Abstracts SHA256 context for NSS / OpenSSL.

base/sha2.cc

Index: base/sha2.cc
diff --git a/base/sha2.cc b/base/sha2.cc
index c0fd0ab5d596eb7cd2e1202e32707bdd04f9cae6..709c29ef01a6fb7306f829c5be2cbea625482597 100644
--- a/base/sha2.cc
+++ b/base/sha2.cc
@@ -11,7 +11,7 @@
 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()),
@@ -26,4 +26,36 @@ std::string SHA256HashString(const std::string& str) {
   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