text: /* Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #ifndef SSL_PRIVATE_H
  #define SSL_PRIVATE_H
  
  /**
   * @file  ssl_private.h
   * @brief Internal interfaces private to mod_ssl.
   *
   * @defgroup MOD_SSL_PRIVATE Private
   * @ingroup MOD_SSL
   * @{
   */
  
  /** Apache headers */
  #include "httpd.h"
  #include "http_config.h"
  #include "http_core.h"
  #include "http_log.h"
  #include "http_main.h"
  #include "http_connection.h"
  #include "http_request.h"
  #include "http_protocol.h"
  #include "http_vhost.h"
  #include "util_script.h"
  #include "util_filter.h"
  #include "util_ebcdic.h"
  #include "util_mutex.h"
  #include "apr.h"
  #include "apr_strings.h"
  #define APR_WANT_STRFUNC
  #define APR_WANT_MEMFUNC
  #include "apr_want.h"
  #include "apr_tables.h"
  #include "apr_lib.h"
  #include "apr_fnmatch.h"
  #include "apr_strings.h"
  #include "apr_global_mutex.h"
  #include "apr_optional.h"
  #include "ap_socache.h"
  #include "mod_auth.h"
  
  /* The #ifdef macros are only defined AFTER including the above
   * therefore we cannot include these system files at the top  :-(
   */
  #if APR_HAVE_STDLIB_H
  #include <stdlib.h>
  #endif
  #if APR_HAVE_SYS_TIME_H
  #include <sys/time.h>
  #endif
  #if APR_HAVE_UNISTD_H
  #include <unistd.h> /* needed for STDIN_FILENO et.al., at least on FreeBSD */
  #endif
  
  #ifndef FALSE
  #define FALSE 0
  #endif
  
  #ifndef TRUE
  #define TRUE !FALSE
  #endif
  
  #ifndef BOOL
  #define BOOL unsigned int
  #endif
  
  #include "ap_expr.h"
  
  /* OpenSSL headers */
  #include <openssl/opensslv.h>
  #if (OPENSSL_VERSION_NUMBER >= 0x10001000)
  /* must be defined before including ssl.h */
  #define OPENSSL_NO_SSL_INTERN
  #endif
  #include <openssl/ssl.h>
  #include <openssl/err.h>
  #include <openssl/x509.h>
  #include <openssl/pem.h>
  #include <openssl/crypto.h>
  #include <openssl/evp.h>
  #include <openssl/rand.h>
  #include <openssl/x509v3.h>
  #include <openssl/x509_vfy.h>
  #include <openssl/ocsp.h>
  
  /* Avoid tripping over an engine build installed globally and detected
   * when the user points at an explicit non-engine flavor of OpenSSL
   */
  #if defined(HAVE_OPENSSL_ENGINE_H) && defined(HAVE_ENGINE_INIT)
  #include <openssl/engine.h>
  #endif
  
  #if (OPENSSL_VERSION_NUMBER < 0x0090801f)
  #error mod_ssl requires OpenSSL 0.9.8a or later
  #endif
  
  /**
   * ...shifting sands of OpenSSL...
   * Note: when adding support for new OpenSSL features, avoid explicit
   * version number checks whenever possible, and use "feature-based"
   * detection instead (check for definitions of constants or functions)
   */
  #if (OPENSSL_VERSION_NUMBER >= 0x10000000)
  #define MODSSL_SSL_CIPHER_CONST const
  #define MODSSL_SSL_METHOD_CONST const
  #else
  #define MODSSL_SSL_CIPHER_CONST
  #define MODSSL_SSL_METHOD_CONST
  #endif
  
  #if defined(OPENSSL_FIPS)
  #define HAVE_FIPS
  #endif
  
  #if defined(SSL_OP_NO_TLSv1_2)
  #define HAVE_TLSV1_X
  #endif
  
  #if defined(SSL_CONF_FLAG_FILE)
  #define HAVE_SSL_CONF_CMD
  #endif
  
  /**
    * The following features all depend on TLS extension support.
    * Within this block, check again for features (not version numbers).
    */
  #if !defined(OPENSSL_NO_TLSEXT) && defined(SSL_set_tlsext_host_name)
  
  #define HAVE_TLSEXT
  
  /* ECC: make sure we have at least 1.0.0 */
  #if !defined(OPENSSL_NO_EC) && defined(TLSEXT_ECPOINTFORMAT_uncompressed)
  #define HAVE_ECC
  #endif
  
  /* OCSP stapling */
  #if !defined(OPENSSL_NO_OCSP) && defined(SSL_CTX_set_tlsext_status_cb)
  #define HAVE_OCSP_STAPLING
  /* backward compatibility with OpenSSL < 1.0 */
  #ifndef sk_OPENSSL_STRING_num
  #define sk_OPENSSL_STRING_num sk_num
  #endif
  #ifndef sk_OPENSSL_STRING_value
  #define sk_OPENSSL_STRING_value sk_value
  #endif
  #ifndef sk_OPENSSL_STRING_pop
  #define sk_OPENSSL_STRING_pop sk_pop
  #endif
  #endif
  
  /* TLS session tickets */
  #if defined(SSL_CTX_set_tlsext_ticket_key_cb)
  #define HAVE_TLS_SESSION_TICKETS
  #define TLSEXT_TICKET_KEY_LEN 48
  #ifndef tlsext_tick_md
  #ifdef OPENSSL_NO_SHA256
  #define tlsext_tick_md EVP_sha1
  #else
  #define tlsext_tick_md EVP_sha256
  #endif
  #endif
  #endif
  
  /* Secure Remote Password */
  #if !defined(OPENSSL_NO_SRP) && defined(SSL_CTRL_SET_TLS_EXT_SRP_USERNAME_CB)
  #define HAVE_SRP
  #include <openssl/srp.h>
  #endif
  
  /* ALPN Protocol Negotiation */
  #if defined(TLSEXT_TYPE_application_layer_protocol_negotiation)
  #define HAVE_TLS_ALPN
  #endif
  
  #endif /* !defined(OPENSSL_NO_TLSEXT) && defined(SSL_set_tlsext_host_name) */
  
  /* mod_ssl headers */
  #include "ssl_util_ssl.h"
  
  APLOG_USE_MODULE(ssl);
  
  /*
   * Provide reasonable default for some defines
   */
  #ifndef PFALSE
  #define PFALSE ((void *)FALSE)
  #endif
  #ifndef PTRUE
  #define PTRUE ((void *)TRUE)
  #endif
  #ifndef UNSET
  #define UNSET (-1)
  #endif
  #ifndef NUL
  #define NUL '\0'
  #endif
  #ifndef RAND_MAX
  #include <limits.h>
  #define RAND_MAX INT_MAX
  #endif
  
  /**
   * Provide reasonable defines for some types
   */
  #ifndef UCHAR
  #define UCHAR unsigned char
  #endif
  
  /**
   * Provide useful shorthands
   */
  #define strEQ(s1,s2)     (strcmp(s1,s2)        == 0)
  #define strNE(s1,s2)     (strcmp(s1,s2)        != 0)
  #define strEQn(s1,s2,n)  (strncmp(s1,s2,n)     == 0)
  #define strNEn(s1,s2,n)  (strncmp(s1,s2,n)     != 0)
  
  #define strcEQ(s1,s2)    (strcasecmp(s1,s2)    == 0)
  #define strcNE(s1,s2)    (strcasecmp(s1,s2)    != 0)
  #define strcEQn(s1,s2,n) (strncasecmp(s1,s2,n) == 0)
  #define strcNEn(s1,s2,n) (strncasecmp(s1,s2,n) != 0)
  
  #define strIsEmpty(s)    (s == NULL || s[0] == NUL)
  
  #define myConnConfig(c) \
  (SSLConnRec *)ap_get_module_config(c->conn_config, &ssl_module)
  #define myCtxConfig(sslconn, sc) (sslconn->is_proxy ? sc->proxy : sc->server)
  #define myConnConfigSet(c, val) \
  ap_set_module_config(c->conn_config, &ssl_module, val)
  #define mySrvConfig(srv) (SSLSrvConfigRec *)ap_get_module_config(srv->module_config,  &ssl_module)
  #define myDirConfig(req) (SSLDirConfigRec *)ap_get_module_config(req->per_dir_config, &ssl_module)
  #define myModConfig(srv) (mySrvConfig((srv)))->mc
  #define mySrvFromConn(c) (myConnConfig(c))->server
  #define mySrvConfigFromConn(c) mySrvConfig(mySrvFromConn(c))
  #define myModConfigFromConn(c) myModConfig(mySrvFromConn(c))
  
  /**
   * Defaults for the configuration
   */
  #ifndef SSL_SESSION_CACHE_TIMEOUT
  #define SSL_SESSION_CACHE_TIMEOUT  300
  #endif
  
  /* Default setting for per-dir reneg buffer. */
  #ifndef DEFAULT_RENEG_BUFFER_SIZE
  #define DEFAULT_RENEG_BUFFER_SIZE (128 * 1024)
  #endif
  
  /* Default for OCSP response validity */
  #ifndef DEFAULT_OCSP_MAX_SKEW
  #define DEFAULT_OCSP_MAX_SKEW (60 * 5)
  #endif
  
  /* Default timeout for OCSP queries */
  #ifndef DEFAULT_OCSP_TIMEOUT
  #define DEFAULT_OCSP_TIMEOUT 10
  #endif
  
  /*
   * For better backwards compatibility with the SSLCertificate[Key]File
   * and SSLPassPhraseDialog ("exec" type) directives in 2.4.7 and earlier
   */
  #ifdef HAVE_ECC
  #define CERTKEYS_IDX_MAX 2
  #else
  #define CERTKEYS_IDX_MAX 1
  #endif
  
  /**
   * Define the SSL options
   */
  #define SSL_OPT_NONE           (0)
  #define SSL_OPT_RELSET         (1<<0)
  #define SSL_OPT_STDENVVARS     (1<<1)
  #define SSL_OPT_EXPORTCERTDATA (1<<3)
  #define SSL_OPT_FAKEBASICAUTH  (1<<4)
  #define SSL_OPT_STRICTREQUIRE  (1<<5)
  #define SSL_OPT_OPTRENEGOTIATE (1<<6)
  #define SSL_OPT_LEGACYDNFORMAT (1<<7)
  typedef int ssl_opt_t;
  
  /**
   * Define the SSL Protocol options
   */
  #define SSL_PROTOCOL_NONE  (0)
  #ifndef OPENSSL_NO_SSL3
  #define SSL_PROTOCOL_SSLV3 (1<<1)
  #endif
  #define SSL_PROTOCOL_TLSV1 (1<<2)
  #ifndef OPENSSL_NO_SSL3
  #define SSL_PROTOCOL_BASIC (SSL_PROTOCOL_SSLV3|SSL_PROTOCOL_TLSV1)
  #else
  #define SSL_PROTOCOL_BASIC (SSL_PROTOCOL_TLSV1)
  #endif
  #ifdef HAVE_TLSV1_X
  #define SSL_PROTOCOL_TLSV1_1 (1<<3)
  #define SSL_PROTOCOL_TLSV1_2 (1<<4)
  #define SSL_PROTOCOL_ALL   (SSL_PROTOCOL_BASIC| \
                              SSL_PROTOCOL_TLSV1_1|SSL_PROTOCOL_TLSV1_2)
  #else
  #define SSL_PROTOCOL_ALL   (SSL_PROTOCOL_BASIC)
  #endif
  #ifndef OPENSSL_NO_SSL3
  #define SSL_PROTOCOL_DEFAULT (SSL_PROTOCOL_ALL & ~SSL_PROTOCOL_SSLV3)
  #else
  #define SSL_PROTOCOL_DEFAULT (SSL_PROTOCOL_ALL)
  #endif
  typedef int ssl_proto_t;
  
  /**
   * Define the SSL verify levels
   */
  typedef enum {
      SSL_CVERIFY_UNSET           = UNSET,
      SSL_CVERIFY_NONE            = 0,
      SSL_CVERIFY_OPTIONAL        = 1,
      SSL_CVERIFY_REQUIRE         = 2,
      SSL_CVERIFY_OPTIONAL_NO_CA  = 3
  } ssl_verify_t;
  
  #define SSL_VERIFY_PEER_STRICT \
       (SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT)
  
  #define ssl_verify_error_is_optional(errnum) \
     ((errnum == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT) \
      || (errnum == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN) \
      || (errnum == X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY) \
      || (errnum == X509_V_ERR_CERT_UNTRUSTED) \
      || (errnum == X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE))
  
  /**
    * CRL checking mask (mode | flags)
    */
  typedef enum {
      SSL_CRLCHECK_NONE  = (0),
      SSL_CRLCHECK_LEAF  = (1 << 0),
      SSL_CRLCHECK_CHAIN = (1 << 1),
  
  #define SSL_CRLCHECK_FLAGS (~0x3)
      SSL_CRLCHECK_NO_CRL_FOR_CERT_OK = (1 << 2)
  } ssl_crlcheck_t;
  
  /**
   * Define the SSL pass phrase dialog types
   */
  typedef enum {
      SSL_PPTYPE_UNSET   = UNSET,
      SSL_PPTYPE_BUILTIN = 0,
      SSL_PPTYPE_FILTER  = 1,
      SSL_PPTYPE_PIPE    = 2
  } ssl_pphrase_t;
  
  /**
   * Define the Path Checking modes
   */
  #define SSL_PCM_EXISTS     1
  #define SSL_PCM_ISREG      2
  #define SSL_PCM_ISDIR      4
  #define SSL_PCM_ISNONZERO  8
  typedef unsigned int ssl_pathcheck_t;
  
  /**
   * Define the SSL enabled state
   */
  typedef enum {
      SSL_ENABLED_UNSET    = UNSET,
      SSL_ENABLED_FALSE    = 0,
      SSL_ENABLED_TRUE     = 1,
      SSL_ENABLED_OPTIONAL = 3
  } ssl_enabled_t;
  
  /**
   * Define the SSL requirement structure
   */
  typedef struct {
      const char     *cpExpr;
      ap_expr_info_t *mpExpr;
  } ssl_require_t;
  
  /**
   * Define the SSL random number generator seeding source
   */
  typedef enum {
      SSL_RSCTX_STARTUP = 1,
      SSL_RSCTX_CONNECT = 2
  } ssl_rsctx_t;
  typedef enum {
      SSL_RSSRC_BUILTIN = 1,
      SSL_RSSRC_FILE    = 2,
      SSL_RSSRC_EXEC    = 3,
      SSL_RSSRC_EGD     = 4
  } ssl_rssrc_t;
  typedef struct {
      ssl_rsctx_t  nCtx;
      ssl_rssrc_t  nSrc;
      char        *cpPath;
      int          nBytes;
  } ssl_randseed_t;
  
  /**
   * Define the structure of an ASN.1 anything
   */
  typedef struct {
      long int       nData;
      unsigned char *cpData;
      apr_time_t     source_mtime;
  } ssl_asn1_t;
  
  /**
   * Define the mod_ssl per-module configuration structure
   * (i.e. the global configuration for each httpd process)
   */
  
  typedef enum {
      SSL_SHUTDOWN_TYPE_UNSET,
      SSL_SHUTDOWN_TYPE_STANDARD,
      SSL_SHUTDOWN_TYPE_UNCLEAN,
      SSL_SHUTDOWN_TYPE_ACCURATE
  } ssl_shutdown_type_e;
  
  typedef struct {
      SSL *ssl;
      const char *client_dn;
      X509 *client_cert;
      ssl_shutdown_type_e shutdown_type;
      const char *verify_info;
      const char *verify_error;
      int verify_depth;
      int is_proxy;
      int disabled;
      enum {
          NON_SSL_OK = 0,        /* is SSL request, or error handling completed */
          NON_SSL_SEND_REQLINE,  /* Need to send the fake request line */
          NON_SSL_SEND_HDR_SEP,  /* Need to send the header separator */
          NON_SSL_SET_ERROR_MSG  /* Need to set the error message */
      } non_ssl_request;
  
      /* Track the handshake/renegotiation state for the connection so
       * that all client-initiated renegotiations can be rejected, as a
       * partial fix for CVE-2009-3555. */
      enum {
          RENEG_INIT = 0, /* Before initial handshake */
          RENEG_REJECT, /* After initial handshake; any client-initiated
                         * renegotiation should be rejected */
          RENEG_ALLOW, /* A server-initiated renegotiation is taking
                        * place (as dictated by configuration) */
          RENEG_ABORT /* Renegotiation initiated by client, abort the
                       * connection */
      } reneg_state;
  
      server_rec *server;
      
      const char *cipher_suite; /* cipher suite used in last reneg */
  } SSLConnRec;
  
  /* BIG FAT WARNING: SSLModConfigRec has unusual memory lifetime: it is
   * allocated out of the "process" pool and only a single such
   * structure is created and used for the lifetime of the process.
   * (The process pool is s->process->pool and is stored in the .pPool
   * field.)  Most members of this structure are likewise allocated out
   * of the process pool, but notably sesscache and sesscache_context
   * are not.
   *
   * The structure is treated as mostly immutable after a single config
   * parse has completed; the post_config hook (ssl_init_Module) flips
   * the bFixed flag to true and subsequent invocations of the config
   * callbacks hence do nothing.
   *
   * This odd lifetime strategy is used so that encrypted private keys
   * can be decrypted once at startup and continue to be used across
   * subsequent server reloads where the interactive password prompt is
   * not possible.
  
   * It is really an ABI nightmare waiting to happen since DSOs are
   * reloaded across restarts, and nothing prevents the struct type
   * changing across such reloads, yet the cached structure will be
   * assumed to match regardless.
   *
   * This should really be fixed using a smaller structure which only
   * stores that which is absolutely necessary (the private keys, maybe
   * the random seed), and have that structure be strictly ABI-versioned
   * for safety.
   */
  typedef struct {
      pid_t           pid;
      apr_pool_t     *pPool;
      BOOL            bFixed;
  
      /* OpenSSL SSL_SESS_CACHE_* flags: */
      long            sesscache_mode;
  
      /* The configured provider, and associated private data
       * structure. */
      const ap_socache_provider_t *sesscache;
      ap_socache_instance_t *sesscache_context;
  
      apr_global_mutex_t   *pMutex;
      apr_array_header_t   *aRandSeed;
      apr_hash_t     *tVHostKeys;
  
      /* A hash table of pointers to ssl_asn1_t structures.  The structures
       * are used to store private keys in raw DER format (serialized OpenSSL
       * PrivateKey structures).  The table is indexed by (vhost-id,
       * index), for example the string "vhost.example.com:443:0". */
      apr_hash_t     *tPrivateKey;
  
  #if defined(HAVE_OPENSSL_ENGINE_H) && defined(HAVE_ENGINE_INIT)
      const char     *szCryptoDevice;
  #endif
  
  #ifdef HAVE_OCSP_STAPLING
      const ap_socache_provider_t *stapling_cache;
      ap_socache_instance_t *stapling_cache_context;
      apr_global_mutex_t   *stapling_cache_mutex;
      apr_global_mutex_t   *stapling_refresh_mutex;
  #endif
  } SSLModConfigRec;
  
  /** Structure representing configured filenames for certs and keys for
   * a given vhost */
  typedef struct {
      /* Lists of configured certs and keys for this server */
      apr_array_header_t *cert_files;
      apr_array_header_t *key_files;
  
      /** Certificates which specify the set of CA names which should be
       * sent in the CertificateRequest message: */
      const char  *ca_name_path;
      const char  *ca_name_file;
  } modssl_pk_server_t;
  
  typedef struct {
      /** proxy can have any number of cert/key pairs */
      const char  *cert_file;
      const char  *cert_path;
      const char  *ca_cert_file;
      STACK_OF(X509_INFO) *certs; /* Contains End Entity certs */
      STACK_OF(X509) **ca_certs; /* Contains ONLY chain certs for
                                  * each item in certs.
                                  * (ptr to array of ptrs) */
  } modssl_pk_proxy_t;
  
  /** stuff related to authentication that can also be per-dir */
  typedef struct {
      /** known/trusted CAs */
      const char  *ca_cert_path;
      const char  *ca_cert_file;
  
      const char  *cipher_suite;
  
      /** for client or downstream server authentication */
      int          verify_depth;
      ssl_verify_t verify_mode;
  } modssl_auth_ctx_t;
  
  #ifdef HAVE_TLS_SESSION_TICKETS
  typedef struct {
      const char *file_path;
      unsigned char key_name[16];
      unsigned char hmac_secret[16];
      unsigned char aes_key[16];
  } modssl_ticket_key_t;
  #endif
  
  #ifdef HAVE_SSL_CONF_CMD
  typedef struct {
      const char *name;
      const char *value;
  } ssl_ctx_param_t;
  #endif
  
  typedef struct SSLSrvConfigRec SSLSrvConfigRec;
  
  typedef struct {
      SSLSrvConfigRec *sc; /** pointer back to server config */
      SSL_CTX *ssl_ctx;
  
      /** we are one or the other */
      modssl_pk_server_t *pks;
      modssl_pk_proxy_t  *pkp;
  
  #ifdef HAVE_TLS_SESSION_TICKETS
      modssl_ticket_key_t *ticket_key;
  #endif
  
      ssl_proto_t  protocol;
      int protocol_set;
  
      /** config for handling encrypted keys */
      ssl_pphrase_t pphrase_dialog_type;
      const char   *pphrase_dialog_path;
  
      const char  *cert_chain;
  
      /** certificate revocation list */
      const char    *crl_path;
      const char    *crl_file;
      int            crl_check_mask;
  
  #ifdef HAVE_OCSP_STAPLING
      /** OCSP stapling options */
      BOOL        stapling_enabled;
      long        stapling_resptime_skew;
      long        stapling_resp_maxage;
      int         stapling_cache_timeout;
      BOOL        stapling_return_errors;
      BOOL        stapling_fake_trylater;
      int         stapling_errcache_timeout;
      apr_interval_time_t stapling_responder_timeout;
      const char *stapling_force_url;
  #endif
  
  #ifdef HAVE_SRP
      char *srp_vfile;
      char *srp_unknown_user_seed;
      SRP_VBASE  *srp_vbase;
  #endif
  
      modssl_auth_ctx_t auth;
  
      BOOL ocsp_enabled; /* true if OCSP verification enabled */
      BOOL ocsp_force_default; /* true if the default responder URL is
                                * used regardless of per-cert URL */
      const char *ocsp_responder; /* default responder URL */
      long ocsp_resptime_skew;
      long ocsp_resp_maxage;
      apr_interval_time_t ocsp_responder_timeout;
      BOOL ocsp_use_request_nonce;
      apr_uri_t *proxy_uri;
  
  #ifdef HAVE_SSL_CONF_CMD
      SSL_CONF_CTX *ssl_ctx_config; /* Configuration context */
      apr_array_header_t *ssl_ctx_param; /* parameters to pass to SSL_CTX */
  #endif
  } modssl_ctx_t;
  
  struct SSLSrvConfigRec {
      SSLModConfigRec *mc;
      ssl_enabled_t    enabled;
      BOOL             proxy_enabled;
      const char      *vhost_id;
      int              vhost_id_len;
      int              session_cache_timeout;
      BOOL             cipher_server_pref;
      BOOL             insecure_reneg;
      modssl_ctx_t    *server;
      modssl_ctx_t    *proxy;
      ssl_enabled_t    proxy_ssl_check_peer_expire;
      ssl_enabled_t    proxy_ssl_check_peer_cn;
      ssl_enabled_t    proxy_ssl_check_peer_name;
  #ifdef HAVE_TLSEXT
      ssl_enabled_t    strict_sni_vhost_check;
  #endif
  #ifdef HAVE_FIPS
      BOOL             fips;
  #endif
  #ifndef OPENSSL_NO_COMP
      BOOL             compression;
  #endif
      BOOL             session_tickets;
  };
  
  /**
   * Define the mod_ssl per-directory configuration structure
   * (i.e. the local configuration for all &lt;Directory>
   *  and .htaccess contexts)
   */
  typedef struct {
      BOOL          bSSLRequired;
      apr_array_header_t *aRequirement;
      ssl_opt_t     nOptions;
      ssl_opt_t     nOptionsAdd;
      ssl_opt_t     nOptionsDel;
      const char   *szCipherSuite;
      ssl_verify_t  nVerifyClient;
      int           nVerifyDepth;
      const char   *szCACertificatePath;
      const char   *szCACertificateFile;
      const char   *szUserName;
      apr_size_t    nRenegBufferSize;
  } SSLDirConfigRec;
  
  /**
   *  function prototypes
   */
  
  /**  API glue structures  */
  extern module AP_MODULE_DECLARE_DATA ssl_module;
  
  /**  configuration handling   */
  SSLModConfigRec *ssl_config_global_create(server_rec *);
  void         ssl_config_global_fix(SSLModConfigRec *);
  BOOL         ssl_config_global_isfixed(SSLModConfigRec *);
  void        *ssl_config_server_create(apr_pool_t *, server_rec *);
  void        *ssl_config_server_merge(apr_pool_t *, void *, void *);
  void        *ssl_config_perdir_create(apr_pool_t *, char *);
  void        *ssl_config_perdir_merge(apr_pool_t *, void *, void *);
  const char  *ssl_cmd_SSLPassPhraseDialog(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCryptoDevice(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLRandomSeed(cmd_parms *, void *, const char *, const char *, const char *);
  const char  *ssl_cmd_SSLEngine(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCipherSuite(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCertificateFile(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCertificateKeyFile(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCertificateChainFile(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCACertificatePath(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCACertificateFile(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCADNRequestPath(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCADNRequestFile(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCARevocationPath(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCARevocationFile(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLCARevocationCheck(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLHonorCipherOrder(cmd_parms *cmd, void *dcfg, int flag);
  const char  *ssl_cmd_SSLCompression(cmd_parms *, void *, int flag);
  const char  *ssl_cmd_SSLSessionTickets(cmd_parms *, void *, int flag);
  const char  *ssl_cmd_SSLVerifyClient(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLVerifyDepth(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLSessionCache(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLSessionCacheTimeout(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProtocol(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLOptions(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLRequireSSL(cmd_parms *, void *);
  const char  *ssl_cmd_SSLRequire(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLUserName(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLRenegBufferSize(cmd_parms *cmd, void *dcfg, const char *arg);
  const char  *ssl_cmd_SSLStrictSNIVHostCheck(cmd_parms *cmd, void *dcfg, int flag);
  const char *ssl_cmd_SSLInsecureRenegotiation(cmd_parms *cmd, void *dcfg, int flag);
  
  const char  *ssl_cmd_SSLProxyEngine(cmd_parms *cmd, void *dcfg, int flag);
  const char  *ssl_cmd_SSLProxyProtocol(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyCipherSuite(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyVerify(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyVerifyDepth(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyCACertificatePath(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyCACertificateFile(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyCARevocationPath(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyCARevocationFile(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyCARevocationCheck(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyMachineCertificatePath(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyMachineCertificateFile(cmd_parms *, void *, const char *);
  const char  *ssl_cmd_SSLProxyMachineCertificateChainFile(cmd_parms *, void *, const char *);
  #ifdef HAVE_TLS_SESSION_TICKETS
  const char *ssl_cmd_SSLSessionTicketKeyFile(cmd_parms *cmd, void *dcfg, const char *arg);
  #endif
  const char  *ssl_cmd_SSLProxyCheckPeerExpire(cmd_parms *cmd, void *dcfg, int flag);
  const char  *ssl_cmd_SSLProxyCheckPeerCN(cmd_parms *cmd, void *dcfg, int flag);
  const char  *ssl_cmd_SSLProxyCheckPeerName(cmd_parms *cmd, void *dcfg, int flag);
  
  const char *ssl_cmd_SSLOCSPOverrideResponder(cmd_parms *cmd, void *dcfg, int flag);
  const char *ssl_cmd_SSLOCSPDefaultResponder(cmd_parms *cmd, void *dcfg, const char *arg);
  const char *ssl_cmd_SSLOCSPResponseTimeSkew(cmd_parms *cmd, void *dcfg, const char *arg);
  const char *ssl_cmd_SSLOCSPResponseMaxAge(cmd_parms *cmd, void *dcfg, const char *arg);
  const char *ssl_cmd_SSLOCSPResponderTimeout(cmd_parms *cmd, void *dcfg, const char *arg);
  const char *ssl_cmd_SSLOCSPUseRequestNonce(cmd_parms *cmd, void *dcfg, int flag);
  const char *ssl_cmd_SSLOCSPEnable(cmd_parms *cmd, void *dcfg, int flag);
  const char *ssl_cmd_SSLOCSPProxyURL(cmd_parms *cmd, void *dcfg, const char *arg);
  
  #ifdef HAVE_SSL_CONF_CMD
  const char *ssl_cmd_SSLOpenSSLConfCmd(cmd_parms *cmd, void *dcfg, const char *arg1, const char *arg2);
  #endif
  
  #ifdef HAVE_SRP
  const char *ssl_cmd_SSLSRPVerifierFile(cmd_parms *cmd, void *dcfg, const char *arg);
  const char *ssl_cmd_SSLSRPUnknownUserSeed(cmd_parms *cmd, void *dcfg, const char *arg);
  #endif
  
  const char *ssl_cmd_SSLFIPS(cmd_parms *cmd, void *dcfg, int flag);
  
  /**  module initialization  */
  apr_status_t ssl_init_Module(apr_pool_t *, apr_pool_t *, apr_pool_t *, server_rec *);
  apr_status_t ssl_init_Engine(server_rec *, apr_pool_t *);
  apr_status_t ssl_init_ConfigureServer(server_rec *, apr_pool_t *, apr_pool_t *, SSLSrvConfigRec *,
                                        apr_array_header_t *);
  apr_status_t ssl_init_CheckServers(server_rec *, apr_pool_t *);
  STACK_OF(X509_NAME)
              *ssl_init_FindCAList(server_rec *, apr_pool_t *, const char *, const char *);
  void         ssl_init_Child(apr_pool_t *, server_rec *);
  apr_status_t ssl_init_ModuleKill(void *data);
  
  /**  Apache API hooks  */
  int          ssl_hook_Auth(request_rec *);
  int          ssl_hook_UserCheck(request_rec *);
  int          ssl_hook_Access(request_rec *);
  int          ssl_hook_Fixup(request_rec *);
  int          ssl_hook_ReadReq(request_rec *);
  int          ssl_hook_Upgrade(request_rec *);
  void         ssl_hook_ConfigTest(apr_pool_t *pconf, server_rec *s);
  
  /** Apache authz provisders */
  extern const authz_provider ssl_authz_provider_require_ssl;
  extern const authz_provider ssl_authz_provider_verify_client;
  
  /**  OpenSSL callbacks */
  DH          *ssl_callback_TmpDH(SSL *, int, int);
  int          ssl_callback_SSLVerify(int, X509_STORE_CTX *);
  int          ssl_callback_SSLVerify_CRL(int, X509_STORE_CTX *, conn_rec *);
  int          ssl_callback_proxy_cert(SSL *ssl, X509 **x509, EVP_PKEY **pkey);
  int          ssl_callback_NewSessionCacheEntry(SSL *, SSL_SESSION *);
  SSL_SESSION *ssl_callback_GetSessionCacheEntry(SSL *, unsigned char *, int, int *);
  void         ssl_callback_DelSessionCacheEntry(SSL_CTX *, SSL_SESSION *);
  void         ssl_callback_Info(const SSL *, int, int);
  #ifdef HAVE_TLSEXT
  int          ssl_callback_ServerNameIndication(SSL *, int *, modssl_ctx_t *);
  #endif
  #ifdef HAVE_TLS_SESSION_TICKETS
  int         ssl_callback_SessionTicket(SSL *, unsigned char *, unsigned char *,
                                         EVP_CIPHER_CTX *, HMAC_CTX *, int);
  #endif
  
  #ifdef HAVE_TLS_ALPN
  int ssl_callback_alpn_select(SSL *ssl, const unsigned char **out,
                               unsigned char *outlen, const unsigned char *in,
                               unsigned int inlen, void *arg);
  #endif
  
  /**  Session Cache Support  */
  apr_status_t ssl_scache_init(server_rec *, apr_pool_t *);
  void         ssl_scache_status_register(apr_pool_t *p);
  void         ssl_scache_kill(server_rec *);
  BOOL         ssl_scache_store(server_rec *, UCHAR *, int,
                                apr_time_t, SSL_SESSION *, apr_pool_t *);
  SSL_SESSION *ssl_scache_retrieve(server_rec *, UCHAR *, int, apr_pool_t *);
  void         ssl_scache_remove(server_rec *, UCHAR *, int,
                                 apr_pool_t *);
  
  /** Proxy Support */
  int ssl_proxy_enable(conn_rec *c);
  int ssl_engine_disable(conn_rec *c);
  
  /** OCSP Stapling Support */
  #ifdef HAVE_OCSP_STAPLING
  const char *ssl_cmd_SSLStaplingCache(cmd_parms *, void *, const char *);
  const char *ssl_cmd_SSLUseStapling(cmd_parms *, void *, int);
  const char *ssl_cmd_SSLStaplingResponseTimeSkew(cmd_parms *, void *, const char *);
  const char *ssl_cmd_SSLStaplingResponseMaxAge(cmd_parms *, void *, const char *);
  const char *ssl_cmd_SSLStaplingStandardCacheTimeout(cmd_parms *, void *, const char *);
  const char *ssl_cmd_SSLStaplingErrorCacheTimeout(cmd_parms *, void *, const char *);
  const char *ssl_cmd_SSLStaplingReturnResponderErrors(cmd_parms *, void *, int);
  const char *ssl_cmd_SSLStaplingFakeTryLater(cmd_parms *, void *, int);
  const char *ssl_cmd_SSLStaplingResponderTimeout(cmd_parms *, void *, const char *);
  const char *ssl_cmd_SSLStaplingForceURL(cmd_parms *, void *, const char *);
  apr_status_t modssl_init_stapling(server_rec *, apr_pool_t *, apr_pool_t *, modssl_ctx_t *);
  void         ssl_stapling_certinfo_hash_init(apr_pool_t *);
  int          ssl_stapling_init_cert(server_rec *, apr_pool_t *, apr_pool_t *,
                                      modssl_ctx_t *, X509 *);
  #endif
  #ifdef HAVE_SRP
  int          ssl_callback_SRPServerParams(SSL *, int *, void *);
  #endif
  
  /**  I/O  */
  void         ssl_io_filter_init(conn_rec *, request_rec *r, SSL *);
  void         ssl_io_filter_register(apr_pool_t *);
  long         ssl_io_data_cb(BIO *, int, const char *, int, long, long);
  
  /* ssl_io_buffer_fill fills the setaside buffering of the HTTP request
   * to allow an SSL renegotiation to take place. */
  int          ssl_io_buffer_fill(request_rec *r, apr_size_t maxlen);
  
  /**  PRNG  */
  int          ssl_rand_seed(server_rec *, apr_pool_t *, ssl_rsctx_t, char *);
  
  /**  Utility Functions  */
  char        *ssl_util_vhostid(apr_pool_t *, server_rec *);
  apr_file_t  *ssl_util_ppopen(server_rec *, apr_pool_t *, const char *,
                               const char * const *);
  void         ssl_util_ppclose(server_rec *, apr_pool_t *, apr_file_t *);
  char        *ssl_util_readfilter(server_rec *, apr_pool_t *, const char *,
                                   const char * const *);
  BOOL         ssl_util_path_check(ssl_pathcheck_t, const char *, apr_pool_t *);
  void         ssl_util_thread_setup(apr_pool_t *);
  int          ssl_init_ssl_connection(conn_rec *c, request_rec *r);
  
  BOOL         ssl_util_vhost_matches(const char *servername, server_rec *s);
  
  /**  Pass Phrase Support  */
  apr_status_t ssl_load_encrypted_pkey(server_rec *, apr_pool_t *, int,
                                       const char *, apr_array_header_t **);
  
  /**  Diffie-Hellman Parameter Support  */
  DH           *ssl_dh_GetParamFromFile(const char *);
  #ifdef HAVE_ECC
  EC_GROUP     *ssl_ec_GetParamFromFile(const char *);
  #endif
  
  unsigned char *ssl_asn1_table_set(apr_hash_t *table,
                                    const char *key,
                                    long int length);
  
  ssl_asn1_t *ssl_asn1_table_get(apr_hash_t *table,
                                 const char *key);
  
  void ssl_asn1_table_unset(apr_hash_t *table,
                            const char *key);
  
  /**  Mutex Support  */
  int          ssl_mutex_init(server_rec *, apr_pool_t *);
  int          ssl_mutex_reinit(server_rec *, apr_pool_t *);
  int          ssl_mutex_on(server_rec *);
  int          ssl_mutex_off(server_rec *);
  
  int          ssl_stapling_mutex_reinit(server_rec *, apr_pool_t *);
  
  /* mutex type names for Mutex directive */
  #define SSL_CACHE_MUTEX_TYPE    "ssl-cache"
  #define SSL_STAPLING_CACHE_MUTEX_TYPE "ssl-stapling"
  #define SSL_STAPLING_REFRESH_MUTEX_TYPE "ssl-stapling-refresh"
  
  apr_status_t ssl_die(server_rec *);
  
  /**  Logfile Support  */
  void         ssl_log_ssl_error(const char *, int, int, server_rec *);
  
  /* ssl_log_xerror, ssl_log_cxerror and ssl_log_rxerror are wrappers for the
   * respective ap_log_*error functions and take a certificate as an
   * additional argument (whose details are appended to the log message).
   * The other arguments are interpreted exactly as with their ap_log_*error
   * counterparts. */
  void ssl_log_xerror(const char *file, int line, int level,
                      apr_status_t rv, apr_pool_t *p, server_rec *s,
                      X509 *cert, const char *format, ...)
      __attribute__((format(printf,8,9)));
  
  void ssl_log_cxerror(const char *file, int line, int level,
                       apr_status_t rv, conn_rec *c, X509 *cert,
                       const char *format, ...)
      __attribute__((format(printf,7,8)));
  
  void ssl_log_rxerror(const char *file, int line, int level,
                       apr_status_t rv, request_rec *r, X509 *cert,
                       const char *format, ...)
      __attribute__((format(printf,7,8)));
  
  #define SSLLOG_MARK              __FILE__,__LINE__
  
  /**  Variables  */
  
  /* Register variables for the lifetime of the process pool 'p'. */
  void         ssl_var_register(apr_pool_t *p);
  char        *ssl_var_lookup(apr_pool_t *, server_rec *, conn_rec *, request_rec *, char *);
  apr_array_header_t *ssl_ext_list(apr_pool_t *p, conn_rec *c, int peer, const char *extension);
  
  void         ssl_var_log_config_register(apr_pool_t *p);
  
  /* Extract SSL_*_DN_* variables into table 't' from SSL object 'ssl',
   * allocating from 'p': */
  void modssl_var_extract_dns(apr_table_t *t, SSL *ssl, apr_pool_t *p);
  
  /* Extract SSL_*_SAN_* variables (subjectAltName entries) into table 't'
   * from SSL object 'ssl', allocating from 'p'. */
  void modssl_var_extract_san_entries(apr_table_t *t, SSL *ssl, apr_pool_t *p);
  
  #ifndef OPENSSL_NO_OCSP
  /* Perform OCSP validation of the current cert in the given context.
   * Returns non-zero on success or zero on failure.  On failure, the
   * context error code is set. */
  int modssl_verify_ocsp(X509_STORE_CTX *ctx, SSLSrvConfigRec *sc,
                         server_rec *s, conn_rec *c, apr_pool_t *pool);
  
  /* OCSP helper interface; dispatches the given OCSP request to the
   * responder at the given URI.  Returns the decoded OCSP response
   * object, or NULL on error (in which case, errors will have been
   * logged).  Pool 'p' is used for temporary allocations. */
  OCSP_RESPONSE *modssl_dispatch_ocsp_request(const apr_uri_t *uri,
                                              apr_interval_time_t timeout,
                                              OCSP_REQUEST *request,
                                              conn_rec *c, apr_pool_t *p);
  #endif
  
  /* Retrieve DH parameters for given key length.  Return value should
   * be treated as unmutable, since it is stored in process-global
   * memory. */
  DH *modssl_get_dh_params(unsigned keylen);
  
  #endif /* SSL_PRIVATE_H */
  /** @} */
  
  