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      1 /*
      2  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
      3  *
      4  *  Use of this source code is governed by a BSD-style license
      5  *  that can be found in the LICENSE file in the root of the source
      6  *  tree. An additional intellectual property rights grant can be found
      7  *  in the file PATENTS.  All contributing project authors may
      8  *  be found in the AUTHORS file in the root of the source tree.
      9  */
     10 
     11 #if HAVE_CONFIG_H
     12 #include "config.h"
     13 #endif  // HAVE_CONFIG_H
     14 
     15 #if HAVE_OPENSSL_SSL_H
     16 
     17 #include "webrtc/base/opensslstreamadapter.h"
     18 
     19 #include <openssl/bio.h>
     20 #include <openssl/crypto.h>
     21 #include <openssl/err.h>
     22 #include <openssl/rand.h>
     23 #include <openssl/tls1.h>
     24 #include <openssl/x509v3.h>
     25 
     26 #include <vector>
     27 
     28 #include "webrtc/base/common.h"
     29 #include "webrtc/base/logging.h"
     30 #include "webrtc/base/safe_conversions.h"
     31 #include "webrtc/base/stream.h"
     32 #include "webrtc/base/openssl.h"
     33 #include "webrtc/base/openssladapter.h"
     34 #include "webrtc/base/openssldigest.h"
     35 #include "webrtc/base/opensslidentity.h"
     36 #include "webrtc/base/stringutils.h"
     37 #include "webrtc/base/thread.h"
     38 
     39 namespace rtc {
     40 
     41 #if (OPENSSL_VERSION_NUMBER >= 0x10001000L)
     42 #define HAVE_DTLS_SRTP
     43 #endif
     44 
     45 #ifdef HAVE_DTLS_SRTP
     46 // SRTP cipher suite table. |internal_name| is used to construct a
     47 // colon-separated profile strings which is needed by
     48 // SSL_CTX_set_tlsext_use_srtp().
     49 struct SrtpCipherMapEntry {
     50   const char* internal_name;
     51   const int id;
     52 };
     53 
     54 // This isn't elegant, but it's better than an external reference
     55 static SrtpCipherMapEntry SrtpCipherMap[] = {
     56     {"SRTP_AES128_CM_SHA1_80", SRTP_AES128_CM_SHA1_80},
     57     {"SRTP_AES128_CM_SHA1_32", SRTP_AES128_CM_SHA1_32},
     58     {nullptr, 0}};
     59 #endif
     60 
     61 #ifndef OPENSSL_IS_BORINGSSL
     62 
     63 // Cipher name table. Maps internal OpenSSL cipher ids to the RFC name.
     64 struct SslCipherMapEntry {
     65   uint32_t openssl_id;
     66   const char* rfc_name;
     67 };
     68 
     69 #define DEFINE_CIPHER_ENTRY_SSL3(name)  {SSL3_CK_##name, "TLS_"#name}
     70 #define DEFINE_CIPHER_ENTRY_TLS1(name)  {TLS1_CK_##name, "TLS_"#name}
     71 
     72 // There currently is no method available to get a RFC-compliant name for a
     73 // cipher suite from BoringSSL, so we need to define the mapping manually here.
     74 // This should go away once BoringSSL supports "SSL_CIPHER_standard_name"
     75 // (as available in OpenSSL if compiled with tracing enabled) or a similar
     76 // method.
     77 static const SslCipherMapEntry kSslCipherMap[] = {
     78   // TLS v1.0 ciphersuites from RFC2246.
     79   DEFINE_CIPHER_ENTRY_SSL3(RSA_RC4_128_SHA),
     80   {SSL3_CK_RSA_DES_192_CBC3_SHA,
     81       "TLS_RSA_WITH_3DES_EDE_CBC_SHA"},
     82 
     83   // AES ciphersuites from RFC3268.
     84   {TLS1_CK_RSA_WITH_AES_128_SHA,
     85       "TLS_RSA_WITH_AES_128_CBC_SHA"},
     86   {TLS1_CK_DHE_RSA_WITH_AES_128_SHA,
     87       "TLS_DHE_RSA_WITH_AES_128_CBC_SHA"},
     88   {TLS1_CK_RSA_WITH_AES_256_SHA,
     89       "TLS_RSA_WITH_AES_256_CBC_SHA"},
     90   {TLS1_CK_DHE_RSA_WITH_AES_256_SHA,
     91       "TLS_DHE_RSA_WITH_AES_256_CBC_SHA"},
     92 
     93   // ECC ciphersuites from RFC4492.
     94   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_RC4_128_SHA),
     95   {TLS1_CK_ECDHE_ECDSA_WITH_DES_192_CBC3_SHA,
     96       "TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA"},
     97   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_AES_128_CBC_SHA),
     98   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_AES_256_CBC_SHA),
     99 
    100   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_RC4_128_SHA),
    101   {TLS1_CK_ECDHE_RSA_WITH_DES_192_CBC3_SHA,
    102       "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA"},
    103   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_AES_128_CBC_SHA),
    104   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_AES_256_CBC_SHA),
    105 
    106   // TLS v1.2 ciphersuites.
    107   {TLS1_CK_RSA_WITH_AES_128_SHA256,
    108       "TLS_RSA_WITH_AES_128_CBC_SHA256"},
    109   {TLS1_CK_RSA_WITH_AES_256_SHA256,
    110       "TLS_RSA_WITH_AES_256_CBC_SHA256"},
    111   {TLS1_CK_DHE_RSA_WITH_AES_128_SHA256,
    112       "TLS_DHE_RSA_WITH_AES_128_CBC_SHA256"},
    113   {TLS1_CK_DHE_RSA_WITH_AES_256_SHA256,
    114       "TLS_DHE_RSA_WITH_AES_256_CBC_SHA256"},
    115 
    116   // TLS v1.2 GCM ciphersuites from RFC5288.
    117   DEFINE_CIPHER_ENTRY_TLS1(RSA_WITH_AES_128_GCM_SHA256),
    118   DEFINE_CIPHER_ENTRY_TLS1(RSA_WITH_AES_256_GCM_SHA384),
    119   DEFINE_CIPHER_ENTRY_TLS1(DHE_RSA_WITH_AES_128_GCM_SHA256),
    120   DEFINE_CIPHER_ENTRY_TLS1(DHE_RSA_WITH_AES_256_GCM_SHA384),
    121   DEFINE_CIPHER_ENTRY_TLS1(DH_RSA_WITH_AES_128_GCM_SHA256),
    122   DEFINE_CIPHER_ENTRY_TLS1(DH_RSA_WITH_AES_256_GCM_SHA384),
    123 
    124   // ECDH HMAC based ciphersuites from RFC5289.
    125   {TLS1_CK_ECDHE_ECDSA_WITH_AES_128_SHA256,
    126       "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256"},
    127   {TLS1_CK_ECDHE_ECDSA_WITH_AES_256_SHA384,
    128       "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384"},
    129   {TLS1_CK_ECDHE_RSA_WITH_AES_128_SHA256,
    130       "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256"},
    131   {TLS1_CK_ECDHE_RSA_WITH_AES_256_SHA384,
    132       "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384"},
    133 
    134   // ECDH GCM based ciphersuites from RFC5289.
    135   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_AES_128_GCM_SHA256),
    136   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_AES_256_GCM_SHA384),
    137   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_AES_128_GCM_SHA256),
    138   DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_AES_256_GCM_SHA384),
    139 
    140   {0, NULL}
    141 };
    142 #endif  // #ifndef OPENSSL_IS_BORINGSSL
    143 
    144 #if defined(_MSC_VER)
    145 #pragma warning(push)
    146 #pragma warning(disable : 4309)
    147 #pragma warning(disable : 4310)
    148 #endif  // defined(_MSC_VER)
    149 
    150 // Default cipher used between OpenSSL/BoringSSL stream adapters.
    151 // This needs to be updated when the default of the SSL library changes.
    152 // static_cast<uint16_t> causes build warnings on windows platform.
    153 static int kDefaultSslCipher10 =
    154     static_cast<uint16_t>(TLS1_CK_ECDHE_RSA_WITH_AES_256_CBC_SHA);
    155 static int kDefaultSslEcCipher10 =
    156     static_cast<uint16_t>(TLS1_CK_ECDHE_ECDSA_WITH_AES_256_CBC_SHA);
    157 #ifdef OPENSSL_IS_BORINGSSL
    158 static int kDefaultSslCipher12 =
    159     static_cast<uint16_t>(TLS1_CK_ECDHE_RSA_WITH_AES_128_GCM_SHA256);
    160 static int kDefaultSslEcCipher12 =
    161     static_cast<uint16_t>(TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256);
    162 // Fallback cipher for DTLS 1.2 if hardware-accelerated AES-GCM is unavailable.
    163 // TODO(davidben): Switch to the standardized CHACHA20_POLY1305 variant when
    164 // available.
    165 static int kDefaultSslCipher12NoAesGcm =
    166     static_cast<uint16_t>(TLS1_CK_ECDHE_RSA_CHACHA20_POLY1305_OLD);
    167 static int kDefaultSslEcCipher12NoAesGcm =
    168     static_cast<uint16_t>(TLS1_CK_ECDHE_ECDSA_CHACHA20_POLY1305_OLD);
    169 #else  // !OPENSSL_IS_BORINGSSL
    170 // OpenSSL sorts differently than BoringSSL, so the default cipher doesn't
    171 // change between TLS 1.0 and TLS 1.2 with the current setup.
    172 static int kDefaultSslCipher12 =
    173     static_cast<uint16_t>(TLS1_CK_ECDHE_RSA_WITH_AES_256_CBC_SHA);
    174 static int kDefaultSslEcCipher12 =
    175     static_cast<uint16_t>(TLS1_CK_ECDHE_ECDSA_WITH_AES_256_CBC_SHA);
    176 #endif
    177 
    178 #if defined(_MSC_VER)
    179 #pragma warning(pop)
    180 #endif  // defined(_MSC_VER)
    181 
    182 //////////////////////////////////////////////////////////////////////
    183 // StreamBIO
    184 //////////////////////////////////////////////////////////////////////
    185 
    186 static int stream_write(BIO* h, const char* buf, int num);
    187 static int stream_read(BIO* h, char* buf, int size);
    188 static int stream_puts(BIO* h, const char* str);
    189 static long stream_ctrl(BIO* h, int cmd, long arg1, void* arg2);
    190 static int stream_new(BIO* h);
    191 static int stream_free(BIO* data);
    192 
    193 // TODO(davidben): This should be const once BoringSSL is assumed.
    194 static BIO_METHOD methods_stream = {
    195   BIO_TYPE_BIO,
    196   "stream",
    197   stream_write,
    198   stream_read,
    199   stream_puts,
    200   0,
    201   stream_ctrl,
    202   stream_new,
    203   stream_free,
    204   NULL,
    205 };
    206 
    207 static BIO_METHOD* BIO_s_stream() { return(&methods_stream); }
    208 
    209 static BIO* BIO_new_stream(StreamInterface* stream) {
    210   BIO* ret = BIO_new(BIO_s_stream());
    211   if (ret == NULL)
    212     return NULL;
    213   ret->ptr = stream;
    214   return ret;
    215 }
    216 
    217 // bio methods return 1 (or at least non-zero) on success and 0 on failure.
    218 
    219 static int stream_new(BIO* b) {
    220   b->shutdown = 0;
    221   b->init = 1;
    222   b->num = 0;  // 1 means end-of-stream
    223   b->ptr = 0;
    224   return 1;
    225 }
    226 
    227 static int stream_free(BIO* b) {
    228   if (b == NULL)
    229     return 0;
    230   return 1;
    231 }
    232 
    233 static int stream_read(BIO* b, char* out, int outl) {
    234   if (!out)
    235     return -1;
    236   StreamInterface* stream = static_cast<StreamInterface*>(b->ptr);
    237   BIO_clear_retry_flags(b);
    238   size_t read;
    239   int error;
    240   StreamResult result = stream->Read(out, outl, &read, &error);
    241   if (result == SR_SUCCESS) {
    242     return checked_cast<int>(read);
    243   } else if (result == SR_EOS) {
    244     b->num = 1;
    245   } else if (result == SR_BLOCK) {
    246     BIO_set_retry_read(b);
    247   }
    248   return -1;
    249 }
    250 
    251 static int stream_write(BIO* b, const char* in, int inl) {
    252   if (!in)
    253     return -1;
    254   StreamInterface* stream = static_cast<StreamInterface*>(b->ptr);
    255   BIO_clear_retry_flags(b);
    256   size_t written;
    257   int error;
    258   StreamResult result = stream->Write(in, inl, &written, &error);
    259   if (result == SR_SUCCESS) {
    260     return checked_cast<int>(written);
    261   } else if (result == SR_BLOCK) {
    262     BIO_set_retry_write(b);
    263   }
    264   return -1;
    265 }
    266 
    267 static int stream_puts(BIO* b, const char* str) {
    268   return stream_write(b, str, checked_cast<int>(strlen(str)));
    269 }
    270 
    271 static long stream_ctrl(BIO* b, int cmd, long num, void* ptr) {
    272   RTC_UNUSED(num);
    273   RTC_UNUSED(ptr);
    274 
    275   switch (cmd) {
    276     case BIO_CTRL_RESET:
    277       return 0;
    278     case BIO_CTRL_EOF:
    279       return b->num;
    280     case BIO_CTRL_WPENDING:
    281     case BIO_CTRL_PENDING:
    282       return 0;
    283     case BIO_CTRL_FLUSH:
    284       return 1;
    285     case BIO_CTRL_DGRAM_QUERY_MTU:
    286       // openssl defaults to mtu=256 unless we return something here.
    287       // The handshake doesn't actually need to send packets above 1k,
    288       // so this seems like a sensible value that should work in most cases.
    289       // Webrtc uses the same value for video packets.
    290       return 1200;
    291     default:
    292       return 0;
    293   }
    294 }
    295 
    296 /////////////////////////////////////////////////////////////////////////////
    297 // OpenSSLStreamAdapter
    298 /////////////////////////////////////////////////////////////////////////////
    299 
    300 OpenSSLStreamAdapter::OpenSSLStreamAdapter(StreamInterface* stream)
    301     : SSLStreamAdapter(stream),
    302       state_(SSL_NONE),
    303       role_(SSL_CLIENT),
    304       ssl_read_needs_write_(false),
    305       ssl_write_needs_read_(false),
    306       ssl_(NULL),
    307       ssl_ctx_(NULL),
    308       custom_verification_succeeded_(false),
    309       ssl_mode_(SSL_MODE_TLS),
    310       ssl_max_version_(SSL_PROTOCOL_TLS_12) {}
    311 
    312 OpenSSLStreamAdapter::~OpenSSLStreamAdapter() {
    313   Cleanup();
    314 }
    315 
    316 void OpenSSLStreamAdapter::SetIdentity(SSLIdentity* identity) {
    317   ASSERT(!identity_);
    318   identity_.reset(static_cast<OpenSSLIdentity*>(identity));
    319 }
    320 
    321 void OpenSSLStreamAdapter::SetServerRole(SSLRole role) {
    322   role_ = role;
    323 }
    324 
    325 bool OpenSSLStreamAdapter::GetPeerCertificate(SSLCertificate** cert) const {
    326   if (!peer_certificate_)
    327     return false;
    328 
    329   *cert = peer_certificate_->GetReference();
    330   return true;
    331 }
    332 
    333 bool OpenSSLStreamAdapter::SetPeerCertificateDigest(const std::string
    334                                                     &digest_alg,
    335                                                     const unsigned char*
    336                                                     digest_val,
    337                                                     size_t digest_len) {
    338   ASSERT(!peer_certificate_);
    339   ASSERT(peer_certificate_digest_algorithm_.size() == 0);
    340   ASSERT(ssl_server_name_.empty());
    341   size_t expected_len;
    342 
    343   if (!OpenSSLDigest::GetDigestSize(digest_alg, &expected_len)) {
    344     LOG(LS_WARNING) << "Unknown digest algorithm: " << digest_alg;
    345     return false;
    346   }
    347   if (expected_len != digest_len)
    348     return false;
    349 
    350   peer_certificate_digest_value_.SetData(digest_val, digest_len);
    351   peer_certificate_digest_algorithm_ = digest_alg;
    352 
    353   return true;
    354 }
    355 
    356 std::string OpenSSLStreamAdapter::SslCipherSuiteToName(int cipher_suite) {
    357 #ifdef OPENSSL_IS_BORINGSSL
    358   const SSL_CIPHER* ssl_cipher = SSL_get_cipher_by_value(cipher_suite);
    359   if (!ssl_cipher) {
    360     return std::string();
    361   }
    362   char* cipher_name = SSL_CIPHER_get_rfc_name(ssl_cipher);
    363   std::string rfc_name = std::string(cipher_name);
    364   OPENSSL_free(cipher_name);
    365   return rfc_name;
    366 #else
    367   for (const SslCipherMapEntry* entry = kSslCipherMap; entry->rfc_name;
    368        ++entry) {
    369     if (cipher_suite == static_cast<int>(entry->openssl_id)) {
    370       return entry->rfc_name;
    371     }
    372   }
    373   return std::string();
    374 #endif
    375 }
    376 
    377 bool OpenSSLStreamAdapter::GetSslCipherSuite(int* cipher_suite) {
    378   if (state_ != SSL_CONNECTED)
    379     return false;
    380 
    381   const SSL_CIPHER* current_cipher = SSL_get_current_cipher(ssl_);
    382   if (current_cipher == NULL) {
    383     return false;
    384   }
    385 
    386   *cipher_suite = static_cast<uint16_t>(SSL_CIPHER_get_id(current_cipher));
    387   return true;
    388 }
    389 
    390 // Key Extractor interface
    391 bool OpenSSLStreamAdapter::ExportKeyingMaterial(const std::string& label,
    392                                                 const uint8_t* context,
    393                                                 size_t context_len,
    394                                                 bool use_context,
    395                                                 uint8_t* result,
    396                                                 size_t result_len) {
    397 #ifdef HAVE_DTLS_SRTP
    398   int i;
    399 
    400   i = SSL_export_keying_material(ssl_, result, result_len, label.c_str(),
    401                                  label.length(), const_cast<uint8_t*>(context),
    402                                  context_len, use_context);
    403 
    404   if (i != 1)
    405     return false;
    406 
    407   return true;
    408 #else
    409   return false;
    410 #endif
    411 }
    412 
    413 bool OpenSSLStreamAdapter::SetDtlsSrtpCryptoSuites(
    414     const std::vector<int>& ciphers) {
    415 #ifdef HAVE_DTLS_SRTP
    416   std::string internal_ciphers;
    417 
    418   if (state_ != SSL_NONE)
    419     return false;
    420 
    421   for (std::vector<int>::const_iterator cipher = ciphers.begin();
    422        cipher != ciphers.end(); ++cipher) {
    423     bool found = false;
    424     for (SrtpCipherMapEntry* entry = SrtpCipherMap; entry->internal_name;
    425          ++entry) {
    426       if (*cipher == entry->id) {
    427         found = true;
    428         if (!internal_ciphers.empty())
    429           internal_ciphers += ":";
    430         internal_ciphers += entry->internal_name;
    431         break;
    432       }
    433     }
    434 
    435     if (!found) {
    436       LOG(LS_ERROR) << "Could not find cipher: " << *cipher;
    437       return false;
    438     }
    439   }
    440 
    441   if (internal_ciphers.empty())
    442     return false;
    443 
    444   srtp_ciphers_ = internal_ciphers;
    445   return true;
    446 #else
    447   return false;
    448 #endif
    449 }
    450 
    451 bool OpenSSLStreamAdapter::GetDtlsSrtpCryptoSuite(int* crypto_suite) {
    452 #ifdef HAVE_DTLS_SRTP
    453   ASSERT(state_ == SSL_CONNECTED);
    454   if (state_ != SSL_CONNECTED)
    455     return false;
    456 
    457   const SRTP_PROTECTION_PROFILE *srtp_profile =
    458       SSL_get_selected_srtp_profile(ssl_);
    459 
    460   if (!srtp_profile)
    461     return false;
    462 
    463   *crypto_suite = srtp_profile->id;
    464   ASSERT(!SrtpCryptoSuiteToName(*crypto_suite).empty());
    465   return true;
    466 #else
    467   return false;
    468 #endif
    469 }
    470 
    471 int OpenSSLStreamAdapter::StartSSLWithServer(const char* server_name) {
    472   ASSERT(server_name != NULL && server_name[0] != '\0');
    473   ssl_server_name_ = server_name;
    474   return StartSSL();
    475 }
    476 
    477 int OpenSSLStreamAdapter::StartSSLWithPeer() {
    478   ASSERT(ssl_server_name_.empty());
    479   // It is permitted to specify peer_certificate_ only later.
    480   return StartSSL();
    481 }
    482 
    483 void OpenSSLStreamAdapter::SetMode(SSLMode mode) {
    484   ASSERT(state_ == SSL_NONE);
    485   ssl_mode_ = mode;
    486 }
    487 
    488 void OpenSSLStreamAdapter::SetMaxProtocolVersion(SSLProtocolVersion version) {
    489   ASSERT(ssl_ctx_ == NULL);
    490   ssl_max_version_ = version;
    491 }
    492 
    493 //
    494 // StreamInterface Implementation
    495 //
    496 
    497 StreamResult OpenSSLStreamAdapter::Write(const void* data, size_t data_len,
    498                                          size_t* written, int* error) {
    499   LOG(LS_VERBOSE) << "OpenSSLStreamAdapter::Write(" << data_len << ")";
    500 
    501   switch (state_) {
    502   case SSL_NONE:
    503     // pass-through in clear text
    504     return StreamAdapterInterface::Write(data, data_len, written, error);
    505 
    506   case SSL_WAIT:
    507   case SSL_CONNECTING:
    508     return SR_BLOCK;
    509 
    510   case SSL_CONNECTED:
    511     break;
    512 
    513   case SSL_ERROR:
    514   case SSL_CLOSED:
    515   default:
    516     if (error)
    517       *error = ssl_error_code_;
    518     return SR_ERROR;
    519   }
    520 
    521   // OpenSSL will return an error if we try to write zero bytes
    522   if (data_len == 0) {
    523     if (written)
    524       *written = 0;
    525     return SR_SUCCESS;
    526   }
    527 
    528   ssl_write_needs_read_ = false;
    529 
    530   int code = SSL_write(ssl_, data, checked_cast<int>(data_len));
    531   int ssl_error = SSL_get_error(ssl_, code);
    532   switch (ssl_error) {
    533   case SSL_ERROR_NONE:
    534     LOG(LS_VERBOSE) << " -- success";
    535     ASSERT(0 < code && static_cast<unsigned>(code) <= data_len);
    536     if (written)
    537       *written = code;
    538     return SR_SUCCESS;
    539   case SSL_ERROR_WANT_READ:
    540     LOG(LS_VERBOSE) << " -- error want read";
    541     ssl_write_needs_read_ = true;
    542     return SR_BLOCK;
    543   case SSL_ERROR_WANT_WRITE:
    544     LOG(LS_VERBOSE) << " -- error want write";
    545     return SR_BLOCK;
    546 
    547   case SSL_ERROR_ZERO_RETURN:
    548   default:
    549     Error("SSL_write", (ssl_error ? ssl_error : -1), false);
    550     if (error)
    551       *error = ssl_error_code_;
    552     return SR_ERROR;
    553   }
    554   // not reached
    555 }
    556 
    557 StreamResult OpenSSLStreamAdapter::Read(void* data, size_t data_len,
    558                                         size_t* read, int* error) {
    559   LOG(LS_VERBOSE) << "OpenSSLStreamAdapter::Read(" << data_len << ")";
    560   switch (state_) {
    561     case SSL_NONE:
    562       // pass-through in clear text
    563       return StreamAdapterInterface::Read(data, data_len, read, error);
    564 
    565     case SSL_WAIT:
    566     case SSL_CONNECTING:
    567       return SR_BLOCK;
    568 
    569     case SSL_CONNECTED:
    570       break;
    571 
    572     case SSL_CLOSED:
    573       return SR_EOS;
    574 
    575     case SSL_ERROR:
    576     default:
    577       if (error)
    578         *error = ssl_error_code_;
    579       return SR_ERROR;
    580   }
    581 
    582   // Don't trust OpenSSL with zero byte reads
    583   if (data_len == 0) {
    584     if (read)
    585       *read = 0;
    586     return SR_SUCCESS;
    587   }
    588 
    589   ssl_read_needs_write_ = false;
    590 
    591   int code = SSL_read(ssl_, data, checked_cast<int>(data_len));
    592   int ssl_error = SSL_get_error(ssl_, code);
    593   switch (ssl_error) {
    594     case SSL_ERROR_NONE:
    595       LOG(LS_VERBOSE) << " -- success";
    596       ASSERT(0 < code && static_cast<unsigned>(code) <= data_len);
    597       if (read)
    598         *read = code;
    599 
    600       if (ssl_mode_ == SSL_MODE_DTLS) {
    601         // Enforce atomic reads -- this is a short read
    602         unsigned int pending = SSL_pending(ssl_);
    603 
    604         if (pending) {
    605           LOG(LS_INFO) << " -- short DTLS read. flushing";
    606           FlushInput(pending);
    607           if (error)
    608             *error = SSE_MSG_TRUNC;
    609           return SR_ERROR;
    610         }
    611       }
    612       return SR_SUCCESS;
    613     case SSL_ERROR_WANT_READ:
    614       LOG(LS_VERBOSE) << " -- error want read";
    615       return SR_BLOCK;
    616     case SSL_ERROR_WANT_WRITE:
    617       LOG(LS_VERBOSE) << " -- error want write";
    618       ssl_read_needs_write_ = true;
    619       return SR_BLOCK;
    620     case SSL_ERROR_ZERO_RETURN:
    621       LOG(LS_VERBOSE) << " -- remote side closed";
    622       return SR_EOS;
    623       break;
    624     default:
    625       LOG(LS_VERBOSE) << " -- error " << code;
    626       Error("SSL_read", (ssl_error ? ssl_error : -1), false);
    627       if (error)
    628         *error = ssl_error_code_;
    629       return SR_ERROR;
    630   }
    631   // not reached
    632 }
    633 
    634 void OpenSSLStreamAdapter::FlushInput(unsigned int left) {
    635   unsigned char buf[2048];
    636 
    637   while (left) {
    638     // This should always succeed
    639     int toread = (sizeof(buf) < left) ? sizeof(buf) : left;
    640     int code = SSL_read(ssl_, buf, toread);
    641 
    642     int ssl_error = SSL_get_error(ssl_, code);
    643     ASSERT(ssl_error == SSL_ERROR_NONE);
    644 
    645     if (ssl_error != SSL_ERROR_NONE) {
    646       LOG(LS_VERBOSE) << " -- error " << code;
    647       Error("SSL_read", (ssl_error ? ssl_error : -1), false);
    648       return;
    649     }
    650 
    651     LOG(LS_VERBOSE) << " -- flushed " << code << " bytes";
    652     left -= code;
    653   }
    654 }
    655 
    656 void OpenSSLStreamAdapter::Close() {
    657   Cleanup();
    658   ASSERT(state_ == SSL_CLOSED || state_ == SSL_ERROR);
    659   StreamAdapterInterface::Close();
    660 }
    661 
    662 StreamState OpenSSLStreamAdapter::GetState() const {
    663   switch (state_) {
    664     case SSL_WAIT:
    665     case SSL_CONNECTING:
    666       return SS_OPENING;
    667     case SSL_CONNECTED:
    668       return SS_OPEN;
    669     default:
    670       return SS_CLOSED;
    671   };
    672   // not reached
    673 }
    674 
    675 void OpenSSLStreamAdapter::OnEvent(StreamInterface* stream, int events,
    676                                    int err) {
    677   int events_to_signal = 0;
    678   int signal_error = 0;
    679   ASSERT(stream == this->stream());
    680   if ((events & SE_OPEN)) {
    681     LOG(LS_VERBOSE) << "OpenSSLStreamAdapter::OnEvent SE_OPEN";
    682     if (state_ != SSL_WAIT) {
    683       ASSERT(state_ == SSL_NONE);
    684       events_to_signal |= SE_OPEN;
    685     } else {
    686       state_ = SSL_CONNECTING;
    687       if (int err = BeginSSL()) {
    688         Error("BeginSSL", err, true);
    689         return;
    690       }
    691     }
    692   }
    693   if ((events & (SE_READ|SE_WRITE))) {
    694     LOG(LS_VERBOSE) << "OpenSSLStreamAdapter::OnEvent"
    695                  << ((events & SE_READ) ? " SE_READ" : "")
    696                  << ((events & SE_WRITE) ? " SE_WRITE" : "");
    697     if (state_ == SSL_NONE) {
    698       events_to_signal |= events & (SE_READ|SE_WRITE);
    699     } else if (state_ == SSL_CONNECTING) {
    700       if (int err = ContinueSSL()) {
    701         Error("ContinueSSL", err, true);
    702         return;
    703       }
    704     } else if (state_ == SSL_CONNECTED) {
    705       if (((events & SE_READ) && ssl_write_needs_read_) ||
    706           (events & SE_WRITE)) {
    707         LOG(LS_VERBOSE) << " -- onStreamWriteable";
    708         events_to_signal |= SE_WRITE;
    709       }
    710       if (((events & SE_WRITE) && ssl_read_needs_write_) ||
    711           (events & SE_READ)) {
    712         LOG(LS_VERBOSE) << " -- onStreamReadable";
    713         events_to_signal |= SE_READ;
    714       }
    715     }
    716   }
    717   if ((events & SE_CLOSE)) {
    718     LOG(LS_VERBOSE) << "OpenSSLStreamAdapter::OnEvent(SE_CLOSE, " << err << ")";
    719     Cleanup();
    720     events_to_signal |= SE_CLOSE;
    721     // SE_CLOSE is the only event that uses the final parameter to OnEvent().
    722     ASSERT(signal_error == 0);
    723     signal_error = err;
    724   }
    725   if (events_to_signal)
    726     StreamAdapterInterface::OnEvent(stream, events_to_signal, signal_error);
    727 }
    728 
    729 int OpenSSLStreamAdapter::StartSSL() {
    730   ASSERT(state_ == SSL_NONE);
    731 
    732   if (StreamAdapterInterface::GetState() != SS_OPEN) {
    733     state_ = SSL_WAIT;
    734     return 0;
    735   }
    736 
    737   state_ = SSL_CONNECTING;
    738   if (int err = BeginSSL()) {
    739     Error("BeginSSL", err, false);
    740     return err;
    741   }
    742 
    743   return 0;
    744 }
    745 
    746 int OpenSSLStreamAdapter::BeginSSL() {
    747   ASSERT(state_ == SSL_CONNECTING);
    748   // The underlying stream has open. If we are in peer-to-peer mode
    749   // then a peer certificate must have been specified by now.
    750   ASSERT(!ssl_server_name_.empty() ||
    751          !peer_certificate_digest_algorithm_.empty());
    752   LOG(LS_INFO) << "BeginSSL: "
    753                << (!ssl_server_name_.empty() ? ssl_server_name_ :
    754                                                "with peer");
    755 
    756   BIO* bio = NULL;
    757 
    758   // First set up the context
    759   ASSERT(ssl_ctx_ == NULL);
    760   ssl_ctx_ = SetupSSLContext();
    761   if (!ssl_ctx_)
    762     return -1;
    763 
    764   bio = BIO_new_stream(static_cast<StreamInterface*>(stream()));
    765   if (!bio)
    766     return -1;
    767 
    768   ssl_ = SSL_new(ssl_ctx_);
    769   if (!ssl_) {
    770     BIO_free(bio);
    771     return -1;
    772   }
    773 
    774   SSL_set_app_data(ssl_, this);
    775 
    776   SSL_set_bio(ssl_, bio, bio);  // the SSL object owns the bio now.
    777 #ifndef OPENSSL_IS_BORINGSSL
    778   if (ssl_mode_ == SSL_MODE_DTLS) {
    779     // Enable read-ahead for DTLS so whole packets are read from internal BIO
    780     // before parsing. This is done internally by BoringSSL for DTLS.
    781     SSL_set_read_ahead(ssl_, 1);
    782   }
    783 #endif
    784 
    785   SSL_set_mode(ssl_, SSL_MODE_ENABLE_PARTIAL_WRITE |
    786                SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
    787 
    788   // Specify an ECDH group for ECDHE ciphers, otherwise they cannot be
    789   // negotiated when acting as the server. Use NIST's P-256 which is commonly
    790   // supported.
    791   EC_KEY* ecdh = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
    792   if (ecdh == NULL)
    793     return -1;
    794   SSL_set_options(ssl_, SSL_OP_SINGLE_ECDH_USE);
    795   SSL_set_tmp_ecdh(ssl_, ecdh);
    796   EC_KEY_free(ecdh);
    797 
    798   // Do the connect
    799   return ContinueSSL();
    800 }
    801 
    802 int OpenSSLStreamAdapter::ContinueSSL() {
    803   LOG(LS_VERBOSE) << "ContinueSSL";
    804   ASSERT(state_ == SSL_CONNECTING);
    805 
    806   // Clear the DTLS timer
    807   Thread::Current()->Clear(this, MSG_TIMEOUT);
    808 
    809   int code = (role_ == SSL_CLIENT) ? SSL_connect(ssl_) : SSL_accept(ssl_);
    810   int ssl_error;
    811   switch (ssl_error = SSL_get_error(ssl_, code)) {
    812     case SSL_ERROR_NONE:
    813       LOG(LS_VERBOSE) << " -- success";
    814 
    815       if (!SSLPostConnectionCheck(ssl_, ssl_server_name_.c_str(), NULL,
    816                                   peer_certificate_digest_algorithm_)) {
    817         LOG(LS_ERROR) << "TLS post connection check failed";
    818         return -1;
    819       }
    820 
    821       state_ = SSL_CONNECTED;
    822       StreamAdapterInterface::OnEvent(stream(), SE_OPEN|SE_READ|SE_WRITE, 0);
    823       break;
    824 
    825     case SSL_ERROR_WANT_READ: {
    826         LOG(LS_VERBOSE) << " -- error want read";
    827         struct timeval timeout;
    828         if (DTLSv1_get_timeout(ssl_, &timeout)) {
    829           int delay = timeout.tv_sec * 1000 + timeout.tv_usec/1000;
    830 
    831           Thread::Current()->PostDelayed(delay, this, MSG_TIMEOUT, 0);
    832         }
    833       }
    834       break;
    835 
    836     case SSL_ERROR_WANT_WRITE:
    837       LOG(LS_VERBOSE) << " -- error want write";
    838       break;
    839 
    840     case SSL_ERROR_ZERO_RETURN:
    841     default:
    842       LOG(LS_VERBOSE) << " -- error " << code;
    843       return (ssl_error != 0) ? ssl_error : -1;
    844   }
    845 
    846   return 0;
    847 }
    848 
    849 void OpenSSLStreamAdapter::Error(const char* context, int err, bool signal) {
    850   LOG(LS_WARNING) << "OpenSSLStreamAdapter::Error("
    851                   << context << ", " << err << ")";
    852   state_ = SSL_ERROR;
    853   ssl_error_code_ = err;
    854   Cleanup();
    855   if (signal)
    856     StreamAdapterInterface::OnEvent(stream(), SE_CLOSE, err);
    857 }
    858 
    859 void OpenSSLStreamAdapter::Cleanup() {
    860   LOG(LS_INFO) << "Cleanup";
    861 
    862   if (state_ != SSL_ERROR) {
    863     state_ = SSL_CLOSED;
    864     ssl_error_code_ = 0;
    865   }
    866 
    867   if (ssl_) {
    868     int ret = SSL_shutdown(ssl_);
    869     if (ret < 0) {
    870       LOG(LS_WARNING) << "SSL_shutdown failed, error = "
    871                       << SSL_get_error(ssl_, ret);
    872     }
    873 
    874     SSL_free(ssl_);
    875     ssl_ = NULL;
    876   }
    877   if (ssl_ctx_) {
    878     SSL_CTX_free(ssl_ctx_);
    879     ssl_ctx_ = NULL;
    880   }
    881   identity_.reset();
    882   peer_certificate_.reset();
    883 
    884   // Clear the DTLS timer
    885   Thread::Current()->Clear(this, MSG_TIMEOUT);
    886 }
    887 
    888 
    889 void OpenSSLStreamAdapter::OnMessage(Message* msg) {
    890   // Process our own messages and then pass others to the superclass
    891   if (MSG_TIMEOUT == msg->message_id) {
    892     LOG(LS_INFO) << "DTLS timeout expired";
    893     DTLSv1_handle_timeout(ssl_);
    894     ContinueSSL();
    895   } else {
    896     StreamInterface::OnMessage(msg);
    897   }
    898 }
    899 
    900 SSL_CTX* OpenSSLStreamAdapter::SetupSSLContext() {
    901   SSL_CTX *ctx = NULL;
    902 
    903 #ifdef OPENSSL_IS_BORINGSSL
    904     ctx = SSL_CTX_new(ssl_mode_ == SSL_MODE_DTLS ?
    905         DTLS_method() : TLS_method());
    906     // Version limiting for BoringSSL will be done below.
    907 #else
    908   const SSL_METHOD* method;
    909   switch (ssl_max_version_) {
    910     case SSL_PROTOCOL_TLS_10:
    911     case SSL_PROTOCOL_TLS_11:
    912       // OpenSSL doesn't support setting min/max versions, so we always use
    913       // (D)TLS 1.0 if a max. version below the max. available is requested.
    914       if (ssl_mode_ == SSL_MODE_DTLS) {
    915         if (role_ == SSL_CLIENT) {
    916           method = DTLSv1_client_method();
    917         } else {
    918           method = DTLSv1_server_method();
    919         }
    920       } else {
    921         if (role_ == SSL_CLIENT) {
    922           method = TLSv1_client_method();
    923         } else {
    924           method = TLSv1_server_method();
    925         }
    926       }
    927       break;
    928     case SSL_PROTOCOL_TLS_12:
    929     default:
    930       if (ssl_mode_ == SSL_MODE_DTLS) {
    931 #if (OPENSSL_VERSION_NUMBER >= 0x10002000L)
    932         // DTLS 1.2 only available starting from OpenSSL 1.0.2
    933         if (role_ == SSL_CLIENT) {
    934           method = DTLS_client_method();
    935         } else {
    936           method = DTLS_server_method();
    937         }
    938 #else
    939         if (role_ == SSL_CLIENT) {
    940           method = DTLSv1_client_method();
    941         } else {
    942           method = DTLSv1_server_method();
    943         }
    944 #endif
    945       } else {
    946 #if (OPENSSL_VERSION_NUMBER >= 0x10100000L)
    947         // New API only available starting from OpenSSL 1.1.0
    948         if (role_ == SSL_CLIENT) {
    949           method = TLS_client_method();
    950         } else {
    951           method = TLS_server_method();
    952         }
    953 #else
    954         if (role_ == SSL_CLIENT) {
    955           method = SSLv23_client_method();
    956         } else {
    957           method = SSLv23_server_method();
    958         }
    959 #endif
    960       }
    961       break;
    962   }
    963   ctx = SSL_CTX_new(method);
    964 #endif  // OPENSSL_IS_BORINGSSL
    965 
    966   if (ctx == NULL)
    967     return NULL;
    968 
    969 #ifdef OPENSSL_IS_BORINGSSL
    970   SSL_CTX_set_min_proto_version(ctx, ssl_mode_ == SSL_MODE_DTLS ?
    971       DTLS1_VERSION : TLS1_VERSION);
    972   switch (ssl_max_version_) {
    973     case SSL_PROTOCOL_TLS_10:
    974       SSL_CTX_set_max_proto_version(ctx, ssl_mode_ == SSL_MODE_DTLS ?
    975           DTLS1_VERSION : TLS1_VERSION);
    976       break;
    977     case SSL_PROTOCOL_TLS_11:
    978       SSL_CTX_set_max_proto_version(ctx, ssl_mode_ == SSL_MODE_DTLS ?
    979           DTLS1_VERSION : TLS1_1_VERSION);
    980       break;
    981     case SSL_PROTOCOL_TLS_12:
    982     default:
    983       SSL_CTX_set_max_proto_version(ctx, ssl_mode_ == SSL_MODE_DTLS ?
    984           DTLS1_2_VERSION : TLS1_2_VERSION);
    985       break;
    986   }
    987 #endif
    988 
    989   if (identity_ && !identity_->ConfigureIdentity(ctx)) {
    990     SSL_CTX_free(ctx);
    991     return NULL;
    992   }
    993 
    994 #if !defined(NDEBUG)
    995   SSL_CTX_set_info_callback(ctx, OpenSSLAdapter::SSLInfoCallback);
    996 #endif
    997 
    998   int mode = SSL_VERIFY_PEER;
    999   if (client_auth_enabled()) {
   1000     // Require a certificate from the client.
   1001     // Note: Normally this is always true in production, but it may be disabled
   1002     // for testing purposes (e.g. SSLAdapter unit tests).
   1003     mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
   1004   }
   1005 
   1006   SSL_CTX_set_verify(ctx, mode, SSLVerifyCallback);
   1007   SSL_CTX_set_verify_depth(ctx, 4);
   1008   // Select list of available ciphers. Note that !SHA256 and !SHA384 only
   1009   // remove HMAC-SHA256 and HMAC-SHA384 cipher suites, not GCM cipher suites
   1010   // with SHA256 or SHA384 as the handshake hash.
   1011   // This matches the list of SSLClientSocketOpenSSL in Chromium.
   1012   SSL_CTX_set_cipher_list(ctx,
   1013       "DEFAULT:!NULL:!aNULL:!SHA256:!SHA384:!aECDH:!AESGCM+AES256:!aPSK");
   1014 
   1015 #ifdef HAVE_DTLS_SRTP
   1016   if (!srtp_ciphers_.empty()) {
   1017     if (SSL_CTX_set_tlsext_use_srtp(ctx, srtp_ciphers_.c_str())) {
   1018       SSL_CTX_free(ctx);
   1019       return NULL;
   1020     }
   1021   }
   1022 #endif
   1023 
   1024   return ctx;
   1025 }
   1026 
   1027 int OpenSSLStreamAdapter::SSLVerifyCallback(int ok, X509_STORE_CTX* store) {
   1028   // Get our SSL structure from the store
   1029   SSL* ssl = reinterpret_cast<SSL*>(X509_STORE_CTX_get_ex_data(
   1030                                         store,
   1031                                         SSL_get_ex_data_X509_STORE_CTX_idx()));
   1032   OpenSSLStreamAdapter* stream =
   1033     reinterpret_cast<OpenSSLStreamAdapter*>(SSL_get_app_data(ssl));
   1034 
   1035   if (stream->peer_certificate_digest_algorithm_.empty()) {
   1036     return 0;
   1037   }
   1038   X509* cert = X509_STORE_CTX_get_current_cert(store);
   1039   int depth = X509_STORE_CTX_get_error_depth(store);
   1040 
   1041   // For now We ignore the parent certificates and verify the leaf against
   1042   // the digest.
   1043   //
   1044   // TODO(jiayl): Verify the chain is a proper chain and report the chain to
   1045   // |stream->peer_certificate_|.
   1046   if (depth > 0) {
   1047     LOG(LS_INFO) << "Ignored chained certificate at depth " << depth;
   1048     return 1;
   1049   }
   1050 
   1051   unsigned char digest[EVP_MAX_MD_SIZE];
   1052   size_t digest_length;
   1053   if (!OpenSSLCertificate::ComputeDigest(
   1054            cert,
   1055            stream->peer_certificate_digest_algorithm_,
   1056            digest, sizeof(digest),
   1057            &digest_length)) {
   1058     LOG(LS_WARNING) << "Failed to compute peer cert digest.";
   1059     return 0;
   1060   }
   1061 
   1062   Buffer computed_digest(digest, digest_length);
   1063   if (computed_digest != stream->peer_certificate_digest_value_) {
   1064     LOG(LS_WARNING) << "Rejected peer certificate due to mismatched digest.";
   1065     return 0;
   1066   }
   1067   // Ignore any verification error if the digest matches, since there is no
   1068   // value in checking the validity of a self-signed cert issued by untrusted
   1069   // sources.
   1070   LOG(LS_INFO) << "Accepted peer certificate.";
   1071 
   1072   // Record the peer's certificate.
   1073   stream->peer_certificate_.reset(new OpenSSLCertificate(cert));
   1074   return 1;
   1075 }
   1076 
   1077 // This code is taken from the "Network Security with OpenSSL"
   1078 // sample in chapter 5
   1079 bool OpenSSLStreamAdapter::SSLPostConnectionCheck(SSL* ssl,
   1080                                                   const char* server_name,
   1081                                                   const X509* peer_cert,
   1082                                                   const std::string
   1083                                                   &peer_digest) {
   1084   ASSERT(server_name != NULL);
   1085   bool ok;
   1086   if (server_name[0] != '\0') {  // traditional mode
   1087     ok = OpenSSLAdapter::VerifyServerName(ssl, server_name, ignore_bad_cert());
   1088 
   1089     if (ok) {
   1090       ok = (SSL_get_verify_result(ssl) == X509_V_OK ||
   1091             custom_verification_succeeded_);
   1092     }
   1093   } else {  // peer-to-peer mode
   1094     ASSERT((peer_cert != NULL) || (!peer_digest.empty()));
   1095     // no server name validation
   1096     ok = true;
   1097   }
   1098 
   1099   if (!ok && ignore_bad_cert()) {
   1100     LOG(LS_ERROR) << "SSL_get_verify_result(ssl) = "
   1101                   << SSL_get_verify_result(ssl);
   1102     LOG(LS_INFO) << "Other TLS post connection checks failed.";
   1103     ok = true;
   1104   }
   1105 
   1106   return ok;
   1107 }
   1108 
   1109 bool OpenSSLStreamAdapter::HaveDtls() {
   1110   return true;
   1111 }
   1112 
   1113 bool OpenSSLStreamAdapter::HaveDtlsSrtp() {
   1114 #ifdef HAVE_DTLS_SRTP
   1115   return true;
   1116 #else
   1117   return false;
   1118 #endif
   1119 }
   1120 
   1121 bool OpenSSLStreamAdapter::HaveExporter() {
   1122 #ifdef HAVE_DTLS_SRTP
   1123   return true;
   1124 #else
   1125   return false;
   1126 #endif
   1127 }
   1128 
   1129 int OpenSSLStreamAdapter::GetDefaultSslCipherForTest(SSLProtocolVersion version,
   1130                                                      KeyType key_type) {
   1131   if (key_type == KT_RSA) {
   1132     switch (version) {
   1133       case SSL_PROTOCOL_TLS_10:
   1134       case SSL_PROTOCOL_TLS_11:
   1135         return kDefaultSslCipher10;
   1136       case SSL_PROTOCOL_TLS_12:
   1137       default:
   1138 #ifdef OPENSSL_IS_BORINGSSL
   1139         if (EVP_has_aes_hardware()) {
   1140           return kDefaultSslCipher12;
   1141         } else {
   1142           return kDefaultSslCipher12NoAesGcm;
   1143         }
   1144 #else  // !OPENSSL_IS_BORINGSSL
   1145         return kDefaultSslCipher12;
   1146 #endif
   1147     }
   1148   } else if (key_type == KT_ECDSA) {
   1149     switch (version) {
   1150       case SSL_PROTOCOL_TLS_10:
   1151       case SSL_PROTOCOL_TLS_11:
   1152         return kDefaultSslEcCipher10;
   1153       case SSL_PROTOCOL_TLS_12:
   1154       default:
   1155 #ifdef OPENSSL_IS_BORINGSSL
   1156         if (EVP_has_aes_hardware()) {
   1157           return kDefaultSslEcCipher12;
   1158         } else {
   1159           return kDefaultSslEcCipher12NoAesGcm;
   1160         }
   1161 #else  // !OPENSSL_IS_BORINGSSL
   1162         return kDefaultSslEcCipher12;
   1163 #endif
   1164     }
   1165   } else {
   1166     RTC_NOTREACHED();
   1167     return kDefaultSslEcCipher12;
   1168   }
   1169 }
   1170 
   1171 }  // namespace rtc
   1172 
   1173 #endif  // HAVE_OPENSSL_SSL_H
   1174