Linux Cross Reference
Nginx/event/ngx_event_openssl.c

   
   /*
    * Copyright (C) Igor Sysoev
    */
   
   
   #include <ngx_config.h>
   #include <ngx_core.h>
   #include <ngx_event.h>
  
  
  typedef struct {
      ngx_uint_t  engine;   /* unsigned  engine:1; */
  } ngx_openssl_conf_t;
  
  
  static int ngx_http_ssl_verify_callback(int ok, X509_STORE_CTX *x509_store);
  static void ngx_ssl_handshake_handler(ngx_event_t *ev);
  static ngx_int_t ngx_ssl_handle_recv(ngx_connection_t *c, int n);
  static void ngx_ssl_write_handler(ngx_event_t *wev);
  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_cache_init(ngx_shm_zone_t *shm_zone,
      void *data);
  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,
      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);
  
  static void *ngx_openssl_create_conf(ngx_cycle_t *cycle);
  static char *ngx_openssl_engine(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
  static void ngx_openssl_exit(ngx_cycle_t *cycle);
  
  
  static ngx_command_t  ngx_openssl_commands[] = {
  
      { ngx_string("ssl_engine"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
        ngx_openssl_engine,
        0,
        0,
        NULL },
  
        ngx_null_command
  };
  
  
  static ngx_core_module_t  ngx_openssl_module_ctx = {
      ngx_string("openssl"),
      ngx_openssl_create_conf,
      NULL
  };
  
  
  ngx_module_t  ngx_openssl_module = {
      NGX_MODULE_V1,
      &ngx_openssl_module_ctx,               /* module context */
      ngx_openssl_commands,                  /* module directives */
      NGX_CORE_MODULE,                       /* module type */
      NULL,                                  /* init master */
      NULL,                                  /* init module */
      NULL,                                  /* init process */
      NULL,                                  /* init thread */
      NULL,                                  /* exit thread */
      NULL,                                  /* exit process */
      ngx_openssl_exit,                      /* exit master */
      NGX_MODULE_V1_PADDING
  };
  
  
  static long  ngx_ssl_protocols[] = {
      SSL_OP_NO_SSLv2|SSL_OP_NO_SSLv3|SSL_OP_NO_TLSv1,
      SSL_OP_NO_SSLv3|SSL_OP_NO_TLSv1,
      SSL_OP_NO_SSLv2|SSL_OP_NO_TLSv1,
      SSL_OP_NO_TLSv1,
      SSL_OP_NO_SSLv2|SSL_OP_NO_SSLv3,
      SSL_OP_NO_SSLv3,
      SSL_OP_NO_SSLv2,
      0,
  };
  
  
  int  ngx_ssl_connection_index;
  int  ngx_ssl_server_conf_index;
  int  ngx_ssl_session_cache_index;
  
  
  ngx_int_t
  ngx_ssl_init(ngx_log_t *log)
  {
     OPENSSL_config(NULL);
 
     SSL_library_init();
     SSL_load_error_strings();
 
     ENGINE_load_builtin_engines();
 
     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;
     }
 
     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;
     }
 
     /* client side options */
 
     SSL_CTX_set_options(ssl->ctx, SSL_OP_MICROSOFT_SESS_ID_BUG);
     SSL_CTX_set_options(ssl->ctx, SSL_OP_NETSCAPE_CHALLENGE_BUG);
     SSL_CTX_set_options(ssl->ctx, SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG);
 
     /* server side options */
 
     SSL_CTX_set_options(ssl->ctx, SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG);
     SSL_CTX_set_options(ssl->ctx, SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER);
 
     /* this option allow a potential SSL 2.0 rollback (CAN-2005-2969) */
     SSL_CTX_set_options(ssl->ctx, SSL_OP_MSIE_SSLV2_RSA_PADDING);
 
     SSL_CTX_set_options(ssl->ctx, SSL_OP_SSLEAY_080_CLIENT_DH_BUG);
     SSL_CTX_set_options(ssl->ctx, SSL_OP_TLS_D5_BUG);
     SSL_CTX_set_options(ssl->ctx, SSL_OP_TLS_BLOCK_PADDING_BUG);
 
     SSL_CTX_set_options(ssl->ctx, SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS);
 
     SSL_CTX_set_options(ssl->ctx, SSL_OP_SINGLE_DH_USE);
 
     if (ngx_ssl_protocols[protocols >> 1] != 0) {
         SSL_CTX_set_options(ssl->ctx, ngx_ssl_protocols[protocols >> 1]);
     }
 
     SSL_CTX_set_read_ahead(ssl->ctx, 1);
 
     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)
 {
     if (ngx_conf_full_name(cf->cycle, cert, 1) != NGX_OK) {
         return NGX_ERROR;
     }
 
     if (SSL_CTX_use_certificate_chain_file(ssl->ctx, (char *) cert->data)
         == 0)
     {
         ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                       "SSL_CTX_use_certificate_chain_file(\"%s\") failed",
                       cert->data);
         return NGX_ERROR;
     }
 
     if (ngx_conf_full_name(cf->cycle, key, 1) != NGX_OK) {
         return NGX_ERROR;
     }
 
     if (SSL_CTX_use_PrivateKey_file(ssl->ctx, (char *) key->data,
                                     SSL_FILETYPE_PEM)
         == 0)
     {
         ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0,
                       "SSL_CTX_use_PrivateKey_file(\"%s\") failed", key->data);
         return NGX_ERROR;
     }
 
     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_http_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;
     }
 
     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;
     }
 
     /*
      * before 0.9.7h and 0.9.8 SSL_load_client_CA_file()
      * always leaved an error in the error queue
      */
 
     ERR_clear_error();
 
     SSL_CTX_set_client_CA_list(ssl->ctx, list);
 
     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_http_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);
 
     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);
     subject = sname ? X509_NAME_oneline(sname, NULL, 0) : "(none)";
 
     iname = X509_get_issuer_name(cert);
     issuer = iname ? X509_NAME_oneline(iname, NULL, 0) : "(none)";
 
     ngx_log_debug5(NGX_LOG_DEBUG_EVENT, c->log, 0,
                    "verify:%d, error:%d, depth:%d, "
                    "subject:\"%s\",issuer: \"%s\"",
                    ok, err, depth, subject, issuer);
 
     if (sname) {
         OPENSSL_free(subject);
     }
 
     if (iname) {
         OPENSSL_free(issuer);
     }
 #endif
 
     return 1;
 }
 
 
 ngx_int_t
 ngx_ssl_generate_rsa512_key(ngx_ssl_t *ssl)
 {
     RSA  *key;
 
     if (SSL_CTX_need_tmp_RSA(ssl->ctx) == 0) {
         return NGX_OK;
     }
 
     key = RSA_generate_key(512, RSA_F4, NULL, NULL);
 
     if (key) {
         SSL_CTX_set_tmp_rsa(ssl->ctx, key);
 
         RSA_free(key);
 
         return NGX_OK;
     }
 
     ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "RSA_generate_key(512) failed");
 
     return NGX_ERROR;
 }
 
 
 ngx_int_t
 ngx_ssl_dhparam(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *file)
 {
     DH   *dh;
     BIO  *bio;
 
     /*
      * -----BEGIN DH PARAMETERS-----
      * MIGHAoGBALu8LcrYRnSQfEP89YDpz9vZWKP1aLQtSwju1OsPs1BMbAMCducQgAxc
      * y7qokiYUxb7spWWl/fHSh6K8BJvmd4Bg6RqSp1fjBI9osHb302zI8pul34HcLKcl
      * 7OZicMyaUDXYzs7vnqAnSmOrHlj6/UmI0PZdFGdX2gcd8EXP4WubAgEC
      * -----END DH PARAMETERS-----
      */
 
     static unsigned char dh1024_p[] = {
         0xBB, 0xBC, 0x2D, 0xCA, 0xD8, 0x46, 0x74, 0x90, 0x7C, 0x43, 0xFC, 0xF5,
         0x80, 0xE9, 0xCF, 0xDB, 0xD9, 0x58, 0xA3, 0xF5, 0x68, 0xB4, 0x2D, 0x4B,
         0x08, 0xEE, 0xD4, 0xEB, 0x0F, 0xB3, 0x50, 0x4C, 0x6C, 0x03, 0x02, 0x76,
         0xE7, 0x10, 0x80, 0x0C, 0x5C, 0xCB, 0xBA, 0xA8, 0x92, 0x26, 0x14, 0xC5,
         0xBE, 0xEC, 0xA5, 0x65, 0xA5, 0xFD, 0xF1, 0xD2, 0x87, 0xA2, 0xBC, 0x04,
         0x9B, 0xE6, 0x77, 0x80, 0x60, 0xE9, 0x1A, 0x92, 0xA7, 0x57, 0xE3, 0x04,
         0x8F, 0x68, 0xB0, 0x76, 0xF7, 0xD3, 0x6C, 0xC8, 0xF2, 0x9B, 0xA5, 0xDF,
         0x81, 0xDC, 0x2C, 0xA7, 0x25, 0xEC, 0xE6, 0x62, 0x70, 0xCC, 0x9A, 0x50,
         0x35, 0xD8, 0xCE, 0xCE, 0xEF, 0x9E, 0xA0, 0x27, 0x4A, 0x63, 0xAB, 0x1E,
         0x58, 0xFA, 0xFD, 0x49, 0x88, 0xD0, 0xF6, 0x5D, 0x14, 0x67, 0x57, 0xDA,
         0x07, 0x1D, 0xF0, 0x45, 0xCF, 0xE1, 0x6B, 0x9B
     };
 
     static unsigned char dh1024_g[] = { 0x02 };
 
 
     if (file->len == 0) {
 
         dh = DH_new();
         if (dh == NULL) {
             ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "DH_new() failed");
             return NGX_ERROR;
         }
 
         dh->p = BN_bin2bn(dh1024_p, sizeof(dh1024_p), NULL);
         dh->g = BN_bin2bn(dh1024_g, sizeof(dh1024_g), NULL);
 
         if (dh->p == NULL || dh->g == NULL) {
             ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "BN_bin2bn() failed");
             DH_free(dh);
             return NGX_ERROR;
         }
 
         SSL_CTX_set_tmp_dh(ssl->ctx, dh);
 
         DH_free(dh);
 
         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_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->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);
     }
 
     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;
 
     return NGX_OK;
 }
 
 
 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_handshake(ngx_connection_t *c)
 {
     int        n, sslerr;
     ngx_err_t  err;
 
     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 (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)
         {
         char         buf[129], *s, *d;
         SSL_CIPHER  *cipher;
 
         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
 
         c->ssl->handshaked = 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;
 
         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) {
         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;
         }
 
         return NGX_AGAIN;
     }
 
     if (sslerr == SSL_ERROR_WANT_WRITE) {
         c->write->ready = 0;
         c->read->handler = ngx_ssl_handshake_handler;
         c->write->handler = ngx_ssl_handshake_handler;
 
         if (ngx_handle_write_event(c->write, 0) != NGX_OK) {
             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_log_error(NGX_LOG_INFO, c->log, err,
                       "peer closed connection in SSL handshake");
 
         return NGX_ERROR;
     }
 
     c->read->error = 1;
 
     ngx_ssl_connection_error(c, sslerr, err, "SSL_do_handshake() failed");
 
     return NGX_ERROR;
 }
 
 
 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)
 {
     u_char     *last;
     ssize_t     n, bytes;
     ngx_buf_t  *b;
 
     bytes = 0;
 
     b = cl->buf;
     last = b->last;
 
     for ( ;; ) {
 
         n = ngx_ssl_recv(c, last, b->end - last);
 
         if (n > 0) {
             last += n;
             bytes += n;
 
             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;
 
     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) {
                 return bytes;
             }
 
             buf += n;
 
             continue;
         }
 
         if (bytes) {
             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 thruogh */
 
         case NGX_AGAIN:
             return c->ssl->last;
         }
     }
 }
 
 
 static ngx_int_t
 ngx_ssl_handle_recv(ngx_connection_t *c, int n)
 {
     int        sslerr;
     ngx_err_t  err;
 
     if (n > 0) {
 
         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) {
         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");
 
         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;
     }
 
     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_write_handler(ngx_event_t *wev)
 {
     ngx_connection_t  *c;
 
     c = wev->data;
 
     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) {
                 c->buffered |= NGX_SSL_BUFFERED;
                 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 uint32_t value - the page size */
 
     if (limit == 0 || limit > (off_t) (NGX_MAX_UINT32_VALUE - ngx_pagesize)) {
         limit = NGX_MAX_UINT32_VALUE - ngx_pagesize;
     }
 
     buf = c->ssl->buf;
 
     if (buf == NULL) {
         buf = ngx_create_temp_buf(c->pool, NGX_SSL_BUFSIZE);
         if (buf == NULL) {
             return NGX_CHAIN_ERROR;
         }
 
         c->ssl->buf = buf;
     }
 
     if (buf->start == NULL) {
         buf->start = ngx_palloc(c->pool, NGX_SSL_BUFSIZE);
         if (buf->start == NULL) {
             return NGX_CHAIN_ERROR;
         }
 
         buf->pos = buf->start;
         buf->last = buf->start;
         buf->end = buf->start + NGX_SSL_BUFSIZE;
     }
 
     send = 0;
     flush = (in == NULL) ? 1 : 0;
 
     for ( ;; ) {
 
         while (in && buf->last < buf->end) {
             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);
                 flush = 1;
             }
 
             ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
                            "SSL buf copy: %d", size);
 
             ngx_memcpy(buf->last, in->buf->pos, size);
 
             buf->last += size;
 
             in->buf->pos += size;
 
             if (in->buf->pos == in->buf->last) {
                 in = in->next;
             }
         }
 
         size = buf->last - buf->pos;
 
         if (!flush && buf->last < buf->end && c->ssl->buffer) {
             break;
         }
 
         n = ngx_ssl_write(c, buf->pos, size);
 
         if (n == NGX_ERROR) {
             return NGX_CHAIN_ERROR;
         }
 
         if (n == NGX_AGAIN) {
             c->buffered |= NGX_SSL_BUFFERED;
             return in;
         }
 
         buf->pos += n;
         send += n;
         c->sent += n;
 
         if (n < size) {
             break;
         }
 
         if (buf->pos == buf->last) {
             buf->pos = buf->start;
             buf->last = buf->start;
         }
 
         if (in == NULL || send == limit) {
             break;
         }
     }
 
     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;
 
     ngx_ssl_clear_error(c->log);
 
     ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL to write: %d", 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->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);
         }
 
         return n;
     }
 
     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) {
         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");
 
         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() failed");
 
     return NGX_ERROR;
 }
 
 
 static void
 ngx_ssl_read_handler(ngx_event_t *rev)
 {
     ngx_connection_t  *c;
 
     c = rev->data;
 
     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;
 
     if (c->timedout) {
         mode = SSL_RECEIVED_SHUTDOWN|SSL_SENT_SHUTDOWN;
 
     } 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;
         }
     }
 
     SSL_set_shutdown(c->ssl->connection, mode);
 
     ngx_ssl_clear_error(c->log);
 
     n = SSL_shutdown(c->ssl->connection);
 
     ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_shutdown: %d", n);
 
     sslerr = 0;
 
     /* SSL_shutdown() never returns -1, on error it returns 0 */
 
     if (n != 1 && ERR_peek_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 (n == 1 || sslerr == 0 || sslerr == SSL_ERROR_ZERO_RETURN) {
         SSL_free(c->ssl->connection);
         c->ssl = NULL;
 
         return NGX_OK;
     }
 
     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 (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 (sslerr == SSL_ERROR_WANT_READ) {
             ngx_add_timer(c->read, 30000);
         }
 
         return NGX_AGAIN;
     }
 
     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;
 
     return NGX_ERROR;
 }
 
 
 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
             || 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_DIGEST_CHECK_FAILED                           /*  149 */
             || n == SSL_R_NO_CIPHERS_PASSED                          /*  182 */
             || n == SSL_R_NO_SHARED_CIPHER                           /*  193 */
             || n == SSL_R_UNEXPECTED_MESSAGE                         /*  244 */
             || n == SSL_R_UNEXPECTED_RECORD                          /*  245 */
             || n == SSL_R_WRONG_VERSION_NUMBER                       /*  267 */
             || n == SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC        /*  281 */
             || n == 1000 /* SSL_R_SSLV3_ALERT_CLOSE_NOTIFY */
             || 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 */
         {
             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, ...)
 {
     u_long    n;
     va_list   args;
     u_char   *p, *last;
     u_char    errstr[NGX_MAX_CONF_ERRSTR];
 
     last = errstr + NGX_MAX_CONF_ERRSTR;
 
     va_start(args, fmt);
     p = ngx_vslprintf(errstr, last - 1, fmt, args);
     va_end(args);
 
     p = ngx_cpystrn(p, (u_char *) " (SSL:", last - p);
 
     for ( ;; ) {
 
         n = ERR_get_error();
 
         if (n == 0) {
             break;
         }
 
         if (p >= last) {
             continue;
         }
 
         *p++ = ' ';
 
         ERR_error_string_n(n, (char *) p, last - p);
 
         while (p < last && *p) {
             p++;
         }
     }
 
     ngx_log_error(level, log, err, "%s)", errstr);
 }
 
 
 ngx_int_t
 ngx_ssl_session_cache(ngx_ssl_t *ssl, ngx_str_t *sess_ctx,
     ssize_t builtin_session_cache, ngx_shm_zone_t *shm_zone, time_t timeout)
 {
     long  cache_mode;
 
     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);
 
     SSL_CTX_set_session_id_context(ssl->ctx, sess_ctx->data, sess_ctx->len);
 
     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);
         }
     }
 
     SSL_CTX_set_timeout(ssl->ctx, (long) timeout);
 
     if (shm_zone) {
         shm_zone->init = ngx_ssl_session_cache_init;
 
         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_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;
     }
 
     if (shm_zone->shm.exists) {
         shm_zone->data = data;
         return NGX_OK;
     }
 
     shpool = (ngx_slab_pool_t *) shm_zone->shm.addr;
 
     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);
 
     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;
     uint32_t                  hash;
     SSL_CTX                  *ssl_ctx;
     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 = SSL_get_SSL_CTX(ssl_conn);
     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) {
         goto failed;
     }
 
 #if (NGX_PTR_SIZE == 8)
 
     id = sess_id->sess_id;
 
 #else
 
     id = ngx_slab_alloc_locked(shpool, sess->session_id_length);
     if (id == NULL) {
         goto failed;
     }
 
 #endif
 
     ngx_memcpy(cached_sess, buf, len);
 
     ngx_memcpy(id, sess->session_id, sess->session_id_length);
 
     hash = ngx_crc32_short(sess->session_id, sess->session_id_length);
 
     ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
                    "ssl new session: %08XD:%d:%d",
                    hash, sess->session_id_length, len);
 
     sess_id->node.key = hash;
     sess_id->node.data = (u_char) sess->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 add new SSL session to the session cache");
 
     return 0;
 }
 
 
 static ngx_ssl_session_t *
 ngx_ssl_get_cached_session(ngx_ssl_conn_t *ssl_conn, u_char *id, int len,
     int *copy)
 {
 #if OPENSSL_VERSION_NUMBER >= 0x0090707fL
     const
 #endif
     u_char                   *p;
     uint32_t                  hash;
     ngx_int_t                 rc;
     ngx_shm_zone_t           *shm_zone;
     ngx_slab_pool_t          *shpool;
     ngx_connection_t         *c;
     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];
 
     c = ngx_ssl_get_connection(ssl_conn);
 
     hash = ngx_crc32_short(id, (size_t) len);
     *copy = 0;
 
     ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                    "ssl get session: %08XD:%d", hash, len);
 
     shm_zone = SSL_CTX_get_ex_data(SSL_get_SSL_CTX(ssl_conn),
                                    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 */
 
         do {
             sess_id = (ngx_ssl_sess_id_t *) node;
 
             rc = ngx_memn2cmp(id, sess_id->id,
                               (size_t) len, (size_t) node->data);
             if (rc == 0) {
 
                 if (sess_id->expire > ngx_time()) {
                     ngx_memcpy(buf, sess_id->session, sess_id->len);
 
                     ngx_shmtx_unlock(&shpool->mutex);
 
                     p = buf;
                     sess = d2i_SSL_SESSION(NULL, &p, sess_id->len);
 
                     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;
 
         } while (node != sentinel && hash == node->key);
 
         break;
     }
 
 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)
 {
     size_t                    len;
     u_char                   *id;
     uint32_t                  hash;
     ngx_int_t                 rc;
     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 = sess->session_id;
     len = (size_t) sess->session_id_length;
 
     hash = ngx_crc32_short(id, len);
 
     ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ngx_cycle->log, 0,
                    "ssl remove session: %08XD:%uz", 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 */
 
         do {
             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;
 
         } while (node != sentinel && hash == node->key);
 
         break;
     }
 
 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);
 }
 
 
 void
 ngx_ssl_cleanup_ctx(void *data)
 {
     ngx_ssl_t  *ssl = data;
 
     SSL_CTX_free(ssl->ctx);
 }
 
 
 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_session_id(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
 {
     int           len;
     u_char       *p, *buf;
     SSL_SESSION  *sess;
 
     sess = SSL_get0_session(c->ssl->connection);
 
     len = i2d_SSL_SESSION(sess, NULL);
 
     buf = ngx_alloc(len, c->log);
     if (buf == NULL) {
         return NGX_ERROR;
     }
 
     s->len = 2 * len;
     s->data = ngx_pnalloc(pool, 2 * len);
     if (s->data == NULL) {
         ngx_free(buf);
         return NGX_ERROR;
     }
 
     p = buf;
     i2d_SSL_SESSION(sess, &p);
 
     ngx_hex_dump(s->data, buf, len);
 
     ngx_free(buf);
 
     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_subject_dn(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);
 
     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(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);
 
     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) {
         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_client_verify(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
 {
     X509  *cert;
 
     if (SSL_get_verify_result(c->ssl->connection) != X509_V_OK) {
         s->len = sizeof("FAILED") - 1;
         s->data = (u_char *) "FAILED";
 
         return NGX_OK;
     }
 
     cert = SSL_get_peer_certificate(c->ssl->connection);
 
     if (cert) {
         s->len = sizeof("SUCCESS") - 1;
         s->data = (u_char *) "SUCCESS";
 
     } else {
         s->len = sizeof("NONE") - 1;
         s->data = (u_char *) "NONE";
     }
 
     X509_free(cert);
 
     return NGX_OK;
 }
 
 
 static void *
 ngx_openssl_create_conf(ngx_cycle_t *cycle)
 {
     ngx_openssl_conf_t  *oscf;
 
     oscf = ngx_pcalloc(cycle->pool, sizeof(ngx_openssl_conf_t));
     if (oscf == NULL) {
         return NULL;
     }
 
     /*
      * set by ngx_pcalloc():
      *
      *     oscf->engine = 0;
      */
 
     return oscf;
 }
 
 
 static char *
 ngx_openssl_engine(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 {
     ngx_openssl_conf_t *oscf = conf;
 
     ENGINE     *engine;
     ngx_str_t  *value;
 
     if (oscf->engine) {
         return "is duplicate";
     }
 
     oscf->engine = 1;
 
     value = cf->args->elts;
 
     engine = ENGINE_by_id((const char *) value[1].data);
 
     if (engine == NULL) {
         ngx_ssl_error(NGX_LOG_WARN, cf->log, 0,
                       "ENGINE_by_id(\"%V\") failed", &value[1]);
         return NGX_CONF_ERROR;
     }
 
     if (ENGINE_set_default(engine, ENGINE_METHOD_ALL) == 0) {
         ngx_ssl_error(NGX_LOG_WARN, cf->log, 0,
                       "ENGINE_set_default(\"%V\", ENGINE_METHOD_ALL) failed",
                       &value[1]);
 
         ENGINE_free(engine);
 
         return NGX_CONF_ERROR;
     }
 
     ENGINE_free(engine);
 
     return NGX_CONF_OK;
 }
 
 
 static void
 ngx_openssl_exit(ngx_cycle_t *cycle)
 {
     ENGINE_cleanup();
 }