Use size_t as the type of key_length and digest_length arguments of HMAC.

crypto/hmac_openssl.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 <openssl/hmac.h>
 
 #include <algorithm>
 #include <vector>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stl_util.h"
 #include "crypto/openssl_util.h"
 
 namespace crypto {
 
 struct HMACPlatformData {
   std::vector<unsigned char> 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) {
+bool HMAC::Init(const unsigned char* key, size_t key_length) {
   // Init must not be called more than once on the same HMAC object.
   DCHECK(plat_->key.empty());
 
   plat_->key.assign(key, key + key_length);
   return true;
 }
 
 HMAC::~HMAC() {
   // Zero out key copy.
   plat_->key.assign(plat_->key.size(), 0);
   STLClearObject(&plat_->key);
 }
 
 bool HMAC::Sign(const base::StringPiece& data,
                 unsigned char* digest,
-                int digest_length) const {
-  DCHECK_GE(digest_length, 0);
+                size_t digest_length) const {
   DCHECK(!plat_->key.empty());  // Init must be called before Sign.
 
   ScopedOpenSSLSafeSizeBuffer<EVP_MAX_MD_SIZE> result(digest, digest_length);
   return ::HMAC(hash_alg_ == SHA1 ? EVP_sha1() : EVP_sha256(),
                 &plat_->key[0], plat_->key.size(),
                 reinterpret_cast<const unsigned char*>(data.data()),
                 data.size(),
                 result.safe_buffer(), NULL);
 }
 
 }  // namespace crypto