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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/*
* Blowfish
* (C) 1999-2011 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/blowfish.h>
#include <botan/loadstor.h>
namespace Botan {
/*
* Blowfish Encryption
*/
void Blowfish::encrypt_n(const byte in[], byte out[], size_t blocks) const
{
const u32bit* S1 = &S[0];
const u32bit* S2 = &S[256];
const u32bit* S3 = &S[512];
const u32bit* S4 = &S[768];
for(size_t i = 0; i != blocks; ++i)
{
u32bit L = load_be<u32bit>(in, 0);
u32bit R = load_be<u32bit>(in, 1);
for(size_t j = 0; j != 16; j += 2)
{
L ^= P[j];
R ^= ((S1[get_byte(0, L)] + S2[get_byte(1, L)]) ^
S3[get_byte(2, L)]) + S4[get_byte(3, L)];
R ^= P[j+1];
L ^= ((S1[get_byte(0, R)] + S2[get_byte(1, R)]) ^
S3[get_byte(2, R)]) + S4[get_byte(3, R)];
}
L ^= P[16]; R ^= P[17];
store_be(out, R, L);
in += BLOCK_SIZE;
out += BLOCK_SIZE;
}
}
/*
* Blowfish Decryption
*/
void Blowfish::decrypt_n(const byte in[], byte out[], size_t blocks) const
{
const u32bit* S1 = &S[0];
const u32bit* S2 = &S[256];
const u32bit* S3 = &S[512];
const u32bit* S4 = &S[768];
for(size_t i = 0; i != blocks; ++i)
{
u32bit L = load_be<u32bit>(in, 0);
u32bit R = load_be<u32bit>(in, 1);
for(size_t j = 17; j != 1; j -= 2)
{
L ^= P[j];
R ^= ((S1[get_byte(0, L)] + S2[get_byte(1, L)]) ^
S3[get_byte(2, L)]) + S4[get_byte(3, L)];
R ^= P[j-1];
L ^= ((S1[get_byte(0, R)] + S2[get_byte(1, R)]) ^
S3[get_byte(2, R)]) + S4[get_byte(3, R)];
}
L ^= P[1]; R ^= P[0];
store_be(out, R, L);
in += BLOCK_SIZE;
out += BLOCK_SIZE;
}
}
/*
* Blowfish Key Schedule
*/
void Blowfish::key_schedule(const byte key[], size_t length)
{
P.resize(18);
std::copy(P_INIT, P_INIT + 18, P.begin());
S.resize(1024);
std::copy(S_INIT, S_INIT + 1024, S.begin());
const byte null_salt[16] = { 0 };
key_expansion(key, length, null_salt);
}
void Blowfish::key_expansion(const byte key[],
size_t length,
const byte salt[16])
{
for(size_t i = 0, j = 0; i != 18; ++i, j += 4)
P[i] ^= make_u32bit(key[(j ) % length], key[(j+1) % length],
key[(j+2) % length], key[(j+3) % length]);
u32bit L = 0, R = 0;
generate_sbox(P, L, R, salt, 0);
generate_sbox(S, L, R, salt, 2);
}
/*
* Modified key schedule used for bcrypt password hashing
*/
void Blowfish::eks_key_schedule(const byte key[], size_t length,
const byte salt[16], size_t workfactor)
{
// Truncate longer passwords to the 56 byte limit Blowfish enforces
length = std::min<size_t>(length, 55);
if(workfactor == 0)
throw std::invalid_argument("Bcrypt work factor must be at least 1");
/*
* On a 2.8 GHz Core-i7, workfactor == 18 takes about 25 seconds to
* hash a password. This seems like a reasonable upper bound for the
* time being.
*/
if(workfactor > 18)
throw std::invalid_argument("Requested Bcrypt work factor too large");
P.resize(18);
std::copy(P_INIT, P_INIT + 18, P.begin());
S.resize(1024);
std::copy(S_INIT, S_INIT + 1024, S.begin());
key_expansion(key, length, salt);
const byte null_salt[16] = { 0 };
const size_t rounds = 1 << workfactor;
for(size_t r = 0; r != rounds; ++r)
{
key_expansion(key, length, null_salt);
key_expansion(salt, 16, null_salt);
}
}
/*
* Generate one of the Sboxes
*/
void Blowfish::generate_sbox(secure_vector<u32bit>& box,
u32bit& L, u32bit& R,
const byte salt[16],
size_t salt_off) const
{
const u32bit* S1 = &S[0];
const u32bit* S2 = &S[256];
const u32bit* S3 = &S[512];
const u32bit* S4 = &S[768];
for(size_t i = 0; i != box.size(); i += 2)
{
L ^= load_be<u32bit>(salt, (i + salt_off) % 4);
R ^= load_be<u32bit>(salt, (i + salt_off + 1) % 4);
for(size_t j = 0; j != 16; j += 2)
{
L ^= P[j];
R ^= ((S1[get_byte(0, L)] + S2[get_byte(1, L)]) ^
S3[get_byte(2, L)]) + S4[get_byte(3, L)];
R ^= P[j+1];
L ^= ((S1[get_byte(0, R)] + S2[get_byte(1, R)]) ^
S3[get_byte(2, R)]) + S4[get_byte(3, R)];
}
u32bit T = R; R = L ^ P[16]; L = T ^ P[17];
box[i] = L;
box[i+1] = R;
}
}
/*
* Clear memory of sensitive data
*/
void Blowfish::clear()
{
P.clear();
S.clear();
}
}
|
