1 /* Functions to compute MD4 message digest of files or memory blocks.
2 according to the definition of MD4 in RFC 1320 from April 1992.
3 Copyright (C) 1995,1996,1997,1999,2000,2001,2002,2003,2005,2006,2008
4 Free Software Foundation, Inc.
6 This program is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
20 /* Adapted by Simon Josefsson from gnulib md5.? and Libgcrypt
30 #include <sys/types.h>
33 # include "unlocked-io.h"
36 #ifdef WORDS_BIGENDIAN
38 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
43 #define BLOCKSIZE 4096
44 #if BLOCKSIZE % 64 != 0
45 # error "invalid BLOCKSIZE"
48 /* This array contains the bytes used to pad the buffer to the next
49 64-byte boundary. (RFC 1320, 3.1: Step 1) */
50 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
53 /* Initialize structure containing state of computation.
54 (RFC 1320, 3.3: Step 3) */
56 md4_init_ctx (struct md4_ctx *ctx)
63 ctx->total[0] = ctx->total[1] = 0;
67 /* Copy the 4 byte value from v into the memory location pointed to by *cp,
68 If your architecture allows unaligned access this is equivalent to
69 * (uint32_t *) cp = v */
71 set_uint32 (char *cp, uint32_t v)
73 memcpy (cp, &v, sizeof v);
76 /* Put result from CTX in first 16 bytes following RESBUF. The result
77 must be in little endian byte order. */
79 md4_read_ctx (const struct md4_ctx *ctx, void *resbuf)
82 set_uint32 (r + 0 * sizeof ctx->A, SWAP (ctx->A));
83 set_uint32 (r + 1 * sizeof ctx->B, SWAP (ctx->B));
84 set_uint32 (r + 2 * sizeof ctx->C, SWAP (ctx->C));
85 set_uint32 (r + 3 * sizeof ctx->D, SWAP (ctx->D));
90 /* Process the remaining bytes in the internal buffer and the usual
91 prolog according to the standard and write the result to RESBUF. */
93 md4_finish_ctx (struct md4_ctx *ctx, void *resbuf)
95 /* Take yet unprocessed bytes into account. */
96 uint32_t bytes = ctx->buflen;
99 /* Now count remaining bytes. */
100 ctx->total[0] += bytes;
101 if (ctx->total[0] < bytes)
104 pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
105 memcpy (&((char*)ctx->buffer)[bytes], fillbuf, pad);
107 /* Put the 64-bit file length in *bits* at the end of the buffer. */
108 ctx->buffer[(bytes + pad) / 4] = SWAP (ctx->total[0] << 3);
109 ctx->buffer[(bytes + pad) / 4 + 1] = SWAP ((ctx->total[1] << 3) |
110 (ctx->total[0] >> 29));
112 /* Process last bytes. */
113 md4_process_block (ctx->buffer, bytes + pad + 8, ctx);
115 return md4_read_ctx (ctx, resbuf);
118 /* Compute MD4 message digest for bytes read from STREAM. The
119 resulting message digest number will be written into the 16 bytes
120 beginning at RESBLOCK. */
122 md4_stream (FILE * stream, void *resblock)
125 char buffer[BLOCKSIZE + 72];
128 /* Initialize the computation context. */
131 /* Iterate over full file contents. */
134 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
135 computation function processes the whole buffer so that with the
136 next round of the loop another block can be read. */
140 /* Read block. Take care for partial reads. */
143 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
147 if (sum == BLOCKSIZE)
152 /* Check for the error flag IFF N == 0, so that we don't
153 exit the loop after a partial read due to e.g., EAGAIN
157 goto process_partial_block;
160 /* We've read at least one byte, so ignore errors. But always
161 check for EOF, since feof may be true even though N > 0.
162 Otherwise, we could end up calling fread after EOF. */
164 goto process_partial_block;
167 /* Process buffer with BLOCKSIZE bytes. Note that
170 md4_process_block (buffer, BLOCKSIZE, &ctx);
173 process_partial_block:;
175 /* Process any remaining bytes. */
177 md4_process_bytes (buffer, sum, &ctx);
179 /* Construct result in desired memory. */
180 md4_finish_ctx (&ctx, resblock);
184 /* Compute MD4 message digest for LEN bytes beginning at BUFFER. The
185 result is always in little endian byte order, so that a byte-wise
186 output yields to the wanted ASCII representation of the message
189 md4_buffer (const char *buffer, size_t len, void *resblock)
193 /* Initialize the computation context. */
196 /* Process whole buffer but last len % 64 bytes. */
197 md4_process_bytes (buffer, len, &ctx);
199 /* Put result in desired memory area. */
200 return md4_finish_ctx (&ctx, resblock);
204 md4_process_bytes (const void *buffer, size_t len, struct md4_ctx *ctx)
206 /* When we already have some bits in our internal buffer concatenate
207 both inputs first. */
208 if (ctx->buflen != 0)
210 size_t left_over = ctx->buflen;
211 size_t add = 128 - left_over > len ? len : 128 - left_over;
213 memcpy (&((char*)ctx->buffer)[left_over], buffer, add);
216 if (ctx->buflen > 64)
218 md4_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
221 /* The regions in the following copy operation cannot overlap. */
222 memcpy (ctx->buffer, &((char*)ctx->buffer)[(left_over + add) & ~63],
226 buffer = (const char *) buffer + add;
230 /* Process available complete blocks. */
233 #if !_STRING_ARCH_unaligned
234 /* To check alignment gcc has an appropriate operator. Other
237 # define UNALIGNED_P(p) (((uintptr_t) p) % __alignof__ (uint32_t) != 0)
239 # define alignof(type) offsetof (struct { char c; type x; }, x)
240 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
242 if (UNALIGNED_P (buffer))
245 md4_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
246 buffer = (const char *) buffer + 64;
252 md4_process_block (buffer, len & ~63, ctx);
253 buffer = (const char *) buffer + (len & ~63);
258 /* Move remaining bytes in internal buffer. */
261 size_t left_over = ctx->buflen;
263 memcpy (&((char*)ctx->buffer)[left_over], buffer, len);
267 md4_process_block (ctx->buffer, 64, ctx);
269 memcpy (ctx->buffer, &ctx->buffer[16], left_over);
271 ctx->buflen = left_over;
275 /* --- Code below is the primary difference between md5.c and md4.c --- */
277 /* MD4 round constants */
278 #define K1 0x5a827999
279 #define K2 0x6ed9eba1
281 /* Round functions. */
282 #define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
283 #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
284 #define H(x, y, z) ((x) ^ (y) ^ (z))
285 #define rol(x, n) (((x) << (n)) | ((uint32_t) (x) >> (32 - (n))))
286 #define R1(a,b,c,d,k,s) a=rol(a+F(b,c,d)+x[k],s);
287 #define R2(a,b,c,d,k,s) a=rol(a+G(b,c,d)+x[k]+K1,s);
288 #define R3(a,b,c,d,k,s) a=rol(a+H(b,c,d)+x[k]+K2,s);
290 /* Process LEN bytes of BUFFER, accumulating context into CTX.
291 It is assumed that LEN % 64 == 0. */
294 md4_process_block (const void *buffer, size_t len, struct md4_ctx *ctx)
296 const uint32_t *words = buffer;
297 size_t nwords = len / sizeof (uint32_t);
298 const uint32_t *endp = words + nwords;
305 /* First increment the byte count. RFC 1320 specifies the possible
306 length of the file up to 2^64 bits. Here we only compute the
307 number of bytes. Do a double word increment. */
308 ctx->total[0] += len;
309 if (ctx->total[0] < len)
312 /* Process all bytes in the buffer with 64 bytes in each round of
317 for (t = 0; t < 16; t++)
319 x[t] = SWAP (*words);
324 R1 (A, B, C, D, 0, 3);
325 R1 (D, A, B, C, 1, 7);
326 R1 (C, D, A, B, 2, 11);
327 R1 (B, C, D, A, 3, 19);
328 R1 (A, B, C, D, 4, 3);
329 R1 (D, A, B, C, 5, 7);
330 R1 (C, D, A, B, 6, 11);
331 R1 (B, C, D, A, 7, 19);
332 R1 (A, B, C, D, 8, 3);
333 R1 (D, A, B, C, 9, 7);
334 R1 (C, D, A, B, 10, 11);
335 R1 (B, C, D, A, 11, 19);
336 R1 (A, B, C, D, 12, 3);
337 R1 (D, A, B, C, 13, 7);
338 R1 (C, D, A, B, 14, 11);
339 R1 (B, C, D, A, 15, 19);
342 R2 (A, B, C, D, 0, 3);
343 R2 (D, A, B, C, 4, 5);
344 R2 (C, D, A, B, 8, 9);
345 R2 (B, C, D, A, 12, 13);
346 R2 (A, B, C, D, 1, 3);
347 R2 (D, A, B, C, 5, 5);
348 R2 (C, D, A, B, 9, 9);
349 R2 (B, C, D, A, 13, 13);
350 R2 (A, B, C, D, 2, 3);
351 R2 (D, A, B, C, 6, 5);
352 R2 (C, D, A, B, 10, 9);
353 R2 (B, C, D, A, 14, 13);
354 R2 (A, B, C, D, 3, 3);
355 R2 (D, A, B, C, 7, 5);
356 R2 (C, D, A, B, 11, 9);
357 R2 (B, C, D, A, 15, 13);
360 R3 (A, B, C, D, 0, 3);
361 R3 (D, A, B, C, 8, 9);
362 R3 (C, D, A, B, 4, 11);
363 R3 (B, C, D, A, 12, 15);
364 R3 (A, B, C, D, 2, 3);
365 R3 (D, A, B, C, 10, 9);
366 R3 (C, D, A, B, 6, 11);
367 R3 (B, C, D, A, 14, 15);
368 R3 (A, B, C, D, 1, 3);
369 R3 (D, A, B, C, 9, 9);
370 R3 (C, D, A, B, 5, 11);
371 R3 (B, C, D, A, 13, 15);
372 R3 (A, B, C, D, 3, 3);
373 R3 (D, A, B, C, 11, 9);
374 R3 (C, D, A, B, 7, 11);
375 R3 (B, C, D, A, 15, 15);