Make USE_OPENSSL and USE_NSS mutually exclusive

base/sha2_openssl.cc

Index: base/sha2_openssl.cc
diff --git a/base/sha2_openssl.cc b/base/sha2_openssl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..afbce2f4f3485b530e9f4eea0fca471266f914f4
--- /dev/null
+++ b/base/sha2_openssl.cc
@@ -0,0 +1,30 @@
+// Copyright (c) 2010 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 <openssl/ssl.h>
+
+#include "base/basictypes.h"
+#include "base/openssl_util.h"
+#include "base/stl_util-inl.h"
+
+namespace base {
+
+void SHA256HashString(const std::string& str, void* output, size_t len) {
+  COMPILE_ASSERT(SHA256_LENGTH == SHA256_DIGEST_LENGTH,
+                 API_and_OpenSSL_SHA256_lengths_must_match);
+  ScopedOpenSSLSafeSizeBuffer<SHA256_DIGEST_LENGTH> result(
+      reinterpret_cast<unsigned char*>(output), len);
+  ::SHA256(reinterpret_cast<const unsigned char*>(str.data()), str.size(),
+           result.safe_buffer());
+}
+
+std::string SHA256HashString(const std::string& str) {
+  std::string output(SHA256_LENGTH, 0);
+  SHA256HashString(str, string_as_array(&output), output.size());
+  return output;
+}
+
+}  // namespace base