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