vtls.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

/* This file is for implementing all "generic" SSL functions that all libcurl
   internals should use. It is then responsible for calling the proper
   "backend" function.

   SSL-functions in libcurl should call functions in this source file, and not
   to any specific SSL-layer.

   Curl_ssl_ - prefix for generic ones
   Curl_ossl_ - prefix for OpenSSL ones
   Curl_gtls_ - prefix for GnuTLS ones
   Curl_nss_ - prefix for NSS ones
   Curl_gskit_ - prefix for GSKit ones
   Curl_polarssl_ - prefix for PolarSSL ones
   Curl_cyassl_ - prefix for CyaSSL ones
   Curl_schannel_ - prefix for Schannel SSPI ones
   Curl_darwinssl_ - prefix for SecureTransport (Darwin) ones

   Note that this source code uses curlssl_* functions, and they are all
   defines/macros #defined by the lib-specific header files.

   "SSL/TLS Strong Encryption: An Introduction"
   https://httpd.apache.org/docs/2.0/ssl/ssl_intro.html
*/

#include "curl_setup.h"

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif

#include "urldata.h"

#include "vtls.h" /* generic SSL protos etc */
#include "slist.h"
#include "sendf.h"
#include "rawstr.h"
#include "url.h"
#include "progress.h"
#include "share.h"
#include "timeval.h"
#include "curl_md5.h"
#include "warnless.h"
#include "curl_base64.h"
#include "curl_printf.h"

/* The last #include files should be: */
#include "curl_memory.h"
#include "memdebug.h"

/* convenience macro to check if this handle is using a shared SSL session */
#define SSLSESSION_SHARED(data) (data->share &&                        \
                                 (data->share->specifier &             \
                                  (1<<CURL_LOCK_DATA_SSL_SESSION)))

static bool safe_strequal(char* str1, char* str2)
{
  if(str1 && str2)
    /* both pointers point to something then compare them */
    return (0 != Curl_raw_equal(str1, str2)) ? TRUE : FALSE;
  else
    /* if both pointers are NULL then treat them as equal */
    return (!str1 && !str2) ? TRUE : FALSE;
}

bool
Curl_ssl_config_matches(struct ssl_config_data* data,
                        struct ssl_config_data* needle)
{
  if((data->version == needle->version) &&
     (data->verifypeer == needle->verifypeer) &&
     (data->verifyhost == needle->verifyhost) &&
     safe_strequal(data->CApath, needle->CApath) &&
     safe_strequal(data->CAfile, needle->CAfile) &&
     safe_strequal(data->random_file, needle->random_file) &&
     safe_strequal(data->egdsocket, needle->egdsocket) &&
     safe_strequal(data->cipher_list, needle->cipher_list))
    return TRUE;

  return FALSE;
}

bool
Curl_clone_ssl_config(struct ssl_config_data *source,
                      struct ssl_config_data *dest)
{
  dest->sessionid = source->sessionid;
  dest->verifyhost = source->verifyhost;
  dest->verifypeer = source->verifypeer;
  dest->version = source->version;

  if(source->CAfile) {
    dest->CAfile = strdup(source->CAfile);
    if(!dest->CAfile)
      return FALSE;
  }
  else
    dest->CAfile = NULL;

  if(source->CApath) {
    dest->CApath = strdup(source->CApath);
    if(!dest->CApath)
      return FALSE;
  }
  else
    dest->CApath = NULL;

  if(source->cipher_list) {
    dest->cipher_list = strdup(source->cipher_list);
    if(!dest->cipher_list)
      return FALSE;
  }
  else
    dest->cipher_list = NULL;

  if(source->egdsocket) {
    dest->egdsocket = strdup(source->egdsocket);
    if(!dest->egdsocket)
      return FALSE;
  }
  else
    dest->egdsocket = NULL;

  if(source->random_file) {
    dest->random_file = strdup(source->random_file);
    if(!dest->random_file)
      return FALSE;
  }
  else
    dest->random_file = NULL;

  if(source->clientcert) {
    dest->clientcert = strdup(source->clientcert);
    if(!dest->clientcert)
      return FALSE;
    dest->sessionid = FALSE;
  }
  else
    dest->clientcert = NULL;

  return TRUE;
}

void Curl_free_ssl_config(struct ssl_config_data* sslc)
{
  Curl_safefree(sslc->CAfile);
  Curl_safefree(sslc->CApath);
  Curl_safefree(sslc->cipher_list);
  Curl_safefree(sslc->egdsocket);
  Curl_safefree(sslc->random_file);
  Curl_safefree(sslc->clientcert);
}


/*
 * Curl_rand() returns a random unsigned integer, 32bit.
 *
 * This non-SSL function is put here only because this file is the only one
 * with knowledge of what the underlying SSL libraries provide in terms of
 * randomizers.
 *
 * NOTE: 'data' may be passed in as NULL when coming from external API without
 * easy handle!
 *
 */

unsigned int Curl_rand(struct Curl_easy *data)
{
  unsigned int r = 0;
  static unsigned int randseed;
  static bool seeded = FALSE;

#ifdef CURLDEBUG