1 #include "os.h"
2 #include <libsec.h>
3 
4 /*
5  *  rfc1321 requires that I include this.  The code is new.  The constants
6  *  all come from the rfc (hence the copyright).  We trade a table for the
7  *  macros in rfc.  The total size is a lot less. -- presotto
8  *
9  *	Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
10  *	rights reserved.
11  *
12  *	License to copy and use this software is granted provided that it
13  *	is identified as the "RSA Data Security, Inc. MD5 Message-Digest
14  *	Algorithm" in all material mentioning or referencing this software
15  *	or this function.
16  *
17  *	License is also granted to make and use derivative works provided
18  *	that such works are identified as "derived from the RSA Data
19  *	Security, Inc. MD5 Message-Digest Algorithm" in all material
20  *	mentioning or referencing the derived work.
21  *
22  *	RSA Data Security, Inc. makes no representations concerning either
23  *	the merchantability of this software or the suitability of this
24  *	software forany particular purpose. It is provided "as is"
25  *	without express or implied warranty of any kind.
26  *	These notices must be retained in any copies of any part of this
27  *	documentation and/or software.
28  */
29 
30 static void encode(uchar*, u32int*, ulong);
31 
32 extern void _md5block(uchar*, ulong, u32int*);
33 
34 MD5state*
35 md5(uchar *p, ulong len, uchar *digest, MD5state *s)
36 {
37 	u32int x[16];
38 	uchar buf[128];
39 	int i;
40 	uchar *e;
41 
42 	if(s == nil){
43 		s = malloc(sizeof(*s));
44 		if(s == nil)
45 			return nil;
46 		memset(s, 0, sizeof(*s));
47 		s->malloced = 1;
48 	}
49 
50 	if(s->seeded == 0){
51 		/* seed the state, these constants would look nicer big-endian */
52 		s->state[0] = 0x67452301;
53 		s->state[1] = 0xefcdab89;
54 		s->state[2] = 0x98badcfe;
55 		s->state[3] = 0x10325476;
56 		s->seeded = 1;
57 	}
58 
59 	/* fill out the partial 64 byte block from previous calls */
60 	if(s->blen){
61 		i = 64 - s->blen;
62 		if(len < i)
63 			i = len;
64 		memmove(s->buf + s->blen, p, i);
65 		len -= i;
66 		s->blen += i;
67 		p += i;
68 		if(s->blen == 64){
69 			_md5block(s->buf, s->blen, s->state);
70 			s->len += s->blen;
71 			s->blen = 0;
72 		}
73 	}
74 
75 	/* do 64 byte blocks */
76 	i = len & ~0x3f;
77 	if(i){
78 		_md5block(p, i, s->state);
79 		s->len += i;
80 		len -= i;
81 		p += i;
82 	}
83 
84 	/* save the left overs if not last call */
85 	if(digest == 0){
86 		if(len){
87 			memmove(s->buf, p, len);
88 			s->blen += len;
89 		}
90 		return s;
91 	}
92 
93 	/*
94 	 *  this is the last time through, pad what's left with 0x80,
95 	 *  0's, and the input count to create a multiple of 64 bytes
96 	 */
97 	if(s->blen){
98 		p = s->buf;
99 		len = s->blen;
100 	} else {
101 		memmove(buf, p, len);
102 		p = buf;
103 	}
104 	s->len += len;
105 	e = p + len;
106 	if(len < 56)
107 		i = 56 - len;
108 	else
109 		i = 120 - len;
110 	memset(e, 0, i);
111 	*e = 0x80;
112 	len += i;
113 
114 	/* append the count */
115 	x[0] = s->len<<3;
116 	x[1] = s->len>>29;
117 	encode(p+len, x, 8);
118 
119 	/* digest the last part */
120 	_md5block(p, len+8, s->state);
121 	s->len += len;
122 
123 	/* return result and free state */
124 	encode(digest, s->state, MD5dlen);
125 	if(s->malloced == 1)
126 		free(s);
127 	return nil;
128 }
129 
130 /*
131  *	encodes input (u32int) into output (uchar). Assumes len is
132  *	a multiple of 4.
133  */
134 static void
135 encode(uchar *output, u32int *input, ulong len)
136 {
137 	u32int x;
138 	uchar *e;
139 
140 	for(e = output + len; output < e;) {
141 		x = *input++;
142 		*output++ = x;
143 		*output++ = x >> 8;
144 		*output++ = x >> 16;
145 		*output++ = x >> 24;
146 	}
147 }