xref: /aosp_15_r20/external/federated-compute/fcp/base/random_token.cc (revision 14675a029014e728ec732f129a32e299b2da0601)
1 /*
2  * Copyright 2019 Google LLC
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "fcp/base/random_token.h"
18 
19 #include <string.h>
20 
21 #include <string>
22 
23 #include "absl/strings/escaping.h"
24 #include "fcp/base/monitoring.h"
25 #include "openssl/rand.h"
26 
27 namespace fcp {
28 
Generate()29 RandomToken RandomToken::Generate() {
30   uint64_t words[2];
31   static_assert(sizeof(words) == kRandomTokenSizeInBytes,
32                 "Should match the token size");
33   int r = RAND_bytes(reinterpret_cast<unsigned char*>(words),
34                      kRandomTokenSizeInBytes);
35   FCP_CHECK(r == 1);
36   return RandomToken(words[0], words[1]);
37 }
38 
FromBytes(absl::Span<char const> bytes)39 RandomToken RandomToken::FromBytes(absl::Span<char const> bytes) {
40   FCP_CHECK(bytes.size() == kRandomTokenSizeInBytes);
41 
42   uint64_t words[2];
43   static_assert(sizeof(words) == kRandomTokenSizeInBytes,
44                 "Should match the token size");
45   memcpy(reinterpret_cast<char*>(words), bytes.data(), kRandomTokenSizeInBytes);
46   return RandomToken(words[0], words[1]);
47 }
48 
ToBytes() const49 std::array<char, kRandomTokenSizeInBytes> RandomToken::ToBytes() const {
50   std::array<char, kRandomTokenSizeInBytes> bytes;
51   memcpy(bytes.data(), reinterpret_cast<char const*>(words_),
52          kRandomTokenSizeInBytes);
53   return bytes;
54 }
55 
ToString() const56 std::string RandomToken::ToString() const {
57   return std::string(reinterpret_cast<char const*>(words_),
58                      kRandomTokenSizeInBytes);
59 }
60 
ToPrintableString() const61 std::string RandomToken::ToPrintableString() const {
62   return absl::BytesToHexString(absl::string_view(
63       reinterpret_cast<char const*>(words_), kRandomTokenSizeInBytes));
64 }
65 
66 }  // namespace fcp
67