/src/botan/build/include/botan/internal/gcm.h
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * GCM Mode |
3 | | * (C) 2013 Jack Lloyd |
4 | | * (C) 2016 Daniel Neus, Rohde & Schwarz Cybersecurity |
5 | | * |
6 | | * Botan is released under the Simplified BSD License (see license.txt) |
7 | | */ |
8 | | |
9 | | #ifndef BOTAN_AEAD_GCM_H_ |
10 | | #define BOTAN_AEAD_GCM_H_ |
11 | | |
12 | | #include <botan/aead.h> |
13 | | #include <botan/sym_algo.h> |
14 | | |
15 | | namespace Botan { |
16 | | |
17 | | class BlockCipher; |
18 | | class StreamCipher; |
19 | | class GHASH; |
20 | | |
21 | | /** |
22 | | * GCM Mode |
23 | | */ |
24 | | class GCM_Mode : public AEAD_Mode |
25 | | { |
26 | | public: |
27 | | void set_associated_data(const uint8_t ad[], size_t ad_len) override; |
28 | | |
29 | | std::string name() const override; |
30 | | |
31 | | size_t update_granularity() const override; |
32 | | |
33 | | Key_Length_Specification key_spec() const override; |
34 | | |
35 | | bool valid_nonce_length(size_t len) const override; |
36 | | |
37 | 3.42k | size_t tag_size() const override { return m_tag_size; } |
38 | | |
39 | | void clear() override; |
40 | | |
41 | | void reset() override; |
42 | | |
43 | | std::string provider() const override; |
44 | | protected: |
45 | | GCM_Mode(BlockCipher* cipher, size_t tag_size); |
46 | | |
47 | | ~GCM_Mode(); |
48 | | |
49 | | static const size_t GCM_BS = 16; |
50 | | |
51 | | const size_t m_tag_size; |
52 | | const std::string m_cipher_name; |
53 | | |
54 | | std::unique_ptr<StreamCipher> m_ctr; |
55 | | std::unique_ptr<GHASH> m_ghash; |
56 | | private: |
57 | | void start_msg(const uint8_t nonce[], size_t nonce_len) override; |
58 | | |
59 | | void key_schedule(const uint8_t key[], size_t length) override; |
60 | | |
61 | | secure_vector<uint8_t> m_y0; |
62 | | }; |
63 | | |
64 | | /** |
65 | | * GCM Encryption |
66 | | */ |
67 | | class GCM_Encryption final : public GCM_Mode |
68 | | { |
69 | | public: |
70 | | /** |
71 | | * @param cipher the 128 bit block cipher to use |
72 | | * @param tag_size is how big the auth tag will be |
73 | | */ |
74 | | GCM_Encryption(BlockCipher* cipher, size_t tag_size = 16) : |
75 | 323 | GCM_Mode(cipher, tag_size) {} |
76 | | |
77 | | size_t output_length(size_t input_length) const override |
78 | 470 | { return input_length + tag_size(); } |
79 | | |
80 | 0 | size_t minimum_final_size() const override { return 0; } |
81 | | |
82 | | size_t process(uint8_t buf[], size_t size) override; |
83 | | |
84 | | void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override; |
85 | | }; |
86 | | |
87 | | /** |
88 | | * GCM Decryption |
89 | | */ |
90 | | class GCM_Decryption final : public GCM_Mode |
91 | | { |
92 | | public: |
93 | | /** |
94 | | * @param cipher the 128 bit block cipher to use |
95 | | * @param tag_size is how big the auth tag will be |
96 | | */ |
97 | | GCM_Decryption(BlockCipher* cipher, size_t tag_size = 16) : |
98 | 333 | GCM_Mode(cipher, tag_size) {} |
99 | | |
100 | | size_t output_length(size_t input_length) const override |
101 | 261 | { |
102 | 261 | BOTAN_ASSERT(input_length >= tag_size(), "Sufficient input"); |
103 | 261 | return input_length - tag_size(); |
104 | 261 | } |
105 | | |
106 | 267 | size_t minimum_final_size() const override { return tag_size(); } |
107 | | |
108 | | size_t process(uint8_t buf[], size_t size) override; |
109 | | |
110 | | void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override; |
111 | | }; |
112 | | |
113 | | } |
114 | | |
115 | | #endif |