Abstracts SHA256 context for NSS / OpenSSL.

base/crypto/secure_hash_openssl.cc

Index: base/crypto/secure_hash_openssl.cc
diff --git a/base/crypto/secure_hash_openssl.cc b/base/crypto/secure_hash_openssl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..808727932c30cc264d51a31f479d62f751331330
--- /dev/null
+++ b/base/crypto/secure_hash_openssl.cc
@@ -0,0 +1,53 @@
+// 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 "base/crypto/secure_hash.h"
+
+#include <openssl/ssl.h>
+
+#include "base/basictypes.h"
+#include "base/logging.h"
+#include "base/openssl_util.h"
+
+namespace base {
+
+namespace {
+
+class SecureHashSHA256OpenSSL : public SecureHash {
+ public:
+  SecureHashSHA256OpenSSL() {
+    SHA256_Init(&ctx_);
+  }
+
+  virtual ~SecureHashSHA256OpenSSL() {
+    OPENSSL_cleanse(&ctx_, sizeof(ctx_));
+  }
+
+  virtual void Update(const void* input, size_t len) {
+    SHA256_Update(&ctx_, static_cast<const unsigned char*>(input), len);
+  }
+
+  virtual void Finish(void* output, size_t len) {
+    ScopedOpenSSLSafeSizeBuffer<SHA256_DIGEST_LENGTH> result(
+        static_cast<unsigned char*>(output), len);
+    SHA256_Final(result.safe_buffer(), &ctx_);
+  }
+
+ private:
+  SHA256_CTX ctx_;
+};
+
+}  // namespace
+
+SecureHash* SecureHash::Create(Algorithm algorithm) {
+  switch (algorithm) {
+    case SHA256:
+      return new SecureHashSHA256OpenSSL();
+    default:
+      NOTIMPLEMENTED();
+      return NULL;
+  }
+}
+
+}  // namespace base