From 1156115d4ed429628f292ef9a0d597ffc3dac31e Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Thu, 20 Jul 1995 17:52:49 +0000 Subject: [PATCH] . --- lib/md5.c | 353 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ lib/md5.h | 109 +++++++++++++++++++ 2 files changed, 462 insertions(+) create mode 100644 lib/md5.c create mode 100644 lib/md5.h diff --git a/lib/md5.c b/lib/md5.c new file mode 100644 index 000000000..61ae19da3 --- /dev/null +++ b/lib/md5.c @@ -0,0 +1,353 @@ +/* md5.c - 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 Software Foundation, Inc. + + 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* Written by Ulrich Drepper . */ + +#ifdef HAVE_CONFIG_H +# include +#endif + +#include + +#include "md5.h" + +#ifdef WORDS_BIGENDIAN +# define SWAP(n) \ + (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) +#else +# define SWAP(n) (n) +#endif + + +/* This array contains the bytes used to pad the buffer to the next + 64-byte boundary. (RFC 1321, 3.1: Step 1) */ +static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; + + +/* Initialize structure containing state of computation. + (RFC 1321, 3.3: Step 3) */ +void +md5_init_ctx (ctx) + struct md5_ctx *ctx; +{ + ctx->A = 0x67452301; + ctx->B = 0xefcdab89; + ctx->C = 0x98badcfe; + ctx->D = 0x10325476; +} + +/* Put result from CTX in first 16 bytes following RESBUF. The result must + be in little endian byte order. */ +void * +md5_read_ctx (ctx, resbuf) + const struct md5_ctx *ctx; + void *resbuf; +{ + ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A); + ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B); + ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C); + ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D); + + return resbuf; +} + +/* Compute MD5 message digest for bytes read from STREAM. The + resulting message digest number will be written into the 16 bytes + beginning at RESBLOCK. */ +void * +md5_stream (stream, resblock) + FILE *stream; + void *resblock; +{ + /* Important: BLOCKSIZE must be a multiple of 64. */ +#define BLOCKSIZE 4096 + struct md5_ctx ctx; + md5_uint32 len[2]; + char buffer[BLOCKSIZE + 72]; + size_t pad, sum; + + /* Initialize the computation context. */ + md5_init_ctx (&ctx); + + len[0] = 0; + len[1] = 0; + + /* Iterate over full file contents. */ + while (1) + { + /* We read the file in blocks of BLOCKSIZE bytes. One call of the + computation function processes the whole buffer so that with the + next round of the loop another block can be read. */ + size_t n; + sum = 0; + + /* Read block. Take care for partial reads. */ + do + { + n = fread (buffer, 1, BLOCKSIZE - sum, stream); + + sum += n; + } + while (sum < BLOCKSIZE && n != 0); + + /* RFC 1321 specifies the possible length of the file up to 2^64 bits. + Here we only compute the number of bytes. Do a double word + increment. */ + len[0] += sum; + if (len[0] < sum) + ++len[1]; + + /* If end of file is reached, end the loop. */ + if (n == 0) + break; + + /* Process buffer with BLOCKSIZE bytes. Note that + BLOCKSIZE % 64 == 0 + */ + md5_process_block (buffer, BLOCKSIZE, &ctx); + } + + /* We can copy 64 byte because the buffer is always big enough. FILLBUF + contains the needed bits. */ + memcpy (&buffer[sum], fillbuf, 64); + + /* Compute amount of padding bytes needed. Alignment is done to + (N + PAD) % 64 == 56 + There is always at least one byte padded. I.e. even the alignment + is correctly aligned 64 padding bytes are added. */ + pad = sum & 63; + pad = pad >= 56 ? 64 + 56 - pad : 56 - pad; + + /* Put the 64-bit file length in *bits* at the end of the buffer. */ + *(md5_uint32 *) &buffer[sum + pad] = SWAP (len[0] << 3); + *(md5_uint32 *) &buffer[sum + pad + 4] = SWAP ((len[1] << 3) | (len[0] >> 29)); + + /* Process last bytes. */ + md5_process_block (buffer, sum + pad + 8, &ctx); + + /* Construct result in desired memory. */ + return md5_read_ctx (&ctx, resblock); +} + +/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The + result is always in little endian byte order, so that a byte-wise + output yields to the wanted ASCII representation of the message + digest. */ +void * +md5_buffer (buffer, len, resblock) + const char *buffer; + size_t len; + void *resblock; +{ + struct md5_ctx ctx; + char restbuf[64 + 72]; + size_t blocks = len & ~63; + size_t pad, rest; + + /* Initialize the computation context. */ + md5_init_ctx (&ctx); + + /* Process whole buffer but last len % 64 bytes. */ + md5_process_block (buffer, blocks, &ctx); + + /* REST bytes are not processed yet. */ + rest = len - blocks; + /* Copy to own buffer. */ + memcpy (restbuf, &buffer[blocks], rest); + /* Append needed fill bytes at end of buffer. We can copy 64 byte + because the buffer is always big enough. */ + memcpy (&restbuf[rest], fillbuf, 64); + + /* PAD bytes are used for padding to correct alignment. Note that + always at least one byte is padded. */ + pad = rest >= 56 ? 64 + 56 - rest : 56 - rest; + + /* Put length of buffer in *bits* in last eight bytes. */ + *(md5_uint32 *) &restbuf[rest + pad] = SWAP (len << 3); + *(md5_uint32 *) &restbuf[rest + pad + 4] = SWAP (len >> 29); + + /* Process last bytes. */ + md5_process_block (restbuf, rest + pad + 8, &ctx); + + /* Put result in desired memory area. */ + return md5_read_ctx (&ctx, resblock); +} + + +/* 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)) + +/* Process LEN bytes of BUFFER, accumulating context into CTX. + It is assumed that LEN % 64 == 0. */ + +void +md5_process_block (buffer, len, ctx) + const void *buffer; + size_t len; + struct md5_ctx *ctx; +{ + md5_uint32 correct_words[16]; + const md5_uint32 *words = buffer; + size_t nwords = len / sizeof (md5_uint32); + const md5_uint32 *endp = words + nwords; + md5_uint32 A = ctx->A; + md5_uint32 B = ctx->B; + md5_uint32 C = ctx->C; + md5_uint32 D = ctx->D; + + /* Process all bytes in the buffer with 64 bytes in each round of + the loop. */ + while (words < endp) + { + md5_uint32 *cwp = correct_words; + md5_uint32 A_save = A; + md5_uint32 B_save = B; + md5_uint32 C_save = C; + md5_uint32 D_save = D; + + /* 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. */ + +#define OP(a, b, c, d, s, T) \ + do \ + { \ + a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \ + ++words; \ + CYCLIC (a, s); \ + a += b; \ + } \ + while (0) + + /* It is unfortunate that C does not provide an operator for + cyclic rotation. Hope the C compiler is smart enough. */ +#define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s))) + + /* 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..64 + */ + + /* Round 1. */ + OP (A, B, C, D, 7, 0xd76aa478); + OP (D, A, B, C, 12, 0xe8c7b756); + OP (C, D, A, B, 17, 0x242070db); + OP (B, C, D, A, 22, 0xc1bdceee); + OP (A, B, C, D, 7, 0xf57c0faf); + OP (D, A, B, C, 12, 0x4787c62a); + OP (C, D, A, B, 17, 0xa8304613); + OP (B, C, D, A, 22, 0xfd469501); + OP (A, B, C, D, 7, 0x698098d8); + OP (D, A, B, C, 12, 0x8b44f7af); + OP (C, D, A, B, 17, 0xffff5bb1); + OP (B, C, D, A, 22, 0x895cd7be); + OP (A, B, C, D, 7, 0x6b901122); + OP (D, A, B, C, 12, 0xfd987193); + OP (C, D, A, B, 17, 0xa679438e); + OP (B, C, D, A, 22, 0x49b40821); + + /* For the 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. */ +#undef OP +#define OP(f, a, b, c, d, k, s, T) \ + do \ + { \ + a += f (b, c, d) + correct_words[k] + T; \ + CYCLIC (a, s); \ + a += b; \ + } \ + while (0) + + /* Round 2. */ + OP (FG, A, B, C, D, 1, 5, 0xf61e2562); + OP (FG, D, A, B, C, 6, 9, 0xc040b340); + OP (FG, C, D, A, B, 11, 14, 0x265e5a51); + OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa); + OP (FG, A, B, C, D, 5, 5, 0xd62f105d); + OP (FG, D, A, B, C, 10, 9, 0x02441453); + OP (FG, C, D, A, B, 15, 14, 0xd8a1e681); + OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8); + OP (FG, A, B, C, D, 9, 5, 0x21e1cde6); + OP (FG, D, A, B, C, 14, 9, 0xc33707d6); + OP (FG, C, D, A, B, 3, 14, 0xf4d50d87); + OP (FG, B, C, D, A, 8, 20, 0x455a14ed); + OP (FG, A, B, C, D, 13, 5, 0xa9e3e905); + OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8); + OP (FG, C, D, A, B, 7, 14, 0x676f02d9); + OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a); + + /* Round 3. */ + OP (FH, A, B, C, D, 5, 4, 0xfffa3942); + OP (FH, D, A, B, C, 8, 11, 0x8771f681); + OP (FH, C, D, A, B, 11, 16, 0x6d9d6122); + OP (FH, B, C, D, A, 14, 23, 0xfde5380c); + OP (FH, A, B, C, D, 1, 4, 0xa4beea44); + OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9); + OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60); + OP (FH, B, C, D, A, 10, 23, 0xbebfbc70); + OP (FH, A, B, C, D, 13, 4, 0x289b7ec6); + OP (FH, D, A, B, C, 0, 11, 0xeaa127fa); + OP (FH, C, D, A, B, 3, 16, 0xd4ef3085); + OP (FH, B, C, D, A, 6, 23, 0x04881d05); + OP (FH, A, B, C, D, 9, 4, 0xd9d4d039); + OP (FH, D, A, B, C, 12, 11, 0xe6db99e5); + OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8); + OP (FH, B, C, D, A, 2, 23, 0xc4ac5665); + + /* Round 4. */ + OP (FI, A, B, C, D, 0, 6, 0xf4292244); + OP (FI, D, A, B, C, 7, 10, 0x432aff97); + OP (FI, C, D, A, B, 14, 15, 0xab9423a7); + OP (FI, B, C, D, A, 5, 21, 0xfc93a039); + OP (FI, A, B, C, D, 12, 6, 0x655b59c3); + OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92); + OP (FI, C, D, A, B, 10, 15, 0xffeff47d); + OP (FI, B, C, D, A, 1, 21, 0x85845dd1); + OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f); + OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0); + OP (FI, C, D, A, B, 6, 15, 0xa3014314); + OP (FI, B, C, D, A, 13, 21, 0x4e0811a1); + OP (FI, A, B, C, D, 4, 6, 0xf7537e82); + OP (FI, D, A, B, C, 11, 10, 0xbd3af235); + OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb); + OP (FI, B, C, D, A, 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. */ + ctx->A = A; + ctx->B = B; + ctx->C = C; + ctx->D = D; +} diff --git a/lib/md5.h b/lib/md5.h new file mode 100644 index 000000000..501b4d233 --- /dev/null +++ b/lib/md5.h @@ -0,0 +1,109 @@ +/* md5.h - Declaration of functions and data types used for MD5 sum + computing library functions. + Copyright (C) 1995 Free Software Foundation, Inc. + +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. */ + +#ifndef _MD5_H +#define _MD5_H + +#include + +#if defined HAVE_LIMITS_H || _LIBC +# include +#endif + +/* The following contortions are an attempt to use the C preprocessor + to determine an unsigned integral type that is 32 bits wide. An + alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but + doing that would require that the configure script compile and *run* + the resulting executable. Locally running cross-compiled executables + is usually not possible. */ + +#if defined __STDC__ && __STDC__ +# define UINT_MAX_32_BITS 4294967295U +#else +# define UINT_MAX_32_BITS 0xFFFFFFFF +#endif + +/* If UINT_MAX isn't defined, assume it's a 32-bit type. + This should be valid for all systems GNU cares about because + that doesn't include 16-bit systems, and only modern systems + (that certainly have ) have 64+-bit integral types. */ + +#ifndef UINT_MAX +# define UINT_MAX UINT_MAX_32_BITS +#endif + +#if UINT_MAX == UINT_MAX_32_BITS + typedef unsigned int md5_uint32; +#else +# if USHRT_MAX == UINT_MAX_32_BITS + typedef unsigned short md5_uint32; +# else +# if ULONG_MAX == UINT_MAX_32_BITS + typedef unsigned long md5_uint32; +# else + /* The following line is intended to evoke an error. + Using #error is not portable enough. */ + "Cannot determine unsigned 32-bit data type." +# endif +# endif +#endif + +/* Structure to save state of computation between the single steps. */ +struct md5_ctx +{ + md5_uint32 A; + md5_uint32 B; + md5_uint32 C; + md5_uint32 D; +}; + +/* + * The following three functions are build up the low level used in + * the functions `md5_stream' and `md5_buffer'. + */ + +/* Initialize structure containing state of computation. + (RFC 1321, 3.3: Step 3) */ +void md5_init_ctx __P ((struct md5_ctx *ctx)); + +/* Starting with the result of former calls of this function (or the + initialzation function update the context for the next LEN bytes + starting at BUFFER. + It is necessary that LEN is a multiple of 64!!! */ +void md5_process_block __P ((const void *buffer, size_t len, + struct md5_ctx *ctx)); + +/* Put result from CTX in first 16 bytes following RESBUF. The result is + always in little endian byte order, so that a byte-wise output yields + to the wanted ASCII representation of the message digest. */ +void *md5_read_ctx __P ((const struct md5_ctx *ctx, void *resbuf)); + + +/* Compute MD5 message digest for bytes read from STREAM. The + resulting message digest number will be written into the 16 bytes + beginning at RESBLOCK. */ +void * +md5_stream __P ((FILE *stream, void *resblock)); + +/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The + result is always in little endian byte order, so that a byte-wise + output yields to the wanted ASCII representation of the message + digest. */ +void *md5_buffer __P ((const char *buffer, size_t len, void *resblock)); + +#endif -- 2.11.0