1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
/*
* TLS CBC+HMAC AEAD
* (C) 2016 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_TLS_CBC_HMAC_AEAD_H__
#define BOTAN_TLS_CBC_HMAC_AEAD_H__
#include <botan/aead.h>
#include <botan/block_cipher.h>
#include <botan/mac.h>
namespace Botan {
namespace TLS {
/**
* TLS CBC+HMAC AEAD base class (GenericBlockCipher in TLS spec)
* This is the weird TLS-specific mode, not for general consumption.
*/
class TLS_CBC_HMAC_AEAD_Mode : public AEAD_Mode
{
public:
size_t process(uint8_t buf[], size_t sz) override final;
std::string name() const override final;
void set_associated_data(const byte ad[], size_t ad_len) override;
size_t update_granularity() const override final;
Key_Length_Specification key_spec() const override final;
bool valid_nonce_length(size_t nl) const override final;
size_t tag_size() const override final { return m_tag_size; }
size_t default_nonce_length() const override final { return m_iv_size; }
void clear() override final;
protected:
TLS_CBC_HMAC_AEAD_Mode(const std::string& cipher_name,
size_t cipher_keylen,
const std::string& mac_name,
size_t mac_keylen,
bool use_explicit_iv,
bool use_encrypt_then_mac);
size_t cipher_keylen() const { return m_cipher_keylen; }
size_t mac_keylen() const { return m_mac_keylen; }
size_t iv_size() const { return m_iv_size; }
size_t block_size() const { return m_block_size; }
bool use_encrypt_then_mac() const { return m_use_encrypt_then_mac; }
BlockCipher& cipher() const
{
BOTAN_ASSERT_NONNULL(m_cipher);
return *m_cipher;
}
MessageAuthenticationCode& mac() const
{
BOTAN_ASSERT_NONNULL(m_mac);
return *m_mac;
}
secure_vector<byte>& cbc_state() { return m_cbc_state; }
std::vector<byte>& assoc_data() { return m_ad; }
secure_vector<byte>& msg() { return m_msg; }
std::vector<byte> assoc_data_with_len(uint16_t len);
private:
void start_msg(const byte nonce[], size_t nonce_len) override final;
void key_schedule(const byte key[], size_t length) override final;
const std::string m_cipher_name;
const std::string m_mac_name;
size_t m_cipher_keylen;
size_t m_mac_keylen;
size_t m_iv_size;
size_t m_tag_size;
size_t m_block_size;
bool m_use_encrypt_then_mac;
std::unique_ptr<BlockCipher> m_cipher;
std::unique_ptr<MessageAuthenticationCode> m_mac;
secure_vector<byte> m_cbc_state;
std::vector<byte> m_ad;
secure_vector<byte> m_msg;
};
/**
* TLS_CBC_HMAC_AEAD Encryption
*/
class BOTAN_DLL TLS_CBC_HMAC_AEAD_Encryption final : public TLS_CBC_HMAC_AEAD_Mode
{
public:
/**
*/
TLS_CBC_HMAC_AEAD_Encryption(const std::string& cipher_algo,
const size_t cipher_keylen,
const std::string& mac_algo,
const size_t mac_keylen,
bool use_explicit_iv,
bool use_encrypt_then_mac) :
TLS_CBC_HMAC_AEAD_Mode(cipher_algo,
cipher_keylen,
mac_algo,
mac_keylen,
use_explicit_iv,
use_encrypt_then_mac)
{}
void set_associated_data(const byte ad[], size_t ad_len) override;
size_t output_length(size_t input_length) const override;
size_t minimum_final_size() const override { return 0; }
void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
private:
void cbc_encrypt_record(byte record_contents[], size_t record_len);
};
/**
* TLS_CBC_HMAC_AEAD Decryption
*/
class BOTAN_DLL TLS_CBC_HMAC_AEAD_Decryption final : public TLS_CBC_HMAC_AEAD_Mode
{
public:
/**
*/
TLS_CBC_HMAC_AEAD_Decryption(const std::string& cipher_algo,
const size_t cipher_keylen,
const std::string& mac_algo,
const size_t mac_keylen,
bool use_explicit_iv,
bool use_encrypt_then_mac) :
TLS_CBC_HMAC_AEAD_Mode(cipher_algo,
cipher_keylen,
mac_algo,
mac_keylen,
use_explicit_iv,
use_encrypt_then_mac)
{}
size_t output_length(size_t input_length) const override;
size_t minimum_final_size() const override { return tag_size(); }
void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
private:
void cbc_decrypt_record(byte record_contents[], size_t record_len);
void perform_additional_compressions(size_t plen, size_t padlen);
};
}
}
#endif
|
