Mercurial > pihelp
diff sha1.c @ 0:8705acff2494
lots of stuff
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sat, 01 Jun 2013 01:38:42 +0800 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/sha1.c Sat Jun 01 01:38:42 2013 +0800 @@ -0,0 +1,243 @@ +/* sha1.c */ +/* + This file is part of the AVR-Crypto-Lib. + Copyright (C) 2008, 2009 Daniel Otte ([email protected]) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ +/** + * \file sha1.c + * \author Daniel Otte + * \date 2006-10-08 + * \license GPLv3 or later + * \brief SHA-1 implementation. + * + */ + +#include <string.h> /* memcpy & co */ +#include <stdint.h> +#include "config.h" +#include "debug.h" +#include "sha1.h" + +#ifdef DEBUG +# undef DEBUG +#endif + +#include "cli.h" + +#define LITTLE_ENDIAN + +/********************************************************************************************************/ + +/** + * \brief initialises given SHA-1 context + * + */ +void sha1_init(sha1_ctx_t *state){ + DEBUG_S("\r\nSHA1_INIT"); + state->h[0] = 0x67452301; + state->h[1] = 0xefcdab89; + state->h[2] = 0x98badcfe; + state->h[3] = 0x10325476; + state->h[4] = 0xc3d2e1f0; + state->length = 0; +} + +/********************************************************************************************************/ +/* some helping functions */ +uint32_t rotl32(uint32_t n, uint8_t bits){ + return ((n<<bits) | (n>>(32-bits))); +} + +uint32_t change_endian32(uint32_t x){ + return (((x)<<24) | ((x)>>24) | (((x)& 0x0000ff00)<<8) | (((x)& 0x00ff0000)>>8)); +} + + +/* three SHA-1 inner functions */ +uint32_t ch(uint32_t x, uint32_t y, uint32_t z){ + DEBUG_S("\r\nCH"); + return ((x&y)^((~x)&z)); +} + +uint32_t maj(uint32_t x, uint32_t y, uint32_t z){ + DEBUG_S("\r\nMAJ"); + return ((x&y)^(x&z)^(y&z)); +} + +uint32_t parity(uint32_t x, uint32_t y, uint32_t z){ + DEBUG_S("\r\nPARITY"); + return ((x^y)^z); +} + +/********************************************************************************************************/ +/** + * \brief "add" a block to the hash + * This is the core function of the hash algorithm. To understand how it's working + * and what thoese variables do, take a look at FIPS-182. This is an "alternativ" implementation + */ + +#define MASK 0x0000000f + +typedef uint32_t (*pf_t)(uint32_t x, uint32_t y, uint32_t z); + +void sha1_nextBlock (sha1_ctx_t *state, const void* block){ + uint32_t a[5]; + uint32_t w[16]; + uint32_t temp; + uint8_t t,s,fi, fib; + pf_t f[] = {ch,parity,maj,parity}; + uint32_t k[4]={ 0x5a827999, + 0x6ed9eba1, + 0x8f1bbcdc, + 0xca62c1d6}; + + /* load the w array (changing the endian and so) */ + for(t=0; t<16; ++t){ + w[t] = change_endian32(((uint32_t*)block)[t]); + } + +#if DEBUG + uint8_t dbgi; + for(dbgi=0; dbgi<16; ++dbgi){ + /* + DEBUG_S("\n\rBlock:"); + DEBUG_B(dbgi); + DEBUG_C(':'); + */ + cli_putstr_P(PSTR("\r\nBlock:")); + cli_hexdump(&dbgi, 1); + cli_putc(':'); + cli_hexdump(&(w[dbgi]) ,4); + } +#endif + + /* load the state */ + memcpy(a, state->h, 5*sizeof(uint32_t)); + + + /* the fun stuff */ + for(fi=0,fib=0,t=0; t<=79; ++t){ + s = t & MASK; + if(t>=16){ + #if DEBUG + DEBUG_S("\r\n ws = "); cli_hexdump(&(w[s]), 4); + #endif + w[s] = rotl32( w[(s+13)&MASK] ^ w[(s+8)&MASK] ^ + w[(s+ 2)&MASK] ^ w[s] ,1); + #ifdef DEBUG + DEBUG_S(" --> ws = "); cli_hexdump(&(w[s]), 4); + #endif + } + + uint32_t dtemp; + temp = rotl32(a[0],5) + (dtemp=f[fi](a[1],a[2],a[3])) + a[4] + k[fi] + w[s]; + memmove(&(a[1]), &(a[0]), 4*sizeof(uint32_t)); /* e=d; d=c; c=b; b=a; */ + a[0] = temp; + a[2] = rotl32(a[2],30); /* we might also do rotr32(c,2) */ + fib++; + if(fib==20){ + fib=0; + fi = (fi+1)%4; + } + #if DEBUG + /* debug dump */ + DEBUG_S("\r\nt = "); DEBUG_B(t); + DEBUG_S("; a[]: "); + cli_hexdump(a, 5*4); + DEBUG_S("; k = "); + cli_hexdump(&(k[t/20]), 4); + DEBUG_S("; f(b,c,d) = "); + cli_hexdump(&dtemp, 4); + #endif + } + + /* update the state */ + for(t=0; t<5; ++t){ + state->h[t] += a[t]; + } + state->length += 512; +} + +/********************************************************************************************************/ + +void sha1_lastBlock(sha1_ctx_t *state, const void* block, uint16_t length){ + uint8_t lb[SHA1_BLOCK_BYTES]; /* local block */ + while(length>=SHA1_BLOCK_BITS){ + sha1_nextBlock(state, block); + length -= SHA1_BLOCK_BITS; + block = (uint8_t*)block + SHA1_BLOCK_BYTES; + } + state->length += length; + memset(lb, 0, SHA1_BLOCK_BYTES); + memcpy (lb, block, (length+7)>>3); + + /* set the final one bit */ + lb[length>>3] |= 0x80>>(length & 0x07); + + if (length>512-64-1){ /* not enouth space for 64bit length value */ + sha1_nextBlock(state, lb); + state->length -= 512; + memset(lb, 0, SHA1_BLOCK_BYTES); + } + /* store the 64bit length value */ +#if defined LITTLE_ENDIAN + /* this is now rolled up */ + uint8_t i; + for (i=0; i<8; ++i){ + lb[56+i] = ((uint8_t*)&(state->length))[7-i]; + } +#elif defined BIG_ENDIAN + *((uint64_t)&(lb[56])) = state->length; +#endif + sha1_nextBlock(state, lb); +} + +/********************************************************************************************************/ + +void sha1_ctx2hash (void *dest, sha1_ctx_t *state){ +#if defined LITTLE_ENDIAN + uint8_t i; + for(i=0; i<5; ++i){ + ((uint32_t*)dest)[i] = change_endian32(state->h[i]); + } +#elif BIG_ENDIAN + if (dest != state->h) + memcpy(dest, state->h, SHA1_HASH_BITS/8); +#else +# error unsupported endian type! +#endif +} + +/********************************************************************************************************/ +/** + * + * + */ +void sha1 (void *dest, const void* msg, uint32_t length){ + sha1_ctx_t s; + DEBUG_S("\r\nBLA BLUB"); + sha1_init(&s); + while(length & (~0x0001ff)){ /* length>=512 */ + DEBUG_S("\r\none block"); + sha1_nextBlock(&s, msg); + msg = (uint8_t*)msg + SHA1_BLOCK_BITS/8; /* increment pointer to next block */ + length -= SHA1_BLOCK_BITS; + } + sha1_lastBlock(&s, msg, length); + sha1_ctx2hash(dest, &s); +} + +