| Index: crypto/hmac_win.cc
|
| diff --git a/crypto/hmac_win.cc b/crypto/hmac_win.cc
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..99b3a60d57efb41fd73f30084e8a080ef77fd30c
|
| --- /dev/null
|
| +++ b/crypto/hmac_win.cc
|
| @@ -0,0 +1,209 @@
|
| +// Copyright (c) 2012 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/hmac.h"
|
| +
|
| +#include <windows.h>
|
| +
|
| +#include <algorithm>
|
| +#include <vector>
|
| +
|
| +#include "base/logging.h"
|
| +#include "crypto/scoped_capi_types.h"
|
| +#include "crypto/third_party/nss/chromium-blapi.h"
|
| +#include "crypto/third_party/nss/chromium-sha256.h"
|
| +#include "crypto/wincrypt_shim.h"
|
| +
|
| +namespace crypto {
|
| +
|
| +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.
|
| +};
|
| +
|
| +// NSS doesn't accept size_t for text size, divide the data into smaller
|
| +// chunks as needed.
|
| +void Wrapped_SHA256_Update(SHA256Context* ctx, const unsigned char* text,
|
| + size_t text_len) {
|
| + const unsigned int kChunkSize = 1 << 30;
|
| + while (text_len > kChunkSize) {
|
| + SHA256_Update(ctx, text, kChunkSize);
|
| + text += kChunkSize;
|
| + text_len -= kChunkSize;
|
| + }
|
| + SHA256_Update(ctx, text, (unsigned int)text_len);
|
| +}
|
| +
|
| +// 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);
|
| + Wrapped_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);
|
| + if (key_len < SHA256_BLOCK_SIZE)
|
| + 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);
|
| + Wrapped_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, (unsigned int) 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, size_t 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) {
|
| + 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 = static_cast<DWORD>(key_length);
|
| + memcpy(key_blob->key_data, key, key_length);
|
| +
|
| + if (!CryptImportKey(plat_->provider_, &key_blob_storage[0],
|
| + (DWORD)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 base::StringPiece& data,
|
| + unsigned char* digest,
|
| + size_t digest_length) const {
|
| + 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 = static_cast<DWORD>(digest_length);
|
| + return !!CryptGetHashParam(hash, HP_HASHVAL, digest, &sha1_size, 0);
|
| +}
|
| +
|
| +} // namespace crypto
|
|
|