Separate http_security_headers from transport_security_state

net/base/hash_value.h

+// Copyright (c) 2012 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_BASE_HASH_VALUE_H_
+#define NET_BASE_HASH_VALUE_H_
+
+#include <string.h>
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/string_piece.h"
+#include "build/build_config.h"
+#include "net/base/net_export.h"
+
+namespace net {
+
+struct NET_EXPORT SHA1HashValue {
+  bool Equals(const SHA1HashValue& other) const {
+    return memcmp(data, other.data, sizeof(data)) == 0;
+  }
+
+  unsigned char data[20];
+};
+
+struct NET_EXPORT SHA256HashValue {
+  bool Equals(const SHA256HashValue& other) const {
+    return memcmp(data, other.data, sizeof(data)) == 0;
+  }
+
+  unsigned char data[32];
+};
+
+enum HashValueTag {
+  HASH_VALUE_SHA1,
+  HASH_VALUE_SHA256,
+
+  // This must always be last.
+  HASH_VALUE_TAGS_COUNT
+};
+
+class NET_EXPORT HashValue {
+ public:
+  explicit HashValue(HashValueTag tag) : tag(tag) {}
+  HashValue() : tag(HASH_VALUE_SHA1) {}
+
+  bool Equals(const HashValue& other) const;
+
+  // Parse/write in this format: "sha1/Guzek9lMwR3KeIS8wwS9gBvVtIg="
+  // i.e. <hash-name>"/"<base64-hash-value>
+  // This format is used for:
+  //   - net_internals display/setting public-key pins
+  //   - logging public-key pins
+  //   - serializing public-key pins

[Ryan Sleevi, 2012/12/07 23:37:21]

comment nit: This feels like an abstraction leak, to have a 'base' class talking
about who depends on it.

// Serializes/Deserializes hashes in the form of
// <hash-name>"/"<base64-hash-value>
// (eg: "sha1/...")
// This format may be persisted to permanent storage, so
// care should be taken before changing the serialization.

[unsafe, 2012/12/08 09:22:42]

Added your comment but left mine as I think its useful to know where this is
used.  I'll remove it if you prefer.

+  //
+  // FromString() parse errors SHALL return false, and MAY leave the
+  //   HashValue containing incorrect data
+  // ToString() errors (ie unknown tag) returns "unknown/"<base64>
+  //   (but ToString() errors should not occur!)

[Ryan Sleevi, 2012/12/07 23:37:21]

comment nit: don't indent the comment here

comment nit: We should probably just say

// Deserializes a HashValue from a string. On error, returns
// false and does not change the contents of HashValue (which
// may contain invalid data)
bool FromString(...)

// Serializes the HashValue to a string. If an invalid HashValue
// is supplied (eg: an unknown hash tag), returns "unknown"/<base64>
std::string ToString() const;

Is there a reason you return <unknown> instead of an empty string? Just curious
the thought behind it.

[unsafe, 2012/12/08 09:22:42]

Replaced with your comments, but your FromString() comment didn't match
behavior, since the code mutates HashValue.tag prior to base64-decoding, so I
tried to make that clearer.
If something goes wrong the error will be more traceable when you see a funky
string with <unknown> in it..  Can change it if you like.

+  bool FromString(const base::StringPiece input);
+  std::string ToString() const;
+
+  size_t size() const;
+  unsigned char* data();
+  const unsigned char* data() const;
+
+  HashValueTag tag;
+
+ private:
+  union {
+    SHA1HashValue sha1;
+    SHA256HashValue sha256;
+  } fingerprint;
+};
+
+typedef std::vector<HashValue> HashValueVector;
+
+
+class SHA1HashValueLessThan {
+ public:
+  bool operator()(const SHA1HashValue& lhs,
+                  const SHA1HashValue& rhs) const {
+    return memcmp(lhs.data, rhs.data, sizeof(lhs.data)) < 0;
+  }
+};
+
+class SHA256HashValueLessThan {
+ public:
+  bool operator()(const SHA256HashValue& lhs,
+                  const SHA256HashValue& rhs) const {
+    return memcmp(lhs.data, rhs.data, sizeof(lhs.data)) < 0;
+  }
+};
+
+class HashValuesEqual {
+  public:
+  explicit HashValuesEqual(const HashValue& fingerprint) :
+      fingerprint_(fingerprint) {}
+
+  bool operator()(const HashValue& other) const {
+    return fingerprint_.Equals(other);
+  }
+
+  const HashValue& fingerprint_;
+};
+
+
+// IsSHA1HashInSortedArray returns true iff |hash| is in |array|, a sorted
+// array of SHA1 hashes.
+bool IsSHA1HashInSortedArray(const SHA1HashValue& hash,
+                             const uint8* array,
+                             size_t array_byte_len);
+
+}  // namespace net
+
+#endif  // NET_BASE_HASH_VALUE_H_