Botan 2.1.0 Crypto and TLS for C++11

- Main Page
- Namespaces
- Classes
- Files

- File List
- File Members

chacha20poly1305.h
Go to the documentation of this file.
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 */
24 class BOTAN_DLL ChaCha20Poly1305_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 { return "ChaCha20Poly1305"; }
30
31 size_t update_granularity() const override { return 64; }
32
33 Key_Length_Specification key_spec() const override
34 { return Key_Length_Specification(32); }
35
36 bool valid_nonce_length(size_t n) const override;
37
38 size_t tag_size() const override { return 16; }
39
40 void clear() override;
41
42 void reset() override;
43
44 protected:
45 std::unique_ptr<StreamCipher> m_chacha;
46 std::unique_ptr<MessageAuthenticationCode> m_poly1305;
47
48 ChaCha20Poly1305_Mode();
49
50 secure_vector<uint8_t> m_ad;
51 size_t m_nonce_len = 0;
52 size_t m_ctext_len = 0;
53
54 bool cfrg_version() const { return m_nonce_len == 12; }
55 void update_len(size_t len);
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
62 /**
63 * ChaCha20Poly1305 Encryption
64 */
65 class BOTAN_DLL ChaCha20Poly1305_Encryption final : public ChaCha20Poly1305_Mode
66 {
67 public:
68 size_t output_length(size_t input_length) const override
69 { return input_length + tag_size(); }
70
71 size_t minimum_final_size() const override { return 0; }
72
73 size_t process(uint8_t buf[], size_t size) override;
74
75 void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
76 };
77
78 /**
79 * ChaCha20Poly1305 Decryption
80 */
81 class BOTAN_DLL ChaCha20Poly1305_Decryption final : public ChaCha20Poly1305_Mode
82 {
83 public:
84 size_t output_length(size_t input_length) const override
85 {
86 BOTAN_ASSERT(input_length >= tag_size(), "Sufficient input");
87 return input_length - tag_size();
88 }
89
90 size_t minimum_final_size() const override { return tag_size(); }
91
92 size_t process(uint8_t buf[], size_t size) override;
93
94 void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
95 };
96
97 }
98
99 #endif
Botan::ChaCha20Poly1305_Mode::m_poly1305
std::unique_ptr< MessageAuthenticationCode > m_poly1305
Definition: chacha20poly1305.h:46
Botan::Key_Length_Specification
Definition: key_spec.h:18
Botan::ChaCha20Poly1305_Mode::m_chacha
std::unique_ptr< StreamCipher > m_chacha
Definition: chacha20poly1305.h:45
Botan::ChaCha20Poly1305_Decryption
Definition: chacha20poly1305.h:81
BOTAN_ASSERT
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:27
Botan::ChaCha20Poly1305_Decryption::minimum_final_size
size_t minimum_final_size() const override
Definition: chacha20poly1305.h:90
Botan::ChaCha20Poly1305_Encryption
Definition: chacha20poly1305.h:65
Botan::secure_vector
std::vector< T, secure_allocator< T >> secure_vector
Definition: secmem.h:121
Botan::ChaCha20Poly1305_Encryption::minimum_final_size
size_t minimum_final_size() const override
Definition: chacha20poly1305.h:71
Botan::ChaCha20Poly1305_Mode::tag_size
size_t tag_size() const override
Definition: chacha20poly1305.h:38
Botan::ChaCha20Poly1305_Mode::m_ad
secure_vector< uint8_t > m_ad
Definition: chacha20poly1305.h:50
Botan
Definition: alg_id.cpp:13
Botan::ChaCha20Poly1305_Mode::cfrg_version
bool cfrg_version() const
Definition: chacha20poly1305.h:54
Botan::ChaCha20Poly1305_Encryption::output_length
size_t output_length(size_t input_length) const override
Definition: chacha20poly1305.h:68
Botan::ChaCha20Poly1305_Decryption::output_length
size_t output_length(size_t input_length) const override
Definition: chacha20poly1305.h:84
Botan::AEAD_Mode
Definition: aead.h:22
Botan::ChaCha20Poly1305_Mode
Definition: chacha20poly1305.h:24
Botan::ChaCha20Poly1305_Mode::key_spec
Key_Length_Specification key_spec() const override
Definition: chacha20poly1305.h:33
Botan::ChaCha20Poly1305_Mode::name
std::string name() const override
Definition: chacha20poly1305.h:29
Botan::ChaCha20Poly1305_Mode::update_granularity
size_t update_granularity() const override
Definition: chacha20poly1305.h:31