Botan 2.19.3
Crypto and TLS for C&
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
16BOTAN_FUTURE_INTERNAL_HEADER(chacha20poly1305.h)
17
18namespace Botan {
19
20/**
21* Base class
22* See draft-irtf-cfrg-chacha20-poly1305-03 for specification
23* If a nonce of 64 bits is used the older version described in
24* draft-agl-tls-chacha20poly1305-04 is used instead.
25* If a nonce of 192 bits is used, XChaCha20Poly1305 is selected.
26*/
28 {
29 public:
30 void set_associated_data(const uint8_t ad[], size_t ad_len) override;
31
32 bool associated_data_requires_key() const override { return false; }
33
34 std::string name() const override { return "ChaCha20Poly1305"; }
35
36 size_t update_granularity() const override { return 64; }
37
39 { return Key_Length_Specification(32); }
40
41 bool valid_nonce_length(size_t n) const override;
42
43 size_t tag_size() const override { return 16; }
44
45 void clear() override;
46
47 void reset() override;
48
49 protected:
50 std::unique_ptr<StreamCipher> m_chacha;
51 std::unique_ptr<MessageAuthenticationCode> m_poly1305;
52
54
56 size_t m_nonce_len = 0;
57 size_t m_ctext_len = 0;
58
59 bool cfrg_version() const { return m_nonce_len == 12 || m_nonce_len == 24; }
60 void update_len(size_t len);
61 private:
62 void start_msg(const uint8_t nonce[], size_t nonce_len) override;
63
64 void key_schedule(const uint8_t key[], size_t length) override;
65 };
66
67/**
68* ChaCha20Poly1305 Encryption
69*/
71 {
72 public:
73 size_t output_length(size_t input_length) const override
74 { return input_length + tag_size(); }
75
76 size_t minimum_final_size() const override { return 0; }
77
78 size_t process(uint8_t buf[], size_t size) override;
79
80 void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
81 };
82
83/**
84* ChaCha20Poly1305 Decryption
85*/
87 {
88 public:
89 size_t output_length(size_t input_length) const override
90 {
91 BOTAN_ASSERT(input_length >= tag_size(), "Sufficient input");
92 return input_length - tag_size();
93 }
94
95 size_t minimum_final_size() const override { return tag_size(); }
96
97 size_t process(uint8_t buf[], size_t size) override;
98
99 void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) override;
100 };
101
102}
103
104#endif
#define BOTAN_ASSERT(expr, assertion_made)
Definition assert.h:55
virtual void set_associated_data(const uint8_t ad[], size_t ad_len)=0
size_t output_length(size_t input_length) const override
size_t minimum_final_size() const override
size_t minimum_final_size() const override
size_t output_length(size_t input_length) const override
secure_vector< uint8_t > m_ad
std::string name() const override
std::unique_ptr< StreamCipher > m_chacha
size_t update_granularity() const override
size_t tag_size() const override
bool associated_data_requires_key() const override
Key_Length_Specification key_spec() const override
std::unique_ptr< MessageAuthenticationCode > m_poly1305
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0
virtual size_t process(uint8_t msg[], size_t msg_len)=0
virtual void reset()=0
virtual void finish(secure_vector< uint8_t > &final_block, size_t offset=0)=0
virtual size_t tag_size() const
virtual bool valid_nonce_length(size_t nonce_len) const =0
virtual void clear()=0
int(* final)(unsigned char *, CTX *)
#define BOTAN_PUBLIC_API(maj, min)
Definition compiler.h:31
#define BOTAN_FUTURE_INTERNAL_HEADER(hdr)
Definition compiler.h:136
std::vector< T, secure_allocator< T > > secure_vector
Definition secmem.h:65