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/* Functions to compute MD5 message digest of files or memory blocks.
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according to the definition of MD5 in RFC 1321 from April 1992.
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Copyright (C) 1995,1996,1997,1999,2000,2001,2005,2006,2008
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Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 3, or (at your option) any
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
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#include <sys/types.h>
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# include "unlocked-io.h"
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# if __BYTE_ORDER == __BIG_ENDIAN
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# define WORDS_BIGENDIAN 1
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/* We need to keep the namespace clean so define the MD5 function
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protected using leading __ . */
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# define md5_init_ctx __md5_init_ctx
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# define md5_process_block __md5_process_block
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# define md5_process_bytes __md5_process_bytes
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# define md5_finish_ctx __md5_finish_ctx
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# define md5_read_ctx __md5_read_ctx
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# define md5_stream __md5_stream
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# define md5_buffer __md5_buffer
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#ifdef WORDS_BIGENDIAN
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(((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
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#define BLOCKSIZE 4096
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#if BLOCKSIZE % 64 != 0
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# error "invalid BLOCKSIZE"
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/* This array contains the bytes used to pad the buffer to the next
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64-byte boundary. (RFC 1321, 3.1: Step 1) */
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static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
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/* Initialize structure containing state of computation.
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(RFC 1321, 3.3: Step 3) */
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md5_init_ctx (struct md5_ctx *ctx)
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ctx->total[0] = ctx->total[1] = 0;
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/* Copy the 4 byte value from v into the memory location pointed to by *cp,
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If your architecture allows unaligned access this is equivalent to
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* (uint32_t *) cp = v */
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set_uint32 (char *cp, uint32_t v)
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memcpy (cp, &v, sizeof v);
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/* Put result from CTX in first 16 bytes following RESBUF. The result
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must be in little endian byte order. */
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md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
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set_uint32 (r + 0 * sizeof ctx->A, SWAP (ctx->A));
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set_uint32 (r + 1 * sizeof ctx->B, SWAP (ctx->B));
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set_uint32 (r + 2 * sizeof ctx->C, SWAP (ctx->C));
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set_uint32 (r + 3 * sizeof ctx->D, SWAP (ctx->D));
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/* Process the remaining bytes in the internal buffer and the usual
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prolog according to the standard and write the result to RESBUF. */
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md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
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/* Take yet unprocessed bytes into account. */
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uint32_t bytes = ctx->buflen;
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size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
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/* Now count remaining bytes. */
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ctx->total[0] += bytes;
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if (ctx->total[0] < bytes)
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/* Put the 64-bit file length in *bits* at the end of the buffer. */
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ctx->buffer[size - 2] = SWAP (ctx->total[0] << 3);
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ctx->buffer[size - 1] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
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memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
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/* Process last bytes. */
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md5_process_block (ctx->buffer, size * 4, ctx);
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return md5_read_ctx (ctx, resbuf);
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/* Compute MD5 message digest for bytes read from STREAM. The
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resulting message digest number will be written into the 16 bytes
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beginning at RESBLOCK. */
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md5_stream (FILE *stream, void *resblock)
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char buffer[BLOCKSIZE + 72];
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/* Initialize the computation context. */
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/* Iterate over full file contents. */
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/* We read the file in blocks of BLOCKSIZE bytes. One call of the
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computation function processes the whole buffer so that with the
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next round of the loop another block can be read. */
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/* Read block. Take care for partial reads. */
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n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
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if (sum == BLOCKSIZE)
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/* Check for the error flag IFF N == 0, so that we don't
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exit the loop after a partial read due to e.g., EAGAIN
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goto process_partial_block;
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/* We've read at least one byte, so ignore errors. But always
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check for EOF, since feof may be true even though N > 0.
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Otherwise, we could end up calling fread after EOF. */
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goto process_partial_block;
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/* Process buffer with BLOCKSIZE bytes. Note that
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md5_process_block (buffer, BLOCKSIZE, &ctx);
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process_partial_block:
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/* Process any remaining bytes. */
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md5_process_bytes (buffer, sum, &ctx);
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/* Construct result in desired memory. */
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md5_finish_ctx (&ctx, resblock);
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/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
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result is always in little endian byte order, so that a byte-wise
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output yields to the wanted ASCII representation of the message
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md5_buffer (const char *buffer, size_t len, void *resblock)
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/* Initialize the computation context. */
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/* Process whole buffer but last len % 64 bytes. */
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md5_process_bytes (buffer, len, &ctx);
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/* Put result in desired memory area. */
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return md5_finish_ctx (&ctx, resblock);
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md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx)
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/* When we already have some bits in our internal buffer concatenate
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both inputs first. */
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if (ctx->buflen != 0)
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size_t left_over = ctx->buflen;
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size_t add = 128 - left_over > len ? len : 128 - left_over;
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memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
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if (ctx->buflen > 64)
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md5_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
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/* The regions in the following copy operation cannot overlap. */
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&((char *) ctx->buffer)[(left_over + add) & ~63],
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buffer = (const char *) buffer + add;
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/* Process available complete blocks. */
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#if !_STRING_ARCH_unaligned
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# define alignof(type) offsetof (struct { char c; type x; }, x)
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# define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
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if (UNALIGNED_P (buffer))
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md5_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
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buffer = (const char *) buffer + 64;
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md5_process_block (buffer, len & ~63, ctx);
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buffer = (const char *) buffer + (len & ~63);
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/* Move remaining bytes in internal buffer. */
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size_t left_over = ctx->buflen;
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memcpy (&((char *) ctx->buffer)[left_over], buffer, len);
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md5_process_block (ctx->buffer, 64, ctx);
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memcpy (ctx->buffer, &ctx->buffer[16], left_over);
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ctx->buflen = left_over;
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/* These are the four functions used in the four steps of the MD5 algorithm
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and defined in the RFC 1321. The first function is a little bit optimized
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(as found in Colin Plumbs public domain implementation). */
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/* #define FF(b, c, d) ((b & c) | (~b & d)) */
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#define FF(b, c, d) (d ^ (b & (c ^ d)))
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#define FG(b, c, d) FF (d, b, c)
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#define FH(b, c, d) (b ^ c ^ d)
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#define FI(b, c, d) (c ^ (b | ~d))
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/* Process LEN bytes of BUFFER, accumulating context into CTX.
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It is assumed that LEN % 64 == 0. */
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md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
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uint32_t correct_words[16];
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const uint32_t *words = buffer;
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size_t nwords = len / sizeof (uint32_t);
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const uint32_t *endp = words + nwords;
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/* First increment the byte count. RFC 1321 specifies the possible
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length of the file up to 2^64 bits. Here we only compute the
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number of bytes. Do a double word increment. */
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ctx->total[0] += len;
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if (ctx->total[0] < len)
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/* Process all bytes in the buffer with 64 bytes in each round of
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uint32_t *cwp = correct_words;
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/* First round: using the given function, the context and a constant
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the next context is computed. Because the algorithms processing
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unit is a 32-bit word and it is determined to work on words in
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little endian byte order we perhaps have to change the byte order
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before the computation. To reduce the work for the next steps
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we store the swapped words in the array CORRECT_WORDS. */
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#define OP(a, b, c, d, s, T) \
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a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \
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/* It is unfortunate that C does not provide an operator for
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cyclic rotation. Hope the C compiler is smart enough. */
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#define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
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/* Before we start, one word to the strange constants.
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They are defined in RFC 1321 as
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T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
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Here is an equivalent invocation using Perl:
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perl -e 'foreach(1..64){printf "0x%08x\n", int (4294967296 * abs (sin $_))}'
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OP (A, B, C, D, 7, 0xd76aa478);
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OP (D, A, B, C, 12, 0xe8c7b756);
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OP (C, D, A, B, 17, 0x242070db);
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OP (B, C, D, A, 22, 0xc1bdceee);
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OP (A, B, C, D, 7, 0xf57c0faf);
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OP (D, A, B, C, 12, 0x4787c62a);
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OP (C, D, A, B, 17, 0xa8304613);
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OP (B, C, D, A, 22, 0xfd469501);
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OP (A, B, C, D, 7, 0x698098d8);
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OP (D, A, B, C, 12, 0x8b44f7af);
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OP (C, D, A, B, 17, 0xffff5bb1);
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OP (B, C, D, A, 22, 0x895cd7be);
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OP (A, B, C, D, 7, 0x6b901122);
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OP (D, A, B, C, 12, 0xfd987193);
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OP (C, D, A, B, 17, 0xa679438e);
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OP (B, C, D, A, 22, 0x49b40821);
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/* For the second to fourth round we have the possibly swapped words
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in CORRECT_WORDS. Redefine the macro to take an additional first
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argument specifying the function to use. */
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#define OP(f, a, b, c, d, k, s, T) \
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a += f (b, c, d) + correct_words[k] + T; \
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OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
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OP (FG, D, A, B, C, 6, 9, 0xc040b340);
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OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
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OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
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OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
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OP (FG, D, A, B, C, 10, 9, 0x02441453);
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OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
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OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
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OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
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OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
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OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
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OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
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OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
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OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
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OP (FG, C, D, A, B, 7, 14, 0x676f02d9);
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OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
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OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
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OP (FH, D, A, B, C, 8, 11, 0x8771f681);
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OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
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OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
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OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
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OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
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OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);
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OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
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OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
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OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
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OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
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OP (FH, B, C, D, A, 6, 23, 0x04881d05);
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OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);
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OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
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OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
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OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);
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OP (FI, A, B, C, D, 0, 6, 0xf4292244);
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OP (FI, D, A, B, C, 7, 10, 0x432aff97);
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OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
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OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
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OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
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OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);
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OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
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OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
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OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);
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OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
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OP (FI, C, D, A, B, 6, 15, 0xa3014314);
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OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
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OP (FI, A, B, C, D, 4, 6, 0xf7537e82);
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OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
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OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
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OP (FI, B, C, D, A, 9, 21, 0xeb86d391);
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/* Add the starting values of the context. */
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/* Put checksum in context given as argument. */
added
removed
md5/md5.c
