WebCrypto: Implement digest() using NSS

content/renderer/webcrypto_impl_nss.cc

+// Copyright (c) 2013 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 "content/renderer/webcrypto_impl.h"
+
+#include <sechash.h>
+
+#include "base/logging.h"
+#include "crypto/nss_util.h"
+#include "third_party/WebKit/public/platform/WebArrayBuffer.h"
+#include "third_party/WebKit/public/platform/WebCryptoAlgorithm.h"
+
+namespace content {
+
+bool WebCryptoImpl::digestInternal(
+    const WebKit::WebCryptoAlgorithm& algorithm,
+    const unsigned char* data,
+    size_t data_size,
+    WebKit::WebArrayBuffer* buffer) {
+  HASH_HashType hash_type = HASH_AlgNULL;
+
+  switch (algorithm.id()) {
+    case WebKit::WebCryptoAlgorithmIdSha1:
+      hash_type = HASH_AlgSHA1;
+      break;
+    case WebKit::WebCryptoAlgorithmIdSha224:
+      hash_type = HASH_AlgSHA224;
+      break;
+    case WebKit::WebCryptoAlgorithmIdSha256:
+      hash_type = HASH_AlgSHA256;
+      break;
+    case WebKit::WebCryptoAlgorithmIdSha384:
+      hash_type = HASH_AlgSHA384;
+      break;
+    case WebKit::WebCryptoAlgorithmIdSha512:
+      hash_type = HASH_AlgSHA512;
+      break;
+    default:
+      // Not a digest algorithm.
+      return false;
+  }
+
+  crypto::EnsureNSSInit();
+
+  HASHContext* context = HASH_Create(hash_type);
+  if (!context) {
+    return false;
+  }
+
+  HASH_Begin(context);
+
+  HASH_Update(context, data, data_size);
+
+  size_t hash_result_length = HASH_ResultLenContext(context);
+  DCHECK_LE(hash_result_length, static_cast<size_t>(HASH_LENGTH_MAX));
+
+  *buffer = WebKit::WebArrayBuffer::create(hash_result_length, 1);
+
+  unsigned char* digest = reinterpret_cast<unsigned char*>(buffer->data());
+
+  uint32 result_length = 0;
+  HASH_End(context, digest, &result_length, hash_result_length);
+
+  HASH_Destroy(context);
+
+  return result_length == hash_result_length;
+}
+
+}  // namespace content