Torne (Richard Coles) | 5821806 | 2012-11-14 11:43:16 +0000 | [diff] [blame] | 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 "crypto/ec_private_key.h" |
| 6 | |
| 7 | extern "C" { |
| 8 | // Work around NSS missing SEC_BEGIN_PROTOS in secmodt.h. This must come before |
| 9 | // other NSS headers. |
| 10 | #include <secmodt.h> |
| 11 | } |
| 12 | |
| 13 | #include <cryptohi.h> |
| 14 | #include <keyhi.h> |
| 15 | #include <pk11pub.h> |
| 16 | #include <secmod.h> |
| 17 | |
| 18 | #include "base/lazy_instance.h" |
| 19 | #include "base/logging.h" |
| 20 | #include "base/memory/scoped_ptr.h" |
| 21 | #include "crypto/nss_util.h" |
| 22 | #include "crypto/nss_util_internal.h" |
| 23 | #include "crypto/scoped_nss_types.h" |
| 24 | #include "crypto/third_party/nss/chromium-nss.h" |
| 25 | |
| 26 | namespace { |
| 27 | |
| 28 | PK11SlotInfo* GetKeySlot() { |
| 29 | return crypto::GetPublicNSSKeySlot(); |
| 30 | } |
| 31 | |
| 32 | class EllipticCurveSupportChecker { |
| 33 | public: |
| 34 | EllipticCurveSupportChecker() { |
| 35 | // NOTE: we can do this check here only because we use the NSS internal |
| 36 | // slot. If we support other slots in the future, checking whether they |
| 37 | // support ECDSA may block NSS, and the value may also change as devices are |
| 38 | // inserted/removed, so we would need to re-check on every use. |
| 39 | crypto::EnsureNSSInit(); |
| 40 | crypto::ScopedPK11Slot slot(GetKeySlot()); |
| 41 | supported_ = PK11_DoesMechanism(slot.get(), CKM_EC_KEY_PAIR_GEN) && |
| 42 | PK11_DoesMechanism(slot.get(), CKM_ECDSA); |
| 43 | } |
| 44 | |
| 45 | bool Supported() { |
| 46 | return supported_; |
| 47 | } |
| 48 | |
| 49 | private: |
| 50 | bool supported_; |
| 51 | }; |
| 52 | |
| 53 | static base::LazyInstance<EllipticCurveSupportChecker>::Leaky |
| 54 | g_elliptic_curve_supported = LAZY_INSTANCE_INITIALIZER; |
| 55 | |
| 56 | // Copied from rsa_private_key_nss.cc. |
| 57 | static bool ReadAttribute(SECKEYPrivateKey* key, |
| 58 | CK_ATTRIBUTE_TYPE type, |
| 59 | std::vector<uint8>* output) { |
| 60 | SECItem item; |
| 61 | SECStatus rv; |
| 62 | rv = PK11_ReadRawAttribute(PK11_TypePrivKey, key, type, &item); |
| 63 | if (rv != SECSuccess) { |
| 64 | DLOG(ERROR) << "PK11_ReadRawAttribute: " << PORT_GetError(); |
| 65 | return false; |
| 66 | } |
| 67 | |
| 68 | output->assign(item.data, item.data + item.len); |
| 69 | SECITEM_FreeItem(&item, PR_FALSE); |
| 70 | return true; |
| 71 | } |
| 72 | |
| 73 | } // namespace |
| 74 | |
| 75 | namespace crypto { |
| 76 | |
| 77 | ECPrivateKey::~ECPrivateKey() { |
| 78 | if (key_) |
| 79 | SECKEY_DestroyPrivateKey(key_); |
| 80 | if (public_key_) |
| 81 | SECKEY_DestroyPublicKey(public_key_); |
| 82 | } |
| 83 | |
| 84 | // static |
| 85 | bool ECPrivateKey::IsSupported() { |
| 86 | return g_elliptic_curve_supported.Get().Supported(); |
| 87 | } |
| 88 | |
| 89 | // static |
| 90 | ECPrivateKey* ECPrivateKey::Create() { |
| 91 | return CreateWithParams(PR_FALSE /* not permanent */, |
| 92 | PR_FALSE /* not sensitive */); |
| 93 | } |
| 94 | |
| 95 | // static |
| 96 | ECPrivateKey* ECPrivateKey::CreateSensitive() { |
| 97 | #if defined(USE_NSS) |
| 98 | return CreateWithParams(PR_TRUE /* permanent */, |
| 99 | PR_TRUE /* sensitive */); |
| 100 | #else |
| 101 | // If USE_NSS is not defined, we initialize NSS with no databases, so we can't |
| 102 | // create permanent keys. |
| 103 | NOTREACHED(); |
| 104 | return NULL; |
| 105 | #endif |
| 106 | } |
| 107 | |
| 108 | // static |
| 109 | ECPrivateKey* ECPrivateKey::CreateFromEncryptedPrivateKeyInfo( |
| 110 | const std::string& password, |
| 111 | const std::vector<uint8>& encrypted_private_key_info, |
| 112 | const std::vector<uint8>& subject_public_key_info) { |
| 113 | return CreateFromEncryptedPrivateKeyInfoWithParams( |
| 114 | password, |
| 115 | encrypted_private_key_info, |
| 116 | subject_public_key_info, |
| 117 | PR_FALSE /* not permanent */, |
| 118 | PR_FALSE /* not sensitive */); |
| 119 | } |
| 120 | |
| 121 | // static |
| 122 | ECPrivateKey* ECPrivateKey::CreateSensitiveFromEncryptedPrivateKeyInfo( |
| 123 | const std::string& password, |
| 124 | const std::vector<uint8>& encrypted_private_key_info, |
| 125 | const std::vector<uint8>& subject_public_key_info) { |
| 126 | #if defined(USE_NSS) |
| 127 | return CreateFromEncryptedPrivateKeyInfoWithParams( |
| 128 | password, |
| 129 | encrypted_private_key_info, |
| 130 | subject_public_key_info, |
| 131 | PR_TRUE /* permanent */, |
| 132 | PR_TRUE /* sensitive */); |
| 133 | #else |
| 134 | // If USE_NSS is not defined, we initialize NSS with no databases, so we can't |
| 135 | // create permanent keys. |
| 136 | NOTREACHED(); |
| 137 | return NULL; |
| 138 | #endif |
| 139 | } |
| 140 | |
| 141 | // static |
| 142 | bool ECPrivateKey::ImportFromEncryptedPrivateKeyInfo( |
| 143 | const std::string& password, |
| 144 | const uint8* encrypted_private_key_info, |
| 145 | size_t encrypted_private_key_info_len, |
| 146 | CERTSubjectPublicKeyInfo* decoded_spki, |
| 147 | bool permanent, |
| 148 | bool sensitive, |
| 149 | SECKEYPrivateKey** key, |
| 150 | SECKEYPublicKey** public_key) { |
| 151 | ScopedPK11Slot slot(GetKeySlot()); |
| 152 | if (!slot.get()) |
| 153 | return false; |
| 154 | |
| 155 | *public_key = SECKEY_ExtractPublicKey(decoded_spki); |
| 156 | |
| 157 | if (!*public_key) { |
| 158 | DLOG(ERROR) << "SECKEY_ExtractPublicKey: " << PORT_GetError(); |
| 159 | return false; |
| 160 | } |
| 161 | |
| 162 | SECItem encoded_epki = { |
| 163 | siBuffer, |
| 164 | const_cast<unsigned char*>(encrypted_private_key_info), |
| 165 | static_cast<unsigned>(encrypted_private_key_info_len) |
| 166 | }; |
| 167 | SECKEYEncryptedPrivateKeyInfo epki; |
| 168 | memset(&epki, 0, sizeof(epki)); |
| 169 | |
| 170 | ScopedPLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE)); |
| 171 | |
| 172 | SECStatus rv = SEC_QuickDERDecodeItem( |
| 173 | arena.get(), |
| 174 | &epki, |
| 175 | SEC_ASN1_GET(SECKEY_EncryptedPrivateKeyInfoTemplate), |
| 176 | &encoded_epki); |
| 177 | if (rv != SECSuccess) { |
| 178 | DLOG(ERROR) << "SEC_QuickDERDecodeItem: " << PORT_GetError(); |
| 179 | SECKEY_DestroyPublicKey(*public_key); |
| 180 | *public_key = NULL; |
| 181 | return false; |
| 182 | } |
| 183 | |
| 184 | SECItem password_item = { |
| 185 | siBuffer, |
| 186 | reinterpret_cast<unsigned char*>(const_cast<char*>(password.data())), |
| 187 | static_cast<unsigned>(password.size()) |
| 188 | }; |
| 189 | |
| 190 | rv = ImportEncryptedECPrivateKeyInfoAndReturnKey( |
| 191 | slot.get(), |
| 192 | &epki, |
| 193 | &password_item, |
| 194 | NULL, // nickname |
| 195 | &(*public_key)->u.ec.publicValue, |
| 196 | permanent, |
| 197 | sensitive, |
| 198 | key, |
| 199 | NULL); // wincx |
| 200 | if (rv != SECSuccess) { |
| 201 | DLOG(ERROR) << "ImportEncryptedECPrivateKeyInfoAndReturnKey: " |
| 202 | << PORT_GetError(); |
| 203 | SECKEY_DestroyPublicKey(*public_key); |
| 204 | *public_key = NULL; |
| 205 | return false; |
| 206 | } |
| 207 | |
| 208 | return true; |
| 209 | } |
| 210 | |
| 211 | bool ECPrivateKey::ExportEncryptedPrivateKey( |
| 212 | const std::string& password, |
| 213 | int iterations, |
| 214 | std::vector<uint8>* output) { |
| 215 | // We export as an EncryptedPrivateKeyInfo bundle instead of a plain PKCS #8 |
| 216 | // PrivateKeyInfo because PK11_ImportDERPrivateKeyInfoAndReturnKey doesn't |
| 217 | // support EC keys. |
| 218 | // https://bugzilla.mozilla.org/show_bug.cgi?id=327773 |
| 219 | SECItem password_item = { |
| 220 | siBuffer, |
| 221 | reinterpret_cast<unsigned char*>(const_cast<char*>(password.data())), |
| 222 | static_cast<unsigned>(password.size()) |
| 223 | }; |
| 224 | |
| 225 | SECKEYEncryptedPrivateKeyInfo* encrypted = PK11_ExportEncryptedPrivKeyInfo( |
| 226 | NULL, // Slot, optional. |
| 227 | SEC_OID_PKCS12_V2_PBE_WITH_SHA1_AND_3KEY_TRIPLE_DES_CBC, |
| 228 | &password_item, |
| 229 | key_, |
| 230 | iterations, |
| 231 | NULL); // wincx. |
| 232 | |
| 233 | if (!encrypted) { |
| 234 | DLOG(ERROR) << "PK11_ExportEncryptedPrivKeyInfo: " << PORT_GetError(); |
| 235 | return false; |
| 236 | } |
| 237 | |
| 238 | ScopedPLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE)); |
| 239 | SECItem der_key = {siBuffer, NULL, 0}; |
| 240 | SECItem* encoded_item = SEC_ASN1EncodeItem( |
| 241 | arena.get(), |
| 242 | &der_key, |
| 243 | encrypted, |
| 244 | SEC_ASN1_GET(SECKEY_EncryptedPrivateKeyInfoTemplate)); |
| 245 | SECKEY_DestroyEncryptedPrivateKeyInfo(encrypted, PR_TRUE); |
| 246 | if (!encoded_item) { |
| 247 | DLOG(ERROR) << "SEC_ASN1EncodeItem: " << PORT_GetError(); |
| 248 | return false; |
| 249 | } |
| 250 | |
| 251 | output->assign(der_key.data, der_key.data + der_key.len); |
| 252 | |
| 253 | return true; |
| 254 | } |
| 255 | |
| 256 | bool ECPrivateKey::ExportPublicKey(std::vector<uint8>* output) { |
| 257 | ScopedSECItem der_pubkey( |
| 258 | SECKEY_EncodeDERSubjectPublicKeyInfo(public_key_)); |
| 259 | if (!der_pubkey.get()) { |
| 260 | return false; |
| 261 | } |
| 262 | |
| 263 | output->assign(der_pubkey->data, der_pubkey->data + der_pubkey->len); |
| 264 | return true; |
| 265 | } |
| 266 | |
| 267 | bool ECPrivateKey::ExportValue(std::vector<uint8>* output) { |
| 268 | return ReadAttribute(key_, CKA_VALUE, output); |
| 269 | } |
| 270 | |
| 271 | bool ECPrivateKey::ExportECParams(std::vector<uint8>* output) { |
| 272 | return ReadAttribute(key_, CKA_EC_PARAMS, output); |
| 273 | } |
| 274 | |
| 275 | ECPrivateKey::ECPrivateKey() : key_(NULL), public_key_(NULL) {} |
| 276 | |
| 277 | // static |
| 278 | ECPrivateKey* ECPrivateKey::CreateWithParams(bool permanent, |
| 279 | bool sensitive) { |
| 280 | EnsureNSSInit(); |
| 281 | |
| 282 | scoped_ptr<ECPrivateKey> result(new ECPrivateKey); |
| 283 | |
| 284 | ScopedPK11Slot slot(GetKeySlot()); |
| 285 | if (!slot.get()) |
| 286 | return NULL; |
| 287 | |
| 288 | SECOidData* oid_data = SECOID_FindOIDByTag(SEC_OID_SECG_EC_SECP256R1); |
| 289 | if (!oid_data) { |
| 290 | DLOG(ERROR) << "SECOID_FindOIDByTag: " << PORT_GetError(); |
| 291 | return NULL; |
| 292 | } |
| 293 | |
| 294 | // SECKEYECParams is a SECItem containing the DER encoded ASN.1 ECParameters |
| 295 | // value. For a named curve, that is just the OBJECT IDENTIFIER of the curve. |
| 296 | // In addition to the oid data, the encoding requires one byte for the ASN.1 |
| 297 | // tag and one byte for the length (assuming the length is <= 127). |
| 298 | DCHECK_LE(oid_data->oid.len, 127U); |
| 299 | std::vector<unsigned char> parameters_buf(2 + oid_data->oid.len); |
| 300 | SECKEYECParams ec_parameters = { |
| 301 | siDEROID, ¶meters_buf[0], |
| 302 | static_cast<unsigned>(parameters_buf.size()) |
| 303 | }; |
| 304 | |
| 305 | ec_parameters.data[0] = SEC_ASN1_OBJECT_ID; |
| 306 | ec_parameters.data[1] = oid_data->oid.len; |
| 307 | memcpy(ec_parameters.data + 2, oid_data->oid.data, oid_data->oid.len); |
| 308 | |
| 309 | result->key_ = PK11_GenerateKeyPair(slot.get(), |
| 310 | CKM_EC_KEY_PAIR_GEN, |
| 311 | &ec_parameters, |
| 312 | &result->public_key_, |
| 313 | permanent, |
| 314 | sensitive, |
| 315 | NULL); |
| 316 | if (!result->key_) { |
| 317 | DLOG(ERROR) << "PK11_GenerateKeyPair: " << PORT_GetError(); |
| 318 | return NULL; |
| 319 | } |
| 320 | |
| 321 | return result.release(); |
| 322 | } |
| 323 | |
| 324 | // static |
| 325 | ECPrivateKey* ECPrivateKey::CreateFromEncryptedPrivateKeyInfoWithParams( |
| 326 | const std::string& password, |
| 327 | const std::vector<uint8>& encrypted_private_key_info, |
| 328 | const std::vector<uint8>& subject_public_key_info, |
| 329 | bool permanent, |
| 330 | bool sensitive) { |
| 331 | EnsureNSSInit(); |
| 332 | |
| 333 | scoped_ptr<ECPrivateKey> result(new ECPrivateKey); |
| 334 | |
| 335 | SECItem encoded_spki = { |
| 336 | siBuffer, |
| 337 | const_cast<unsigned char*>(&subject_public_key_info[0]), |
| 338 | static_cast<unsigned>(subject_public_key_info.size()) |
| 339 | }; |
| 340 | CERTSubjectPublicKeyInfo* decoded_spki = SECKEY_DecodeDERSubjectPublicKeyInfo( |
| 341 | &encoded_spki); |
| 342 | if (!decoded_spki) { |
| 343 | DLOG(ERROR) << "SECKEY_DecodeDERSubjectPublicKeyInfo: " << PORT_GetError(); |
| 344 | return NULL; |
| 345 | } |
| 346 | |
| 347 | bool success = ECPrivateKey::ImportFromEncryptedPrivateKeyInfo( |
| 348 | password, |
| 349 | &encrypted_private_key_info[0], |
| 350 | encrypted_private_key_info.size(), |
| 351 | decoded_spki, |
| 352 | permanent, |
| 353 | sensitive, |
| 354 | &result->key_, |
| 355 | &result->public_key_); |
| 356 | |
| 357 | SECKEY_DestroySubjectPublicKeyInfo(decoded_spki); |
| 358 | |
| 359 | if (success) |
| 360 | return result.release(); |
| 361 | |
| 362 | return NULL; |
| 363 | } |
| 364 | |
| 365 | } // namespace crypto |