special(b);
              BIO_set_retry_reason(b, BIO_RR_SSL_X509_LOOKUP);
              break;
          default:
              break;
          }
          break;
      case BIO_CTRL_DUP:
          dbio = (BIO *)ptr;
          dbs = BIO_get_data(dbio);
          SSL_free(dbs->ssl);
          dbs->ssl = SSL_dup(ssl);
          dbs->num_renegotiates = bs->num_renegotiates;
          dbs->renegotiate_count = bs->renegotiate_count;
          dbs->byte_count = bs->byte_count;
          dbs->renegotiate_timeout = bs->renegotiate_timeout;
          dbs->last_time = bs->last_time;
          ret = (dbs->ssl != NULL);
          break;
      case BIO_C_GET_FD:
          ret = BIO_ctrl(ssl->rbio, cmd, num, ptr);
          break;
      case BIO_CTRL_SET_CALLBACK:
          ret = 0; /* use callback ctrl */
          break;
      default:
          ret = BIO_ctrl(ssl->rbio, cmd, num, ptr);
          break;
      }
      return ret;
  }
  
  static long ssl_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
  {
      SSL *ssl;
      BIO_SSL *bs;
      long ret = 1;
  
      bs = BIO_get_data(b);
      ssl = bs->ssl;
      switch (cmd) {
      case BIO_CTRL_SET_CALLBACK:
          ret = BIO_callback_ctrl(ssl->rbio, cmd, fp);
          break;
      default:
          ret = 0;
          break;
      }
      return ret;
  }
  
  static int ssl_puts(BIO *bp, const char *str)
  {
      int n, ret;
  
      n = strlen(str);
      ret = BIO_write(bp, str, n);
      return ret;
  }
  
  BIO *BIO_new_buffer_ssl_connect(SSL_CTX *ctx)
  {
  #ifndef OPENSSL_NO_SOCK
      BIO *ret = NULL, *buf = NULL, *ssl = NULL;
  
      if ((buf = BIO_new(BIO_f_buffer())) == NULL)
          return NULL;
      if ((ssl = BIO_new_ssl_connect(ctx)) == NULL)
          goto err;
      if ((ret = BIO_push(buf, ssl)) == NULL)
          goto err;
      return ret;
   err:
      BIO_free(buf);
      BIO_free(ssl);
  #endif
      return NULL;
  }
  
  BIO *BIO_new_ssl_connect(SSL_CTX *ctx)
  {
  #ifndef OPENSSL_NO_SOCK
      BIO *ret = NULL, *con = NULL, *ssl = NULL;
  
      if ((con = BIO_new(BIO_s_connect())) == NULL)
          return NULL;
      if ((ssl = BIO_new_ssl(ctx, 1)) == NULL)
          goto err;
      if ((ret = BIO_push(ssl, con)) == NULL)
          goto err;
      return ret;
   err:
      BIO_free(con);
  #endif
      return NULL;
  }
  
  BIO *BIO_new_ssl(SSL_CTX *ctx, int client)
  {
      BIO *ret;
      SSL *ssl;
  
      if ((ret = BIO_new(BIO_f_ssl())) == NULL)
          return NULL;
      if ((ssl = SSL_new(ctx)) == NULL) {
          BIO_free(ret);
          return NULL;
      }
      if (client)
          SSL_set_connect_state(ssl);
      else
          SSL_set_accept_state(ssl);
  
      BIO_set_ssl(ret, ssl, BIO_CLOSE);
      return ret;
  }
  
  int BIO_ssl_copy_session_id(BIO *t, BIO *f)
  {
      BIO_SSL *tdata, *fdata;
      t = BIO_find_type(t, BIO_TYPE_SSL);
      f = BIO_find_type(f, BIO_TYPE_SSL);
      if ((t == NULL) || (f == NULL))
          return 0;
      tdata = BIO_get_data(t);
      fdata = BIO_get_data(f);
      if ((tdata->ssl == NULL) || (fdata->ssl == NULL))
          return 0;
      if (!SSL_copy_session_id(tdata->ssl, (fdata->ssl)))
          return 0;
      return 1;
  }
  
  void BIO_ssl_shutdown(BIO *b)
  {
      BIO_SSL *bdata;
  
      for (; b != NULL; b = BIO_next(b)) {
          if (BIO_method_type(b) != BIO_TYPE_SSL)
              continue;
          bdata = BIO_get_data(b);
          if (bdata != NULL && bdata->ssl != NULL)
              SSL_shutdown(bdata->ssl);
      }
  }
  