ssluse.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2007, 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 http://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.
 *
 * $Id$
 ***************************************************************************/

/*
 * Source file for all OpenSSL-specific code for the TLS/SSL layer. No code
 * but sslgen.c should ever call or use these functions.
 */

/*
 * The original SSLeay-using code for curl was written by Linas Vepstas and
 * Sampo Kellomaki 1998.
 */

#include "setup.h"

#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif

#include "urldata.h"
#include "sendf.h"
#include "formdata.h" /* for the boundary function */
#include "url.h" /* for the ssl config check function */
#include "inet_pton.h"
#include "ssluse.h"
#include "connect.h"
#include "strequal.h"
#include "select.h"
#include "sslgen.h"

#define _MPRINTF_REPLACE /* use the internal *printf() functions */
#include <curl/mprintf.h>

#ifdef USE_SSLEAY

#ifdef USE_OPENSSL
#include <openssl/rand.h>
#include <openssl/x509v3.h>
#else
#include <rand.h>
#include <x509v3.h>
#endif

#include "memory.h"
#include "easyif.h" /* for Curl_convert_from_utf8 prototype */

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

#ifndef min
#define min(a, b)   ((a) < (b) ? (a) : (b))
#endif

#if OPENSSL_VERSION_NUMBER >= 0x0090581fL
#define HAVE_SSL_GET1_SESSION 1
#else
#undef HAVE_SSL_GET1_SESSION
#endif

#if OPENSSL_VERSION_NUMBER >= 0x00904100L
#define HAVE_USERDATA_IN_PWD_CALLBACK 1
#else
#undef HAVE_USERDATA_IN_PWD_CALLBACK
#endif

#if OPENSSL_VERSION_NUMBER >= 0x00907001L
/* ENGINE_load_private_key() takes four arguments */
#define HAVE_ENGINE_LOAD_FOUR_ARGS
#else
/* ENGINE_load_private_key() takes three arguments */
#undef HAVE_ENGINE_LOAD_FOUR_ARGS
#endif

#if (OPENSSL_VERSION_NUMBER >= 0x00903001L) && defined(HAVE_OPENSSL_PKCS12_H)
/* OpenSSL has PKCS 12 support */
#define HAVE_PKCS12_SUPPORT
#else
/* OpenSSL/SSLEay does not have PKCS12 support */
#undef HAVE_PKCS12_SUPPORT
#endif

#if OPENSSL_VERSION_NUMBER >= 0x00906001L
#define HAVE_ERR_ERROR_STRING_N 1
#endif

#if OPENSSL_VERSION_NUMBER >= 0x00909000L
#define SSL_METHOD_QUAL const
#else
#define SSL_METHOD_QUAL
#endif

/*
 * Number of bytes to read from the random number seed file. This must be
 * a finite value (because some entropy "files" like /dev/urandom have
 * an infinite length), but must be large enough to provide enough
 * entopy to properly seed OpenSSL's PRNG.
 */
#define RAND_LOAD_LENGTH 1024

#ifndef HAVE_USERDATA_IN_PWD_CALLBACK
static char global_passwd[64];
#endif

static int passwd_callback(char *buf, int num, int verify
#ifdef HAVE_USERDATA_IN_PWD_CALLBACK
                           /* This was introduced in 0.9.4, we can set this
                              using SSL_CTX_set_default_passwd_cb_userdata()
                              */
                           , void *global_passwd
#endif
                           )
{
  if(verify)
    fprintf(stderr, "%s\n", buf);
  else {
    if(num > (int)strlen((char *)global_passwd)) {
      strcpy(buf, global_passwd);
      return (int)strlen(buf);
    }
  }
  return 0;
}

/*
 * rand_enough() is a function that returns TRUE if we have seeded the random
 * engine properly. We use some preprocessor magic to provide a seed_enough()
 * macro to use, just to prevent a compiler warning on this function if we
 * pass in an argument that is never used.
 */

#ifdef HAVE_RAND_STATUS
#define seed_enough(x) rand_enough()
static bool rand_enough(void)
{
  return (bool)(0 != RAND_status());
}
#else
#define seed_enough(x) rand_enough(x)
static bool rand_enough(int nread)
{
  /* this is a very silly decision to make */
  return (bool)(nread > 500);
}
#endif

static int ossl_seed(struct SessionHandle *data)
{
  char *buf = data->state.buffer; /* point to the big buffer */
  int nread=0;

  /* Q: should we add support for a random file name as a libcurl option?
     A: Yes, it is here */

#ifndef RANDOM_FILE
  /* if RANDOM_FILE isn't defined, we only perform this if an option tells
     us to! */
  if(data->set.ssl.random_file)
#define RANDOM_FILE "" /* doesn't matter won't be used */
#endif
  {
    /* let the option override the define */
    nread += RAND_load_file((data->set.str[STRING_SSL_RANDOM_FILE]?
                             data->set.str[STRING_SSL_RANDOM_FILE]:
                             RANDOM_FILE),
                            RAND_LOAD_LENGTH);
    if(seed_enough(nread))
      return nread;
  }

#if defined(HAVE_RAND_EGD)
  /* only available in OpenSSL 0.9.5 and later */
  /* EGD_SOCKET is set at configure time or not at all */
#ifndef EGD_SOCKET
  /* If we don't have the define set, we only do this if the egd-option
     is set */
  if(data->set.str[STRING_SSL_EGDSOCKET])
#define EGD_SOCKET "" /* doesn't matter won't be used */