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Diffstat (limited to 'library/md5.c')
| -rw-r--r-- | library/md5.c | 650 |
1 files changed, 650 insertions, 0 deletions
diff --git a/library/md5.c b/library/md5.c new file mode 100644 index 00000000..041860b4 --- /dev/null +++ b/library/md5.c @@ -0,0 +1,650 @@ +/* + * Functions to compute MD5 message digest of files or memory blocks + * according to the definition of MD5 in RFC 1321 from April 1992. + * Copyright (C) 1995, 1996 Free Software Foundation, Inc. NOTE: The + * canonical source of this file is maintained with the GNU C Library. + * Bugs can be reported to bug-glibc@prep.ai.mit.edu. + * + * 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 2, 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, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA + * 02111-1307, USA. + * + * Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. + * Modified by Gray Watson <http://256.com/gray/>, 1997. + * + * $Id: md5.c,v 1.7 2006/03/05 15:38:09 gray Exp $ + */ + +/* + * NOTE: during quick performance tests on a Sun Sparc Ultra 1 and an + * Alpha 255 300, these functions performed upwards of 3mb/sec + * including disk I/O time. + */ + +/* + * MD5 Test Suite from RFC1321: http://ds.internic.net:/rfc/rfc1321.txt + * + * MD5 ("") = d41d8cd98f00b204e9800998ecf8427e + * MD5 ("a") = 0cc175b9c0f1b6a831c399e269772661 + * MD5 ("abc") = 900150983cd24fb0d6963f7d28e17f72 + * MD5 ("message digest") = f96b697d7cb7938d525a2f31aaf161d0 + * MD5 ("abcdefghijklmnopqrstuvwxyz") = c3fcd3d76192e4007dfb496cca67e13b + * MD5 ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") = + * d174ab98d277d9f5a5611c2c9f419d9f + * MD5 ("123456789012345678901234567890123456789012345678901234567890123456 + * 78901234567890") = 57edf4a22be3c955ac49da2e2107b67a + */ + +#include <stdlib.h> +#include <string.h> +#include <sys/types.h> +#include "md5.h" + +#define HEX_STRING "0123456789abcdef" /* to convert to hex */ +#define BLOCK_SIZE_MASK (MD5_BLOCK_SIZE - 1) + +/* + * Define my endian-ness. Could not do in a portable manner using the + * include files -- grumble. + */ +#if defined(__alpha) || defined(WIN32) || defined(__i386__) +/* + * little endian + */ +#define SWAP(n) (n) +#endif + +#if defined(__sparc) || defined(__powerpc__) +/* + * big endian - big is better + */ +#define SWAP(n) \ + (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) +#endif + +/* + * These are the four functions used in the four steps of the MD5 + * algorithm and defined in the RFC 1321. The first function is a + * little bit optimized (as found in Colin Plumbs public domain + * implementation). + */ +/* #define FF(b, c, d) ((b & c) | (~b & d)) */ +#define FF(b, c, d) (d ^ (b & (c ^ d))) +#define FG(b, c, d) FF(d, b, c) +#define FH(b, c, d) (b ^ c ^ d) +#define FI(b, c, d) (c ^ (b | ~d)) + +/* + * It is unfortunate that C does not provide an operator for cyclic + * rotation. Hope the C compiler is smart enough. -- Modified to + * remove the w = at the front - Gray 2/97 + */ +#define CYCLIC(w, s) ((w << s) | (w >> (32 - s))) + +/* + * First Round: using the given function, the context and a constant + * the next context is computed. Because the algorithms processing + * unit is a 32-bit word and it is determined to work on words in + * little endian byte order we perhaps have to change the byte order + * before the computation. To reduce the work for the next steps we + * store the swapped words in the array CORRECT_WORDS. -- Modified to + * fix the handling of unaligned buffer spaces - Gray 7/97 + */ +#define OP1(a, b, c, d, b_p, c_p, s, T) \ + do { \ + memcpy(c_p, b_p, sizeof(md5_uint32)); \ + *c_p = SWAP(*c_p); \ + a += FF (b, c, d) + *c_p + T; \ + a = CYCLIC (a, s); \ + a += b; \ + b_p = (char *)b_p + sizeof(md5_uint32); \ + c_p++; \ + } while (0) + +/* + * Second to Fourth Round: we have the possibly swapped words in + * CORRECT_WORDS. Redefine the macro to take an additional first + * argument specifying the function to use. + */ +#define OP234(FUNC, a, b, c, d, k, s, T) \ + do { \ + a += FUNC (b, c, d) + k + T; \ + a = CYCLIC (a, s); \ + a += b; \ + } while (0) + +/****************************** local routines *******************************/ + +/* + * process_block + * + * DESCRIPTION: + * + * Process a block of bytes into a MD5 state structure. + * + * RETURNS: + * + * None. + * + * ARGUMENTS: + * + * md5_p - Pointer to MD5 structure from which we are getting the result. + * + * buffer - A buffer of bytes whose MD5 signature we are calculating. + * + * buf_len - The length of the buffer. + */ +static void process_block(md5_t *md5_p, const void *buffer, + const unsigned int buf_len) +{ + md5_uint32 correct[16]; + const void *buf_p = buffer, *end_p; + unsigned int words_n; + md5_uint32 A, B, C, D; + + words_n = buf_len / sizeof(md5_uint32); + end_p = (char *)buf_p + words_n * sizeof(md5_uint32); + + A = md5_p->md_A; + B = md5_p->md_B; + C = md5_p->md_C; + D = md5_p->md_D; + + /* + * First increment the byte count. RFC 1321 specifies the possible + * length of the file up to 2^64 bits. Here we only compute the + * number of bytes with a double word increment. Modified to do + * this to better avoid overflows in the lower word -- Gray 10/97. + */ + if (md5_p->md_total[0] > MAX_MD5_UINT32 - buf_len) + { + md5_p->md_total[1]++; + md5_p->md_total[0] -= (MAX_MD5_UINT32 + 1 - buf_len); + } + else + { + md5_p->md_total[0] += buf_len; + } + + /* + * Process all bytes in the buffer with MD5_BLOCK bytes in each + * round of the loop. + */ + while (buf_p < end_p) + { + md5_uint32 A_save, B_save, C_save, D_save; + md5_uint32 *corr_p = correct; + + A_save = A; + B_save = B; + C_save = C; + D_save = D; + + /* + * Before we start, one word to the strange constants. They are + * defined in RFC 1321 as + * + * T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..MD5_BLOCK + */ + + /* Round 1. */ + OP1 (A, B, C, D, buf_p, corr_p, 7, 0xd76aa478); + OP1 (D, A, B, C, buf_p, corr_p, 12, 0xe8c7b756); + OP1 (C, D, A, B, buf_p, corr_p, 17, 0x242070db); + OP1 (B, C, D, A, buf_p, corr_p, 22, 0xc1bdceee); + OP1 (A, B, C, D, buf_p, corr_p, 7, 0xf57c0faf); + OP1 (D, A, B, C, buf_p, corr_p, 12, 0x4787c62a); + OP1 (C, D, A, B, buf_p, corr_p, 17, 0xa8304613); + OP1 (B, C, D, A, buf_p, corr_p, 22, 0xfd469501); + OP1 (A, B, C, D, buf_p, corr_p, 7, 0x698098d8); + OP1 (D, A, B, C, buf_p, corr_p, 12, 0x8b44f7af); + OP1 (C, D, A, B, buf_p, corr_p, 17, 0xffff5bb1); + OP1 (B, C, D, A, buf_p, corr_p, 22, 0x895cd7be); + OP1 (A, B, C, D, buf_p, corr_p, 7, 0x6b901122); + OP1 (D, A, B, C, buf_p, corr_p, 12, 0xfd987193); + OP1 (C, D, A, B, buf_p, corr_p, 17, 0xa679438e); + OP1 (B, C, D, A, buf_p, corr_p, 22, 0x49b40821); + + /* Round 2. */ + OP234 (FG, A, B, C, D, correct[ 1], 5, 0xf61e2562); + OP234 (FG, D, A, B, C, correct[ 6], 9, 0xc040b340); + OP234 (FG, C, D, A, B, correct[ 11], 14, 0x265e5a51); + OP234 (FG, B, C, D, A, correct[ 0], 20, 0xe9b6c7aa); + OP234 (FG, A, B, C, D, correct[ 5], 5, 0xd62f105d); + OP234 (FG, D, A, B, C, correct[ 10], 9, 0x02441453); + OP234 (FG, C, D, A, B, correct[ 15], 14, 0xd8a1e681); + OP234 (FG, B, C, D, A, correct[ 4], 20, 0xe7d3fbc8); + OP234 (FG, A, B, C, D, correct[ 9], 5, 0x21e1cde6); + OP234 (FG, D, A, B, C, correct[ 14], 9, 0xc33707d6); + OP234 (FG, C, D, A, B, correct[ 3], 14, 0xf4d50d87); + OP234 (FG, B, C, D, A, correct[ 8], 20, 0x455a14ed); + OP234 (FG, A, B, C, D, correct[ 13], 5, 0xa9e3e905); + OP234 (FG, D, A, B, C, correct[ 2], 9, 0xfcefa3f8); + OP234 (FG, C, D, A, B, correct[ 7], 14, 0x676f02d9); + OP234 (FG, B, C, D, A, correct[ 12], 20, 0x8d2a4c8a); + + /* Round 3. */ + OP234 (FH, A, B, C, D, correct[ 5], 4, 0xfffa3942); + OP234 (FH, D, A, B, C, correct[ 8], 11, 0x8771f681); + OP234 (FH, C, D, A, B, correct[ 11], 16, 0x6d9d6122); + OP234 (FH, B, C, D, A, correct[ 14], 23, 0xfde5380c); + OP234 (FH, A, B, C, D, correct[ 1], 4, 0xa4beea44); + OP234 (FH, D, A, B, C, correct[ 4], 11, 0x4bdecfa9); + OP234 (FH, C, D, A, B, correct[ 7], 16, 0xf6bb4b60); + OP234 (FH, B, C, D, A, correct[ 10], 23, 0xbebfbc70); + OP234 (FH, A, B, C, D, correct[ 13], 4, 0x289b7ec6); + OP234 (FH, D, A, B, C, correct[ 0], 11, 0xeaa127fa); + OP234 (FH, C, D, A, B, correct[ 3], 16, 0xd4ef3085); + OP234 (FH, B, C, D, A, correct[ 6], 23, 0x04881d05); + OP234 (FH, A, B, C, D, correct[ 9], 4, 0xd9d4d039); + OP234 (FH, D, A, B, C, correct[ 12], 11, 0xe6db99e5); + OP234 (FH, C, D, A, B, correct[ 15], 16, 0x1fa27cf8); + OP234 (FH, B, C, D, A, correct[ 2], 23, 0xc4ac5665); + + /* Round 4. */ + OP234 (FI, A, B, C, D, correct[ 0], 6, 0xf4292244); + OP234 (FI, D, A, B, C, correct[ 7], 10, 0x432aff97); + OP234 (FI, C, D, A, B, correct[ 14], 15, 0xab9423a7); + OP234 (FI, B, C, D, A, correct[ 5], 21, 0xfc93a039); + OP234 (FI, A, B, C, D, correct[ 12], 6, 0x655b59c3); + OP234 (FI, D, A, B, C, correct[ 3], 10, 0x8f0ccc92); + OP234 (FI, C, D, A, B, correct[ 10], 15, 0xffeff47d); + OP234 (FI, B, C, D, A, correct[ 1], 21, 0x85845dd1); + OP234 (FI, A, B, C, D, correct[ 8], 6, 0x6fa87e4f); + OP234 (FI, D, A, B, C, correct[ 15], 10, 0xfe2ce6e0); + OP234 (FI, C, D, A, B, correct[ 6], 15, 0xa3014314); + OP234 (FI, B, C, D, A, correct[ 13], 21, 0x4e0811a1); + OP234 (FI, A, B, C, D, correct[ 4], 6, 0xf7537e82); + OP234 (FI, D, A, B, C, correct[ 11], 10, 0xbd3af235); + OP234 (FI, C, D, A, B, correct[ 2], 15, 0x2ad7d2bb); + OP234 (FI, B, C, D, A, correct[ 9], 21, 0xeb86d391); + + /* Add the starting values of the context. */ + A += A_save; + B += B_save; + C += C_save; + D += D_save; + } + + /* Put checksum in context given as argument. */ + md5_p->md_A = A; + md5_p->md_B = B; + md5_p->md_C = C; + md5_p->md_D = D; +} + +/* + * md5_get_result + * + * DESCRIPTION: + * + * Copy the resulting MD5 signature from MD5_P into the first 16 bytes + * (MD5_SIZE) of the result buffer. + * + * RETURNS: + * + * None. + * + * ARGUMENTS: + * + * md5_p - Pointer to MD5 structure from which we are getting the result. + * + * result - A 16 byte buffer that will contain the MD5 signature. + */ +static void md5_get_result(const md5_t *md5_p, void *result) +{ + md5_uint32 hold; + void *res_p = result; + + hold = SWAP(md5_p->md_A); + memcpy(res_p, &hold, sizeof(md5_uint32)); + res_p = (char *)res_p + sizeof(md5_uint32); + + hold = SWAP(md5_p->md_B); + memcpy(res_p, &hold, sizeof(md5_uint32)); + res_p = (char *)res_p + sizeof(md5_uint32); + + hold = SWAP(md5_p->md_C); + memcpy(res_p, &hold, sizeof(md5_uint32)); + res_p = (char *)res_p + sizeof(md5_uint32); + + hold = SWAP(md5_p->md_D); + memcpy(res_p, &hold, sizeof(md5_uint32)); +} + +/***************************** exported routines *****************************/ + +/* + * md5_init + * + * DESCRIPTION: + * + * Initialize structure containing state of MD5 computation. (RFC 1321, + * 3.3: Step 3). This is for progressive MD5 calculations only. If + * you have the complete string available, md5_buffer should be used. + * md5_process should be called for each bunch of bytes and after the + * last process call, md5_finish should be called to get the + * signature. + * + * RETURNS: + * + * None. + * + * ARGUMENTS: + * + * md5_p - Pointer to md5 structure that we are initializing. + */ +void md5_init(md5_t *md5_p) +{ + md5_p->md_A = 0x67452301; + md5_p->md_B = 0xefcdab89; + md5_p->md_C = 0x98badcfe; + md5_p->md_D = 0x10325476; + + md5_p->md_total[0] = 0; + md5_p->md_total[1] = 0; + md5_p->md_buf_len = 0; +} + +/* + * md5_process + * + * DESCRIPTION: + * + * This function is used to progressively calculate a MD5 signature some + * number of bytes at a time. If you have the complete string + * available, md5_buffer should be used. The MD5 structure should + * have been initialized with md5_init and after the last process + * call, md5_finish should be called to get the results. + * + * RETURNS: + * + * None. + * + * ARGUMENTS: + * + * md5_p - Pointer to MD5 structure which we are progressively updating. + * + * buffer - A buffer of bytes whose MD5 signature we are calculating. + * + * buf_len - The length of the buffer. + */ +void md5_process(md5_t *md5_p, const void *buffer, + const unsigned int buf_len) +{ + unsigned int len = buf_len; + unsigned int in_block, add; + + /* + * When we already have some bytes in our internal buffer, copy some + * from the user to fill the block. + */ + if (md5_p->md_buf_len > 0) + { + + in_block = md5_p->md_buf_len; + if (in_block + len > sizeof(md5_p->md_buffer)) + { + add = sizeof(md5_p->md_buffer) - in_block; + } + else + { + add = len; + } + + memcpy (md5_p->md_buffer + in_block, buffer, add); + md5_p->md_buf_len += add; + in_block += add; + + if (in_block > MD5_BLOCK_SIZE) + { + process_block (md5_p, md5_p->md_buffer, in_block & ~BLOCK_SIZE_MASK); + /* the regions in the following copy operation will not overlap. */ + memcpy (md5_p->md_buffer, + md5_p->md_buffer + (in_block & ~BLOCK_SIZE_MASK), + in_block & BLOCK_SIZE_MASK); + md5_p->md_buf_len = in_block & BLOCK_SIZE_MASK; + } + + buffer = (const char *)buffer + add; + len -= add; + } + + /* process available complete blocks right from the user buffer */ + if (len > MD5_BLOCK_SIZE) + { + process_block (md5_p, buffer, len & ~BLOCK_SIZE_MASK); + buffer = (const char *) buffer + (len & ~BLOCK_SIZE_MASK); + len &= BLOCK_SIZE_MASK; + } + + /* copy remaining bytes into the internal buffer */ + if (len > 0) + { + memcpy (md5_p->md_buffer, buffer, len); + md5_p->md_buf_len = len; + } +} + +/* + * md5_finish + * + * DESCRIPTION: + * + * Finish a progressing MD5 calculation and copy the resulting MD5 + * signature into the result buffer which should be 16 bytes + * (MD5_SIZE). After this call, the MD5 structure is invalid. + * + * RETURNS: + * + * None. + * + * ARGUMENTS: + * + * md5_p - Pointer to MD5 structure which we are finishing. + * + * signature - A 16 byte buffer that will contain the MD5 signature. + */ +void md5_finish(md5_t *md5_p, void *signature) +{ + md5_uint32 bytes, hold; + int pad; + + /* take yet unprocessed bytes into account */ + bytes = md5_p->md_buf_len; + + /* + * Count remaining bytes. Modified to do this to better avoid + * overflows in the lower word -- Gray 10/97. + */ + if (md5_p->md_total[0] > MAX_MD5_UINT32 - bytes) + { + md5_p->md_total[1]++; + md5_p->md_total[0] -= (MAX_MD5_UINT32 + 1 - bytes); + } + else + { + md5_p->md_total[0] += bytes; + } + + /* + * Pad the buffer to the next MD5_BLOCK-byte boundary. (RFC 1321, + * 3.1: Step 1). We need enough room for two size words and the + * bytes left in the buffer. For some reason even if we are equal + * to the block-size, we add an addition block of pad bytes. + */ + pad = MD5_BLOCK_SIZE - (sizeof(md5_uint32) * 2) - bytes; + if (pad <= 0) + { + pad += MD5_BLOCK_SIZE; + } + + /* + * Modified from a fixed array to this assignment and memset to be + * more flexible with block-sizes -- Gray 10/97. + */ + if (pad > 0) + { + /* some sort of padding start byte */ + md5_p->md_buffer[bytes] = (unsigned char)0x80; + if (pad > 1) + { + memset (md5_p->md_buffer + bytes + 1, 0, pad - 1); + } + bytes += pad; + } + + /* + * Put the 64-bit file length in _bits_ (i.e. *8) at the end of the + * buffer. + */ + hold = SWAP((md5_p->md_total[0] & 0x1FFFFFFF) << 3); + memcpy(md5_p->md_buffer + bytes, &hold, sizeof(md5_uint32)); + bytes += sizeof(md5_uint32); + + /* shift the high word over by 3 and add in the top 3 bits from the low */ + hold = SWAP((md5_p->md_total[1] << 3) | + ((md5_p->md_total[0] & 0xE0000000) >> 29)); + memcpy(md5_p->md_buffer + bytes, &hold, sizeof(md5_uint32)); + bytes += sizeof(md5_uint32); + + /* process last bytes, the padding chars, and size words */ + process_block(md5_p, md5_p->md_buffer, bytes); + md5_get_result(md5_p, signature); +} + +/* + * md5_buffer + * + * DESCRIPTION: + * + * This function is used to calculate a MD5 signature for a buffer of + * bytes. If you only have part of a buffer that you want to process + * then md5_init, md5_process, and md5_finish should be used. + * + * RETURNS: + * + * None. + * + * ARGUMENTS: + * + * buffer - A buffer of bytes whose MD5 signature we are calculating. + * + * buf_len - The length of the buffer. + * + * signature - A 16 byte buffer that will contain the MD5 signature. + */ +void md5_buffer(const char *buffer, const unsigned int buf_len, + void *signature) +{ + md5_t md5; + + /* initialize the computation context */ + md5_init(&md5); + + /* process whole buffer but last buf_len % MD5_BLOCK bytes */ + md5_process(&md5, buffer, buf_len); + + /* put result in desired memory area */ + md5_finish(&md5, signature); +} + +/* + * md5_sig_to_string + * + * DESCRIPTION: + * + * Convert a MD5 signature in a 16 byte buffer into a hexadecimal string + * representation. + * + * RETURNS: + * + * None. + * + * ARGUMENTS: + * + * signature - a 16 byte buffer that contains the MD5 signature. + * + * str - a string of charactes which should be at least 33 bytes long (2 + * characters per MD5 byte and 1 for the \0). + * + * str_len - the length of the string. + */ +void md5_sig_to_string(void *signature, char *str, const int str_len) +{ + unsigned char *sig_p; + char *str_p, *max_p; + unsigned int high, low; + + str_p = str; + max_p = str + str_len; + + for (sig_p = (unsigned char *)signature; + sig_p < (unsigned char *)signature + MD5_SIZE; + sig_p++) + { + high = *sig_p / 16; + low = *sig_p % 16; + /* account for 2 chars */ + if (str_p + 1 >= max_p) + { + break; + } + *str_p++ = HEX_STRING[high]; + *str_p++ = HEX_STRING[low]; + } + /* account for 2 chars */ + if (str_p < max_p) + { + *str_p++ = '\0'; + } +} + +/* + * md5_sig_from_string + * + * DESCRIPTION: + * + * Convert a MD5 signature from a hexadecimal string representation into + * a 16 byte buffer. + * + * RETURNS: + * + * None. + * + * ARGUMENTS: + * + * signature - A 16 byte buffer that will contain the MD5 signature. + * + * str - A string of charactes which _must_ be at least 32 bytes long (2 + * characters per MD5 byte). + */ +void md5_sig_from_string(void *signature, const char *str) +{ + unsigned char *sig_p; + const char *str_p; + char *hex; + unsigned int high, low, val; + + hex = HEX_STRING; + sig_p = signature; + + for (str_p = str; str_p < str + MD5_SIZE * 2; str_p += 2) + { + high = strchr(hex, *str_p) - hex; + low = strchr(hex, *(str_p + 1)) - hex; + val = high * 16 + low; + *sig_p++ = val; + } +} |