xref: /plan9/sys/src/libsec/port/sha2_64.c (revision 7bc319fb0923feebf3ecec8ba4171959fa2265e2)
1 /*
2  * sha2 64-bit
3  */
4 #include <u.h>
5 #include <libc.h>
6 #include <libsec.h>
7 
8 static void encode32(uchar*, u32int*, ulong);
9 static DigestState* sha2_64(uchar *, ulong, uchar *, SHA2_256state *, int);
10 
11 extern void _sha2block64(uchar*, ulong, u32int*);
12 
13 /*
14  *  for sha2_224 and sha2_256, len must be multiple of 64 for all but
15  *  the last call.  There must be room in the input buffer to pad.
16  *
17  *  Note: sha2_224 calls sha2_256block as sha2_224, just uses different
18  *  initial seed and produces a 224b hash result.  otherwise it's
19  *  the same as sha2_256.
20  */
21 
22 SHA2_224state*
sha2_224(uchar * p,ulong len,uchar * digest,SHA2_224state * s)23 sha2_224(uchar *p, ulong len, uchar *digest, SHA2_224state *s)
24 {
25 	if(s == nil) {
26 		s = mallocz(sizeof(*s), 1);
27 		if(s == nil)
28 			return nil;
29 		s->malloced = 1;
30 	}
31 	if(s->seeded == 0){
32 		/*
33 		 * seed the state with the first 32 bits of the fractional
34 		 * parts of the square roots of the first 8 primes 2..19).
35 		 */
36 		s->state[0] = 0xc1059ed8;
37 		s->state[1] = 0x367cd507;
38 		s->state[2] = 0x3070dd17;
39 		s->state[3] = 0xf70e5939;
40 		s->state[4] = 0xffc00b31;
41 		s->state[5] = 0x68581511;
42 		s->state[6] = 0x64f98fa7;
43 		s->state[7] = 0xbefa4fa4;
44 		s->seeded = 1;
45 	}
46 	return sha2_64(p, len, digest, s, SHA2_224dlen);
47 }
48 
49 SHA2_256state*
sha2_256(uchar * p,ulong len,uchar * digest,SHA2_256state * s)50 sha2_256(uchar *p, ulong len, uchar *digest, SHA2_256state *s)
51 {
52 	if(s == nil) {
53 		s = mallocz(sizeof(*s), 1);
54 		if(s == nil)
55 			return nil;
56 		s->malloced = 1;
57 	}
58 	if(s->seeded == 0){
59 		/*
60 		 * seed the state with the first 32 bits of the fractional
61 		 * parts of the square roots of the first 8 primes 2..19).
62 		 */
63 		s->state[0] = 0x6a09e667;
64 		s->state[1] = 0xbb67ae85;
65 		s->state[2] = 0x3c6ef372;
66 		s->state[3] = 0xa54ff53a;
67 		s->state[4] = 0x510e527f;
68 		s->state[5] = 0x9b05688c;
69 		s->state[6] = 0x1f83d9ab;
70 		s->state[7] = 0x5be0cd19;
71 		s->seeded = 1;
72 	}
73 	return sha2_64(p, len, digest, s, SHA2_256dlen);
74 }
75 
76 /* common 64 byte block padding and count code for SHA2_224 and SHA2_256 */
77 static DigestState*
sha2_64(uchar * p,ulong len,uchar * digest,SHA2_256state * s,int dlen)78 sha2_64(uchar *p, ulong len, uchar *digest, SHA2_256state *s, int dlen)
79 {
80 	int i;
81 	u32int x[16];
82 	uchar buf[128];
83 	uchar *e;
84 
85 	/* fill out the partial 64 byte block from previous calls */
86 	if(s->blen){
87 		i = 64 - s->blen;
88 		if(len < i)
89 			i = len;
90 		memmove(s->buf + s->blen, p, i);
91 		len -= i;
92 		s->blen += i;
93 		p += i;
94 		if(s->blen == 64){
95 			_sha2block64(s->buf, s->blen, s->state);
96 			s->len += s->blen;
97 			s->blen = 0;
98 		}
99 	}
100 
101 	/* do 64 byte blocks */
102 	i = len & ~(64-1);
103 	if(i){
104 		_sha2block64(p, i, s->state);
105 		s->len += i;
106 		len -= i;
107 		p += i;
108 	}
109 
110 	/* save the left overs if not last call */
111 	if(digest == 0){
112 		if(len){
113 			memmove(s->buf, p, len);
114 			s->blen += len;
115 		}
116 		return s;
117 	}
118 
119 	/*
120 	 *  this is the last time through, pad what's left with 0x80,
121 	 *  0's, and the input count to create a multiple of 64 bytes.
122 	 */
123 	if(s->blen){
124 		p = s->buf;
125 		len = s->blen;
126 	} else {
127 		memmove(buf, p, len);
128 		p = buf;
129 	}
130 	s->len += len;
131 	e = p + len;
132 	if(len < 56)
133 		i = 56 - len;
134 	else
135 		i = 120 - len;
136 	memset(e, 0, i);
137 	*e = 0x80;
138 	len += i;
139 
140 	/* append the count */
141 	x[0] = s->len>>29;
142 	x[1] = s->len<<3;
143 	encode32(p+len, x, 8);
144 
145 	/* digest the last part */
146 	_sha2block64(p, len+8, s->state);
147 	s->len += len+8;
148 
149 	/* return result and free state */
150 	encode32(digest, s->state, dlen);
151 	if(s->malloced == 1)
152 		free(s);
153 	return nil;
154 }
155 
156 /*
157  * Encodes input (ulong) into output (uchar).
158  * Assumes len is a multiple of 4.
159  */
160 static void
encode32(uchar * output,u32int * input,ulong len)161 encode32(uchar *output, u32int *input, ulong len)
162 {
163 	u32int x;
164 	uchar *e;
165 
166 	for(e = output + len; output < e;) {
167 		x = *input++;
168 		*output++ = x >> 24;
169 		*output++ = x >> 16;
170 		*output++ = x >> 8;
171 		*output++ = x;
172 	}
173 }
174 
175 DigestState*
hmac_sha2_224(uchar * p,ulong len,uchar * key,ulong klen,uchar * digest,DigestState * s)176 hmac_sha2_224(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest,
177 	DigestState *s)
178 {
179 	return hmac_x(p, len, key, klen, digest, s, sha2_224, SHA2_224dlen);
180 }
181 
182 DigestState*
hmac_sha2_256(uchar * p,ulong len,uchar * key,ulong klen,uchar * digest,DigestState * s)183 hmac_sha2_256(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest,
184 	DigestState *s)
185 {
186 	return hmac_x(p, len, key, klen, digest, s, sha2_256, SHA2_256dlen);
187 }
188