net/socket/nss_ssl_util.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/socket/nss_ssl_util.h"
   6
   7 #include <nss.h>
   8 #include <secerr.h>
   9 #include <ssl.h>
  10 #include <sslerr.h>
  11 #include <sslproto.h>
  12
  13 #include <string>
  14
  15 #include "base/bind.h"
  16 #include "base/cpu.h"
  17 #include "base/lazy_instance.h"
  18 #include "base/logging.h"
  19 #include "base/memory/singleton.h"
  20 #include "base/threading/thread_restrictions.h"
  21 #include "base/values.h"
  22 #include "build/build_config.h"
  23 #include "crypto/nss_util.h"
  24 #include "net/base/net_errors.h"
  25 #include "net/base/nss_memio.h"
  26 #include "net/log/net_log.h"
  27
  28 #if defined(OS_WIN)
  29 #include "base/win/windows_version.h"
  30 #endif
  31
  32 namespace net {
  33
  34 namespace {
  35
  36 // CiphersRemove takes a zero-terminated array of cipher suite ids in
  37 // |to_remove| and sets every instance of them in |ciphers| to zero. It returns
  38 // true if it found and removed every element of |to_remove|. It assumes that
  39 // there are no duplicates in |ciphers| nor in |to_remove|.
  40 bool CiphersRemove(const uint16* to_remove, uint16* ciphers, size_t num) {
  41   size_t i, found = 0;
  42
  43   for (i = 0; ; i++) {
  44     if (to_remove[i] == 0)
  45       break;
  46
  47     for (size_t j = 0; j < num; j++) {
  48       if (to_remove[i] == ciphers[j]) {
  49         ciphers[j] = 0;
  50         found++;
  51         break;
  52       }
  53     }
  54   }
  55
  56   return found == i;
  57 }
  58
  59 // CiphersCompact takes an array of cipher suite ids in |ciphers|, where some
  60 // entries are zero, and moves the entries so that all the non-zero elements
  61 // are compacted at the end of the array.
  62 void CiphersCompact(uint16* ciphers, size_t num) {
  63   size_t j = num - 1;
  64
  65   for (size_t i = num - 1; i < num; i--) {
  66     if (ciphers[i] == 0)
  67       continue;
  68     ciphers[j--] = ciphers[i];
  69   }
  70 }
  71
  72 // CiphersCopy copies the zero-terminated array |in| to |out|. It returns the
  73 // number of cipher suite ids copied.
  74 size_t CiphersCopy(const uint16* in, uint16* out) {
  75   for (size_t i = 0; ; i++) {
  76     if (in[i] == 0)
  77       return i;
  78     out[i] = in[i];
  79   }
  80 }
  81
  82 base::Value* NetLogSSLErrorCallback(int net_error,
  83                                     int ssl_lib_error,
  84                                     NetLog::LogLevel /* log_level */) {
  85   base::DictionaryValue* dict = new base::DictionaryValue();
  86   dict->SetInteger("net_error", net_error);
  87   if (ssl_lib_error)
  88     dict->SetInteger("ssl_lib_error", ssl_lib_error);
  89   return dict;
  90 }
  91
  92 class NSSSSLInitSingleton {
  93  public:
  94   NSSSSLInitSingleton() : model_fd_(NULL) {
  95     crypto::EnsureNSSInit();
  96
  97     NSS_SetDomesticPolicy();
  98
  99     const PRUint16* const ssl_ciphers = SSL_GetImplementedCiphers();
 100     const PRUint16 num_ciphers = SSL_GetNumImplementedCiphers();
 101
 102     // Disable ECDSA cipher suites on platforms that do not support ECDSA
 103     // signed certificates, as servers may use the presence of such
 104     // ciphersuites as a hint to send an ECDSA certificate.
 105     bool disableECDSA = false;
 106 #if defined(OS_WIN)
 107     if (base::win::GetVersion() < base::win::VERSION_VISTA)
 108       disableECDSA = true;
 109 #endif
 110
 111     // Explicitly enable exactly those ciphers with keys of at least 80 bits.
 112     for (int i = 0; i < num_ciphers; i++) {
 113       SSLCipherSuiteInfo info;
 114       if (SSL_GetCipherSuiteInfo(ssl_ciphers[i], &info,
 115                                  sizeof(info)) == SECSuccess) {
 116         bool enabled = info.effectiveKeyBits >= 80;
 117         if (info.authAlgorithm == ssl_auth_ecdsa && disableECDSA)
 118           enabled = false;
 119
 120         // Trim the list of cipher suites in order to keep the size of the
 121         // ClientHello down. DSS, ECDH, CAMELLIA, SEED, ECC+3DES, and
 122         // HMAC-SHA256 cipher suites are disabled.
 123         if (info.symCipher == ssl_calg_camellia ||
 124             info.symCipher == ssl_calg_seed ||
 125             (info.symCipher == ssl_calg_3des && info.keaType != ssl_kea_rsa) ||
 126             info.authAlgorithm == ssl_auth_dsa ||
 127             info.macAlgorithm == ssl_hmac_sha256 ||
 128             info.nonStandard ||
 129             strcmp(info.keaTypeName, "ECDH") == 0) {
 130           enabled = false;
 131         }
 132
 133         SSL_CipherPrefSetDefault(ssl_ciphers[i], enabled);
 134       }
 135     }
 136
 137     // Enable SSL.
 138     SSL_OptionSetDefault(SSL_SECURITY, PR_TRUE);
 139
 140     // Calculate the order of ciphers that we'll use for NSS sockets. (Note
 141     // that, even if a cipher is specified in the ordering, it must still be
 142     // enabled in order to be included in a ClientHello.)
 143     //
 144     // Our top preference cipher suites are either forward-secret AES-GCM or
 145     // forward-secret ChaCha20-Poly1305. If the local machine has AES-NI then
 146     // we prefer AES-GCM, otherwise ChaCha20. The remainder of the cipher suite
 147     // preference is inheriented from NSS. */
 148     static const uint16 chacha_ciphers[] = {
 149       TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
 150       TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
 151       0,
 152     };
 153     static const uint16 aes_gcm_ciphers[] = {
 154       TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
 155       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
 156       TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,
 157       0,
 158     };
 159     scoped_ptr<uint16[]> ciphers(new uint16[num_ciphers]);
 160     memcpy(ciphers.get(), ssl_ciphers, sizeof(uint16)*num_ciphers);
 161
 162     if (CiphersRemove(chacha_ciphers, ciphers.get(), num_ciphers) &&
 163         CiphersRemove(aes_gcm_ciphers, ciphers.get(), num_ciphers)) {
 164       CiphersCompact(ciphers.get(), num_ciphers);
 165
 166       const uint16* preference_ciphers = chacha_ciphers;
 167       const uint16* other_ciphers = aes_gcm_ciphers;
 168       base::CPU cpu;
 169
 170       if (cpu.has_aesni() && cpu.has_avx()) {
 171         preference_ciphers = aes_gcm_ciphers;
 172         other_ciphers = chacha_ciphers;
 173       }
 174       unsigned i = CiphersCopy(preference_ciphers, ciphers.get());
 175       CiphersCopy(other_ciphers, &ciphers[i]);
 176
 177       if ((model_fd_ = memio_CreateIOLayer(1, 1)) == NULL ||
 178           SSL_ImportFD(NULL, model_fd_) == NULL ||
 179           SECSuccess !=
 180               SSL_CipherOrderSet(model_fd_, ciphers.get(), num_ciphers)) {
 181         NOTREACHED();
 182         if (model_fd_) {
 183           PR_Close(model_fd_);
 184           model_fd_ = NULL;
 185         }
 186       }
 187     }
 188
 189     // All other SSL options are set per-session by SSLClientSocket and
 190     // SSLServerSocket.
 191   }
 192
 193   PRFileDesc* GetModelSocket() {
 194     return model_fd_;
 195   }
 196
 197   ~NSSSSLInitSingleton() {
 198     // Have to clear the cache, or NSS_Shutdown fails with SEC_ERROR_BUSY.
 199     SSL_ClearSessionCache();
 200     if (model_fd_)
 201       PR_Close(model_fd_);
 202   }
 203
 204  private:
 205   PRFileDesc* model_fd_;
 206 };
 207
 208 base::LazyInstance<NSSSSLInitSingleton>::Leaky g_nss_ssl_init_singleton =
 209     LAZY_INSTANCE_INITIALIZER;
 210
 211 }  // anonymous namespace
 212
 213 // Initialize the NSS SSL library if it isn't already initialized.  This must
 214 // be called before any other NSS SSL functions.  This function is
 215 // thread-safe, and the NSS SSL library will only ever be initialized once.
 216 // The NSS SSL library will be properly shut down on program exit.
 217 void EnsureNSSSSLInit() {
 218   // Initializing SSL causes us to do blocking IO.
 219   // Temporarily allow it until we fix
 220   //   http://code.google.com/p/chromium/issues/detail?id=59847
 221   base::ThreadRestrictions::ScopedAllowIO allow_io;
 222
 223   g_nss_ssl_init_singleton.Get();
 224 }
 225
 226 PRFileDesc* GetNSSModelSocket() {
 227   return g_nss_ssl_init_singleton.Get().GetModelSocket();
 228 }
 229
 230 // Map a Chromium net error code to an NSS error code.
 231 // See _MD_unix_map_default_error in the NSS source
 232 // tree for inspiration.
 233 PRErrorCode MapErrorToNSS(int result) {
 234   if (result >=0)
 235     return result;
 236
 237   switch (result) {
 238     case ERR_IO_PENDING:
 239       return PR_WOULD_BLOCK_ERROR;
 240     case ERR_ACCESS_DENIED:
 241     case ERR_NETWORK_ACCESS_DENIED:
 242       // For connect, this could be mapped to PR_ADDRESS_NOT_SUPPORTED_ERROR.
 243       return PR_NO_ACCESS_RIGHTS_ERROR;
 244     case ERR_NOT_IMPLEMENTED:
 245       return PR_NOT_IMPLEMENTED_ERROR;
 246     case ERR_SOCKET_NOT_CONNECTED:
 247       return PR_NOT_CONNECTED_ERROR;
 248     case ERR_INTERNET_DISCONNECTED:  // Equivalent to ENETDOWN.
 249       return PR_NETWORK_UNREACHABLE_ERROR;  // Best approximation.
 250     case ERR_CONNECTION_TIMED_OUT:
 251     case ERR_TIMED_OUT:
 252       return PR_IO_TIMEOUT_ERROR;
 253     case ERR_CONNECTION_RESET:
 254       return PR_CONNECT_RESET_ERROR;
 255     case ERR_CONNECTION_ABORTED:
 256       return PR_CONNECT_ABORTED_ERROR;
 257     case ERR_CONNECTION_REFUSED:
 258       return PR_CONNECT_REFUSED_ERROR;
 259     case ERR_ADDRESS_UNREACHABLE:
 260       return PR_HOST_UNREACHABLE_ERROR;  // Also PR_NETWORK_UNREACHABLE_ERROR.
 261     case ERR_ADDRESS_INVALID:
 262       return PR_ADDRESS_NOT_AVAILABLE_ERROR;
 263     case ERR_NAME_NOT_RESOLVED:
 264       return PR_DIRECTORY_LOOKUP_ERROR;
 265     default:
 266       LOG(WARNING) << "MapErrorToNSS " << result
 267                    << " mapped to PR_UNKNOWN_ERROR";
 268       return PR_UNKNOWN_ERROR;
 269   }
 270 }
 271
 272 // The default error mapping function.
 273 // Maps an NSS error code to a network error code.
 274 int MapNSSError(PRErrorCode err) {
 275   // TODO(port): fill this out as we learn what's important
 276   switch (err) {
 277     case PR_WOULD_BLOCK_ERROR:
 278       return ERR_IO_PENDING;
 279     case PR_ADDRESS_NOT_SUPPORTED_ERROR:  // For connect.
 280     case PR_NO_ACCESS_RIGHTS_ERROR:
 281       return ERR_ACCESS_DENIED;
 282     case PR_IO_TIMEOUT_ERROR:
 283       return ERR_TIMED_OUT;
 284     case PR_CONNECT_RESET_ERROR:
 285       return ERR_CONNECTION_RESET;
 286     case PR_CONNECT_ABORTED_ERROR:
 287       return ERR_CONNECTION_ABORTED;
 288     case PR_CONNECT_REFUSED_ERROR:
 289       return ERR_CONNECTION_REFUSED;
 290     case PR_NOT_CONNECTED_ERROR:
 291       return ERR_SOCKET_NOT_CONNECTED;
 292     case PR_HOST_UNREACHABLE_ERROR:
 293     case PR_NETWORK_UNREACHABLE_ERROR:
 294       return ERR_ADDRESS_UNREACHABLE;
 295     case PR_ADDRESS_NOT_AVAILABLE_ERROR:
 296       return ERR_ADDRESS_INVALID;
 297     case PR_INVALID_ARGUMENT_ERROR:
 298       return ERR_INVALID_ARGUMENT;
 299     case PR_END_OF_FILE_ERROR:
 300       return ERR_CONNECTION_CLOSED;
 301     case PR_NOT_IMPLEMENTED_ERROR:
 302       return ERR_NOT_IMPLEMENTED;
 303
 304     case SEC_ERROR_LIBRARY_FAILURE:
 305       return ERR_UNEXPECTED;
 306     case SEC_ERROR_INVALID_ARGS:
 307       return ERR_INVALID_ARGUMENT;
 308     case SEC_ERROR_NO_MEMORY:
 309       return ERR_OUT_OF_MEMORY;
 310     case SEC_ERROR_NO_KEY:
 311       return ERR_SSL_CLIENT_AUTH_CERT_NO_PRIVATE_KEY;
 312     case SEC_ERROR_INVALID_KEY:
 313     case SSL_ERROR_SIGN_HASHES_FAILURE:
 314       LOG(ERROR) << "ERR_SSL_CLIENT_AUTH_SIGNATURE_FAILED: NSS error " << err
 315                  << ", OS error " << PR_GetOSError();
 316       return ERR_SSL_CLIENT_AUTH_SIGNATURE_FAILED;
 317     // A handshake (initial or renegotiation) may fail because some signature
 318     // (for example, the signature in the ServerKeyExchange message for an
 319     // ephemeral Diffie-Hellman cipher suite) is invalid.
 320     case SEC_ERROR_BAD_SIGNATURE:
 321       return ERR_SSL_PROTOCOL_ERROR;
 322
 323     case SSL_ERROR_SSL_DISABLED:
 324       return ERR_NO_SSL_VERSIONS_ENABLED;
 325     case SSL_ERROR_NO_CYPHER_OVERLAP:
 326     case SSL_ERROR_PROTOCOL_VERSION_ALERT:
 327     case SSL_ERROR_UNSUPPORTED_VERSION:
 328       return ERR_SSL_VERSION_OR_CIPHER_MISMATCH;
 329     case SSL_ERROR_HANDSHAKE_FAILURE_ALERT:
 330     case SSL_ERROR_HANDSHAKE_UNEXPECTED_ALERT:
 331     case SSL_ERROR_ILLEGAL_PARAMETER_ALERT:
 332       return ERR_SSL_PROTOCOL_ERROR;
 333     case SSL_ERROR_DECOMPRESSION_FAILURE_ALERT:
 334       return ERR_SSL_DECOMPRESSION_FAILURE_ALERT;
 335     case SSL_ERROR_BAD_MAC_ALERT:
 336       return ERR_SSL_BAD_RECORD_MAC_ALERT;
 337     case SSL_ERROR_DECRYPT_ERROR_ALERT:
 338       return ERR_SSL_DECRYPT_ERROR_ALERT;
 339     case SSL_ERROR_UNRECOGNIZED_NAME_ALERT:
 340       return ERR_SSL_UNRECOGNIZED_NAME_ALERT;
 341     case SSL_ERROR_UNSAFE_NEGOTIATION:
 342       return ERR_SSL_UNSAFE_NEGOTIATION;
 343     case SSL_ERROR_WEAK_SERVER_EPHEMERAL_DH_KEY:
 344       return ERR_SSL_WEAK_SERVER_EPHEMERAL_DH_KEY;
 345     case SSL_ERROR_HANDSHAKE_NOT_COMPLETED:
 346       return ERR_SSL_HANDSHAKE_NOT_COMPLETED;
 347     case SEC_ERROR_BAD_KEY:
 348     case SSL_ERROR_EXTRACT_PUBLIC_KEY_FAILURE:
 349     // TODO(wtc): the following errors may also occur in contexts unrelated
 350     // to the peer's public key.  We should add new error codes for them, or
 351     // map them to ERR_SSL_BAD_PEER_PUBLIC_KEY only in the right context.
 352     // General unsupported/unknown key algorithm error.
 353     case SEC_ERROR_UNSUPPORTED_KEYALG:
 354     // General DER decoding errors.
 355     case SEC_ERROR_BAD_DER:
 356     case SEC_ERROR_EXTRA_INPUT:
 357       return ERR_SSL_BAD_PEER_PUBLIC_KEY;
 358     // During renegotiation, the server presented a different certificate than
 359     // was used earlier.
 360     case SSL_ERROR_WRONG_CERTIFICATE:
 361       return ERR_SSL_SERVER_CERT_CHANGED;
 362     case SSL_ERROR_INAPPROPRIATE_FALLBACK_ALERT:
 363       return ERR_SSL_INAPPROPRIATE_FALLBACK;
 364
 365     default: {
 366       const char* err_name = PR_ErrorToName(err);
 367       if (err_name == NULL)
 368         err_name = "";
 369       if (IS_SSL_ERROR(err)) {
 370         LOG(WARNING) << "Unknown SSL error " << err << " (" << err_name << ")"
 371                      << " mapped to net::ERR_SSL_PROTOCOL_ERROR";
 372         return ERR_SSL_PROTOCOL_ERROR;
 373       }
 374       LOG(WARNING) << "Unknown error " << err << " (" << err_name << ")"
 375                    << " mapped to net::ERR_FAILED";
 376       return ERR_FAILED;
 377     }
 378   }
 379 }
 380
 381 // Returns parameters to attach to the NetLog when we receive an error in
 382 // response to a call to an NSS function.  Used instead of
 383 // NetLogSSLErrorCallback with events of type TYPE_SSL_NSS_ERROR.
 384 base::Value* NetLogSSLFailedNSSFunctionCallback(
 385     const char* function,
 386     const char* param,
 387     int ssl_lib_error,
 388     NetLog::LogLevel /* log_level */) {
 389   base::DictionaryValue* dict = new base::DictionaryValue();
 390   dict->SetString("function", function);
 391   if (param[0] != '\0')
 392     dict->SetString("param", param);
 393   dict->SetInteger("ssl_lib_error", ssl_lib_error);
 394   return dict;
 395 }
 396
 397 void LogFailedNSSFunction(const BoundNetLog& net_log,
 398                           const char* function,
 399                           const char* param) {
 400   DCHECK(function);
 401   DCHECK(param);
 402   net_log.AddEvent(
 403       NetLog::TYPE_SSL_NSS_ERROR,
 404       base::Bind(&NetLogSSLFailedNSSFunctionCallback,
 405                  function, param, PR_GetError()));
 406 }
 407
 408 NetLog::ParametersCallback CreateNetLogSSLErrorCallback(int net_error,
 409                                                         int ssl_lib_error) {
 410   return base::Bind(&NetLogSSLErrorCallback, net_error, ssl_lib_error);
 411 }
 412
 413 }  // namespace net