1 // Copyright 2016 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/unguessable_token.h"
6
7 #include "base/format_macros.h"
8 #include "base/rand_util.h"
9 #include "base/strings/stringprintf.h"
10
11 namespace base {
12
UnguessableToken(uint64_t high,uint64_t low)13 UnguessableToken::UnguessableToken(uint64_t high, uint64_t low)
14 : high_(high), low_(low) {}
15
ToString() const16 std::string UnguessableToken::ToString() const {
17 return base::StringPrintf("%016" PRIX64 "%016" PRIX64, high_, low_);
18 }
19
20 // static
Create()21 UnguessableToken UnguessableToken::Create() {
22 UnguessableToken token;
23 // Use base::RandBytes instead of crypto::RandBytes, because crypto calls the
24 // base version directly, and to prevent the dependency from base/ to crypto/.
25 base::RandBytes(&token, sizeof(token));
26 return token;
27 }
28
29 // static
Deserialize(uint64_t high,uint64_t low)30 UnguessableToken UnguessableToken::Deserialize(uint64_t high, uint64_t low) {
31 // Receiving a zeroed out UnguessableToken from another process means that it
32 // was never initialized via Create(). Treat this case as a security issue.
33 DCHECK(!(high == 0 && low == 0));
34 return UnguessableToken(high, low);
35 }
36
operator <<(std::ostream & out,const UnguessableToken & token)37 std::ostream& operator<<(std::ostream& out, const UnguessableToken& token) {
38 return out << "(" << token.ToString() << ")";
39 }
40
41 } // namespace base
42