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
|
/*
* CBC mode
* (C) 1999-2007,2013 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_MODE_CBC_H__
#define BOTAN_MODE_CBC_H__
#include <botan/cipher_mode.h>
#include <botan/block_cipher.h>
#include <botan/mode_pad.h>
namespace Botan {
/**
* CBC Mode
*/
class BOTAN_DLL CBC_Mode : public Cipher_Mode
{
public:
std::string name() const override;
size_t update_granularity() const override;
Key_Length_Specification key_spec() const override;
size_t default_nonce_length() const override;
bool valid_nonce_length(size_t n) const override;
void clear() override;
protected:
CBC_Mode(BlockCipher* cipher, BlockCipherModePaddingMethod* padding);
const BlockCipher& cipher() const { return *m_cipher; }
const BlockCipherModePaddingMethod& padding() const
{
BOTAN_ASSERT_NONNULL(m_padding);
return *m_padding;
}
secure_vector<byte>& state() { return m_state; }
byte* state_ptr() { return m_state.data(); }
private:
secure_vector<byte> start_raw(const byte nonce[], size_t nonce_len) override;
void key_schedule(const byte key[], size_t length) override;
std::unique_ptr<BlockCipher> m_cipher;
std::unique_ptr<BlockCipherModePaddingMethod> m_padding;
secure_vector<byte> m_state;
};
/**
* CBC Encryption
*/
class BOTAN_DLL CBC_Encryption : public CBC_Mode
{
public:
CBC_Encryption(BlockCipher* cipher, BlockCipherModePaddingMethod* padding) :
CBC_Mode(cipher, padding) {}
void update(secure_vector<byte>& blocks, size_t offset = 0) override;
void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
size_t output_length(size_t input_length) const override;
size_t minimum_final_size() const override;
};
/**
* CBC Encryption with ciphertext stealing (CBC-CS3 variant)
*/
class BOTAN_DLL CTS_Encryption final : public CBC_Encryption
{
public:
explicit CTS_Encryption(BlockCipher* cipher) : CBC_Encryption(cipher, nullptr) {}
size_t output_length(size_t input_length) const override;
void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
size_t minimum_final_size() const override;
bool valid_nonce_length(size_t n) const override;
};
/**
* CBC Decryption
*/
class BOTAN_DLL CBC_Decryption : public CBC_Mode
{
public:
CBC_Decryption(BlockCipher* cipher, BlockCipherModePaddingMethod* padding) :
CBC_Mode(cipher, padding), m_tempbuf(update_granularity()) {}
void update(secure_vector<byte>& blocks, size_t offset = 0) override;
void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
size_t output_length(size_t input_length) const override;
size_t minimum_final_size() const override;
private:
secure_vector<byte> m_tempbuf;
};
/**
* CBC Decryption with ciphertext stealing (CBC-CS3 variant)
*/
class BOTAN_DLL CTS_Decryption final : public CBC_Decryption
{
public:
explicit CTS_Decryption(BlockCipher* cipher) : CBC_Decryption(cipher, nullptr) {}
void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
size_t minimum_final_size() const override;
bool valid_nonce_length(size_t n) const override;
};
}
#endif
|
