/src/botan/build/include/botan/internal/chacha20poly1305.h
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * ChaCha20Poly1305 AEAD |
3 | | * (C) 2014 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_CHACHA20_POLY1305_H_ |
10 | | #define BOTAN_AEAD_CHACHA20_POLY1305_H_ |
11 | | |
12 | | #include <botan/aead.h> |
13 | | #include <botan/stream_cipher.h> |
14 | | #include <botan/mac.h> |
15 | | |
16 | | namespace Botan { |
17 | | |
18 | | /** |
19 | | * Base class |
20 | | * See draft-irtf-cfrg-chacha20-poly1305-03 for specification |
21 | | * If a nonce of 64 bits is used the older version described in |
22 | | * draft-agl-tls-chacha20poly1305-04 is used instead. |
23 | | * If a nonce of 192 bits is used, XChaCha20Poly1305 is selected. |
24 | | */ |
25 | | class ChaCha20Poly1305_Mode : public AEAD_Mode |
26 | | { |
27 | | public: |
28 | | void set_associated_data(const uint8_t ad[], size_t ad_len) override; |
29 | | |
30 | 0 | bool associated_data_requires_key() const override { return false; } |
31 | | |
32 | 0 | std::string name() const override { return "ChaCha20Poly1305"; } |
33 | | |
34 | 0 | size_t update_granularity() const override { return 64; } |
35 | | |
36 | | Key_Length_Specification key_spec() const override |
37 | 75 | { return Key_Length_Specification(32); } |
38 | | |
39 | | bool valid_nonce_length(size_t n) const override; |
40 | | |
41 | 351 | size_t tag_size() const override { return 16; } |
42 | | |
43 | | void clear() override; |
44 | | |
45 | | void reset() override; |
46 | | |
47 | | protected: |
48 | | std::unique_ptr<StreamCipher> m_chacha; |
49 | | std::unique_ptr<MessageAuthenticationCode> m_poly1305; |
50 | | |
51 | | ChaCha20Poly1305_Mode(); |
52 | | |
53 | | secure_vector<uint8_t> m_ad; |
54 | | size_t m_nonce_len = 0; |
55 | | size_t m_ctext_len = 0; |
56 | | |
57 | 162 | bool cfrg_version() const { return m_nonce_len == 12 || m_nonce_len == 24; } |
58 | | void update_len(size_t len); |
59 | | private: |
60 | | void start_msg(const uint8_t nonce[], size_t nonce_len) override; |
61 | | |
62 | | void key_schedule(const uint8_t key[], size_t length) override; |
63 | | }; |
64 | | |
65 | | /** |
66 | | * ChaCha20Poly1305 Encryption |
67 | | */ |
68 | | class ChaCha20Poly1305_Encryption final : public ChaCha20Poly1305_Mode |
69 | | { |
70 | | public: |
71 | | size_t output_length(size_t input_length) const override |
72 | 45 | { return input_length + tag_size(); } |
73 | | |
74 | 0 | size_t minimum_final_size() const override { return 0; } |
75 | | |
76 | | size_t process(uint8_t buf[], size_t size) override; |
77 | | |
78 | | void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override; |
79 | | }; |
80 | | |
81 | | /** |
82 | | * ChaCha20Poly1305 Decryption |
83 | | */ |
84 | | class ChaCha20Poly1305_Decryption final : public ChaCha20Poly1305_Mode |
85 | | { |
86 | | public: |
87 | | size_t output_length(size_t input_length) const override |
88 | 36 | { |
89 | 36 | BOTAN_ASSERT(input_length >= tag_size(), "Sufficient input"); |
90 | 36 | return input_length - tag_size(); |
91 | 36 | } |
92 | | |
93 | 36 | size_t minimum_final_size() const override { return tag_size(); } |
94 | | |
95 | | size_t process(uint8_t buf[], size_t size) override; |
96 | | |
97 | | void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override; |
98 | | }; |
99 | | |
100 | | } |
101 | | |
102 | | #endif |