Abstracts SHA256 context for NSS / OpenSSL.

base/sha2.cc

 // Copyright (c) 2006-2008 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/sha2.h"
 
 #include "base/stl_util-inl.h"
 #include "base/third_party/nss/blapi.h"
 #include "base/third_party/nss/sha256.h"
 
 namespace base {
 
 void SHA256HashString(const std::string& str, void* output, size_t len) {
-  SHA256Context ctx;
+  ::SHA256Context ctx;
 
   SHA256_Begin(&ctx);
   SHA256_Update(&ctx, reinterpret_cast<const unsigned char*>(str.data()),
                 static_cast<unsigned int>(str.length()));
   SHA256_End(&ctx, static_cast<unsigned char*>(output), NULL,
              static_cast<unsigned int>(len));
 }
 
 std::string SHA256HashString(const std::string& str) {
   std::string output(SHA256_LENGTH, 0);
   SHA256HashString(str, string_as_array(&output), output.size());
   return output;
 }
 
+namespace {
+
+class SHA256ContextNSS : public SHA256Context {
+ public:
+  SHA256ContextNSS() {
+    SHA256_Begin(&ctx_);
+  }
+
+  virtual ~SHA256ContextNSS() {
+  }
+
+  virtual void Update(const std::string& str) {
+    SHA256_Update(&ctx_, reinterpret_cast<const unsigned char*>(str.data()),
+                  static_cast<unsigned int>(str.length()));
+
+  }
+
+  virtual void Finish(void* output, size_t len) {
+    SHA256_End(&ctx_, static_cast<unsigned char*>(output), NULL,
+               static_cast<unsigned int>(len));
+  }
+
+ private:
+  ::SHA256Context ctx_;
+};
+
+}  // namespace
+
+SHA256Context* SHA256Context::Create() {
+  return new SHA256ContextNSS();
+}
+
 }  // namespace base