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
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
32 #include <sys/types.h>
35 # include "unlocked-io.h"
38 #ifdef WORDS_BIGENDIAN
40 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
45 #define BLOCKSIZE 4096
46 #if BLOCKSIZE % 64 != 0
47 # error "invalid BLOCKSIZE"
50 /* This array contains the bytes used to pad the buffer to the next
51 64-byte boundary. (RFC 1320, 3.1: Step 1) */
52 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
55 /* Initialize structure containing state of computation.
56 (RFC 1320, 3.3: Step 3) */
58 md4_init_ctx (struct md4_ctx *ctx)
65 ctx->total[0] = ctx->total[1] = 0;
69 /* Put result from CTX in first 16 bytes following RESBUF. The result
70 must be in little endian byte order.
72 IMPORTANT: On some systems it is required that RESBUF is correctly
73 aligned for a 32 bits value. */
75 md4_read_ctx (const struct md4_ctx *ctx, void *resbuf)
77 ((uint32_t *) resbuf)[0] = SWAP (ctx->A);
78 ((uint32_t *) resbuf)[1] = SWAP (ctx->B);
79 ((uint32_t *) resbuf)[2] = SWAP (ctx->C);
80 ((uint32_t *) resbuf)[3] = SWAP (ctx->D);
85 /* Process the remaining bytes in the internal buffer and the usual
86 prolog according to the standard and write the result to RESBUF.
88 IMPORTANT: On some systems it is required that RESBUF is correctly
89 aligned for a 32 bits value. */
91 md4_finish_ctx (struct md4_ctx *ctx, void *resbuf)
93 /* Take yet unprocessed bytes into account. */
94 uint32_t bytes = ctx->buflen;
97 /* Now count remaining bytes. */
98 ctx->total[0] += bytes;
99 if (ctx->total[0] < bytes)
102 pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
103 memcpy (&((char*)ctx->buffer)[bytes], fillbuf, pad);
105 /* Put the 64-bit file length in *bits* at the end of the buffer. */
106 ctx->buffer[(bytes + pad) / 4] = SWAP (ctx->total[0] << 3);
107 ctx->buffer[(bytes + pad) / 4 + 1] = SWAP ((ctx->total[1] << 3) |
108 (ctx->total[0] >> 29));
110 /* Process last bytes. */
111 md4_process_block (ctx->buffer, bytes + pad + 8, ctx);
113 return md4_read_ctx (ctx, resbuf);
116 /* Compute MD4 message digest for bytes read from STREAM. The
117 resulting message digest number will be written into the 16 bytes
118 beginning at RESBLOCK. */
120 md4_stream (FILE * stream, void *resblock)
123 char buffer[BLOCKSIZE + 72];
126 /* Initialize the computation context. */
129 /* Iterate over full file contents. */
132 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
133 computation function processes the whole buffer so that with the
134 next round of the loop another block can be read. */
138 /* Read block. Take care for partial reads. */
141 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
145 if (sum == BLOCKSIZE)
150 /* Check for the error flag IFF N == 0, so that we don't
151 exit the loop after a partial read due to e.g., EAGAIN
155 goto process_partial_block;
158 /* We've read at least one byte, so ignore errors. But always
159 check for EOF, since feof may be true even though N > 0.
160 Otherwise, we could end up calling fread after EOF. */
162 goto process_partial_block;
165 /* Process buffer with BLOCKSIZE bytes. Note that
168 md4_process_block (buffer, BLOCKSIZE, &ctx);
171 process_partial_block:;
173 /* Process any remaining bytes. */
175 md4_process_bytes (buffer, sum, &ctx);
177 /* Construct result in desired memory. */
178 md4_finish_ctx (&ctx, resblock);
182 /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
183 result is always in little endian byte order, so that a byte-wise
184 output yields to the wanted ASCII representation of the message
187 md4_buffer (const char *buffer, size_t len, void *resblock)
191 /* Initialize the computation context. */
194 /* Process whole buffer but last len % 64 bytes. */
195 md4_process_bytes (buffer, len, &ctx);
197 /* Put result in desired memory area. */
198 return md4_finish_ctx (&ctx, resblock);
202 md4_process_bytes (const void *buffer, size_t len, struct md4_ctx *ctx)
204 /* When we already have some bits in our internal buffer concatenate
205 both inputs first. */
206 if (ctx->buflen != 0)
208 size_t left_over = ctx->buflen;
209 size_t add = 128 - left_over > len ? len : 128 - left_over;
211 memcpy (&((char*)ctx->buffer)[left_over], buffer, add);
214 if (ctx->buflen > 64)
216 md4_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
219 /* The regions in the following copy operation cannot overlap. */
220 memcpy (ctx->buffer, &((char*)ctx->buffer)[(left_over + add) & ~63],
224 buffer = (const char *) buffer + add;
228 /* Process available complete blocks. */
231 #if !_STRING_ARCH_unaligned
232 /* To check alignment gcc has an appropriate operator. Other
235 # define UNALIGNED_P(p) (((uintptr_t) p) % __alignof__ (uint32_t) != 0)
237 # define alignof(type) offsetof (struct { char c; type x; }, x)
238 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
240 if (UNALIGNED_P (buffer))
243 md4_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
244 buffer = (const char *) buffer + 64;
250 md4_process_block (buffer, len & ~63, ctx);
251 buffer = (const char *) buffer + (len & ~63);
256 /* Move remaining bytes in internal buffer. */
259 size_t left_over = ctx->buflen;
261 memcpy (&((char*)ctx->buffer)[left_over], buffer, len);
265 md4_process_block (ctx->buffer, 64, ctx);
267 memcpy (ctx->buffer, &ctx->buffer[16], left_over);
269 ctx->buflen = left_over;
273 /* --- Code below is the primary difference between md5.c and md4.c --- */
275 /* MD4 round constants */
276 #define K1 0x5a827999L
277 #define K2 0x6ed9eba1L
279 /* Round functions. */
280 #define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
281 #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
282 #define H(x, y, z) ((x) ^ (y) ^ (z))
283 #define rol(x,n) ( ((x) << (n)) | ((x) >> (32-(n))) )
284 #define R1(a,b,c,d,k,s) a=rol(a+F(b,c,d)+x[k],s);
285 #define R2(a,b,c,d,k,s) a=rol(a+G(b,c,d)+x[k]+K1,s);
286 #define R3(a,b,c,d,k,s) a=rol(a+H(b,c,d)+x[k]+K2,s);
288 /* Process LEN bytes of BUFFER, accumulating context into CTX.
289 It is assumed that LEN % 64 == 0. */
292 md4_process_block (const void *buffer, size_t len, struct md4_ctx *ctx)
294 const uint32_t *words = buffer;
295 size_t nwords = len / sizeof (uint32_t);
296 const uint32_t *endp = words + nwords;
303 /* First increment the byte count. RFC 1320 specifies the possible
304 length of the file up to 2^64 bits. Here we only compute the
305 number of bytes. Do a double word increment. */
306 ctx->total[0] += len;
307 if (ctx->total[0] < len)
310 /* Process all bytes in the buffer with 64 bytes in each round of
316 for (t = 0; t < 16; t++)
318 x[t] = SWAP (*words);
323 R1 (A, B, C, D, 0, 3);
324 R1 (D, A, B, C, 1, 7);
325 R1 (C, D, A, B, 2, 11);
326 R1 (B, C, D, A, 3, 19);
327 R1 (A, B, C, D, 4, 3);
328 R1 (D, A, B, C, 5, 7);
329 R1 (C, D, A, B, 6, 11);
330 R1 (B, C, D, A, 7, 19);
331 R1 (A, B, C, D, 8, 3);
332 R1 (D, A, B, C, 9, 7);
333 R1 (C, D, A, B, 10, 11);
334 R1 (B, C, D, A, 11, 19);
335 R1 (A, B, C, D, 12, 3);
336 R1 (D, A, B, C, 13, 7);
337 R1 (C, D, A, B, 14, 11);
338 R1 (B, C, D, A, 15, 19);
341 R2 (A, B, C, D, 0, 3);
342 R2 (D, A, B, C, 4, 5);
343 R2 (C, D, A, B, 8, 9);
344 R2 (B, C, D, A, 12, 13);
345 R2 (A, B, C, D, 1, 3);
346 R2 (D, A, B, C, 5, 5);
347 R2 (C, D, A, B, 9, 9);
348 R2 (B, C, D, A, 13, 13);
349 R2 (A, B, C, D, 2, 3);
350 R2 (D, A, B, C, 6, 5);
351 R2 (C, D, A, B, 10, 9);
352 R2 (B, C, D, A, 14, 13);
353 R2 (A, B, C, D, 3, 3);
354 R2 (D, A, B, C, 7, 5);
355 R2 (C, D, A, B, 11, 9);
356 R2 (B, C, D, A, 15, 13);
359 R3 (A, B, C, D, 0, 3);
360 R3 (D, A, B, C, 8, 9);
361 R3 (C, D, A, B, 4, 11);
362 R3 (B, C, D, A, 12, 15);
363 R3 (A, B, C, D, 2, 3);
364 R3 (D, A, B, C, 10, 9);
365 R3 (C, D, A, B, 6, 11);
366 R3 (B, C, D, A, 14, 15);
367 R3 (A, B, C, D, 1, 3);
368 R3 (D, A, B, C, 9, 9);
369 R3 (C, D, A, B, 5, 11);
370 R3 (B, C, D, A, 13, 15);
371 R3 (A, B, C, D, 3, 3);
372 R3 (D, A, B, C, 11, 9);
373 R3 (C, D, A, B, 7, 11);
374 R3 (B, C, D, A, 15, 15);