| // 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 <nss.h> |
| #include <pk11pub.h> |
| |
| #include "base/crypto/scoped_nss_types.h" |
| #include "base/logging.h" |
| #include "base/nss_util.h" |
| #include "base/scoped_ptr.h" |
| |
| namespace base { |
| |
| struct HMACPlatformData { |
| CK_MECHANISM_TYPE mechanism_; |
| ScopedPK11Slot slot_; |
| ScopedPK11SymKey sym_key_; |
| }; |
| |
| HMAC::HMAC(HashAlgorithm hash_alg) |
| : hash_alg_(hash_alg), plat_(new HMACPlatformData()) { |
| // Only SHA-1 and SHA-256 hash algorithms are supported. |
| switch (hash_alg_) { |
| case SHA1: |
| plat_->mechanism_ = CKM_SHA_1_HMAC; |
| break; |
| case SHA256: |
| plat_->mechanism_ = CKM_SHA256_HMAC; |
| break; |
| default: |
| NOTREACHED() << "Unsupported hash algorithm"; |
| break; |
| } |
| } |
| |
| bool HMAC::Init(const unsigned char *key, int key_length) { |
| base::EnsureNSSInit(); |
| |
| if (plat_->slot_.get()) { |
| // Init must not be called more than twice on the same HMAC object. |
| NOTREACHED(); |
| return false; |
| } |
| |
| plat_->slot_.reset(PK11_GetBestSlot(plat_->mechanism_, NULL)); |
| if (!plat_->slot_.get()) { |
| NOTREACHED(); |
| return false; |
| } |
| |
| SECItem key_item; |
| key_item.type = siBuffer; |
| key_item.data = const_cast<unsigned char*>(key); // NSS API isn't const. |
| key_item.len = key_length; |
| |
| plat_->sym_key_.reset(PK11_ImportSymKey(plat_->slot_.get(), |
| plat_->mechanism_, |
| PK11_OriginUnwrap, |
| CKA_SIGN, |
| &key_item, |
| NULL)); |
| if (!plat_->sym_key_.get()) { |
| NOTREACHED(); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| HMAC::~HMAC() { |
| } |
| |
| bool HMAC::Sign(const std::string& data, |
| unsigned char* digest, |
| int digest_length) { |
| if (!plat_->sym_key_.get()) { |
| // Init has not been called before Sign. |
| NOTREACHED(); |
| return false; |
| } |
| |
| SECItem param = { siBuffer, NULL, 0 }; |
| ScopedPK11Context context(PK11_CreateContextBySymKey(plat_->mechanism_, |
| CKA_SIGN, |
| plat_->sym_key_.get(), |
| ¶m)); |
| if (!context.get()) { |
| NOTREACHED(); |
| return false; |
| } |
| |
| if (PK11_DigestBegin(context.get()) != SECSuccess) { |
| NOTREACHED(); |
| return false; |
| } |
| |
| if (PK11_DigestOp(context.get(), |
| reinterpret_cast<const unsigned char*>(data.data()), |
| data.length()) != SECSuccess) { |
| NOTREACHED(); |
| return false; |
| } |
| |
| unsigned int len = 0; |
| if (PK11_DigestFinal(context.get(), |
| digest, &len, digest_length) != SECSuccess) { |
| NOTREACHED(); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| } // namespace base |