Adds a modified copy of talk/base to webrtc/base. It is the first step in migrating talk/base to webrtc/base.

BUG=N/A
R=andrew@webrtc.org, wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/12199004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6107 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/base/sha1digest.h

@@ -0,0 +1,47 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_BASE_SHA1DIGEST_H_
+#define WEBRTC_BASE_SHA1DIGEST_H_
+
+#include "webrtc/base/messagedigest.h"
+#include "webrtc/base/sha1.h"
+
+namespace rtc {
+
+// A simple wrapper for our SHA-1 implementation.
+class Sha1Digest : public MessageDigest {
+ public:
+  enum { kSize = SHA1_DIGEST_SIZE };
+  Sha1Digest() {
+    SHA1Init(&ctx_);
+  }
+  virtual size_t Size() const {
+    return kSize;
+  }
+  virtual void Update(const void* buf, size_t len) {
+    SHA1Update(&ctx_, static_cast<const uint8*>(buf), len);
+  }
+  virtual size_t Finish(void* buf, size_t len) {
+    if (len < kSize) {
+      return 0;
+    }
+    SHA1Final(&ctx_, static_cast<uint8*>(buf));
+    SHA1Init(&ctx_);  // Reset for next use.
+    return kSize;
+  }
+
+ private:
+  SHA1_CTX ctx_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_BASE_SHA1DIGEST_H_