1/*
2 * ftp://ftp.funet.fi/pub/crypt/hash/sha/sha1.c
3 *
4 * SHA-1 in C
5 * By Steve Reid <steve@edmweb.com>
6 * 100% Public Domain
7 *
8 * Test Vectors (from FIPS PUB 180-1)
9 * "abc"
10 * A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
11 * "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
12 * 84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
13 * A million repetitions of "a"
14 * 34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
15 */
16
17/* #define SHA1HANDSOFF * Copies data before messing with it. */
18
19#include <string.h>
20#include <netinet/in.h>	/* htonl() */
21#include "sha1.h"
22
23static void
24SHA1_Transform(u_int32_t[5], const unsigned char[64]);
25
26#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
27
28/* blk0() and blk() perform the initial expand. */
29/* I got the idea of expanding during the round function from SSLeay */
30#define blk0(i) (block->l[i] = htonl(block->l[i]))
31#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
32    ^block->l[(i+2)&15]^block->l[i&15],1))
33
34/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
35#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
36#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
37#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
38#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
39#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
40
41
42/* Hash a single 512-bit block. This is the core of the algorithm. */
43
44static void
45SHA1_Transform(u_int32_t state[5], const unsigned char buffer[64])
46{
47    u_int32_t a, b, c, d, e;
48    typedef union {
49	unsigned char c[64];
50	u_int32_t l[16];
51    } CHAR64LONG16;
52    CHAR64LONG16 *block;
53
54#ifdef SHA1HANDSOFF
55    static unsigned char workspace[64];
56    block = (CHAR64LONG16 *) workspace;
57    memcpy(block, buffer, 64);
58#else
59    block = (CHAR64LONG16 *) buffer;
60#endif
61    /* Copy context->state[] to working vars */
62    a = state[0];
63    b = state[1];
64    c = state[2];
65    d = state[3];
66    e = state[4];
67    /* 4 rounds of 20 operations each. Loop unrolled. */
68    R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
69    R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
70    R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
71    R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
72    R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
73    R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
74    R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
75    R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
76    R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
77    R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
78    R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
79    R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
80    R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
81    R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
82    R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
83    R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
84    R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
85    R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
86    R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
87    R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
88    /* Add the working vars back into context.state[] */
89    state[0] += a;
90    state[1] += b;
91    state[2] += c;
92    state[3] += d;
93    state[4] += e;
94    /* Wipe variables */
95    a = b = c = d = e = 0;
96}
97
98
99/* SHA1Init - Initialize new context */
100
101void
102SHA1_Init(SHA1_CTX *context)
103{
104    /* SHA1 initialization constants */
105    context->state[0] = 0x67452301;
106    context->state[1] = 0xEFCDAB89;
107    context->state[2] = 0x98BADCFE;
108    context->state[3] = 0x10325476;
109    context->state[4] = 0xC3D2E1F0;
110    context->count[0] = context->count[1] = 0;
111}
112
113
114/* Run your data through this. */
115
116void
117SHA1_Update(SHA1_CTX *context, const unsigned char *data, unsigned int len)
118{
119    unsigned int i, j;
120
121    j = (context->count[0] >> 3) & 63;
122    if ((context->count[0] += len << 3) < (len << 3)) context->count[1]++;
123    context->count[1] += (len >> 29);
124    i = 64 - j;
125    while (len >= i) {
126	memcpy(&context->buffer[j], data, i);
127	SHA1_Transform(context->state, context->buffer);
128	data += i;
129	len -= i;
130	i = 64;
131	j = 0;
132    }
133
134    memcpy(&context->buffer[j], data, len);
135}
136
137
138/* Add padding and return the message digest. */
139
140void
141SHA1_Final(unsigned char digest[20], SHA1_CTX *context)
142{
143    u_int32_t i, j;
144    unsigned char finalcount[8];
145
146    for (i = 0; i < 8; i++) {
147        finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)]
148         >> ((3-(i & 3)) * 8) ) & 255);  /* Endian independent */
149    }
150    SHA1_Update(context, (unsigned char *) "\200", 1);
151    while ((context->count[0] & 504) != 448) {
152	SHA1_Update(context, (unsigned char *) "\0", 1);
153    }
154    SHA1_Update(context, finalcount, 8);  /* Should cause a SHA1Transform() */
155    for (i = 0; i < 20; i++) {
156	digest[i] = (unsigned char)
157		     ((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
158    }
159    /* Wipe variables */
160    i = j = 0;
161    memset(context->buffer, 0, 64);
162    memset(context->state, 0, 20);
163    memset(context->count, 0, 8);
164    memset(&finalcount, 0, 8);
165#ifdef SHA1HANDSOFF  /* make SHA1Transform overwrite it's own static vars */
166    SHA1Transform(context->state, context->buffer);
167#endif
168}
169
170