2 * SHA1 hash algorithm. Used in SSH2 as a MAC, and the transform is
3 * also used as a `stirring' function for the PuTTY random number
4 * pool. Implemented directly from the specification by Simon
10 /* ----------------------------------------------------------------------
11 * Core SHA algorithm: processes 16-word blocks into a message digest.
14 #define rol(x,y) ( ((x) << (y)) | (((uint32)x) >> (32-y)) )
16 void SHA_Core_Init(uint32 h
[5])
25 void SHATransform(word32
* digest
, word32
* block
)
31 for (t
= 0; t
< 16; t
++)
34 for (t
= 16; t
< 80; t
++) {
35 word32 tmp
= w
[t
- 3] ^ w
[t
- 8] ^ w
[t
- 14] ^ w
[t
- 16];
45 for (t
= 0; t
< 20; t
++) {
47 rol(a
, 5) + ((b
& c
) | (d
& ~b
)) + e
+ w
[t
] + 0x5a827999;
54 for (t
= 20; t
< 40; t
++) {
55 word32 tmp
= rol(a
, 5) + (b
^ c
^ d
) + e
+ w
[t
] + 0x6ed9eba1;
62 for (t
= 40; t
< 60; t
++) {
64 5) + ((b
& c
) | (b
& d
) | (c
& d
)) + e
+ w
[t
] +
72 for (t
= 60; t
< 80; t
++) {
73 word32 tmp
= rol(a
, 5) + (b
^ c
^ d
) + e
+ w
[t
] + 0xca62c1d6;
88 /* ----------------------------------------------------------------------
89 * Outer SHA algorithm: take an arbitrary length byte string,
90 * convert it into 16-word blocks with the prescribed padding at
91 * the end, and pass those blocks to the core SHA algorithm.
94 void SHA_Init(SHA_State
* s
)
98 s
->lenhi
= s
->lenlo
= 0;
101 void SHA_Bytes(SHA_State
* s
, void *p
, int len
)
103 unsigned char *q
= (unsigned char *) p
;
104 uint32 wordblock
[16];
109 * Update the length field.
112 s
->lenhi
+= (s
->lenlo
< lenw
);
114 if (s
->blkused
&& s
->blkused
+ len
< 64) {
116 * Trivial case: just add to the block.
118 memcpy(s
->block
+ s
->blkused
, q
, len
);
122 * We must complete and process at least one block.
124 while (s
->blkused
+ len
>= 64) {
125 memcpy(s
->block
+ s
->blkused
, q
, 64 - s
->blkused
);
126 q
+= 64 - s
->blkused
;
127 len
-= 64 - s
->blkused
;
128 /* Now process the block. Gather bytes big-endian into words */
129 for (i
= 0; i
< 16; i
++) {
131 (((uint32
) s
->block
[i
* 4 + 0]) << 24) |
132 (((uint32
) s
->block
[i
* 4 + 1]) << 16) |
133 (((uint32
) s
->block
[i
* 4 + 2]) << 8) |
134 (((uint32
) s
->block
[i
* 4 + 3]) << 0);
136 SHATransform(s
->h
, wordblock
);
139 memcpy(s
->block
, q
, len
);
144 void SHA_Final(SHA_State
* s
, unsigned char *output
)
151 if (s
->blkused
>= 56)
152 pad
= 56 + 64 - s
->blkused
;
154 pad
= 56 - s
->blkused
;
156 lenhi
= (s
->lenhi
<< 3) | (s
->lenlo
>> (32 - 3));
157 lenlo
= (s
->lenlo
<< 3);
161 SHA_Bytes(s
, &c
, pad
);
163 c
[0] = (lenhi
>> 24) & 0xFF;
164 c
[1] = (lenhi
>> 16) & 0xFF;
165 c
[2] = (lenhi
>> 8) & 0xFF;
166 c
[3] = (lenhi
>> 0) & 0xFF;
167 c
[4] = (lenlo
>> 24) & 0xFF;
168 c
[5] = (lenlo
>> 16) & 0xFF;
169 c
[6] = (lenlo
>> 8) & 0xFF;
170 c
[7] = (lenlo
>> 0) & 0xFF;
174 for (i
= 0; i
< 5; i
++) {
175 output
[i
* 4] = (s
->h
[i
] >> 24) & 0xFF;
176 output
[i
* 4 + 1] = (s
->h
[i
] >> 16) & 0xFF;
177 output
[i
* 4 + 2] = (s
->h
[i
] >> 8) & 0xFF;
178 output
[i
* 4 + 3] = (s
->h
[i
]) & 0xFF;
182 void SHA_Simple(void *p
, int len
, unsigned char *output
)
187 SHA_Bytes(&s
, p
, len
);
188 SHA_Final(&s
, output
);
191 /* ----------------------------------------------------------------------
192 * The above is the SHA-1 algorithm itself. Now we implement the
193 * HMAC wrapper on it.
196 static SHA_State sha1_cs_mac_s1
, sha1_cs_mac_s2
;
197 static SHA_State sha1_sc_mac_s1
, sha1_sc_mac_s2
;
199 static void sha1_key(SHA_State
* s1
, SHA_State
* s2
,
200 unsigned char *key
, int len
)
202 unsigned char foo
[64];
205 memset(foo
, 0x36, 64);
206 for (i
= 0; i
< len
&& i
< 64; i
++)
209 SHA_Bytes(s1
, foo
, 64);
211 memset(foo
, 0x5C, 64);
212 for (i
= 0; i
< len
&& i
< 64; i
++)
215 SHA_Bytes(s2
, foo
, 64);
217 memset(foo
, 0, 64); /* burn the evidence */
220 static void sha1_cskey(unsigned char *key
)
222 sha1_key(&sha1_cs_mac_s1
, &sha1_cs_mac_s2
, key
, 20);
225 static void sha1_sckey(unsigned char *key
)
227 sha1_key(&sha1_sc_mac_s1
, &sha1_sc_mac_s2
, key
, 20);
230 static void sha1_cskey_buggy(unsigned char *key
)
232 sha1_key(&sha1_cs_mac_s1
, &sha1_cs_mac_s2
, key
, 16);
235 static void sha1_sckey_buggy(unsigned char *key
)
237 sha1_key(&sha1_sc_mac_s1
, &sha1_sc_mac_s2
, key
, 16);
240 static void sha1_do_hmac(SHA_State
* s1
, SHA_State
* s2
,
241 unsigned char *blk
, int len
, unsigned long seq
,
245 unsigned char intermediate
[20];
247 intermediate
[0] = (unsigned char) ((seq
>> 24) & 0xFF);
248 intermediate
[1] = (unsigned char) ((seq
>> 16) & 0xFF);
249 intermediate
[2] = (unsigned char) ((seq
>> 8) & 0xFF);
250 intermediate
[3] = (unsigned char) ((seq
) & 0xFF);
252 s
= *s1
; /* structure copy */
253 SHA_Bytes(&s
, intermediate
, 4);
254 SHA_Bytes(&s
, blk
, len
);
255 SHA_Final(&s
, intermediate
);
256 s
= *s2
; /* structure copy */
257 SHA_Bytes(&s
, intermediate
, 20);
261 static void sha1_generate(unsigned char *blk
, int len
, unsigned long seq
)
263 sha1_do_hmac(&sha1_cs_mac_s1
, &sha1_cs_mac_s2
, blk
, len
, seq
,
267 static int sha1_verify(unsigned char *blk
, int len
, unsigned long seq
)
269 unsigned char correct
[20];
270 sha1_do_hmac(&sha1_sc_mac_s1
, &sha1_sc_mac_s2
, blk
, len
, seq
, correct
);
271 return !memcmp(correct
, blk
+ len
, 20);
274 const struct ssh_mac ssh_sha1
= {
275 sha1_cskey
, sha1_sckey
,
282 const struct ssh_mac ssh_sha1_buggy
= {
283 sha1_cskey_buggy
, sha1_sckey_buggy
,