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author | Kristian Monsen <kristianm@google.com> | 2011-06-28 21:49:31 +0100 |
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committer | Kristian Monsen <kristianm@google.com> | 2011-07-08 17:55:00 +0100 |
commit | ddb351dbec246cf1fab5ec20d2d5520909041de1 (patch) | |
tree | 158e3fb57bdcac07c7f1e767fde3c70687c9fbb1 /crypto/symmetric_key_mac.cc | |
parent | 6b92e04f5f151c896e3088e86f70db7081009308 (diff) | |
download | external_chromium-ddb351dbec246cf1fab5ec20d2d5520909041de1.zip external_chromium-ddb351dbec246cf1fab5ec20d2d5520909041de1.tar.gz external_chromium-ddb351dbec246cf1fab5ec20d2d5520909041de1.tar.bz2 |
Merge Chromium at r12.0.742.93: Initial merge by git
Change-Id: Ic5ee2fec31358bbee305f7e915442377bfa6cda6
Diffstat (limited to 'crypto/symmetric_key_mac.cc')
-rw-r--r-- | crypto/symmetric_key_mac.cc | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/crypto/symmetric_key_mac.cc b/crypto/symmetric_key_mac.cc new file mode 100644 index 0000000..47193a0 --- /dev/null +++ b/crypto/symmetric_key_mac.cc @@ -0,0 +1,155 @@ +// Copyright (c) 2011 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "crypto/symmetric_key.h" + +#include <CommonCrypto/CommonCryptor.h> +#include <CoreFoundation/CFString.h> +#include <Security/cssm.h> + +#include "base/logging.h" +#include "crypto/cssm_init.h" + +namespace { + +CSSM_KEY_TYPE CheckKeyParams(crypto::SymmetricKey::Algorithm algorithm, + size_t key_size_in_bits) { + if (algorithm == crypto::SymmetricKey::AES) { + CHECK(key_size_in_bits == 128 || + key_size_in_bits == 192 || + key_size_in_bits == 256) + << "Invalid key size " << key_size_in_bits << " bits"; + return CSSM_ALGID_AES; + } else { + // FIPS 198 Section 3 requires a HMAC-SHA-1 derived keys to be at least + // (HMAC-SHA-1 output size / 2) to be compliant. Since the ouput size of + // HMAC-SHA-1 is 160 bits, we require at least 80 bits here. + CHECK(algorithm == crypto::SymmetricKey::HMAC_SHA1); + CHECK(key_size_in_bits >= 80 && (key_size_in_bits % 8) == 0) + << "Invalid key size " << key_size_in_bits << " bits"; + return CSSM_ALGID_SHA1HMAC_LEGACY; + } +} + +void* CreateRandomBytes(size_t size) { + CSSM_RETURN err; + CSSM_CC_HANDLE ctx; + err = CSSM_CSP_CreateRandomGenContext(crypto::GetSharedCSPHandle(), + CSSM_ALGID_APPLE_YARROW, + NULL, + size, &ctx); + if (err) { + crypto::LogCSSMError("CSSM_CSP_CreateRandomGenContext", err); + return NULL; + } + CSSM_DATA random_data = {}; + err = CSSM_GenerateRandom(ctx, &random_data); + if (err) { + crypto::LogCSSMError("CSSM_GenerateRandom", err); + random_data.Data = NULL; + } + CSSM_DeleteContext(ctx); + return random_data.Data; // Caller responsible for freeing this +} + +inline CSSM_DATA StringToData(const std::string& str) { + CSSM_DATA data = { + str.size(), + reinterpret_cast<uint8_t*>(const_cast<char*>(str.data())) + }; + return data; +} + +} // namespace + +namespace crypto { + +SymmetricKey::~SymmetricKey() {} + +// static +SymmetricKey* SymmetricKey::GenerateRandomKey(Algorithm algorithm, + size_t key_size_in_bits) { + CheckKeyParams(algorithm, key_size_in_bits); + void* random_bytes = CreateRandomBytes((key_size_in_bits + 7) / 8); + if (!random_bytes) + return NULL; + SymmetricKey *key = new SymmetricKey(random_bytes, key_size_in_bits); + free(random_bytes); + return key; +} + +// static +SymmetricKey* SymmetricKey::DeriveKeyFromPassword(Algorithm algorithm, + const std::string& password, + const std::string& salt, + size_t iterations, + size_t key_size_in_bits) { + // Derived (haha) from cdsaDeriveKey() in Apple's CryptoSample. + CSSM_KEY_TYPE key_type = CheckKeyParams(algorithm, key_size_in_bits); + SymmetricKey* derived_key = NULL; + CSSM_KEY cssm_key = {}; + + CSSM_CC_HANDLE ctx = 0; + CSSM_ACCESS_CREDENTIALS credentials = {}; + CSSM_RETURN err; + CSSM_DATA salt_data = StringToData(salt); + err = CSSM_CSP_CreateDeriveKeyContext(GetSharedCSPHandle(), + CSSM_ALGID_PKCS5_PBKDF2, + key_type, key_size_in_bits, + &credentials, + NULL, + iterations, + &salt_data, + NULL, + &ctx); + if (err) { + LogCSSMError("CSSM_CSP_CreateDeriveKeyContext", err); + return NULL; + } + + CSSM_PKCS5_PBKDF2_PARAMS params = {}; + params.Passphrase = StringToData(password); + params.PseudoRandomFunction = CSSM_PKCS5_PBKDF2_PRF_HMAC_SHA1; + CSSM_DATA param_data = {sizeof(params), reinterpret_cast<uint8_t*>(¶ms)}; + err = CSSM_DeriveKey(ctx, + ¶m_data, + CSSM_KEYUSE_ANY, + CSSM_KEYATTR_RETURN_DATA | CSSM_KEYATTR_EXTRACTABLE, + NULL, + NULL, + &cssm_key); + if (err) { + LogCSSMError("CSSM_DeriveKey", err); + goto exit; + } + + DCHECK_EQ(cssm_key.KeyData.Length, key_size_in_bits / 8); + derived_key = new SymmetricKey(cssm_key.KeyData.Data, key_size_in_bits); + + exit: + CSSM_DeleteContext(ctx); + CSSM_FreeKey(GetSharedCSPHandle(), &credentials, &cssm_key, false); + return derived_key; +} + +// static +SymmetricKey* SymmetricKey::Import(Algorithm algorithm, + const std::string& raw_key) { + return new SymmetricKey(raw_key.data(), raw_key.size() * 8); +} + +SymmetricKey::SymmetricKey(const void *key_data, size_t key_size_in_bits) + : key_(reinterpret_cast<const char*>(key_data), + key_size_in_bits / 8) {} + +bool SymmetricKey::GetRawKey(std::string* raw_key) { + *raw_key = key_; + return true; +} + +CSSM_DATA SymmetricKey::cssm_data() const { + return StringToData(key_); +} + +} // namespace crypto |