Separate the key setting code in the constructor of HMAC class into the Init

method.

Overload the Init method for char* and std::string.

Add DCHECKs to the destruction methods in ~HMAC in hmac_win.cc.

The patch is written by Takeshi Yoshino <tyoshino@google.com>.
Original code review: http://codereview.chromium.org/88062

R=wtc
http://crbug.com/2297
TEST=base_unittests should pass.  Safe browsing should continue to work.
Review URL: http://codereview.chromium.org/113001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@15353 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 15 insertions, 4 deletions

diff --git a/base/hmac.h b/base/hmac.h
index bbfe855..bdd23a9 100644
--- a/base/hmac.h
+++ b/base/hmac.h
@@ -25,12 +25,23 @@ class HMAC {
     SHA1
   };
 
-  HMAC(HashAlgorithm hash_alg, const unsigned char* key, int key_length);
+  explicit HMAC(HashAlgorithm hash_alg);
   ~HMAC();
 
-  // Calculates the HMAC for the message in |data| using the algorithm and key
-  // supplied to the constructor.  The HMAC is returned in |digest|, which
-  // has |digest_length| bytes of storage available.
+  // Initializes this instance using |key| of the length |key_length|. Call Init
+  // only once. It returns false on the second or later calls.
+  bool Init(const unsigned char* key, int key_length);
+
+  // Initializes this instance using |key|. Call Init only once. It returns
+  // false on the second or later calls.
+  bool Init(const std::string& key) {
+    return Init(reinterpret_cast<const unsigned char*>(key.data()),
+                static_cast<int>(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.
   bool Sign(const std::string& data, unsigned char* digest, int digest_length);
 
  private: