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
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
/* aes-ctr.c */
/* AES in CTR mode. */
/* Hongjun Wu, January 2007*/
/* ------------------------------------------------------------------------- */
#include "api.h"
#include "aes256.h"
#include <string.h>
/* ------------------------------------------------------------------------- */
/* key setup for AES-256*/
static void
ECRYPT_keysetup(ECRYPT_ctx* ctx, const u8* key, u32 keysize, u32 ivsize)
{
unsigned int w[Nk*(Nr+1)], temp;
int i, j;
(void) keysize;
(void) ivsize;
(void) sizeof(char[sizeof *ctx == crypto_stream_BEFORENMBYTES ? 1 : -1]);
for( i = 0; i < Nk; i++ ) {
w[i] = key[(i << 2)];
w[i] |= key[(i << 2)+1] << 8;
w[i] |= key[(i << 2)+2] << 16;
w[i] |= (unsigned int) key[(i << 2)+3] << 24;
}
i = Nk;
while( i < Nb*(Nr+1) ) {
temp = w[i-1];
temp = (unsigned int) Sbox[temp & 0xFF] << 24 ^
Sbox[(temp >> 8) & 0xFF] ^
(Sbox[(temp >> 16) & 0xFF] << 8 ) ^
(Sbox[(temp >> 24) & 0xFF] << 16) ^
Rcon[i/Nk];
w[i] = w[i-Nk] ^ temp;
i++;
temp = w[i-1];
w[i] = w[i-Nk] ^ temp;
i++;
temp = w[i-1];
w[i] = w[i-Nk] ^ temp;
i++;
temp = w[i-1];
w[i] = w[i-Nk] ^ temp;
i++;
temp = w[i-1];
temp = Sbox[temp & 0xFF] ^
Sbox[(temp >> 8) & 0xFF] << 8 ^
(Sbox[(temp >> 16) & 0xFF] << 16) ^
((unsigned int) Sbox[(temp >> 24) & 0xFF] << 24);
w[i] = w[i-Nk] ^ temp;
i++;
temp = w[i-1];
w[i] = w[i-Nk] ^ temp;
i++;
temp = w[i-1];
w[i] = w[i-Nk] ^ temp;
i++;
temp = w[i-1];
w[i] = w[i-Nk] ^ temp;
i++;
}
for (i = 0; i <= Nr; i++) {
for (j = 0; j < Nb; j++) {
ctx->round_key[i][j] = SWP32(w[(i<<2)+j]);
}
}
}
/* ------------------------------------------------------------------------- */
static void
ECRYPT_ivsetup(ECRYPT_ctx* ctx, const u8* iv)
{
(void) sizeof(char[(sizeof ctx->counter) == crypto_stream_NONCEBYTES ? 1 : -1]);
memcpy(ctx->counter, iv, crypto_stream_NONCEBYTES);
}
/* ------------------------------------------------------------------------- */
/*compute the intermediate values for the first two rounds*/
static void
partial_precompute_tworounds(ECRYPT_ctx* ctx)
{
u32 x0,x1,x2,x3,y0,y1,y2,y3;
x0 = ctx->counter[0] ^ ctx->round_key[0][0];
x1 = ctx->counter[1] ^ ctx->round_key[0][1];
x2 = ctx->counter[2] ^ ctx->round_key[0][2];
x3 = ctx->counter[3] ^ ctx->round_key[0][3];
x0 &= SWP32(0xffffff00);
round(ctx,x0,x1,x2,x3,y0,y1,y2,y3,1);
ctx->first_round_output_x0 = y0 ^ T0[0];
y0 = 0;
round(ctx,y0,y1,y2,y3,x0,x1,x2,x3,2);
ctx->second_round_output[0] = x0 ^ T0[0];
ctx->second_round_output[1] = x1 ^ T3[0];
ctx->second_round_output[2] = x2 ^ T2[0];
ctx->second_round_output[3] = x3 ^ T1[0];
}
/* ------------------------------------------------------------------------- */
#ifndef CPU_ALIGNED_ACCESS_REQUIRED
# define UNALIGNED_U32_READ(P, I) (((const u32 *)(const void *) (P))[(I)])
#else
static inline uint32_t
UNALIGNED_U32_READ(const u8 * const p, const size_t i)
{
uint32_t t;
(void) sizeof(int[sizeof(*p) == sizeof(char) ? 1 : -1]);
memcpy(&t, p + i * (sizeof t / sizeof *p), sizeof t);
return t;
}
#endif
/* ------------------------------------------------------------------------- */
static void
ECRYPT_process_bytes(int action, ECRYPT_ctx* ctx, const u8* input, u8* output,
u32 msglen)
{
__attribute__((aligned(32))) u8 keystream[16];
u32 i;
(void) action;
memset(keystream, 0, sizeof keystream);
partial_precompute_tworounds(ctx);
for ( ; msglen >= 16; msglen -= 16, input += 16, output += 16) {
aes256_enc_block(ctx->counter, keystream, ctx);
((u32*)output)[0] = UNALIGNED_U32_READ(input, 0) ^ ((u32*)keystream)[0] ^ ctx->round_key[Nr][0];
((u32*)output)[1] = UNALIGNED_U32_READ(input, 1) ^ ((u32*)keystream)[1] ^ ctx->round_key[Nr][1];
((u32*)output)[2] = UNALIGNED_U32_READ(input, 2) ^ ((u32*)keystream)[2] ^ ctx->round_key[Nr][2];
((u32*)output)[3] = UNALIGNED_U32_READ(input, 3) ^ ((u32*)keystream)[3] ^ ctx->round_key[Nr][3];
ctx->counter[0] = SWP32(SWP32(ctx->counter[0]) + 1);
if ((ctx->counter[0] & SWP32(0xff))== 0) {
partial_precompute_tworounds(ctx);
}
}
if (msglen > 0) {
aes256_enc_block(ctx->counter, keystream, ctx);
((u32*)keystream)[0] ^= ctx->round_key[Nr][0];
((u32*)keystream)[1] ^= ctx->round_key[Nr][1];
((u32*)keystream)[2] ^= ctx->round_key[Nr][2];
((u32*)keystream)[3] ^= ctx->round_key[Nr][3];
for (i = 0; i < msglen; i ++) {
output[i] = input[i] ^ keystream[i];
}
}
}
/* ------------------------------------------------------------------------- */
#include "ecrypt-sync.h"
int
crypto_stream_beforenm(unsigned char *c, const unsigned char *k)
{
ECRYPT_ctx * const ctx = (ECRYPT_ctx *) c;
ECRYPT_keysetup(ctx, k, crypto_stream_KEYBYTES * 8,
crypto_stream_NONCEBYTES * 8);
return 0;
}
int
crypto_stream_afternm(unsigned char *out, unsigned long long len,
const unsigned char *nonce, const unsigned char *c)
{
ECRYPT_ctx * const ctx = (ECRYPT_ctx *) c;
unsigned long long i;
ECRYPT_ivsetup(ctx, nonce);
for (i = 0U; i < len; ++i) {
out[i] = 0U;
}
ECRYPT_encrypt_bytes(ctx, (u8 *) out, (u8 *) out, len);
return 0;
}
int
crypto_stream_xor_afternm(unsigned char *out, const unsigned char *in,
unsigned long long len, const unsigned char *nonce,
const unsigned char *c)
{
ECRYPT_ctx * const ctx = (ECRYPT_ctx *) c;
ECRYPT_ivsetup(ctx, nonce);
ECRYPT_encrypt_bytes(ctx, (const u8 *) in, (u8 *) out, len);
return 0;
}
int
crypto_stream(unsigned char *out, unsigned long long outlen,
const unsigned char *n, const unsigned char *k)
{
unsigned char d[crypto_stream_BEFORENMBYTES];
crypto_stream_beforenm(d, k);
crypto_stream_afternm(out, outlen, n, d);
return 0;
}
int crypto_stream_xor(unsigned char *out, const unsigned char *in,
unsigned long long inlen, const unsigned char *n,
const unsigned char *k)
{
unsigned char d[crypto_stream_BEFORENMBYTES];
crypto_stream_beforenm(d, k);
crypto_stream_xor_afternm(out, in, inlen, n, d);
return 0;
}
|
