/src/botan/build/include/botan/internal/ccm.h
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * CCM 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_CCM_H_ |
10 | | #define BOTAN_AEAD_CCM_H_ |
11 | | |
12 | | #include <botan/aead.h> |
13 | | #include <botan/block_cipher.h> |
14 | | |
15 | | namespace Botan { |
16 | | |
17 | | /** |
18 | | * Base class for CCM encryption and decryption |
19 | | * @see RFC 3610 |
20 | | */ |
21 | | class CCM_Mode : public AEAD_Mode |
22 | | { |
23 | | public: |
24 | | size_t process(uint8_t buf[], size_t sz) override; |
25 | | |
26 | | void set_associated_data(const uint8_t ad[], size_t ad_len) override; |
27 | | |
28 | 0 | bool associated_data_requires_key() const override { return false; } |
29 | | |
30 | | std::string name() const override; |
31 | | |
32 | | size_t update_granularity() const override; |
33 | | |
34 | | Key_Length_Specification key_spec() const override; |
35 | | |
36 | | bool valid_nonce_length(size_t) const override; |
37 | | |
38 | | size_t default_nonce_length() const override; |
39 | | |
40 | | void clear() override; |
41 | | |
42 | | void reset() override; |
43 | | |
44 | 762 | size_t tag_size() const override { return m_tag_size; } |
45 | | |
46 | | protected: |
47 | | CCM_Mode(BlockCipher* cipher, size_t tag_size, size_t L); |
48 | | |
49 | 1.36k | size_t L() const { return m_L; } |
50 | | |
51 | 227 | const BlockCipher& cipher() const { return *m_cipher; } |
52 | | |
53 | | void encode_length(uint64_t len, uint8_t out[]); |
54 | | |
55 | | void inc(secure_vector<uint8_t>& C); |
56 | | |
57 | 227 | const secure_vector<uint8_t>& ad_buf() const { return m_ad_buf; } |
58 | | |
59 | 454 | secure_vector<uint8_t>& msg_buf() { return m_msg_buf; } |
60 | | |
61 | | secure_vector<uint8_t> format_b0(size_t msg_size); |
62 | | secure_vector<uint8_t> format_c0(); |
63 | | private: |
64 | | void start_msg(const uint8_t nonce[], size_t nonce_len) override; |
65 | | |
66 | | void key_schedule(const uint8_t key[], size_t length) override; |
67 | | |
68 | | const size_t m_tag_size; |
69 | | const size_t m_L; |
70 | | |
71 | | std::unique_ptr<BlockCipher> m_cipher; |
72 | | secure_vector<uint8_t> m_nonce, m_msg_buf, m_ad_buf; |
73 | | }; |
74 | | |
75 | | /** |
76 | | * CCM Encryption |
77 | | */ |
78 | | class CCM_Encryption final : public CCM_Mode |
79 | | { |
80 | | public: |
81 | | /** |
82 | | * @param cipher a 128-bit block cipher |
83 | | * @param tag_size is how big the auth tag will be (even values |
84 | | * between 4 and 16 are accepted) |
85 | | * @param L length of L parameter. The total message length |
86 | | * must be less than 2**L bytes, and the nonce is 15-L bytes. |
87 | | */ |
88 | | CCM_Encryption(BlockCipher* cipher, size_t tag_size = 16, size_t L = 3) : |
89 | 129 | CCM_Mode(cipher, tag_size, L) {} |
90 | | |
91 | | void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override; |
92 | | |
93 | | size_t output_length(size_t input_length) const override |
94 | 211 | { return input_length + tag_size(); } |
95 | | |
96 | 0 | size_t minimum_final_size() const override { return 0; } |
97 | | }; |
98 | | |
99 | | /** |
100 | | * CCM Decryption |
101 | | */ |
102 | | class CCM_Decryption final : public CCM_Mode |
103 | | { |
104 | | public: |
105 | | /** |
106 | | * @param cipher a 128-bit block cipher |
107 | | * @param tag_size is how big the auth tag will be (even values |
108 | | * between 4 and 16 are accepted) |
109 | | * @param L length of L parameter. The total message length |
110 | | * must be less than 2**L bytes, and the nonce is 15-L bytes. |
111 | | */ |
112 | | CCM_Decryption(BlockCipher* cipher, size_t tag_size = 16, size_t L = 3) : |
113 | 165 | CCM_Mode(cipher, tag_size, L) {} |
114 | | |
115 | | void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override; |
116 | | |
117 | | size_t output_length(size_t input_length) const override |
118 | 16 | { |
119 | 16 | BOTAN_ASSERT(input_length >= tag_size(), "Sufficient input"); |
120 | 16 | return input_length - tag_size(); |
121 | 16 | } |
122 | | |
123 | 17 | size_t minimum_final_size() const override { return tag_size(); } |
124 | | }; |
125 | | |
126 | | } |
127 | | |
128 | | #endif |