Index: base/hmac_win.cc |
=================================================================== |
--- base/hmac_win.cc (revision 81350) |
+++ base/hmac_win.cc (working copy) |
@@ -1,197 +0,0 @@ |
-// Copyright (c) 2010 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 "base/hmac.h" |
- |
-#include <windows.h> |
-#include <wincrypt.h> |
- |
-#include <algorithm> |
-#include <vector> |
- |
-#include "base/crypto/scoped_capi_types.h" |
-#include "base/logging.h" |
-#include "base/third_party/nss/blapi.h" |
-#include "base/third_party/nss/sha256.h" |
- |
-namespace base { |
- |
-namespace { |
- |
-// Implementation of HMAC-SHA-256: |
-// |
-// SHA-256 is supported in Windows XP SP3 or later. We still need to support |
-// Windows XP SP2, so unfortunately we have to implement HMAC-SHA-256 here. |
- |
-enum { |
- SHA256_BLOCK_SIZE = 64 // Block size (in bytes) of the input to SHA-256. |
-}; |
- |
-// See FIPS 198: The Keyed-Hash Message Authentication Code (HMAC). |
-void ComputeHMACSHA256(const unsigned char* key, size_t key_len, |
- const unsigned char* text, size_t text_len, |
- unsigned char* output, size_t output_len) { |
- SHA256Context ctx; |
- |
- // Pre-process the key, if necessary. |
- unsigned char key0[SHA256_BLOCK_SIZE]; |
- if (key_len > SHA256_BLOCK_SIZE) { |
- SHA256_Begin(&ctx); |
- SHA256_Update(&ctx, key, key_len); |
- SHA256_End(&ctx, key0, NULL, SHA256_LENGTH); |
- memset(key0 + SHA256_LENGTH, 0, SHA256_BLOCK_SIZE - SHA256_LENGTH); |
- } else { |
- memcpy(key0, key, key_len); |
- memset(key0 + key_len, 0, SHA256_BLOCK_SIZE - key_len); |
- } |
- |
- unsigned char padded_key[SHA256_BLOCK_SIZE]; |
- unsigned char inner_hash[SHA256_LENGTH]; |
- |
- // XOR key0 with ipad. |
- for (int i = 0; i < SHA256_BLOCK_SIZE; ++i) |
- padded_key[i] = key0[i] ^ 0x36; |
- |
- // Compute the inner hash. |
- SHA256_Begin(&ctx); |
- SHA256_Update(&ctx, padded_key, SHA256_BLOCK_SIZE); |
- SHA256_Update(&ctx, text, text_len); |
- SHA256_End(&ctx, inner_hash, NULL, SHA256_LENGTH); |
- |
- // XOR key0 with opad. |
- for (int i = 0; i < SHA256_BLOCK_SIZE; ++i) |
- padded_key[i] = key0[i] ^ 0x5c; |
- |
- // Compute the outer hash. |
- SHA256_Begin(&ctx); |
- SHA256_Update(&ctx, padded_key, SHA256_BLOCK_SIZE); |
- SHA256_Update(&ctx, inner_hash, SHA256_LENGTH); |
- SHA256_End(&ctx, output, NULL, output_len); |
-} |
- |
-} // namespace |
- |
-struct HMACPlatformData { |
- ~HMACPlatformData() { |
- if (!raw_key_.empty()) { |
- SecureZeroMemory(&raw_key_[0], raw_key_.size()); |
- } |
- |
- // Destroy the key before releasing the provider. |
- key_.reset(); |
- } |
- |
- ScopedHCRYPTPROV provider_; |
- ScopedHCRYPTKEY key_; |
- |
- // For HMAC-SHA-256 only. |
- std::vector<unsigned char> raw_key_; |
-}; |
- |
-HMAC::HMAC(HashAlgorithm hash_alg) |
- : hash_alg_(hash_alg), plat_(new HMACPlatformData()) { |
- // Only SHA-1 and SHA-256 hash algorithms are supported now. |
- DCHECK(hash_alg_ == SHA1 || hash_alg_ == SHA256); |
-} |
- |
-bool HMAC::Init(const unsigned char* key, int key_length) { |
- if (plat_->provider_ || plat_->key_ || !plat_->raw_key_.empty()) { |
- // Init must not be called more than once on the same HMAC object. |
- NOTREACHED(); |
- return false; |
- } |
- |
- if (hash_alg_ == SHA256) { |
- if (key_length < SHA256_LENGTH / 2) |
- return false; // Key is too short. |
- plat_->raw_key_.assign(key, key + key_length); |
- return true; |
- } |
- |
- if (!CryptAcquireContext(plat_->provider_.receive(), NULL, NULL, |
- PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) { |
- NOTREACHED(); |
- return false; |
- } |
- |
- // This code doesn't work on Win2k because PLAINTEXTKEYBLOB and |
- // CRYPT_IPSEC_HMAC_KEY are not supported on Windows 2000. PLAINTEXTKEYBLOB |
- // allows the import of an unencrypted key. For Win2k support, a cubmbersome |
- // exponent-of-one key procedure must be used: |
- // http://support.microsoft.com/kb/228786/en-us |
- // CRYPT_IPSEC_HMAC_KEY allows keys longer than 16 bytes. |
- |
- struct KeyBlob { |
- BLOBHEADER header; |
- DWORD key_size; |
- BYTE key_data[1]; |
- }; |
- size_t key_blob_size = std::max(offsetof(KeyBlob, key_data) + key_length, |
- sizeof(KeyBlob)); |
- std::vector<BYTE> key_blob_storage = std::vector<BYTE>(key_blob_size); |
- KeyBlob* key_blob = reinterpret_cast<KeyBlob*>(&key_blob_storage[0]); |
- key_blob->header.bType = PLAINTEXTKEYBLOB; |
- key_blob->header.bVersion = CUR_BLOB_VERSION; |
- key_blob->header.reserved = 0; |
- key_blob->header.aiKeyAlg = CALG_RC2; |
- key_blob->key_size = key_length; |
- memcpy(key_blob->key_data, key, key_length); |
- |
- if (!CryptImportKey(plat_->provider_, &key_blob_storage[0], |
- key_blob_storage.size(), 0, CRYPT_IPSEC_HMAC_KEY, |
- plat_->key_.receive())) { |
- NOTREACHED(); |
- return false; |
- } |
- |
- // Destroy the copy of the key. |
- SecureZeroMemory(key_blob->key_data, key_length); |
- |
- return true; |
-} |
- |
-HMAC::~HMAC() { |
-} |
- |
-bool HMAC::Sign(const std::string& data, |
- unsigned char* digest, |
- int digest_length) { |
- if (hash_alg_ == SHA256) { |
- if (plat_->raw_key_.empty()) |
- return false; |
- ComputeHMACSHA256(&plat_->raw_key_[0], plat_->raw_key_.size(), |
- reinterpret_cast<const unsigned char*>(data.data()), |
- data.size(), digest, digest_length); |
- return true; |
- } |
- |
- if (!plat_->provider_ || !plat_->key_) |
- return false; |
- |
- if (hash_alg_ != SHA1) { |
- NOTREACHED(); |
- return false; |
- } |
- |
- ScopedHCRYPTHASH hash; |
- if (!CryptCreateHash(plat_->provider_, CALG_HMAC, plat_->key_, 0, |
- hash.receive())) |
- return false; |
- |
- HMAC_INFO hmac_info; |
- memset(&hmac_info, 0, sizeof(hmac_info)); |
- hmac_info.HashAlgid = CALG_SHA1; |
- if (!CryptSetHashParam(hash, HP_HMAC_INFO, |
- reinterpret_cast<BYTE*>(&hmac_info), 0)) |
- return false; |
- |
- if (!CryptHashData(hash, reinterpret_cast<const BYTE*>(data.data()), |
- static_cast<DWORD>(data.size()), 0)) |
- return false; |
- |
- DWORD sha1_size = digest_length; |
- return !!CryptGetHashParam(hash, HP_HASHVAL, digest, &sha1_size, 0); |
-} |
- |
-} // namespace base |