Add static domain security state generator tool.

net/tools/domain_security_preload_generator/spki_hash.h

+// Copyright (c) 2016 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.
+
+#ifndef NET_TOOLS_DOMAIN_SECURITY_PRELOAD_GENERATOR_SPKI_HASH_H_
+#define NET_TOOLS_DOMAIN_SECURITY_PRELOAD_GENERATOR_SPKI_HASH_H_
+
+#include <stdint.h>
+#include <string>
+#include <vector>
+
+namespace net {
+
+namespace {
+// Hashes are always SHA256.
+enum : size_t { kSPKIHashLength = 32 };
+}  // namespace
+
+class SPKIHash {
+ public:
+  SPKIHash();
+  ~SPKIHash();
+
+  // Initalizes a hash from the form sha256/<base64-hash-value>. The preloaded
+  // SPKI hashes are SHA256. Other algorithms are not supported. Returns true
+  // on success and copies the decoded bytes to |data_|. Returns false in case
+  // of an error.
+  bool FromString(const std::string& hash_string);
+
+  // Calculates the SHA256 digest over |*input|. Returns true on success and
+  // copies the bytes to |data_|. Returns false in case of an error.
+  bool CalculateFromBytes(const uint8_t* input, size_t input_length);
+
+  // Returns the size of the hash in bytes. Harcoded to 32 which is the length
+  // of a SHA256 hash.
+  size_t size() const { return kSPKIHashLength; }
+
+  uint8_t* data() { return data_; }
+  const uint8_t* data() const { return data_; };
+
+ private:
+  // The bytes of the hash. Current hashes are SHA256 and thus 32 bytes long.
+  uint8_t data_[kSPKIHashLength];
+};
+
+}  // namespace net
+
+#endif  // NET_TOOLS_DOMAIN_SECURITY_PRELOAD_GENERATOR_SPKI_HASH_H_