ssluse.c

#ifdef ENABLE_IPV6
  struct in6_addr addr;
#else
  struct in_addr addr;
#endif

#ifdef ENABLE_IPV6
  if(conn->bits.ipv6_ip &&
     Curl_inet_pton(AF_INET6, conn->host.name, &addr)) {
    target = GEN_IPADD;
    addrlen = sizeof(struct in6_addr);
  }
  else
#endif
    if(Curl_inet_pton(AF_INET, conn->host.name, &addr)) {
      target = GEN_IPADD;
      addrlen = sizeof(struct in_addr);
    }

  /* get a "list" of alternative names */
  altnames = X509_get_ext_d2i(server_cert, NID_subject_alt_name, NULL, NULL);

  if(altnames) {
    int numalts;
    int i;

    /* get amount of alternatives, RFC2459 claims there MUST be at least
       one, but we don't depend on it... */
    numalts = sk_GENERAL_NAME_num(altnames);

    /* loop through all alternatives while none has matched */
    for (i=0; (i<numalts) && !matched; i++) {
      /* get a handle to alternative name number i */
      const GENERAL_NAME *check = sk_GENERAL_NAME_value(altnames, i);

      /* only check alternatives of the same type the target is */
      if(check->type == target) {
        /* get data and length */
        const char *altptr = (char *)ASN1_STRING_data(check->d.ia5);
        int altlen;

        switch(target) {
        case GEN_DNS: /* name/pattern comparison */
          /* The OpenSSL man page explicitly says: "In general it cannot be
             assumed that the data returned by ASN1_STRING_data() is null
             terminated or does not contain embedded nulls." But also that
             "The actual format of the data will depend on the actual string
             type itself: for example for and IA5String the data will be ASCII"

             Gisle researched the OpenSSL sources:
             "I checked the 0.9.6 and 0.9.8 sources before my patch and
             it always 0-terminates an IA5String."
          */
          if (cert_hostcheck(altptr, conn->host.name))
            matched = TRUE;
          break;

        case GEN_IPADD: /* IP address comparison */
          /* compare alternative IP address if the data chunk is the same size
             our server IP address is */
          altlen = ASN1_STRING_length(check->d.ia5);
          if((altlen == addrlen) && !memcmp(altptr, &addr, altlen))
            matched = TRUE;
          break;
        }
      }
    }
    GENERAL_NAMES_free(altnames);
  }

  if(matched)
    /* an alternative name matched the server hostname */
    infof(data, "\t subjectAltName: %s matched\n", conn->host.dispname);
  else {
    /* we have to look to the last occurence of a commonName in the
       distinguished one to get the most significant one. */
    int j,i=-1 ;

/* The following is done because of a bug in 0.9.6b */

    unsigned char *nulstr = (unsigned char *)"";
    unsigned char *peer_CN = nulstr;

    X509_NAME *name = X509_get_subject_name(server_cert) ;
    if (name)
      while ((j=X509_NAME_get_index_by_NID(name,NID_commonName,i))>=0)
        i=j;

    /* we have the name entry and we will now convert this to a string
       that we can use for comparison. Doing this we support BMPstring,
       UTF8 etc. */

    if (i>=0) {
      ASN1_STRING *tmp = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name,i));

      /* In OpenSSL 0.9.7d and earlier, ASN1_STRING_to_UTF8 fails if the input
         is already UTF-8 encoded. We check for this case and copy the raw
         string manually to avoid the problem. This code can be made
         conditional in the future when OpenSSL has been fixed. Work-around
         brought by Alexis S. L. Carvalho. */
      if (tmp && ASN1_STRING_type(tmp) == V_ASN1_UTF8STRING) {
        j = ASN1_STRING_length(tmp);
        if (j >= 0) {
          peer_CN = OPENSSL_malloc(j+1);
          if (peer_CN) {
            memcpy(peer_CN, ASN1_STRING_data(tmp), j);
            peer_CN[j] = '\0';
          }
        }
      }
      else /* not a UTF8 name */
        j = ASN1_STRING_to_UTF8(&peer_CN, tmp);
    }

    if (peer_CN == nulstr)
       peer_CN = NULL;

    if (!peer_CN) {
      if(data->set.ssl.verifyhost > 1) {
        failf(data,
              "SSL: unable to obtain common name from peer certificate");
        return CURLE_SSL_PEER_CERTIFICATE;
      }
      else {
        /* Consider verifyhost == 1 as an "OK" for a missing CN field, but we
           output a note about the situation */
        infof(data, "\t common name: WARNING couldn't obtain\n");
      }
    }
    else if(!cert_hostcheck((const char *)peer_CN, conn->host.name)) {
      if(data->set.ssl.verifyhost > 1) {
        failf(data, "SSL: certificate subject name '%s' does not match "
              "target host name '%s'", peer_CN, conn->host.dispname);
        OPENSSL_free(peer_CN);
        return CURLE_SSL_PEER_CERTIFICATE ;
      }
      else
        infof(data, "\t common name: %s (does not match '%s')\n",
              peer_CN, conn->host.dispname);
    }
    else {
      infof(data, "\t common name: %s (matched)\n", peer_CN);
      OPENSSL_free(peer_CN);
    }
  }
  return CURLE_OK;
}
#endif

/* The SSL_CTRL_SET_MSG_CALLBACK doesn't exist in ancient OpenSSL versions
   and thus this cannot be done there. */
#ifdef SSL_CTRL_SET_MSG_CALLBACK

static const char *ssl_msg_type(int ssl_ver, int msg)
{
  if (ssl_ver == SSL2_VERSION_MAJOR) {
    switch (msg) {
      case SSL2_MT_ERROR:
        return "Error";
      case SSL2_MT_CLIENT_HELLO:
        return "Client hello";
      case SSL2_MT_CLIENT_MASTER_KEY:
        return "Client key";
      case SSL2_MT_CLIENT_FINISHED:
        return "Client finished";
      case SSL2_MT_SERVER_HELLO:
        return "Server hello";
      case SSL2_MT_SERVER_VERIFY:
        return "Server verify";
      case SSL2_MT_SERVER_FINISHED:
        return "Server finished";
      case SSL2_MT_REQUEST_CERTIFICATE:
        return "Request CERT";
      case SSL2_MT_CLIENT_CERTIFICATE:
        return "Client CERT";
    }
  }
  else if (ssl_ver == SSL3_VERSION_MAJOR) {
    switch (msg) {
      case SSL3_MT_HELLO_REQUEST:
        return "Hello request";
      case SSL3_MT_CLIENT_HELLO:
        return "Client hello";
      case SSL3_MT_SERVER_HELLO:
        return "Server hello";
      case SSL3_MT_CERTIFICATE:
        return "CERT";
      case SSL3_MT_SERVER_KEY_EXCHANGE:
        return "Server key exchange";
      case SSL3_MT_CLIENT_KEY_EXCHANGE:
        return "Client key exchange";
      case SSL3_MT_CERTIFICATE_REQUEST:
        return "Request CERT";
      case SSL3_MT_SERVER_DONE:
        return "Server finished";
      case SSL3_MT_CERTIFICATE_VERIFY:
        return "CERT verify";
      case SSL3_MT_FINISHED:
        return "Finished";
    }
  }
  return "Unknown";
}

static const char *tls_rt_type(int type)
{
  return (
    type == SSL3_RT_CHANGE_CIPHER_SPEC ? "TLS change cipher, " :
    type == SSL3_RT_ALERT              ? "TLS alert, "         :
    type == SSL3_RT_HANDSHAKE          ? "TLS handshake, "     :
    type == SSL3_RT_APPLICATION_DATA   ? "TLS app data, "      :
                                         "TLS Unknown, ");
}


/*
 * Our callback from the SSL/TLS layers.
 */
static void ssl_tls_trace(int direction, int ssl_ver, int content_type,
                          const void *buf, size_t len, const SSL *ssl,
                          struct connectdata *conn)
{
  struct SessionHandle *data;
  const char *msg_name, *tls_rt_name;
  char ssl_buf[1024];
  int  ver, msg_type, txt_len;

  if (!conn || !conn->data || !conn->data->set.fdebug ||
      (direction != 0 && direction != 1))
    return;

  data = conn->data;
  ssl_ver >>= 8;
  ver = (ssl_ver == SSL2_VERSION_MAJOR ? '2' :
         ssl_ver == SSL3_VERSION_MAJOR ? '3' : '?');

  /* SSLv2 doesn't seem to have TLS record-type headers, so OpenSSL
   * always pass-up content-type as 0. But the interesting message-type
   * is at 'buf[0]'.
   */
  if (ssl_ver == SSL3_VERSION_MAJOR && content_type != 0)
    tls_rt_name = tls_rt_type(content_type);
  else
    tls_rt_name = "";

  msg_type = *(char*)buf;
  msg_name = ssl_msg_type(ssl_ver, msg_type);

  txt_len = 1 + snprintf(ssl_buf, sizeof(ssl_buf), "SSLv%c, %s%s (%d):\n",
                         ver, tls_rt_name, msg_name, msg_type);
  Curl_debug(data, CURLINFO_TEXT, ssl_buf, txt_len, NULL);

  Curl_debug(data, (direction == 1) ? CURLINFO_SSL_DATA_OUT :
             CURLINFO_SSL_DATA_IN, (char *)buf, len, NULL);
  (void) ssl;
}
#endif

/* ====================================================== */
CURLcode
Curl_SSLConnect(struct connectdata *conn,
                int sockindex)
{
  CURLcode retcode = CURLE_OK;

#ifdef USE_SSLEAY
  struct SessionHandle *data = conn->data;
  int err;
  long lerr;
  int what;
  char * str;
  SSL_METHOD *req_method;
  SSL_SESSION *ssl_sessionid=NULL;
  ASN1_TIME *certdate;
  curl_socket_t sockfd = conn->sock[sockindex];
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];

  /* mark this is being ssl enabled from here on out. */
  connssl->use = TRUE;

  if(!ssl_seeded || data->set.ssl.random_file || data->set.ssl.egdsocket) {
    /* Make funny stuff to get random input */
    random_the_seed(data);

    ssl_seeded = TRUE;
  }

  /* check to see if we've been told to use an explicit SSL/TLS version */
  switch(data->set.ssl.version) {
  default:
  case CURL_SSLVERSION_DEFAULT:
    /* we try to figure out version */
    req_method = SSLv23_client_method();
    break;
  case CURL_SSLVERSION_TLSv1:
    req_method = TLSv1_client_method();
    break;
  case CURL_SSLVERSION_SSLv2:
    req_method = SSLv2_client_method();
    break;
  case CURL_SSLVERSION_SSLv3:
    req_method = SSLv3_client_method();
    break;
  }

  connssl->ctx = SSL_CTX_new(req_method);

  if(!connssl->ctx) {
    failf(data, "SSL: couldn't create a context!");
    return CURLE_OUT_OF_MEMORY;
  }

#ifdef SSL_CTRL_SET_MSG_CALLBACK
  if (data->set.fdebug) {
    SSL_CTX_callback_ctrl(connssl->ctx, SSL_CTRL_SET_MSG_CALLBACK,
                          ssl_tls_trace);
    SSL_CTX_ctrl(connssl->ctx, SSL_CTRL_SET_MSG_CALLBACK_ARG, 0, conn);
  }
#endif

  /* OpenSSL contains code to work-around lots of bugs and flaws in various
     SSL-implementations. SSL_CTX_set_options() is used to enabled those
     work-arounds. The man page for this option states that SSL_OP_ALL enables
     ll the work-arounds and that "It is usually safe to use SSL_OP_ALL to
     enable the bug workaround options if compatibility with somewhat broken
     implementations is desired."

  */
  SSL_CTX_set_options(connssl->ctx, SSL_OP_ALL);

#if 0
  /*
   * Not sure it's needed to tell SSL_connect() that socket is
   * non-blocking. It doesn't seem to care, but just return with
   * SSL_ERROR_WANT_x.
   */
  if (data->state.used_interface == Curl_if_multi)
    SSL_CTX_ctrl(connssl->ctx, BIO_C_SET_NBIO, 1, NULL);
#endif

  if(data->set.cert) {
    if(!cert_stuff(conn,
                   connssl->ctx,
                   data->set.cert,
                   data->set.cert_type,
                   data->set.key,
                   data->set.key_type)) {
      /* failf() is already done in cert_stuff() */
      return CURLE_SSL_CERTPROBLEM;
    }
  }

  if(data->set.ssl.cipher_list) {
    if(!SSL_CTX_set_cipher_list(connssl->ctx,
                                data->set.ssl.cipher_list)) {
      failf(data, "failed setting cipher list");
      return CURLE_SSL_CIPHER;
    }
  }

  if (data->set.ssl.CAfile || data->set.ssl.CApath) {
    /* tell SSL where to find CA certificates that are used to verify
       the servers certificate. */
    if (!SSL_CTX_load_verify_locations(connssl->ctx, data->set.ssl.CAfile,
                                       data->set.ssl.CApath)) {
      if (data->set.ssl.verifypeer) {
        /* Fail if we insist on successfully verifying the server. */
        failf(data,"error setting certificate verify locations:\n"
              "  CAfile: %s\n  CApath: %s\n",
              data->set.ssl.CAfile ? data->set.ssl.CAfile : "none",
              data->set.ssl.CApath ? data->set.ssl.CApath : "none");
        return CURLE_SSL_CACERT;
      }
      else {
        /* Just continue with a warning if no strict  certificate verification
           is required. */
        infof(data, "error setting certificate verify locations,"
              " continuing anyway:\n");
      }
    }
    else {
      /* Everything is fine. */
      infof(data, "successfully set certificate verify locations:\n");
    }
    infof(data,
          "  CAfile: %s\n"
          "  CApath: %s\n",
          data->set.ssl.CAfile ? data->set.ssl.CAfile : "none",
          data->set.ssl.CApath ? data->set.ssl.CApath : "none");
  }
  /* SSL always tries to verify the peer, this only says whether it should
   * fail to connect if the verification fails, or if it should continue
   * anyway. In the latter case the result of the verification is checked with
   * SSL_get_verify_result() below. */
  SSL_CTX_set_verify(connssl->ctx,
                     data->set.ssl.verifypeer?SSL_VERIFY_PEER:SSL_VERIFY_NONE,
                     cert_verify_callback);

  /* give application a chance to interfere with SSL set up. */
  if(data->set.ssl.fsslctx) {
    retcode = (*data->set.ssl.fsslctx)(data, connssl->ctx,
                                       data->set.ssl.fsslctxp);
    if(retcode) {
      failf(data,"error signaled by ssl ctx callback");
      return retcode;
    }
  }

  /* Lets make an SSL structure */
  connssl->handle = SSL_new(connssl->ctx);
  SSL_set_connect_state(connssl->handle);

  connssl->server_cert = 0x0;

  if(!conn->bits.reuse) {
    /* We're not re-using a connection, check if there's a cached ID we
       can/should use here! */
    if(!Get_SSL_Session(conn, &ssl_sessionid)) {
      /* we got a session id, use it! */
      SSL_set_session(connssl->handle, ssl_sessionid);
      /* Informational message */
      infof (data, "SSL re-using session ID\n");
    }
  }

  /* pass the raw socket into the SSL layers */
  SSL_set_fd(connssl->handle, sockfd);

  while(1) {
    int writefd;
    int readfd;
    long timeout_ms;

    /* Find out if any timeout is set. If not, use 300 seconds.
       Otherwise, figure out the most strict timeout of the two possible one
       and then how much time that has elapsed to know how much time we
       allow for the connect call */
    if(data->set.timeout || data->set.connecttimeout) {
      long has_passed;

      /* Evaluate in milliseconds how much time that has passed */
      has_passed = Curl_tvdiff(Curl_tvnow(), data->progress.t_startsingle);

      /* get the most strict timeout of the ones converted to milliseconds */
      if(data->set.timeout &&
         (data->set.timeout>data->set.connecttimeout))
        timeout_ms = data->set.timeout*1000;
      else
        timeout_ms = data->set.connecttimeout*1000;

      /* subtract the passed time */
      timeout_ms -= has_passed;

      if(timeout_ms < 0) {
        /* a precaution, no need to continue if time already is up */
        failf(data, "SSL connection timeout");
        return CURLE_OPERATION_TIMEOUTED;
      }
    }
    else
      /* no particular time-out has been set */
      timeout_ms= DEFAULT_CONNECT_TIMEOUT;


    readfd = CURL_SOCKET_BAD;
    writefd = CURL_SOCKET_BAD;

    err = SSL_connect(connssl->handle);

    /* 1  is fine
       0  is "not successful but was shut down controlled"
       <0 is "handshake was not successful, because a fatal error occurred" */
    if(1 != err) {
      int detail = SSL_get_error(connssl->handle, err);

      if(SSL_ERROR_WANT_READ == detail)
        readfd = sockfd;
      else if(SSL_ERROR_WANT_WRITE == detail)
        writefd = sockfd;
      else {
        /* untreated error */
        unsigned long errdetail;
        char error_buffer[120]; /* OpenSSL documents that this must be at least
                                   120 bytes long. */
        CURLcode rc;
        const char *cert_problem = NULL;

        errdetail = ERR_get_error(); /* Gets the earliest error code from the
                                        thread's error queue and removes the
                                        entry. */

        switch(errdetail) {
        case 0x1407E086:
          /* 1407E086:
             SSL routines:
             SSL2_SET_CERTIFICATE:
             certificate verify failed */
          /* fall-through */
        case 0x14090086:
          /* 14090086:
             SSL routines:
             SSL3_GET_SERVER_CERTIFICATE:
             certificate verify failed */
          cert_problem = "SSL certificate problem, verify that the CA cert is"
                         " OK. Details:\n";
          rc = CURLE_SSL_CACERT;
          break;
        default:
          rc = CURLE_SSL_CONNECT_ERROR;
          break;
        }

          /* detail is already set to the SSL error above */

        /* If we e.g. use SSLv2 request-method and the server doesn't like us
         * (RST connection etc.), OpenSSL gives no explanation whatsoever and
         * the SO_ERROR is also lost.
         */
        if (CURLE_SSL_CONNECT_ERROR == rc && errdetail == 0) {
          failf(data, "Unknown SSL protocol error in connection to %s:%d ",
                conn->host.name, conn->port);
          return rc;
        }
        /* Could be a CERT problem */

        SSL_strerror(errdetail, error_buffer, sizeof(error_buffer));
        failf(data, "%s%s", cert_problem ? cert_problem : "", error_buffer);
        return rc;
      }
    }
    else
      /* we have been connected fine, get out of the connect loop */
      break;

    while(1) {
      what = Curl_select(readfd, writefd, (int)timeout_ms);
      if(what > 0)
        /* reabable or writable, go loop in the outer loop */
        break;
      else if(0 == what) {
        /* timeout */
        failf(data, "SSL connection timeout");
        return CURLE_OPERATION_TIMEDOUT;
      }
      else {
#if !defined(WIN32) && defined(EINTR)
        /* For platforms without EINTR all errnos are bad */
        if (errno == EINTR)
          continue; /* retry the select() */
#endif
        /* anything other than the unimportant EINTR is fatally bad */
        failf(data, "select on SSL socket, errno: %d", Curl_ourerrno());
        return CURLE_SSL_CONNECT_ERROR;
      }
    } /* while()-loop for the select() */
  } /* while()-loop for the SSL_connect() */

  /* Informational message */
  infof (data, "SSL connection using %s\n",
         SSL_get_cipher(connssl->handle));

  if(!ssl_sessionid) {
    /* Since this is not a cached session ID, then we want to stach this one
       in the cache! */
    Store_SSL_Session(conn, connssl);
  }


  /* Get server's certificate (note: beware of dynamic allocation) - opt */
  /* major serious hack alert -- we should check certificates
   * to authenticate the server; otherwise we risk man-in-the-middle
   * attack
   */

  connssl->server_cert = SSL_get_peer_certificate(connssl->handle);
  if(!connssl->server_cert) {
    failf(data, "SSL: couldn't get peer certificate!");
    return CURLE_SSL_PEER_CERTIFICATE;
  }
  infof (data, "Server certificate:\n");

  str = X509_NAME_oneline(X509_get_subject_name(connssl->server_cert),
                          NULL, 0);
  if(!str) {
    failf(data, "SSL: couldn't get X509-subject!");
    X509_free(connssl->server_cert);
    return CURLE_SSL_CONNECT_ERROR;
  }
  infof(data, "\t subject: %s\n", str);
  CRYPTO_free(str);

  certdate = X509_get_notBefore(connssl->server_cert);
  Curl_ASN1_UTCTIME_output(conn, "\t start date: ", certdate);

  certdate = X509_get_notAfter(connssl->server_cert);
  Curl_ASN1_UTCTIME_output(conn, "\t expire date: ", certdate);

  if(data->set.ssl.verifyhost) {
    retcode = verifyhost(conn, connssl->server_cert);
    if(retcode) {
      X509_free(connssl->server_cert);
      return retcode;
    }
  }

  str = X509_NAME_oneline(X509_get_issuer_name(connssl->server_cert),
                          NULL, 0);
  if(!str) {
    failf(data, "SSL: couldn't get X509-issuer name!");
    retcode = CURLE_SSL_CONNECT_ERROR;
  }
  else {
    infof(data, "\t issuer: %s\n", str);
    CRYPTO_free(str);

    /* We could do all sorts of certificate verification stuff here before
       deallocating the certificate. */

    lerr = data->set.ssl.certverifyresult=
      SSL_get_verify_result(connssl->handle);
    if(data->set.ssl.certverifyresult != X509_V_OK) {
      if(data->set.ssl.verifypeer) {
        /* We probably never reach this, because SSL_connect() will fail
           and we return earlyer if verifypeer is set? */
        failf(data, "SSL certificate verify result: %s (%ld)",
              X509_verify_cert_error_string(lerr), lerr);
        retcode = CURLE_SSL_PEER_CERTIFICATE;
      }
      else
        infof(data, "SSL certificate verify result: %s (%ld),"
              " continuing anyway.\n",
              X509_verify_cert_error_string(err), lerr);
    }
    else
      infof(data, "SSL certificate verify ok.\n");
  }

  X509_free(connssl->server_cert);
#else /* USE_SSLEAY */
  (void)conn;
  (void)sockindex;
#endif
  return retcode;
}