| /* 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) 1995-1997, 1999-2001, 2005-2006, 2008-2012 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 Lesser General Public License as published by the |
| Free Software Foundation; either version 2.1, 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 Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program; if not, see <http://www.gnu.org/licenses/>. */ |
| |
| /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */ |
| |
| #include <config.h> |
| |
| #include "md5.h" |
| |
| #include <stdalign.h> |
| #include <stdint.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 32768 |
| #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; |
| } |
| |
| /* Copy the 4 byte value from v into the memory location pointed to by *cp, |
| If your architecture allows unaligned access this is equivalent to |
| * (uint32_t *) cp = v */ |
| static inline void |
| set_uint32 (char *cp, uint32_t v) |
| { |
| memcpy (cp, &v, sizeof v); |
| } |
| |
| /* Put result from CTX in first 16 bytes following RESBUF. The result |
| must be in little endian byte order. */ |
| void * |
| md5_read_ctx (const struct md5_ctx *ctx, void *resbuf) |
| { |
| char *r = resbuf; |
| set_uint32 (r + 0 * sizeof ctx->A, SWAP (ctx->A)); |
| set_uint32 (r + 1 * sizeof ctx->B, SWAP (ctx->B)); |
| set_uint32 (r + 2 * sizeof ctx->C, SWAP (ctx->C)); |
| set_uint32 (r + 3 * sizeof ctx->D, 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. */ |
| 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; |
| size_t sum; |
| |
| char *buffer = malloc (BLOCKSIZE + 72); |
| if (!buffer) |
| return 1; |
| |
| /* 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)) |
| { |
| free (buffer); |
| 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); |
| free (buffer); |
| 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 UNALIGNED_P(p) ((uintptr_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; |
| } |
