secretencoder.h revision 7c9978567a202d6aa98beac5da5e1b3b34792862 
1// Copyright 2012 Google Inc. All Rights Reserved.
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#ifndef POLO_ENCODING_SECRETENCODER_H_
16#define POLO_ENCODING_SECRETENCODER_H_
17
18#include <stdint.h>
19#include <string>
20#include <vector>
21
22namespace polo {
23namespace encoding {
24
25// Encodes and decodes secret challenges. The decoded secret is displayed to the
26// user on the display device, and entered by the user on the input device. The
27// secret is encoded for transmission on the wire and used for computing pairing
28// keys.
29class SecretEncoder {
30 public:
31  virtual ~SecretEncoder() {}
32
33  // Encodes a byte array representation of a secret to a string.
34  // @param secret the secret bytes
35  // @return a string representation of the given secret
36  virtual std::string EncodeToString(
37      const std::vector<uint8_t>& secret) const = 0;
38
39  // Decodes the string representation of the secret to a byte array.
40  // @param secret a string representation of the secret
41  // @return the decoded secret as a byte array
42  virtual std::vector<uint8_t> DecodeToBytes(
43      const std::string& secret) const = 0;
44
45  // The number of symbols contained in each byte of data. For example, a
46  // hexadecimal encoding has 4 bytes per symbol and therefore 2 symbols per
47  // byte.
48  virtual size_t symbols_per_byte() const = 0;
49};
50
51}  // namespace encoding
52}  // namespace polo
53
54#endif  // POLO_ENCODING_SECRETENCODER_H_
55