2 * sha1.c - implementation of the Secure Hash Algorithm version 1 (FIPS 180-1)
4 * Copyright 2022 Eric Biggers
6 * Permission is hereby granted, free of charge, to any person
7 * obtaining a copy of this software and associated documentation
8 * files (the "Software"), to deal in the Software without
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10 * copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following
15 * The above copyright notice and this permission notice shall be
16 * included in all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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20 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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32 #include "wimlib/endianness.h"
33 #include "wimlib/sha1.h"
34 #include "wimlib/unaligned.h"
36 /* Dummy SHA-1 message digest of all 0's. This is used in the WIM format to
37 * mean "SHA-1 not specified". */
38 const u8 zero_hash[20];
41 * Builds a hexadecimal string representation of a SHA-1 message digest.
43 * The output buffer must be at least 41 characters.
46 sprint_hash(const u8 hash[SHA1_HASH_SIZE], tchar strbuf[SHA1_HASH_STRING_LEN])
51 for (i = 0; i < SHA1_HASH_SIZE; i++) {
54 strbuf[i * 2 + 0] = (high < 10 ? high + '0' : high - 10 + 'a');
55 strbuf[i * 2 + 1] = (low < 10 ? low + '0' : low - 10 + 'a');
60 /* If we use libcrypto (e.g. OpenSSL) then we get all the SHA-1 functions for
61 * free. Otherwise we need to implement them ourselves. */
63 #ifndef WITH_LIBCRYPTO
65 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
67 #define blk0(i) (tmp[i] = be32_to_cpu(load_be32_unaligned(&(block)[(i) * 4])))
69 #define blk(i) (tmp[i & 15] = rol(tmp[(i + 13) & 15] ^ \
72 tmp[(i + 0) & 15], 1))
74 #define R0(v, w, x, y, z, i) \
75 z += ((w & (x ^ y)) ^ y) + blk0(i) + 0x5A827999 + rol(v, 5); \
78 #define R1(v, w, x, y, z, i) \
79 z += ((w & (x ^ y)) ^ y) + blk(i) + 0x5A827999 + rol(v, 5); \
82 #define R2(v, w, x, y, z, i) \
83 z += (w ^ x ^ y) + blk(i) + 0x6ED9EBA1 + rol(v, 5); \
86 #define R3(v, w, x, y, z, i) \
87 z += (((w | x) & y) | (w & x)) + blk(i) + 0x8F1BBCDC + rol(v, 5); \
90 #define R4(v, w, x, y, z, i) \
91 z += (w ^ x ^ y) + blk(i) + 0xCA62C1D6 + rol(v, 5); \
94 /* Hash a single 512-bit block. This is the core of the algorithm. */
96 sha1_transform_default(u32 state[5], const u8 block[64])
101 /* Copy ctx->state[] to working vars */
108 /* 4 rounds of 20 operations each. Loop unrolled. */
109 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);
110 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);
111 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);
112 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);
113 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);
114 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);
115 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);
116 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);
117 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);
118 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);
119 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);
120 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);
121 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);
122 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);
123 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);
124 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);
125 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);
126 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);
127 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);
128 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);
130 /* Add the working vars back into context.state[] */
138 #ifdef ENABLE_SSSE3_SHA1
140 sha1_transform_blocks_ssse3(u32 state[5], const void *data, size_t num_blocks);
142 sha1_transform_blocks_default(u32 state[5], const void *data, size_t num_blocks);
143 # define sha1_transform_blocks sha1_transform_blocks_ssse3
145 # define sha1_transform_blocks sha1_transform_blocks_default
148 #ifndef ENABLE_SSSE3_SHA1
152 sha1_transform_blocks_default(u32 state[5], const void *data, size_t num_blocks)
155 sha1_transform_default(state, data);
157 } while (--num_blocks);
160 /* Initializes the specified SHA-1 context.
162 * After sha1_init(), call sha1_update() zero or more times to provide the data
163 * to be hashed. Then call sha1_final() to get the final hash. */
165 sha1_init(SHA_CTX *ctx)
169 ctx->state[0] = 0x67452301;
170 ctx->state[1] = 0xEFCDAB89;
171 ctx->state[2] = 0x98BADCFE;
172 ctx->state[3] = 0x10325476;
173 ctx->state[4] = 0xC3D2E1F0;
176 /* Updates the SHA-1 context with @len bytes of data. */
178 sha1_update(SHA_CTX *ctx, const void *data, size_t len)
180 unsigned buffered = ctx->bytecount & 63;
182 ctx->bytecount += len;
185 /* Previous block is unfinished. */
186 if (len < 64 - buffered) {
187 memcpy(&ctx->buffer[buffered], data, len);
188 /* Previous block still unfinished. */
191 memcpy(&ctx->buffer[buffered], data, 64 - buffered);
192 /* Finished the previous block. */
193 sha1_transform_blocks(ctx->state, ctx->buffer, 1);
194 data += 64 - buffered;
195 len -= 64 - buffered;
199 /* Process blocks directly from the input data. */
201 sha1_transform_blocks(ctx->state, data, len / 64);
206 /* Copy any remaining bytes to the buffer. */
208 memcpy(ctx->buffer, data, len);
211 /* Pad the message and generate the final SHA-1 message digest. */
213 sha1_final(u8 md[20], SHA_CTX *ctx)
215 /* Logically, we must append 1 bit, then a variable number of 0 bits,
216 * then the message length in bits as a big-endian integer, so that the
217 * final length is a multiple of the block size. */
218 static const u8 padding[64] = {0x80, };
219 be64 finalcount = cpu_to_be64(ctx->bytecount << 3);
221 sha1_update(ctx, padding, 64 - ((ctx->bytecount + 8) & 63));
222 sha1_update(ctx, &finalcount, 8);
224 for (int i = 0; i < 5; i++)
225 store_be32_unaligned(cpu_to_be32(ctx->state[i]), &md[i * 4]);
228 /* Calculate the SHA-1 message digest of the given data. */
230 sha1(const void *data, size_t len, u8 hash[SHA1_HASH_SIZE])
235 sha1_update(&ctx, data, len);
236 sha1_final(hash, &ctx);
239 #endif /* !WITH_LIBCRYPTO */