Move crypto files out of base, to a top level directory.

crypto/hmac_win.cc

+// 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/hmac.h"
+
+#include <windows.h>
+#include <wincrypt.h>
+
+#include <algorithm>
+#include <vector>
+
+#include "base/logging.h"
+#include "crypto/scoped_capi_types.h"
+#include "crypto/third_party/nss/blapi.h"
+#include "crypto/third_party/nss/sha256.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.
+};
+
+// 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 crypto