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 void *sha1_make_context(void)
198 return smalloc(2*sizeof(SHA_State
));
201 static void sha1_free_context(void *handle
)
206 static void sha1_key_internal(void *handle
, unsigned char *key
, int len
)
208 SHA_State
*keys
= (SHA_State
*)handle
;
209 unsigned char foo
[64];
212 memset(foo
, 0x36, 64);
213 for (i
= 0; i
< len
&& i
< 64; i
++)
216 SHA_Bytes(&keys
[0], foo
, 64);
218 memset(foo
, 0x5C, 64);
219 for (i
= 0; i
< len
&& i
< 64; i
++)
222 SHA_Bytes(&keys
[1], foo
, 64);
224 memset(foo
, 0, 64); /* burn the evidence */
227 static void sha1_key(void *handle
, unsigned char *key
)
229 sha1_key_internal(handle
, key
, 20);
232 static void sha1_key_buggy(void *handle
, unsigned char *key
)
234 sha1_key_internal(handle
, key
, 16);
237 static void sha1_do_hmac(void *handle
, unsigned char *blk
, int len
,
238 unsigned long seq
, unsigned char *hmac
)
240 SHA_State
*keys
= (SHA_State
*)handle
;
242 unsigned char intermediate
[20];
244 intermediate
[0] = (unsigned char) ((seq
>> 24) & 0xFF);
245 intermediate
[1] = (unsigned char) ((seq
>> 16) & 0xFF);
246 intermediate
[2] = (unsigned char) ((seq
>> 8) & 0xFF);
247 intermediate
[3] = (unsigned char) ((seq
) & 0xFF);
249 s
= keys
[0]; /* structure copy */
250 SHA_Bytes(&s
, intermediate
, 4);
251 SHA_Bytes(&s
, blk
, len
);
252 SHA_Final(&s
, intermediate
);
253 s
= keys
[1]; /* structure copy */
254 SHA_Bytes(&s
, intermediate
, 20);
258 static void sha1_generate(void *handle
, unsigned char *blk
, int len
,
261 sha1_do_hmac(handle
, blk
, len
, seq
, blk
+ len
);
264 static int sha1_verify(void *handle
, unsigned char *blk
, int len
,
267 unsigned char correct
[20];
268 sha1_do_hmac(handle
, blk
, len
, seq
, correct
);
269 return !memcmp(correct
, blk
+ len
, 20);
272 void hmac_sha1_simple(void *key
, int keylen
, void *data
, int datalen
,
273 unsigned char *output
) {
275 unsigned char intermediate
[20];
277 sha1_key_internal(states
, key
, keylen
);
278 SHA_Bytes(&states
[0], data
, datalen
);
279 SHA_Final(&states
[0], intermediate
);
281 SHA_Bytes(&states
[1], intermediate
, 20);
282 SHA_Final(&states
[1], output
);
285 const struct ssh_mac ssh_sha1
= {
286 sha1_make_context
, sha1_free_context
, sha1_key
,
287 sha1_generate
, sha1_verify
,
292 const struct ssh_mac ssh_sha1_buggy
= {
293 sha1_make_context
, sha1_free_context
, sha1_key_buggy
,
294 sha1_generate
, sha1_verify
,