2 * sha1.c - implementation of the Secure Hash Algorithm version 1 (FIPS 180-1)
4 * The following copying information applies to this specific source code file:
6 * Written in 2014-2015 by Eric Biggers <ebiggers3@gmail.com>
8 * To the extent possible under law, the author(s) have dedicated all copyright
9 * and related and neighboring rights to this software to the public domain
10 * worldwide via the Creative Commons Zero 1.0 Universal Public Domain
11 * Dedication (the "CC0").
13 * This software is distributed in the hope that it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
15 * FOR A PARTICULAR PURPOSE. See the CC0 for more details.
17 * You should have received a copy of the CC0 along with this software; if not
18 * see <http://creativecommons.org/publicdomain/zero/1.0/>.
25 #include "wimlib/endianness.h"
26 #include "wimlib/sha1.h"
27 #include "wimlib/unaligned.h"
29 /* Dummy SHA-1 message digest of all 0's. This is used in the WIM format to
30 * mean "SHA-1 not specified". */
31 const u8 zero_hash[20];
34 * Builds a hexadecimal string representation of a SHA-1 message digest.
36 * The output buffer must be at least 41 characters.
39 sprint_hash(const u8 hash[SHA1_HASH_SIZE], tchar strbuf[SHA1_HASH_SIZE * 2 + 1])
44 for (i = 0; i < SHA1_HASH_SIZE; i++) {
47 strbuf[i * 2 + 0] = (high < 10 ? high + '0' : high - 10 + 'a');
48 strbuf[i * 2 + 1] = (low < 10 ? low + '0' : low - 10 + 'a');
53 /* If we use libcrypto (e.g. OpenSSL) then we get all the SHA-1 functions for
54 * free. Otherwise we need to implement them ourselves. */
56 #ifndef WITH_LIBCRYPTO
58 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
60 #define blk0(i) (tmp[i] = be32_to_cpu(load_be32_unaligned(&(block)[(i) * 4])))
62 #define blk(i) (tmp[i & 15] = rol(tmp[(i + 13) & 15] ^ \
65 tmp[(i + 0) & 15], 1))
67 #define R0(v, w, x, y, z, i) \
68 z += ((w & (x ^ y)) ^ y) + blk0(i) + 0x5A827999 + rol(v, 5); \
71 #define R1(v, w, x, y, z, i) \
72 z += ((w & (x ^ y)) ^ y) + blk(i) + 0x5A827999 + rol(v, 5); \
75 #define R2(v, w, x, y, z, i) \
76 z += (w ^ x ^ y) + blk(i) + 0x6ED9EBA1 + rol(v, 5); \
79 #define R3(v, w, x, y, z, i) \
80 z += (((w | x) & y) | (w & x)) + blk(i) + 0x8F1BBCDC + rol(v, 5); \
83 #define R4(v, w, x, y, z, i) \
84 z += (w ^ x ^ y) + blk(i) + 0xCA62C1D6 + rol(v, 5); \
87 /* Hash a single 512-bit block. This is the core of the algorithm. */
89 sha1_transform_default(u32 state[5], const u8 block[64])
94 /* Copy ctx->state[] to working vars */
101 /* 4 rounds of 20 operations each. Loop unrolled. */
102 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);
103 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);
104 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);
105 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);
106 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);
107 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);
108 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);
109 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);
110 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);
111 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);
112 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);
113 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);
114 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);
115 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);
116 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);
117 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);
118 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);
119 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);
120 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);
121 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);
123 /* Add the working vars back into context.state[] */
131 #ifdef ENABLE_SSSE3_SHA1
133 sha1_transform_blocks_ssse3(u32 state[5], const void *data, size_t num_blocks);
135 sha1_transform_blocks_default(u32 state[5], const void *data, size_t num_blocks);
136 # define sha1_transform_blocks sha1_transform_blocks_ssse3
138 # define sha1_transform_blocks sha1_transform_blocks_default
141 #ifndef ENABLE_SSSE3_SHA1
145 sha1_transform_blocks_default(u32 state[5], const void *data, size_t num_blocks)
148 sha1_transform_default(state, data);
150 } while (--num_blocks);
153 /* Initializes the specified SHA-1 context.
155 * After sha1_init(), call sha1_update() zero or more times to provide the data
156 * to be hashed. Then call sha1_final() to get the final hash. */
158 sha1_init(SHA_CTX *ctx)
162 ctx->state[0] = 0x67452301;
163 ctx->state[1] = 0xEFCDAB89;
164 ctx->state[2] = 0x98BADCFE;
165 ctx->state[3] = 0x10325476;
166 ctx->state[4] = 0xC3D2E1F0;
169 /* Updates the SHA-1 context with @len bytes of data. */
171 sha1_update(SHA_CTX *ctx, const void *data, size_t len)
173 unsigned buffered = ctx->bytecount & 63;
175 ctx->bytecount += len;
178 /* Previous block is unfinished. */
179 if (len < 64 - buffered) {
180 memcpy(&ctx->buffer[buffered], data, len);
181 /* Previous block still unfinished. */
184 memcpy(&ctx->buffer[buffered], data, 64 - buffered);
185 /* Finished the previous block. */
186 sha1_transform_blocks(ctx->state, ctx->buffer, 1);
187 data += 64 - buffered;
188 len -= 64 - buffered;
192 /* Process blocks directly from the input data. */
194 sha1_transform_blocks(ctx->state, data, len / 64);
199 /* Copy any remaining bytes to the buffer. */
201 memcpy(ctx->buffer, data, len);
204 /* Pad the message and generate the final SHA-1 message digest. */
206 sha1_final(u8 md[20], SHA_CTX *ctx)
208 /* Logically, we must append 1 bit, then a variable number of 0 bits,
209 * then the message length in bits as a big-endian integer, so that the
210 * final length is a multiple of the block size. */
211 static const u8 padding[64] = {0x80, };
212 be64 finalcount = cpu_to_be64(ctx->bytecount << 3);
214 sha1_update(ctx, padding, 64 - ((ctx->bytecount + 8) & 63));
215 sha1_update(ctx, &finalcount, 8);
217 for (int i = 0; i < 5; i++)
218 store_be32_unaligned(cpu_to_be32(ctx->state[i]), &md[i * 4]);
221 /* Calculate the SHA-1 message digest of the specified buffer.
222 * @len is the buffer length in bytes. */
224 sha1_buffer(const void *buffer, size_t len, u8 md[20])
229 sha1_update(&ctx, buffer, len);
230 sha1_final(md, &ctx);
233 #endif /* !WITH_LIBCRYPTO */