-/* 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) 1995,1996,1997,1999,2000,2001,2005,2006
- Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
-
-/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
-
-#include <config.h>
-
-#include "md5.h"
-
-#include <stddef.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-
-#if USE_UNLOCKED_IO
-# include "unlocked-io.h"
-#endif
-
-#ifdef _LIBC
-# include <endian.h>
-# if __BYTE_ORDER == __BIG_ENDIAN
-# define WORDS_BIGENDIAN 1
-# endif
-/* We need to keep the namespace clean so define the MD5 function
- protected using leading __ . */
-# define md5_init_ctx __md5_init_ctx
-# define md5_process_block __md5_process_block
-# define md5_process_bytes __md5_process_bytes
-# define md5_finish_ctx __md5_finish_ctx
-# define md5_read_ctx __md5_read_ctx
-# define md5_stream __md5_stream
-# define md5_buffer __md5_buffer
-#endif
-
-#ifdef WORDS_BIGENDIAN
-# define SWAP(n) \
- (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
-#else
-# define SWAP(n) (n)
-#endif
-
-#define BLOCKSIZE 4096
-#if BLOCKSIZE % 64 != 0
-# error "invalid BLOCKSIZE"
-#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-bit value. */
-void *
-md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
-{
- ((uint32_t *) resbuf)[0] = SWAP (ctx->A);
- ((uint32_t *) resbuf)[1] = SWAP (ctx->B);
- ((uint32_t *) resbuf)[2] = SWAP (ctx->C);
- ((uint32_t *) 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-bit value. */
-void *
-md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
-{
- /* Take yet unprocessed bytes into account. */
- uint32_t bytes = ctx->buflen;
- size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
-
- /* Now count remaining bytes. */
- ctx->total[0] += bytes;
- if (ctx->total[0] < bytes)
- ++ctx->total[1];
-
- /* Put the 64-bit file length in *bits* at the end of the buffer. */
- ctx->buffer[size - 2] = SWAP (ctx->total[0] << 3);
- ctx->buffer[size - 1] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
-
- memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
-
- /* Process last bytes. */
- md5_process_block (ctx->buffer, size * 4, ctx);
-
- return md5_read_ctx (ctx, 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. */
-int
-md5_stream (FILE *stream, void *resblock)
-{
- struct md5_ctx ctx;
- char buffer[BLOCKSIZE + 72];
- size_t sum;
-
- /* Initialize the computation context. */
- md5_init_ctx (&ctx);
-
- /* 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. */
- while (1)
- {
- n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
-
- sum += n;
-
- if (sum == BLOCKSIZE)
- break;
-
- if (n == 0)
- {
- /* Check for the error flag IFF N == 0, so that we don't
- exit the loop after a partial read due to e.g., EAGAIN
- or EWOULDBLOCK. */
- if (ferror (stream))
- return 1;
- goto process_partial_block;
- }
-
- /* We've read at least one byte, so ignore errors. But always
- check for EOF, since feof may be true even though N > 0.
- Otherwise, we could end up calling fread after EOF. */
- if (feof (stream))
- goto process_partial_block;
- }
-
- /* Process buffer with BLOCKSIZE bytes. Note that
- BLOCKSIZE % 64 == 0
- */
- md5_process_block (buffer, BLOCKSIZE, &ctx);
- }
-
-process_partial_block:
-
- /* Process any remaining bytes. */
- if (sum > 0)
- md5_process_bytes (buffer, sum, &ctx);
-
- /* Construct result in desired memory. */
- md5_finish_ctx (&ctx, resblock);
- return 0;
-}
-
-/* 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 (&((char *) 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,
- &((char *) ctx->buffer)[(left_over + add) & ~63],
- ctx->buflen);
- }
-
- buffer = (const char *) buffer + add;
- len -= add;
- }
-
- /* Process available complete blocks. */
- if (len >= 64)
- {
-#if !_STRING_ARCH_unaligned
-# define alignof(type) offsetof (struct { char c; type x; }, x)
-# define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
- if (UNALIGNED_P (buffer))
- while (len > 64)
- {
- md5_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
- buffer = (const char *) buffer + 64;
- len -= 64;
- }
- else
-#endif
- {
- md5_process_block (buffer, len & ~63, ctx);
- buffer = (const char *) buffer + (len & ~63);
- len &= 63;
- }
- }
-
- /* Move remaining bytes in internal buffer. */
- if (len > 0)
- {
- size_t left_over = ctx->buflen;
-
- memcpy (&((char *) 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[16], left_over);
- }
- ctx->buflen = left_over;
- }
-}
-
-
-/* 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 (const void *buffer, size_t len, struct md5_ctx *ctx)
-{
- uint32_t correct_words[16];
- const uint32_t *words = buffer;
- size_t nwords = len / sizeof (uint32_t);
- const uint32_t *endp = words + nwords;
- uint32_t A = ctx->A;
- uint32_t B = ctx->B;
- uint32_t C = ctx->C;
- uint32_t D = ctx->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. Do a double word increment. */
- ctx->total[0] += len;
- if (ctx->total[0] < len)
- ++ctx->total[1];
-
- /* Process all bytes in the buffer with 64 bytes in each round of
- the loop. */
- while (words < endp)
- {
- uint32_t *cwp = correct_words;
- uint32_t A_save = A;
- uint32_t B_save = B;
- uint32_t C_save = C;
- uint32_t 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
-
- Here is an equivalent invocation using Perl:
-
- perl -e 'foreach(1..64){printf "0x%08x\n", int (4294967296 * abs (sin $_))}'
- */
-
- /* 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;
-}
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