curl_darwinssl.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 2012-2013, Nick Zitzmann, <nickzman@gmail.com>.
 * Copyright (C) 2012-2013, 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.
 *
 ***************************************************************************/

/*
 * Source file for all iOS and Mac OS X SecureTransport-specific code for the
 * TLS/SSL layer. No code but sslgen.c should ever call or use these functions.
 */

#include "curl_setup.h"

#ifdef USE_DARWINSSL

#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif

#include <Security/Security.h>
#include <Security/SecureTransport.h>
#include <CoreFoundation/CoreFoundation.h>
#include <CommonCrypto/CommonDigest.h>
#if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
#include <sys/sysctl.h>
#endif

#include "urldata.h"
#include "sendf.h"
#include "inet_pton.h"
#include "connect.h"
#include "select.h"
#include "sslgen.h"
#include "curl_darwinssl.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

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

/* From MacTypes.h (which we can't include because it isn't present in iOS: */
#define ioErr -36
#define paramErr -50

/* In Mountain Lion and iOS 5, Apple made some changes to the API. They
   added TLS 1.1 and 1.2 support, and deprecated and replaced some
   functions. You need to build against the Mountain Lion or iOS 5 SDK
   or later to get TLS 1.1 or 1.2 support working in cURL. We'll weak-link
   to the newer functions and use them if present in the user's OS.

   Builders: If you want TLS 1.1 and 1.2 but still want to retain support
   for older cats, don't forget to set the MACOSX_DEPLOYMENT_TARGET
   environmental variable prior to building cURL. */

/* The following two functions were ripped from Apple sample code,
 * with some modifications: */
static OSStatus SocketRead(SSLConnectionRef connection,
                           void *data,          /* owned by
                                                 * caller, data
                                                 * RETURNED */
                           size_t *dataLength)  /* IN/OUT */
{
  size_t bytesToGo = *dataLength;
  size_t initLen = bytesToGo;
  UInt8 *currData = (UInt8 *)data;
  /*int sock = *(int *)connection;*/
  struct ssl_connect_data *connssl = (struct ssl_connect_data *)connection;
  int sock = connssl->ssl_sockfd;
  OSStatus rtn = noErr;
  size_t bytesRead;
  ssize_t rrtn;
  int theErr;

  *dataLength = 0;

  for(;;) {
    bytesRead = 0;
    rrtn = read(sock, currData, bytesToGo);
    if(rrtn <= 0) {
      /* this is guesswork... */
      theErr = errno;
      if(rrtn == 0) { /* EOF = server hung up */
        /* the framework will turn this into errSSLClosedNoNotify */
        rtn = errSSLClosedGraceful;
      }
      else /* do the switch */
        switch(theErr) {
          case ENOENT:
            /* connection closed */
            rtn = errSSLClosedGraceful;
            break;
          case ECONNRESET:
            rtn = errSSLClosedAbort;
            break;
          case EAGAIN:
            rtn = errSSLWouldBlock;
            connssl->ssl_direction = false;
            break;
          default:
            rtn = ioErr;
            break;
        }
      break;
    }
    else {
      bytesRead = rrtn;
    }
    bytesToGo -= bytesRead;
    currData  += bytesRead;

    if(bytesToGo == 0) {
      /* filled buffer with incoming data, done */
      break;
    }
  }
  *dataLength = initLen - bytesToGo;

  return rtn;
}

static OSStatus SocketWrite(SSLConnectionRef connection,
                            const void *data,
                            size_t *dataLength)  /* IN/OUT */
{
  size_t bytesSent = 0;
  /*int sock = *(int *)connection;*/
  struct ssl_connect_data *connssl = (struct ssl_connect_data *)connection;
  int sock = connssl->ssl_sockfd;
  ssize_t length;
  size_t dataLen = *dataLength;
  const UInt8 *dataPtr = (UInt8 *)data;
  OSStatus ortn;
  int theErr;

  *dataLength = 0;

  do {
    length = write(sock,
                   (char*)dataPtr + bytesSent,
                   dataLen - bytesSent);
  } while((length > 0) &&
           ( (bytesSent += length) < dataLen) );

  if(length <= 0) {
    theErr = errno;
    if(theErr == EAGAIN) {
      ortn = errSSLWouldBlock;
      connssl->ssl_direction = true;
    }
    else {
      ortn = ioErr;
    }
  }
  else {
    ortn = noErr;
  }
  *dataLength = bytesSent;
  return ortn;
}

CF_INLINE const char *SSLCipherNameForNumber(SSLCipherSuite cipher) {
  switch (cipher) {
    /* SSL version 3.0 */
    case SSL_RSA_WITH_NULL_MD5:
      return "SSL_RSA_WITH_NULL_MD5";
      break;
    case SSL_RSA_WITH_NULL_SHA:
      return "SSL_RSA_WITH_NULL_SHA";
      break;
    case SSL_RSA_EXPORT_WITH_RC4_40_MD5:
      return "SSL_RSA_EXPORT_WITH_RC4_40_MD5";
      break;
    case SSL_RSA_WITH_RC4_128_MD5:
      return "SSL_RSA_WITH_RC4_128_MD5";
      break;
    case SSL_RSA_WITH_RC4_128_SHA:
      return "SSL_RSA_WITH_RC4_128_SHA";
      break;
    case SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5:
      return "SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5";
      break;
    case SSL_RSA_WITH_IDEA_CBC_SHA:
      return "SSL_RSA_WITH_IDEA_CBC_SHA";
      break;
    case SSL_RSA_EXPORT_WITH_DES40_CBC_SHA:
      return "SSL_RSA_EXPORT_WITH_DES40_CBC_SHA";
      break;
    case SSL_RSA_WITH_DES_CBC_SHA:
      return "SSL_RSA_WITH_DES_CBC_SHA";
      break;
    case SSL_RSA_WITH_3DES_EDE_CBC_SHA:
      return "SSL_RSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case SSL_DH_DSS_EXPORT_WITH_DES40_CBC_SHA:
      return "SSL_DH_DSS_EXPORT_WITH_DES40_CBC_SHA";
      break;
    case SSL_DH_DSS_WITH_DES_CBC_SHA:
      return "SSL_DH_DSS_WITH_DES_CBC_SHA";
      break;
    case SSL_DH_DSS_WITH_3DES_EDE_CBC_SHA:
      return "SSL_DH_DSS_WITH_3DES_EDE_CBC_SHA";
      break;
    case SSL_DH_RSA_EXPORT_WITH_DES40_CBC_SHA:
      return "SSL_DH_RSA_EXPORT_WITH_DES40_CBC_SHA";
      break;
    case SSL_DH_RSA_WITH_DES_CBC_SHA:
      return "SSL_DH_RSA_WITH_DES_CBC_SHA";
      break;
    case SSL_DH_RSA_WITH_3DES_EDE_CBC_SHA:
      return "SSL_DH_RSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA:
      return "SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA";
      break;
    case SSL_DHE_DSS_WITH_DES_CBC_SHA:
      return "SSL_DHE_DSS_WITH_DES_CBC_SHA";
      break;
    case SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA:
      return "SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA";
      break;
    case SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA:
      return "SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA";
      break;
    case SSL_DHE_RSA_WITH_DES_CBC_SHA:
      return "SSL_DHE_RSA_WITH_DES_CBC_SHA";
      break;
    case SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA:
      return "SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case SSL_DH_anon_EXPORT_WITH_RC4_40_MD5:
      return "SSL_DH_anon_EXPORT_WITH_RC4_40_MD5";
      break;
    case SSL_DH_anon_WITH_RC4_128_MD5:
      return "SSL_DH_anon_WITH_RC4_128_MD5";
      break;
    case SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA:
      return "SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA";
      break;
    case SSL_DH_anon_WITH_DES_CBC_SHA:
      return "SSL_DH_anon_WITH_DES_CBC_SHA";
      break;
    case SSL_DH_anon_WITH_3DES_EDE_CBC_SHA:
      return "SSL_DH_anon_WITH_3DES_EDE_CBC_SHA";
      break;
    case SSL_FORTEZZA_DMS_WITH_NULL_SHA:
      return "SSL_FORTEZZA_DMS_WITH_NULL_SHA";
      break;
    case SSL_FORTEZZA_DMS_WITH_FORTEZZA_CBC_SHA:
      return "SSL_FORTEZZA_DMS_WITH_FORTEZZA_CBC_SHA";
      break;
    /* TLS 1.0 with AES (RFC 3268)
       (Apparently these are used in SSLv3 implementations as well.) */
    case TLS_RSA_WITH_AES_128_CBC_SHA:
      return "TLS_RSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DH_DSS_WITH_AES_128_CBC_SHA:
      return "TLS_DH_DSS_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DH_RSA_WITH_AES_128_CBC_SHA:
      return "TLS_DH_RSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DHE_DSS_WITH_AES_128_CBC_SHA:
      return "TLS_DHE_DSS_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DHE_RSA_WITH_AES_128_CBC_SHA:
      return "TLS_DHE_RSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DH_anon_WITH_AES_128_CBC_SHA:
      return "TLS_DH_anon_WITH_AES_128_CBC_SHA";
      break;
    case TLS_RSA_WITH_AES_256_CBC_SHA:
      return "TLS_RSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DH_DSS_WITH_AES_256_CBC_SHA:
      return "TLS_DH_DSS_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DH_RSA_WITH_AES_256_CBC_SHA:
      return "TLS_DH_RSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DHE_DSS_WITH_AES_256_CBC_SHA:
      return "TLS_DHE_DSS_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DHE_RSA_WITH_AES_256_CBC_SHA:
      return "TLS_DHE_RSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DH_anon_WITH_AES_256_CBC_SHA:
      return "TLS_DH_anon_WITH_AES_256_CBC_SHA";
      break;
    /* SSL version 2.0 */
    case SSL_RSA_WITH_RC2_CBC_MD5:
      return "SSL_RSA_WITH_RC2_CBC_MD5";
      break;
    case SSL_RSA_WITH_IDEA_CBC_MD5:
      return "SSL_RSA_WITH_IDEA_CBC_MD5";
      break;
    case SSL_RSA_WITH_DES_CBC_MD5:
      return "SSL_RSA_WITH_DES_CBC_MD5";
      break;
    case SSL_RSA_WITH_3DES_EDE_CBC_MD5:
      return "SSL_RSA_WITH_3DES_EDE_CBC_MD5";
      break;
  }
  return "SSL_NULL_WITH_NULL_NULL";
}

CF_INLINE const char *TLSCipherNameForNumber(SSLCipherSuite cipher) {
  switch(cipher) {
    /* TLS 1.0 with AES (RFC 3268) */
    case TLS_RSA_WITH_AES_128_CBC_SHA:
      return "TLS_RSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DH_DSS_WITH_AES_128_CBC_SHA:
      return "TLS_DH_DSS_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DH_RSA_WITH_AES_128_CBC_SHA:
      return "TLS_DH_RSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DHE_DSS_WITH_AES_128_CBC_SHA:
      return "TLS_DHE_DSS_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DHE_RSA_WITH_AES_128_CBC_SHA:
      return "TLS_DHE_RSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_DH_anon_WITH_AES_128_CBC_SHA:
      return "TLS_DH_anon_WITH_AES_128_CBC_SHA";
      break;
    case TLS_RSA_WITH_AES_256_CBC_SHA:
      return "TLS_RSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DH_DSS_WITH_AES_256_CBC_SHA:
      return "TLS_DH_DSS_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DH_RSA_WITH_AES_256_CBC_SHA:
      return "TLS_DH_RSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DHE_DSS_WITH_AES_256_CBC_SHA:
      return "TLS_DHE_DSS_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DHE_RSA_WITH_AES_256_CBC_SHA:
      return "TLS_DHE_RSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_DH_anon_WITH_AES_256_CBC_SHA:
      return "TLS_DH_anon_WITH_AES_256_CBC_SHA";
      break;
#if defined(__MAC_10_6) || defined(__IPHONE_5_0)
    /* TLS 1.0 with ECDSA (RFC 4492) */
    case TLS_ECDH_ECDSA_WITH_NULL_SHA:
      return "TLS_ECDH_ECDSA_WITH_NULL_SHA";
      break;
    case TLS_ECDH_ECDSA_WITH_RC4_128_SHA:
      return "TLS_ECDH_ECDSA_WITH_RC4_128_SHA";
      break;
    case TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA:
      return "TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA:
      return "TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA:
      return "TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_ECDHE_ECDSA_WITH_NULL_SHA:
      return "TLS_ECDHE_ECDSA_WITH_NULL_SHA";
      break;
    case TLS_ECDHE_ECDSA_WITH_RC4_128_SHA:
      return "TLS_ECDHE_ECDSA_WITH_RC4_128_SHA";
      break;
    case TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA:
      return "TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA:
      return "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA:
      return "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_ECDH_RSA_WITH_NULL_SHA:
      return "TLS_ECDH_RSA_WITH_NULL_SHA";
      break;
    case TLS_ECDH_RSA_WITH_RC4_128_SHA:
      return "TLS_ECDH_RSA_WITH_RC4_128_SHA";
      break;
    case TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA:
      return "TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_ECDH_RSA_WITH_AES_128_CBC_SHA:
      return "TLS_ECDH_RSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_ECDH_RSA_WITH_AES_256_CBC_SHA:
      return "TLS_ECDH_RSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_ECDHE_RSA_WITH_NULL_SHA:
      return "TLS_ECDHE_RSA_WITH_NULL_SHA";
      break;
    case TLS_ECDHE_RSA_WITH_RC4_128_SHA:
      return "TLS_ECDHE_RSA_WITH_RC4_128_SHA";
      break;
    case TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA:
      return "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA:
      return "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA";
      break;
    case TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
      return "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA";
      break;
    case TLS_ECDH_anon_WITH_NULL_SHA:
      return "TLS_ECDH_anon_WITH_NULL_SHA";
      break;
    case TLS_ECDH_anon_WITH_RC4_128_SHA:
      return "TLS_ECDH_anon_WITH_RC4_128_SHA";
      break;
    case TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA:
      return "TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_ECDH_anon_WITH_AES_128_CBC_SHA:
      return "TLS_ECDH_anon_WITH_AES_128_CBC_SHA";
      break;
    case TLS_ECDH_anon_WITH_AES_256_CBC_SHA:
      return "TLS_ECDH_anon_WITH_AES_256_CBC_SHA";
      break;
#endif /* defined(__MAC_10_6) || defined(__IPHONE_5_0) */
#if defined(__MAC_10_8) || defined(__IPHONE_5_0)
    /* TLS 1.2 (RFC 5246) */
    case TLS_RSA_WITH_NULL_MD5:
      return "TLS_RSA_WITH_NULL_MD5";
      break;
    case TLS_RSA_WITH_NULL_SHA:
      return "TLS_RSA_WITH_NULL_SHA";
      break;
    case TLS_RSA_WITH_RC4_128_MD5:
      return "TLS_RSA_WITH_RC4_128_MD5";
      break;
    case TLS_RSA_WITH_RC4_128_SHA:
      return "TLS_RSA_WITH_RC4_128_SHA";
      break;
    case TLS_RSA_WITH_3DES_EDE_CBC_SHA:
      return "TLS_RSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_RSA_WITH_NULL_SHA256:
      return "TLS_RSA_WITH_NULL_SHA256";
      break;
    case TLS_RSA_WITH_AES_128_CBC_SHA256:
      return "TLS_RSA_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_RSA_WITH_AES_256_CBC_SHA256:
      return "TLS_RSA_WITH_AES_256_CBC_SHA256";
      break;
    case TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA:
      return "TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA:
      return "TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA:
      return "TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA:
      return "TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_DH_DSS_WITH_AES_128_CBC_SHA256:
      return "TLS_DH_DSS_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_DH_RSA_WITH_AES_128_CBC_SHA256:
      return "TLS_DH_RSA_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_DHE_DSS_WITH_AES_128_CBC_SHA256:
      return "TLS_DHE_DSS_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_DHE_RSA_WITH_AES_128_CBC_SHA256:
      return "TLS_DHE_RSA_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_DH_DSS_WITH_AES_256_CBC_SHA256:
      return "TLS_DH_DSS_WITH_AES_256_CBC_SHA256";
      break;
    case TLS_DH_RSA_WITH_AES_256_CBC_SHA256:
      return "TLS_DH_RSA_WITH_AES_256_CBC_SHA256";
      break;
    case TLS_DHE_DSS_WITH_AES_256_CBC_SHA256:
      return "TLS_DHE_DSS_WITH_AES_256_CBC_SHA256";
      break;
    case TLS_DHE_RSA_WITH_AES_256_CBC_SHA256:
      return "TLS_DHE_RSA_WITH_AES_256_CBC_SHA256";
      break;
    case TLS_DH_anon_WITH_RC4_128_MD5:
      return "TLS_DH_anon_WITH_RC4_128_MD5";
      break;
    case TLS_DH_anon_WITH_3DES_EDE_CBC_SHA:
      return "TLS_DH_anon_WITH_3DES_EDE_CBC_SHA";
      break;
    case TLS_DH_anon_WITH_AES_128_CBC_SHA256:
      return "TLS_DH_anon_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_DH_anon_WITH_AES_256_CBC_SHA256:
      return "TLS_DH_anon_WITH_AES_256_CBC_SHA256";
      break;
    /* TLS 1.2 with AES GCM (RFC 5288) */
    case TLS_RSA_WITH_AES_128_GCM_SHA256:
      return "TLS_RSA_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_RSA_WITH_AES_256_GCM_SHA384:
      return "TLS_RSA_WITH_AES_256_GCM_SHA384";
      break;
    case TLS_DHE_RSA_WITH_AES_128_GCM_SHA256:
      return "TLS_DHE_RSA_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_DHE_RSA_WITH_AES_256_GCM_SHA384:
      return "TLS_DHE_RSA_WITH_AES_256_GCM_SHA384";
      break;
    case TLS_DH_RSA_WITH_AES_128_GCM_SHA256:
      return "TLS_DH_RSA_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_DH_RSA_WITH_AES_256_GCM_SHA384:
      return "TLS_DH_RSA_WITH_AES_256_GCM_SHA384";
      break;
    case TLS_DHE_DSS_WITH_AES_128_GCM_SHA256:
      return "TLS_DHE_DSS_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_DHE_DSS_WITH_AES_256_GCM_SHA384:
      return "TLS_DHE_DSS_WITH_AES_256_GCM_SHA384";
      break;
    case TLS_DH_DSS_WITH_AES_128_GCM_SHA256:
      return "TLS_DH_DSS_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_DH_DSS_WITH_AES_256_GCM_SHA384:
      return "TLS_DH_DSS_WITH_AES_256_GCM_SHA384";
      break;
    case TLS_DH_anon_WITH_AES_128_GCM_SHA256:
      return "TLS_DH_anon_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_DH_anon_WITH_AES_256_GCM_SHA384:
      return "TLS_DH_anon_WITH_AES_256_GCM_SHA384";
      break;
    /* TLS 1.2 with elliptic curve ciphers (RFC 5289) */
    case TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256:
      return "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384:
      return "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384";
      break;
    case TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256:
      return "TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384:
      return "TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384";
      break;
    case TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256:
      return "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384:
      return "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384";
      break;
    case TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256:
      return "TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256";
      break;
    case TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384:
      return "TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384";
      break;
    case TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256:
      return "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384:
      return "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384";
      break;
    case TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256:
      return "TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384:
      return "TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384";
      break;
    case TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256:
      return "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384:
      return "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384";
      break;
    case TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256:
      return "TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256";
      break;
    case TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384:
      return "TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384";
      break;
    case TLS_EMPTY_RENEGOTIATION_INFO_SCSV:
      return "TLS_EMPTY_RENEGOTIATION_INFO_SCSV";
      break;
#else
    case SSL_RSA_WITH_NULL_MD5:
      return "TLS_RSA_WITH_NULL_MD5";
      break;
    case SSL_RSA_WITH_NULL_SHA:
      return "TLS_RSA_WITH_NULL_SHA";
      break;
    case SSL_RSA_WITH_RC4_128_MD5:
      return "TLS_RSA_WITH_RC4_128_MD5";
      break;
    case SSL_RSA_WITH_RC4_128_SHA:
      return "TLS_RSA_WITH_RC4_128_SHA";
      break;
    case SSL_RSA_WITH_3DES_EDE_CBC_SHA:
      return "TLS_RSA_WITH_3DES_EDE_CBC_SHA";
      break;
    case SSL_DH_anon_WITH_RC4_128_MD5:
      return "TLS_DH_anon_WITH_RC4_128_MD5";
      break;
    case SSL_DH_anon_WITH_3DES_EDE_CBC_SHA:
      return "TLS_DH_anon_WITH_3DES_EDE_CBC_SHA";
      break;
#endif /* defined(__MAC_10_8) || defined(__IPHONE_5_0) */
  }
  return "TLS_NULL_WITH_NULL_NULL";
}

#if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
CF_INLINE void GetDarwinVersionNumber(int *major, int *minor)
{
  int mib[2];
  char *os_version;
  size_t os_version_len;
  char *os_version_major, *os_version_minor/*, *os_version_point*/;

  /* Get the Darwin kernel version from the kernel using sysctl(): */
  mib[0] = CTL_KERN;
  mib[1] = KERN_OSRELEASE;
  if(sysctl(mib, 2, NULL, &os_version_len, NULL, 0) == -1)
    return;
  os_version = malloc(os_version_len*sizeof(char));
  if(!os_version)
    return;
  if(sysctl(mib, 2, os_version, &os_version_len, NULL, 0) == -1) {
    free(os_version);
    return;
  }

  /* Parse the version: */
  os_version_major = strtok(os_version, ".");
  os_version_minor = strtok(NULL, ".");
  /*os_version_point = strtok(NULL, ".");*/
  *major = atoi(os_version_major);
  *minor = atoi(os_version_minor);
  free(os_version);
}
#endif

/* Apple provides a myriad of ways of getting information about a certificate
   into a string. Some aren't available under iOS or newer cats. So here's
   a unified function for getting a string describing the certificate that
   ought to work in all cats starting with Leopard. */
CF_INLINE CFStringRef CopyCertSubject(SecCertificateRef cert)
{
  CFStringRef server_cert_summary = CFSTR("(null)");

#if (TARGET_OS_EMBEDDED || TARGET_OS_IPHONE)
  /* iOS: There's only one way to do this. */
  server_cert_summary = SecCertificateCopySubjectSummary(cert);
#else
#if defined(__MAC_10_7)
  /* Lion & later: Get the long description if we can. */
  if(SecCertificateCopyLongDescription != NULL)
    server_cert_summary =
      SecCertificateCopyLongDescription(NULL, cert, NULL);
  else
#endif /* defined(__MAC_10_7) */
#if defined(__MAC_10_6)
  /* Snow Leopard: Get the certificate summary. */
  if(SecCertificateCopySubjectSummary != NULL)
    server_cert_summary = SecCertificateCopySubjectSummary(cert);
  else
#endif /* defined(__MAC_10_6) */
  /* Leopard is as far back as we go... */
  (void)SecCertificateCopyCommonName(cert, &server_cert_summary);
#endif /* (TARGET_OS_EMBEDDED || TARGET_OS_IPHONE) */
  return server_cert_summary;
}

#if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
static OSStatus CopyIdentityWithLabelOldSchool(char *label,
                                               SecIdentityRef *out_c_a_k)
{
  OSStatus status = errSecItemNotFound;
/* The SecKeychainSearch API was deprecated in Lion, and using it will raise
   deprecation warnings, so let's not compile this unless it's necessary: */
#if MAC_OS_X_VERSION_MIN_REQUIRED < 1070
  SecKeychainAttributeList attr_list;
  SecKeychainAttribute attr;
  SecKeychainSearchRef search = NULL;
  SecCertificateRef cert = NULL;

  /* Set up the attribute list: */
  attr_list.count = 1L;
  attr_list.attr = &attr;

  /* Set up our lone search criterion: */
  attr.tag = kSecLabelItemAttr;
  attr.data = label;
  attr.length = (UInt32)strlen(label);

  /* Start searching: */
  status = SecKeychainSearchCreateFromAttributes(NULL,
                                                 kSecCertificateItemClass,
                                                 &attr_list,
                                                 &search);
  if(status == noErr) {
    status = SecKeychainSearchCopyNext(search,
                                       (SecKeychainItemRef *)&cert);
    if(status == noErr && cert) {
      /* If we found a certificate, does it have a private key? */
      status = SecIdentityCreateWithCertificate(NULL, cert, out_c_a_k);
      CFRelease(cert);
    }
  }

  if(search)
    CFRelease(search);
#else
#pragma unused(label, out_c_a_k)
#endif /* MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_7 */
  return status;
}
#endif /* (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE)) */

static OSStatus CopyIdentityWithLabel(char *label,
                                      SecIdentityRef *out_cert_and_key)
{
  OSStatus status = errSecItemNotFound;

#if defined(__MAC_10_6) || defined(__IPHONE_2_0)
  /* SecItemCopyMatching() was introduced in iOS and Snow Leopard. If it
     exists, let's use that to find the certificate. */
  if(SecItemCopyMatching != NULL) {
    CFTypeRef keys[4];
    CFTypeRef values[4];
    CFDictionaryRef query_dict;
    CFStringRef label_cf = CFStringCreateWithCString(NULL, label,
      kCFStringEncodingUTF8);

    /* Set up our search criteria and expected results: */
    values[0] = kSecClassIdentity; /* we want a certificate and a key */
    keys[0] = kSecClass;
    values[1] = kCFBooleanTrue;    /* we want a reference */
    keys[1] = kSecReturnRef;
    values[2] = kSecMatchLimitOne; /* one is enough, thanks */
    keys[2] = kSecMatchLimit;
    /* identity searches need a SecPolicyRef in order to work */
    values[3] = SecPolicyCreateSSL(false, label_cf);
    keys[3] = kSecMatchPolicy;
    query_dict = CFDictionaryCreate(NULL, (const void **)keys,
                                   (const void **)values, 4L,
                                   &kCFCopyStringDictionaryKeyCallBacks,
                                   &kCFTypeDictionaryValueCallBacks);
    CFRelease(values[3]);
    CFRelease(label_cf);

    /* Do we have a match? */
    status = SecItemCopyMatching(query_dict, (CFTypeRef *)out_cert_and_key);
    CFRelease(query_dict);
  }
  else {
#if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
    /* On Leopard, fall back to SecKeychainSearch. */
    status = CopyIdentityWithLabelOldSchool(label, out_cert_and_key);
#endif /* (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE)) */
  }
#elif (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
  /* For developers building on Leopard, we have no choice but to fall back. */
  status = CopyIdentityWithLabelOldSchool(label, out_cert_and_key);
#endif /* defined(__MAC_10_6) || defined(__IPHONE_2_0) */
  return status;
}

static CURLcode darwinssl_connect_step1(struct connectdata *conn,
                                        int sockindex)
{
  struct SessionHandle *data = conn->data;
  curl_socket_t sockfd = conn->sock[sockindex];
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
#ifdef ENABLE_IPV6
  struct in6_addr addr;
#else
  struct in_addr addr;
#endif
  size_t all_ciphers_count = 0UL, allowed_ciphers_count = 0UL, i;
  SSLCipherSuite *all_ciphers = NULL, *allowed_ciphers = NULL;
  char *ssl_sessionid;
  size_t ssl_sessionid_len;
  OSStatus err = noErr;
#if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
  int darwinver_maj = 0, darwinver_min = 0;

  GetDarwinVersionNumber(&darwinver_maj, &darwinver_min);
#endif

#if defined(__MAC_10_8) || defined(__IPHONE_5_0)
  if(SSLCreateContext != NULL) {  /* use the newer API if avaialble */
    if(connssl->ssl_ctx)
      CFRelease(connssl->ssl_ctx);
    connssl->ssl_ctx = SSLCreateContext(NULL, kSSLClientSide, kSSLStreamType);
    if(!connssl->ssl_ctx) {
      failf(data, "SSL: couldn't create a context!");
      return CURLE_OUT_OF_MEMORY;
    }
  }
  else {
  /* The old ST API does not exist under iOS, so don't compile it: */
#if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
    if(connssl->ssl_ctx)
      (void)SSLDisposeContext(connssl->ssl_ctx);
    err = SSLNewContext(false, &(connssl->ssl_ctx));
    if(err != noErr) {
      failf(data, "SSL: couldn't create a context: OSStatus %d", err);
      return CURLE_OUT_OF_MEMORY;
    }
#endif /* (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE)) */
  }
#else
  if(connssl->ssl_ctx)
    (void)SSLDisposeContext(connssl->ssl_ctx);
  err = SSLNewContext(false, &(connssl->ssl_ctx));
  if(err != noErr) {
    failf(data, "SSL: couldn't create a context: OSStatus %d", err);
    return CURLE_OUT_OF_MEMORY;
  }
#endif /* defined(__MAC_10_8) || defined(__IPHONE_5_0) */
  connssl->ssl_write_buffered_length = 0UL; /* reset buffered write length */

  /* check to see if we've been told to use an explicit SSL/TLS version */
#if defined(__MAC_10_8) || defined(__IPHONE_5_0)
  if(SSLSetProtocolVersionMax != NULL) {
    switch(data->set.ssl.version) {
      case CURL_SSLVERSION_DEFAULT: default:
        (void)SSLSetProtocolVersionMin(connssl->ssl_ctx, kSSLProtocol3);
        (void)SSLSetProtocolVersionMax(connssl->ssl_ctx, kTLSProtocol12);
        break;
      case CURL_SSLVERSION_TLSv1:
        (void)SSLSetProtocolVersionMin(connssl->ssl_ctx, kTLSProtocol1);
        (void)SSLSetProtocolVersionMax(connssl->ssl_ctx, kTLSProtocol12);
        break;
      case CURL_SSLVERSION_SSLv3:
        (void)SSLSetProtocolVersionMin(connssl->ssl_ctx, kSSLProtocol3);
        (void)SSLSetProtocolVersionMax(connssl->ssl_ctx, kSSLProtocol3);
        break;
      case CURL_SSLVERSION_SSLv2:
        (void)SSLSetProtocolVersionMin(connssl->ssl_ctx, kSSLProtocol2);
        (void)SSLSetProtocolVersionMax(connssl->ssl_ctx, kSSLProtocol2);
    }
  }
  else {
#if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
    (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                       kSSLProtocolAll,
                                       false);
    switch (data->set.ssl.version) {
      case CURL_SSLVERSION_DEFAULT: default:
        (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                           kSSLProtocol3,
                                           true);
        (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                           kTLSProtocol1,
                                           true);
        (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                           kTLSProtocol11,
                                           true);
        (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                           kTLSProtocol12,
                                           true);
        break;
      case CURL_SSLVERSION_TLSv1:
        (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                           kTLSProtocol1,
                                           true);
        (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                           kTLSProtocol11,
                                           true);
        (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                           kTLSProtocol12,
                                           true);
        break;
      case CURL_SSLVERSION_SSLv3:
        (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                           kSSLProtocol3,
                                           true);
        break;
      case CURL_SSLVERSION_SSLv2:
        (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                           kSSLProtocol2,
                                           true);
        break;
    }
#endif  /* (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE)) */
  }
#else
  (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx, kSSLProtocolAll, false);
  switch(data->set.ssl.version) {
    default:
    case CURL_SSLVERSION_DEFAULT:
      (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                         kSSLProtocol3,
                                         true);
      (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                         kTLSProtocol1,
                                         true);
      break;
    case CURL_SSLVERSION_TLSv1:
      (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                         kTLSProtocol1,
                                         true);
      break;
    case CURL_SSLVERSION_SSLv2:
      (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                         kSSLProtocol2,
                                         true);
      break;
    case CURL_SSLVERSION_SSLv3:
      (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
                                         kSSLProtocol3,
                                         true);
      break;
  }
#endif /* defined(__MAC_10_8) || defined(__IPHONE_5_0) */

  if(data->set.str[STRING_KEY]) {
    infof(data, "WARNING: SSL: CURLOPT_SSLKEY is ignored by Secure "
                "Transport. The private key must be in the Keychain.");
  }

  if(data->set.str[STRING_CERT]) {
    SecIdentityRef cert_and_key = NULL;

    /* User wants to authenticate with a client cert. Look for it: */
    err = CopyIdentityWithLabel(data->set.str[STRING_CERT], &cert_and_key);
    if(err == noErr) {
      SecCertificateRef cert = NULL;
      CFTypeRef certs_c[1];
      CFArrayRef certs;

      /* If we found one, print it out: */
      err = SecIdentityCopyCertificate(cert_and_key, &cert);
      if(err == noErr) {
        CFStringRef cert_summary = CopyCertSubject(cert);
        char cert_summary_c[128];

        if(cert_summary) {
          memset(cert_summary_c, 0, 128);
          if(CFStringGetCString(cert_summary,
                                cert_summary_c,
                                128,
                                kCFStringEncodingUTF8)) {
            infof(data, "Client certificate: %s\n", cert_summary_c);
          }
          CFRelease(cert_summary);
          CFRelease(cert);
        }
      }
      certs_c[0] = cert_and_key;
      certs = CFArrayCreate(NULL, (const void **)certs_c, 1L,
                            &kCFTypeArrayCallBacks);
      err = SSLSetCertificate(connssl->ssl_ctx, certs);
      if(certs)
        CFRelease(certs);
      if(err != noErr) {
        failf(data, "SSL: SSLSetCertificate() failed: OSStatus %d", err);
        return CURLE_SSL_CERTPROBLEM;
      }
      CFRelease(cert_and_key);
    }
    else {
      failf(data, "SSL: Can't find the certificate \"%s\" and its private key "
                  "in the Keychain.", data->set.str[STRING_CERT]);
      return CURLE_SSL_CERTPROBLEM;
    }
  }

  /* 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. */
#if defined(__MAC_10_6) || defined(__IPHONE_5_0)
  /* Snow Leopard introduced the SSLSetSessionOption() function, but due to
     a library bug with the way the kSSLSessionOptionBreakOnServerAuth flag
     works, it doesn't work as expected under Snow Leopard or Lion.
     So we need to call SSLSetEnableCertVerify() on those older cats in order
     to disable certificate validation if the user turned that off.