diff options
Diffstat (limited to 'locale/programs/md5.c')
| -rw-r--r-- | locale/programs/md5.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/locale/programs/md5.c b/locale/programs/md5.c new file mode 100644 index 0000000000..1434413c04 --- /dev/null +++ b/locale/programs/md5.c @@ -0,0 +1,179 @@ +/* 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) 1995-2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */ + +#include <string.h> +#include <endian.h> +#include "md5.h" + +#if __BYTE_ORDER == __BIG_ENDIAN +# define WORDS_BIGENDIAN 1 +#endif + +#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 (struct md5_ctx *ctx) +{ + ctx->A = 0x67452301; + ctx->B = 0xefcdab89; + ctx->C = 0x98badcfe; + ctx->D = 0x10325476; + + ctx->total[0] = ctx->total[1] = 0; + ctx->buflen = 0; +} + +/* Put result from CTX in first 16 bytes following RESBUF. The result + must be in little endian byte order. + + IMPORTANT: On some systems it is required that RESBUF is correctly + aligned for a 32 bits value. */ +void * +__md5_read_ctx (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; +} + +/* Process the remaining bytes in the internal buffer and the usual + prolog according to the standard and write the result to RESBUF. + + IMPORTANT: On some systems it is required that RESBUF is correctly + aligned for a 32 bits value. */ +void * +__md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) +{ + /* Take yet unprocessed bytes into account. */ + md5_uint32 bytes = ctx->buflen; + size_t pad; + + /* Now count remaining bytes. */ + ctx->total[0] += bytes; + if (ctx->total[0] < bytes) + ++ctx->total[1]; + + pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes; + memcpy (&ctx->buffer[bytes], fillbuf, pad); + + /* Put the 64-bit file length in *bits* at the end of the buffer. */ + ctx->buffer32[(bytes + pad) / 4] = SWAP (ctx->total[0] << 3); + ctx->buffer32[(bytes + pad + 4) / 4] = SWAP ((ctx->total[1] << 3) + | (ctx->total[0] >> 29)); + + /* Process last bytes. */ + __md5_process_block (ctx->buffer, bytes + pad + 8, ctx); + + return __md5_read_ctx (ctx, resbuf); +} + +/* 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 (const char *buffer, size_t len, void *resblock) +{ + struct md5_ctx ctx; + + /* Initialize the computation context. */ + __md5_init_ctx (&ctx); + + /* Process whole buffer but last len % 64 bytes. */ + __md5_process_bytes (buffer, len, &ctx); + + /* Put result in desired memory area. */ + return __md5_finish_ctx (&ctx, resblock); +} + + +void +__md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx) +{ + /* When we already have some bits in our internal buffer concatenate + both inputs first. */ + if (ctx->buflen != 0) + { + size_t left_over = ctx->buflen; + size_t add = 128 - left_over > len ? len : 128 - left_over; + + memcpy (&ctx->buffer[left_over], buffer, add); + ctx->buflen += add; + + if (ctx->buflen > 64) + { + __md5_process_block (ctx->buffer, ctx->buflen & ~63, ctx); + + ctx->buflen &= 63; + /* The regions in the following copy operation cannot overlap. */ + memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63], + ctx->buflen); + } + + buffer = (const char *) buffer + add; + len -= add; + } + + /* Process available complete blocks. */ + if (len >= 64) + { + while (len > 64) + { + __md5_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx); + buffer = (const char *) buffer + 64; + len -= 64; + } + } + + /* Move remaining bytes in internal buffer. */ + if (len > 0) + { + size_t left_over = ctx->buflen; + + memcpy (&ctx->buffer[left_over], buffer, len); + left_over += len; + if (left_over >= 64) + { + __md5_process_block (ctx->buffer, 64, ctx); + left_over -= 64; + memcpy (ctx->buffer, &ctx->buffer[64], left_over); + } + ctx->buflen = left_over; + } +} + +#include <md5-block.c> |