1 /*
2 * Cryptographic API.
3 *
4 * SHA1 Secure Hash Algorithm.
5 *
6 * Derived from cryptoapi implementation, adapted for in-place
7 * scatterlist interface. Originally based on the public domain
8 * implementation written by Steve Reid.
9 *
10 * Copyright (c) Alan Smithee.
11 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
12 * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
13 *
14 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the Free
16 * Software Foundation; either version 2 of the License, or (at your option)
17 * any later version.
18 *
19 */
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/crypto.h>
24 #include <asm/scatterlist.h>
25 #include <asm/byteorder.h>
26
27 #define SHA1_DIGEST_SIZE 20
28 #define SHA1_HMAC_BLOCK_SIZE 64
29
rol(u32 value,u32 bits)30 static inline u32 rol(u32 value, u32 bits)
31 {
32 return (((value) << (bits)) | ((value) >> (32 - (bits))));
33 }
34
35 /* blk0() and blk() perform the initial expand. */
36 /* I got the idea of expanding during the round function from SSLeay */
37 # define blk0(i) block32[i]
38
39 #define blk(i) (block32[i&15] = rol(block32[(i+13)&15]^block32[(i+8)&15] \
40 ^block32[(i+2)&15]^block32[i&15],1))
41
42 /* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
43 #define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5); \
44 w=rol(w,30);
45 #define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5); \
46 w=rol(w,30);
47 #define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
48 #define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5); \
49 w=rol(w,30);
50 #define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
51
52 struct sha1_ctx {
53 u64 count;
54 u32 state[5];
55 u8 buffer[64];
56 };
57
58 /* Hash a single 512-bit block. This is the core of the algorithm. */
sha1_transform(u32 * state,const u8 * in)59 static void sha1_transform(u32 *state, const u8 *in)
60 {
61 u32 a, b, c, d, e;
62 u32 block32[16];
63
64 /* convert/copy data to workspace */
65 for (a = 0; a < sizeof(block32)/sizeof(u32); a++)
66 block32[a] = be32_to_cpu (((const u32 *)in)[a]);
67
68 /* Copy context->state[] to working vars */
69 a = state[0];
70 b = state[1];
71 c = state[2];
72 d = state[3];
73 e = state[4];
74
75 /* 4 rounds of 20 operations each. Loop unrolled. */
76 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);
77 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);
78 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);
79 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);
80 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);
81 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);
82 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);
83 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);
84 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);
85 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);
86 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);
87 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);
88 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);
89 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);
90 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);
91 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);
92 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);
93 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);
94 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);
95 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);
96 /* Add the working vars back into context.state[] */
97 state[0] += a;
98 state[1] += b;
99 state[2] += c;
100 state[3] += d;
101 state[4] += e;
102 /* Wipe variables */
103 a = b = c = d = e = 0;
104 memset (block32, 0x00, sizeof block32);
105 }
106
sha1_init(void * ctx)107 static void sha1_init(void *ctx)
108 {
109 struct sha1_ctx *sctx = ctx;
110 static const struct sha1_ctx initstate = {
111 0,
112 { 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 },
113 { 0, }
114 };
115
116 *sctx = initstate;
117 }
118
sha1_update(void * ctx,const u8 * data,unsigned int len)119 static void sha1_update(void *ctx, const u8 *data, unsigned int len)
120 {
121 struct sha1_ctx *sctx = ctx;
122 unsigned int i, j;
123
124 j = (sctx->count >> 3) & 0x3f;
125 sctx->count += len << 3;
126
127 if ((j + len) > 63) {
128 memcpy(&sctx->buffer[j], data, (i = 64-j));
129 sha1_transform(sctx->state, sctx->buffer);
130 for ( ; i + 63 < len; i += 64) {
131 sha1_transform(sctx->state, &data[i]);
132 }
133 j = 0;
134 }
135 else i = 0;
136 memcpy(&sctx->buffer[j], &data[i], len - i);
137 }
138
139
140 /* Add padding and return the message digest. */
sha1_final(void * ctx,u8 * out)141 static void sha1_final(void* ctx, u8 *out)
142 {
143 struct sha1_ctx *sctx = ctx;
144 u32 i, j, index, padlen;
145 u64 t;
146 u8 bits[8] = { 0, };
147 static const u8 padding[64] = { 0x80, };
148
149 t = sctx->count;
150 bits[7] = 0xff & t; t>>=8;
151 bits[6] = 0xff & t; t>>=8;
152 bits[5] = 0xff & t; t>>=8;
153 bits[4] = 0xff & t; t>>=8;
154 bits[3] = 0xff & t; t>>=8;
155 bits[2] = 0xff & t; t>>=8;
156 bits[1] = 0xff & t; t>>=8;
157 bits[0] = 0xff & t;
158
159 /* Pad out to 56 mod 64 */
160 index = (sctx->count >> 3) & 0x3f;
161 padlen = (index < 56) ? (56 - index) : ((64+56) - index);
162 sha1_update(sctx, padding, padlen);
163
164 /* Append length */
165 sha1_update(sctx, bits, sizeof bits);
166
167 /* Store state in digest */
168 for (i = j = 0; i < 5; i++, j += 4) {
169 u32 t2 = sctx->state[i];
170 out[j+3] = t2 & 0xff; t2>>=8;
171 out[j+2] = t2 & 0xff; t2>>=8;
172 out[j+1] = t2 & 0xff; t2>>=8;
173 out[j ] = t2 & 0xff;
174 }
175
176 /* Wipe context */
177 memset(sctx, 0, sizeof *sctx);
178 }
179
180 static struct crypto_alg alg = {
181 .cra_name = "sha1",
182 .cra_flags = CRYPTO_ALG_TYPE_DIGEST,
183 .cra_blocksize = SHA1_HMAC_BLOCK_SIZE,
184 .cra_ctxsize = sizeof(struct sha1_ctx),
185 .cra_module = THIS_MODULE,
186 .cra_list = LIST_HEAD_INIT(alg.cra_list),
187 .cra_u = { .digest = {
188 .dia_digestsize = SHA1_DIGEST_SIZE,
189 .dia_init = sha1_init,
190 .dia_update = sha1_update,
191 .dia_final = sha1_final } }
192 };
193
init(void)194 static int __init init(void)
195 {
196 return crypto_register_alg(&alg);
197 }
198
fini(void)199 static void __exit fini(void)
200 {
201 crypto_unregister_alg(&alg);
202 }
203
204 module_init(init);
205 module_exit(fini);
206
207 MODULE_LICENSE("GPL");
208 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
209