1 #include "os.h"
2 #include <libsec.h>
3 
4 static void encode(uchar*, u32int*, ulong);
5 
6 extern void _sha1block(uchar*, ulong, u32int*);
7 
8 /*
9  *  we require len to be a multiple of 64 for all but
10  *  the last call.  There must be room in the input buffer
11  *  to pad.
12  */
13 SHA1state*
14 sha1(uchar *p, ulong len, uchar *digest, SHA1state *s)
15 {
16 	uchar buf[128];
17 	u32int x[16];
18 	int i;
19 	uchar *e;
20 
21 	if(s == nil){
22 		s = malloc(sizeof(*s));
23 		if(s == nil)
24 			return nil;
25 		memset(s, 0, sizeof(*s));
26 		s->malloced = 1;
27 	}
28 
29 	if(s->seeded == 0){
30 		/* seed the state, these constants would look nicer big-endian */
31 		s->state[0] = 0x67452301;
32 		s->state[1] = 0xefcdab89;
33 		s->state[2] = 0x98badcfe;
34 		s->state[3] = 0x10325476;
35 		s->state[4] = 0xc3d2e1f0;
36 		s->seeded = 1;
37 	}
38 
39 	/* fill out the partial 64 byte block from previous calls */
40 	if(s->blen){
41 		i = 64 - s->blen;
42 		if(len < i)
43 			i = len;
44 		memmove(s->buf + s->blen, p, i);
45 		len -= i;
46 		s->blen += i;
47 		p += i;
48 		if(s->blen == 64){
49 			_sha1block(s->buf, s->blen, s->state);
50 			s->len += s->blen;
51 			s->blen = 0;
52 		}
53 	}
54 
55 	/* do 64 byte blocks */
56 	i = len & ~0x3f;
57 	if(i){
58 		_sha1block(p, i, s->state);
59 		s->len += i;
60 		len -= i;
61 		p += i;
62 	}
63 
64 	/* save the left overs if not last call */
65 	if(digest == 0){
66 		if(len){
67 			memmove(s->buf, p, len);
68 			s->blen += len;
69 		}
70 		return s;
71 	}
72 
73 	/*
74 	 *  this is the last time through, pad what's left with 0x80,
75 	 *  0's, and the input count to create a multiple of 64 bytes
76 	 */
77 	if(s->blen){
78 		p = s->buf;
79 		len = s->blen;
80 	} else {
81 		memmove(buf, p, len);
82 		p = buf;
83 	}
84 	s->len += len;
85 	e = p + len;
86 	if(len < 56)
87 		i = 56 - len;
88 	else
89 		i = 120 - len;
90 	memset(e, 0, i);
91 	*e = 0x80;
92 	len += i;
93 
94 	/* append the count */
95 	x[0] = s->len>>29;
96 	x[1] = s->len<<3;
97 	encode(p+len, x, 8);
98 
99 	/* digest the last part */
100 	_sha1block(p, len+8, s->state);
101 	s->len += len+8;
102 
103 	/* return result and free state */
104 	encode(digest, s->state, SHA1dlen);
105 	if(s->malloced == 1)
106 		free(s);
107 	return nil;
108 }
109 
110 /*
111  *	encodes input (ulong) into output (uchar). Assumes len is
112  *	a multiple of 4.
113  */
114 static void
115 encode(uchar *output, u32int *input, ulong len)
116 {
117 	u32int x;
118 	uchar *e;
119 
120 	for(e = output + len; output < e;) {
121 		x = *input++;
122 		*output++ = x >> 24;
123 		*output++ = x >> 16;
124 		*output++ = x >> 8;
125 		*output++ = x;
126 	}
127 }