xref: /aosp_15_r20/external/tink/cc/util/keyset_util.cc (revision e7b1675dde1b92d52ec075b0a92829627f2c52a5)
1 // Copyright 2018 Google Inc.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //     http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 //
15 ///////////////////////////////////////////////////////////////////////////////
16 
17 #include "tink/util/keyset_util.h"
18 
19 #include <cstdint>
20 #include <random>
21 
22 #include "proto/tink.pb.h"
23 
24 namespace crypto {
25 namespace tink {
26 
27 namespace {
28 
29 using google::crypto::tink::Keyset;
30 
NewKeyId()31 uint32_t NewKeyId() {
32   std::random_device rd;
33   std::minstd_rand0 gen(rd());
34   std::uniform_int_distribution<uint32_t> dist;
35   return dist(gen);
36 }
37 
38 }  // namespace
39 
GenerateUnusedKeyId(const Keyset & keyset)40 uint32_t GenerateUnusedKeyId(const Keyset& keyset) {
41   while (true) {
42     uint32_t key_id = NewKeyId();
43     bool already_exists = false;
44     for (auto& key : keyset.key()) {
45       if (key.key_id() == key_id) {
46         already_exists = true;
47         break;
48       }
49     }
50     if (!already_exists) return key_id;
51   }
52 }
53 
54 }  // namespace tink
55 }  // namespace crypto
56