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

crypto/hmac.h

 // 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.
 
 // Utility class for calculating the HMAC for a given message. We currently
 // only support SHA1 for the hash algorithm, but this can be extended easily.
 
 #ifndef CRYPTO_HMAC_H_
 #define CRYPTO_HMAC_H_
 
@@ skipping 20 matching lines @@
   explicit HMAC(HashAlgorithm hash_alg);
   ~HMAC();
 
   // Returns the length of digest that this HMAC will create.
   size_t DigestLength() const;
 
   // TODO(abarth): Add a PreferredKeyLength() member function.
 
   // Initializes this instance using |key| of the length |key_length|. Call Init
   // only once. It returns false on the second or later calls.
-  // TODO(abarth): key_length should be a size_t.
   //
   // NOTE: the US Federal crypto standard FIPS 198, Section 3 says:
   //   The size of the key, K, shall be equal to or greater than L/2, where L
   //   is the size of the hash function output.
   // In FIPS 198-1 (and SP-800-107, which describes key size recommendations),
   // this requirement is gone.  But a system crypto library may still enforce
   // this old requirement.  If the key is shorter than this recommended value,
   // Init() may fail.
-  bool Init(const unsigned char* key, int key_length) WARN_UNUSED_RESULT;
+  bool Init(const unsigned char* key, size_t key_length) WARN_UNUSED_RESULT;
 
   // Initializes this instance using |key|. Call Init
   // only once. It returns false on the second or later calls.
   bool Init(SymmetricKey* key) WARN_UNUSED_RESULT;
 
   // Initializes this instance using |key|. Call Init only once. It returns
   // false on the second or later calls.
   bool Init(const base::StringPiece& key) WARN_UNUSED_RESULT {
     return Init(reinterpret_cast<const unsigned char*>(key.data()),
-                static_cast<int>(key.size()));
+                key.size());
   }
 
   // Calculates the HMAC for the message in |data| using the algorithm supplied
   // to the constructor and the key supplied to the Init method. The HMAC is
   // returned in |digest|, which has |digest_length| bytes of storage available.
-  // TODO(abarth): digest_length should be a size_t.
   bool Sign(const base::StringPiece& data, unsigned char* digest,
-            int digest_length) const WARN_UNUSED_RESULT;
+            size_t digest_length) const WARN_UNUSED_RESULT;
 
   // Verifies that the HMAC for the message in |data| equals the HMAC provided
   // in |digest|, using the algorithm supplied to the constructor and the key
   // supplied to the Init method. Use of this method is strongly recommended
   // over using Sign() with a manual comparison (such as memcmp), as such
   // comparisons may result in side-channel disclosures, such as timing, that
   // undermine the cryptographic integrity. |digest| must be exactly
   // |DigestLength()| bytes long.
   bool Verify(const base::StringPiece& data,
               const base::StringPiece& digest) const WARN_UNUSED_RESULT;
 
   // Verifies a truncated HMAC, behaving identical to Verify(), except
   // that |digest| is allowed to be smaller than |DigestLength()|.
   bool VerifyTruncated(
       const base::StringPiece& data,
       const base::StringPiece& digest) const WARN_UNUSED_RESULT;
 
  private:
   HashAlgorithm hash_alg_;
   scoped_ptr<HMACPlatformData> plat_;
 
   DISALLOW_COPY_AND_ASSIGN(HMAC);
 };
 
 }  // namespace crypto
 
 #endif  // CRYPTO_HMAC_H_