xref: /aosp_15_r20/external/tink/cc/crypto_format.h (revision e7b1675dde1b92d52ec075b0a92829627f2c52a5)
1*e7b1675dSTing-Kang Chang // Copyright 2017 Google Inc.
2*e7b1675dSTing-Kang Chang //
3*e7b1675dSTing-Kang Chang // Licensed under the Apache License, Version 2.0 (the "License");
4*e7b1675dSTing-Kang Chang // you may not use this file except in compliance with the License.
5*e7b1675dSTing-Kang Chang // You may obtain a copy of the License at
6*e7b1675dSTing-Kang Chang //
7*e7b1675dSTing-Kang Chang //     http://www.apache.org/licenses/LICENSE-2.0
8*e7b1675dSTing-Kang Chang //
9*e7b1675dSTing-Kang Chang // Unless required by applicable law or agreed to in writing, software
10*e7b1675dSTing-Kang Chang // distributed under the License is distributed on an "AS IS" BASIS,
11*e7b1675dSTing-Kang Chang // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12*e7b1675dSTing-Kang Chang // See the License for the specific language governing permissions and
13*e7b1675dSTing-Kang Chang // limitations under the License.
14*e7b1675dSTing-Kang Chang //
15*e7b1675dSTing-Kang Chang ///////////////////////////////////////////////////////////////////////////////
16*e7b1675dSTing-Kang Chang 
17*e7b1675dSTing-Kang Chang #ifndef TINK_CRYPTO_FORMAT_H_
18*e7b1675dSTing-Kang Chang #define TINK_CRYPTO_FORMAT_H_
19*e7b1675dSTing-Kang Chang 
20*e7b1675dSTing-Kang Chang #include <string>
21*e7b1675dSTing-Kang Chang #include <vector>
22*e7b1675dSTing-Kang Chang 
23*e7b1675dSTing-Kang Chang #include "tink/util/statusor.h"
24*e7b1675dSTing-Kang Chang #include "proto/tink.pb.h"
25*e7b1675dSTing-Kang Chang 
26*e7b1675dSTing-Kang Chang namespace crypto {
27*e7b1675dSTing-Kang Chang namespace tink {
28*e7b1675dSTing-Kang Chang 
29*e7b1675dSTing-Kang Chang // Constants and convenience methods that deal with the format
30*e7b1675dSTing-Kang Chang // of the outputs handled by Tink.
31*e7b1675dSTing-Kang Chang class CryptoFormat {
32*e7b1675dSTing-Kang Chang  public:
33*e7b1675dSTing-Kang Chang   // Prefix size of Tink and Legacy key types.
34*e7b1675dSTing-Kang Chang   static constexpr int kNonRawPrefixSize = 5;
35*e7b1675dSTing-Kang Chang 
36*e7b1675dSTing-Kang Chang   // Legacy prefix starts with \x00 and followed by a 4-byte key id.
37*e7b1675dSTing-Kang Chang   static constexpr int kLegacyPrefixSize = kNonRawPrefixSize;
38*e7b1675dSTing-Kang Chang   static constexpr uint8_t kLegacyStartByte = 0x00;
39*e7b1675dSTing-Kang Chang 
40*e7b1675dSTing-Kang Chang   // Tink prefix starts with \x01 and followed by a 4-byte key id.
41*e7b1675dSTing-Kang Chang   static constexpr int kTinkPrefixSize = kNonRawPrefixSize;
42*e7b1675dSTing-Kang Chang   static constexpr uint8_t kTinkStartByte = 0x01;
43*e7b1675dSTing-Kang Chang 
44*e7b1675dSTing-Kang Chang   // Raw prefix is empty.
45*e7b1675dSTing-Kang Chang   static constexpr int kRawPrefixSize = 0;
46*e7b1675dSTing-Kang Chang   static const absl::string_view kRawPrefix;  // empty string
47*e7b1675dSTing-Kang Chang 
48*e7b1675dSTing-Kang Chang   // Generates the prefix for the outputs handled with the given key_info.
49*e7b1675dSTing-Kang Chang   // Returns an error if the prefix type 'output_prefix_type' is invalid.
50*e7b1675dSTing-Kang Chang   static crypto::tink::util::StatusOr<std::string> GetOutputPrefix(
51*e7b1675dSTing-Kang Chang       const google::crypto::tink::KeysetInfo::KeyInfo& key_info);
52*e7b1675dSTing-Kang Chang };
53*e7b1675dSTing-Kang Chang 
54*e7b1675dSTing-Kang Chang }  // namespace tink
55*e7b1675dSTing-Kang Chang }  // namespace crypto
56*e7b1675dSTing-Kang Chang 
57*e7b1675dSTing-Kang Chang #endif  // TINK_CRYPTO_FORMAT_H_
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