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Diffstat (limited to 'libbb/sha1.c')
| -rw-r--r-- | libbb/sha1.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/libbb/sha1.c b/libbb/sha1.c new file mode 100644 index 0000000..f0d952f --- /dev/null +++ b/libbb/sha1.c @@ -0,0 +1,200 @@ +/* + * Based on shasum from http://www.netsw.org/crypto/hash/ + * Majorly hacked up to use Dr Brian Gladman's sha1 code + * + * Copyright (C) 2002 Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK. + * Copyright (C) 2003 Glenn L. McGrath + * Copyright (C) 2003 Erik Andersen + * + * LICENSE TERMS + * + * The free distribution and use of this software in both source and binary + * form is allowed (with or without changes) provided that: + * + * 1. distributions of this source code include the above copyright + * notice, this list of conditions and the following disclaimer; + * + * 2. distributions in binary form include the above copyright + * notice, this list of conditions and the following disclaimer + * in the documentation and/or other associated materials; + * + * 3. the copyright holder's name is not used to endorse products + * built using this software without specific written permission. + * + * ALTERNATIVELY, provided that this notice is retained in full, this product + * may be distributed under the terms of the GNU General Public License (GPL), + * in which case the provisions of the GPL apply INSTEAD OF those given above. + * + * DISCLAIMER + * + * This software is provided 'as is' with no explicit or implied warranties + * in respect of its properties, including, but not limited to, correctness + * and/or fitness for purpose. + * --------------------------------------------------------------------------- + * Issue Date: 10/11/2002 + * + * This is a byte oriented version of SHA1 that operates on arrays of bytes + * stored in memory. It runs at 22 cycles per byte on a Pentium P4 processor + */ + +#include <fcntl.h> +#include <limits.h> +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "busybox.h" + +# define SHA1_BLOCK_SIZE 64 +# define SHA1_DIGEST_SIZE 20 +# define SHA1_HASH_SIZE SHA1_DIGEST_SIZE +# define SHA2_GOOD 0 +# define SHA2_BAD 1 + +# define rotl32(x,n) (((x) << n) | ((x) >> (32 - n))) + +# define SHA1_MASK (SHA1_BLOCK_SIZE - 1) + +/* reverse byte order in 32-bit words */ +#define ch(x,y,z) ((z) ^ ((x) & ((y) ^ (z)))) +#define parity(x,y,z) ((x) ^ (y) ^ (z)) +#define maj(x,y,z) (((x) & (y)) | ((z) & ((x) | (y)))) + +/* A normal version as set out in the FIPS. This version uses */ +/* partial loop unrolling and is optimised for the Pentium 4 */ +# define rnd(f,k) \ + t = a; a = rotl32(a,5) + f(b,c,d) + e + k + w[i]; \ + e = d; d = c; c = rotl32(b, 30); b = t + + +static void sha1_compile(sha1_ctx_t *ctx) +{ + uint32_t w[80], i, a, b, c, d, e, t; + + /* note that words are compiled from the buffer into 32-bit */ + /* words in big-endian order so an order reversal is needed */ + /* here on little endian machines */ + for (i = 0; i < SHA1_BLOCK_SIZE / 4; ++i) + w[i] = htonl(ctx->wbuf[i]); + + for (i = SHA1_BLOCK_SIZE / 4; i < 80; ++i) + w[i] = rotl32(w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16], 1); + + a = ctx->hash[0]; + b = ctx->hash[1]; + c = ctx->hash[2]; + d = ctx->hash[3]; + e = ctx->hash[4]; + + for (i = 0; i < 20; ++i) { + rnd(ch, 0x5a827999); + } + + for (i = 20; i < 40; ++i) { + rnd(parity, 0x6ed9eba1); + } + + for (i = 40; i < 60; ++i) { + rnd(maj, 0x8f1bbcdc); + } + + for (i = 60; i < 80; ++i) { + rnd(parity, 0xca62c1d6); + } + + ctx->hash[0] += a; + ctx->hash[1] += b; + ctx->hash[2] += c; + ctx->hash[3] += d; + ctx->hash[4] += e; +} + +void sha1_begin(sha1_ctx_t *ctx) +{ + ctx->count[0] = ctx->count[1] = 0; + ctx->hash[0] = 0x67452301; + ctx->hash[1] = 0xefcdab89; + ctx->hash[2] = 0x98badcfe; + ctx->hash[3] = 0x10325476; + ctx->hash[4] = 0xc3d2e1f0; +} + +/* SHA1 hash data in an array of bytes into hash buffer and call the */ +/* hash_compile function as required. */ +void sha1_hash(const void *data, size_t length, sha1_ctx_t *ctx) +{ + uint32_t pos = (uint32_t) (ctx->count[0] & SHA1_MASK); + uint32_t freeb = SHA1_BLOCK_SIZE - pos; + const unsigned char *sp = data; + + if ((ctx->count[0] += length) < length) + ++(ctx->count[1]); + + while (length >= freeb) { /* tranfer whole blocks while possible */ + memcpy(((unsigned char *) ctx->wbuf) + pos, sp, freeb); + sp += freeb; + length -= freeb; + freeb = SHA1_BLOCK_SIZE; + pos = 0; + sha1_compile(ctx); + } + + memcpy(((unsigned char *) ctx->wbuf) + pos, sp, length); +} + +void *sha1_end(void *resbuf, sha1_ctx_t *ctx) +{ + /* SHA1 Final padding and digest calculation */ + #if BB_BIG_ENDIAN + static uint32_t mask[4] = { 0x00000000, 0xff000000, 0xffff0000, 0xffffff00 }; + static uint32_t bits[4] = { 0x80000000, 0x00800000, 0x00008000, 0x00000080 }; + #else + static uint32_t mask[4] = { 0x00000000, 0x000000ff, 0x0000ffff, 0x00ffffff }; + static uint32_t bits[4] = { 0x00000080, 0x00008000, 0x00800000, 0x80000000 }; + #endif /* __BYTE_ORDER */ + + uint8_t *hval = resbuf; + uint32_t i, cnt = (uint32_t) (ctx->count[0] & SHA1_MASK); + + /* mask out the rest of any partial 32-bit word and then set */ + /* the next byte to 0x80. On big-endian machines any bytes in */ + /* the buffer will be at the top end of 32 bit words, on little */ + /* endian machines they will be at the bottom. Hence the AND */ + /* and OR masks above are reversed for little endian systems */ + ctx->wbuf[cnt >> 2] = + (ctx->wbuf[cnt >> 2] & mask[cnt & 3]) | bits[cnt & 3]; + + /* we need 9 or more empty positions, one for the padding byte */ + /* (above) and eight for the length count. If there is not */ + /* enough space pad and empty the buffer */ + if (cnt > SHA1_BLOCK_SIZE - 9) { + if (cnt < 60) + ctx->wbuf[15] = 0; + sha1_compile(ctx); + cnt = 0; + } else /* compute a word index for the empty buffer positions */ + cnt = (cnt >> 2) + 1; + + while (cnt < 14) /* and zero pad all but last two positions */ + ctx->wbuf[cnt++] = 0; + + /* assemble the eight byte counter in the buffer in big-endian */ + /* format */ + + ctx->wbuf[14] = htonl((ctx->count[1] << 3) | (ctx->count[0] >> 29)); + ctx->wbuf[15] = htonl(ctx->count[0] << 3); + + sha1_compile(ctx); + + /* extract the hash value as bytes in case the hash buffer is */ + /* misaligned for 32-bit words */ + + for (i = 0; i < SHA1_DIGEST_SIZE; ++i) + hval[i] = (unsigned char) (ctx->hash[i >> 2] >> 8 * (~i & 3)); + + return resbuf; +} + + |