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1 #ifdef HAVE_CONFIG_H
2 #  include <config.h>
3 #endif
4 
5 #include <stdlib.h>		/* for malloc() */
6 #include <string.h>		/* for memcpy() */
7 
8 #include "private/md5.h"
9 #include "share/alloc.h"
10 #include "share/compat.h"
11 #include "share/endswap.h"
12 
13 /*
14  * This code implements the MD5 message-digest algorithm.
15  * The algorithm is due to Ron Rivest.  This code was
16  * written by Colin Plumb in 1993, no copyright is claimed.
17  * This code is in the public domain; do with it what you wish.
18  *
19  * Equivalent code is available from RSA Data Security, Inc.
20  * This code has been tested against that, and is equivalent,
21  * except that you don't need to include two pages of legalese
22  * with every copy.
23  *
24  * To compute the message digest of a chunk of bytes, declare an
25  * MD5Context structure, pass it to MD5Init, call MD5Update as
26  * needed on buffers full of bytes, and then call MD5Final, which
27  * will fill a supplied 16-byte array with the digest.
28  *
29  * Changed so as no longer to depend on Colin Plumb's `usual.h' header
30  * definitions; now uses stuff from dpkg's config.h.
31  *  - Ian Jackson <ijackson@nyx.cs.du.edu>.
32  * Still in the public domain.
33  *
34  * Josh Coalson: made some changes to integrate with libFLAC.
35  * Still in the public domain.
36  */
37 
38 /* The four core functions - F1 is optimized somewhat */
39 
40 /* #define F1(x, y, z) (x & y | ~x & z) */
41 #define F1(x, y, z) (z ^ (x & (y ^ z)))
42 #define F2(x, y, z) F1(z, x, y)
43 #define F3(x, y, z) (x ^ y ^ z)
44 #define F4(x, y, z) (y ^ (x | ~z))
45 
46 /* This is the central step in the MD5 algorithm. */
47 #define MD5STEP(f,w,x,y,z,in,s) \
48 	 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
49 
50 /*
51  * The core of the MD5 algorithm, this alters an existing MD5 hash to
52  * reflect the addition of 16 longwords of new data.  MD5Update blocks
53  * the data and converts bytes into longwords for this routine.
54  */
FLAC__MD5Transform(FLAC__uint32 buf[4],FLAC__uint32 const in[16])55 static void FLAC__MD5Transform(FLAC__uint32 buf[4], FLAC__uint32 const in[16])
56 {
57 	register FLAC__uint32 a, b, c, d;
58 
59 	a = buf[0];
60 	b = buf[1];
61 	c = buf[2];
62 	d = buf[3];
63 
64 	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
65 	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
66 	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
67 	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
68 	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
69 	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
70 	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
71 	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
72 	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
73 	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
74 	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
75 	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
76 	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
77 	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
78 	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
79 	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
80 
81 	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
82 	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
83 	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
84 	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
85 	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
86 	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
87 	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
88 	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
89 	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
90 	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
91 	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
92 	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
93 	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
94 	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
95 	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
96 	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
97 
98 	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
99 	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
100 	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
101 	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
102 	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
103 	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
104 	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
105 	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
106 	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
107 	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
108 	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
109 	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
110 	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
111 	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
112 	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
113 	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
114 
115 	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
116 	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
117 	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
118 	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
119 	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
120 	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
121 	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
122 	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
123 	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
124 	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
125 	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
126 	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
127 	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
128 	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
129 	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
130 	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
131 
132 	buf[0] += a;
133 	buf[1] += b;
134 	buf[2] += c;
135 	buf[3] += d;
136 }
137 
138 #if WORDS_BIGENDIAN
139 //@@@@@@ OPT: use bswap/intrinsics
byteSwap(FLAC__uint32 * buf,uint32_t words)140 static void byteSwap(FLAC__uint32 *buf, uint32_t words)
141 {
142 	register FLAC__uint32 x;
143 	do {
144 		x = *buf;
145 		x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff);
146 		*buf++ = (x >> 16) | (x << 16);
147 	} while (--words);
148 }
byteSwapX16(FLAC__uint32 * buf)149 static void byteSwapX16(FLAC__uint32 *buf)
150 {
151 	register FLAC__uint32 x;
152 
153 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
154 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
155 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
156 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
157 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
158 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
159 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
160 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
161 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
162 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
163 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
164 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
165 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
166 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
167 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
168 	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf   = (x >> 16) | (x << 16);
169 }
170 #else
171 #define byteSwap(buf, words)
172 #define byteSwapX16(buf)
173 #endif
174 
175 /*
176  * Update context to reflect the concatenation of another buffer full
177  * of bytes.
178  */
FLAC__MD5Update(FLAC__MD5Context * ctx,FLAC__byte const * buf,uint32_t len)179 static void FLAC__MD5Update(FLAC__MD5Context *ctx, FLAC__byte const *buf, uint32_t len)
180 {
181 	FLAC__uint32 t;
182 
183 	/* Update byte count */
184 
185 	t = ctx->bytes[0];
186 	if ((ctx->bytes[0] = t + len) < t)
187 		ctx->bytes[1]++;	/* Carry from low to high */
188 
189 	t = 64 - (t & 0x3f);	/* Space available in ctx->in (at least 1) */
190 	if (t > len) {
191 		memcpy((FLAC__byte *)ctx->in + 64 - t, buf, len);
192 		return;
193 	}
194 	/* First chunk is an odd size */
195 	memcpy((FLAC__byte *)ctx->in + 64 - t, buf, t);
196 	byteSwapX16(ctx->in);
197 	FLAC__MD5Transform(ctx->buf, ctx->in);
198 	buf += t;
199 	len -= t;
200 
201 	/* Process data in 64-byte chunks */
202 	while (len >= 64) {
203 		memcpy(ctx->in, buf, 64);
204 		byteSwapX16(ctx->in);
205 		FLAC__MD5Transform(ctx->buf, ctx->in);
206 		buf += 64;
207 		len -= 64;
208 	}
209 
210 	/* Handle any remaining bytes of data. */
211 	memcpy(ctx->in, buf, len);
212 }
213 
214 /*
215  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
216  * initialization constants.
217  */
FLAC__MD5Init(FLAC__MD5Context * ctx)218 void FLAC__MD5Init(FLAC__MD5Context *ctx)
219 {
220 	ctx->buf[0] = 0x67452301;
221 	ctx->buf[1] = 0xefcdab89;
222 	ctx->buf[2] = 0x98badcfe;
223 	ctx->buf[3] = 0x10325476;
224 
225 	ctx->bytes[0] = 0;
226 	ctx->bytes[1] = 0;
227 
228 	ctx->internal_buf.p8 = 0;
229 	ctx->capacity = 0;
230 }
231 
232 /*
233  * Final wrapup - pad to 64-byte boundary with the bit pattern
234  * 1 0* (64-bit count of bits processed, MSB-first)
235  */
FLAC__MD5Final(FLAC__byte digest[16],FLAC__MD5Context * ctx)236 void FLAC__MD5Final(FLAC__byte digest[16], FLAC__MD5Context *ctx)
237 {
238 	int count = ctx->bytes[0] & 0x3f;	/* Number of bytes in ctx->in */
239 	FLAC__byte *p = (FLAC__byte *)ctx->in + count;
240 
241 	/* Set the first char of padding to 0x80.  There is always room. */
242 	*p++ = 0x80;
243 
244 	/* Bytes of padding needed to make 56 bytes (-8..55) */
245 	count = 56 - 1 - count;
246 
247 	if (count < 0) {	/* Padding forces an extra block */
248 		memset(p, 0, count + 8);
249 		byteSwapX16(ctx->in);
250 		FLAC__MD5Transform(ctx->buf, ctx->in);
251 		p = (FLAC__byte *)ctx->in;
252 		count = 56;
253 	}
254 	memset(p, 0, count);
255 	byteSwap(ctx->in, 14);
256 
257 	/* Append length in bits and transform */
258 	ctx->in[14] = ctx->bytes[0] << 3;
259 	ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
260 	FLAC__MD5Transform(ctx->buf, ctx->in);
261 
262 	byteSwap(ctx->buf, 4);
263 	memcpy(digest, ctx->buf, 16);
264 	if (0 != ctx->internal_buf.p8) {
265 		free(ctx->internal_buf.p8);
266 		ctx->internal_buf.p8 = 0;
267 		ctx->capacity = 0;
268 	}
269 	memset(ctx, 0, sizeof(*ctx));	/* In case it's sensitive */
270 }
271 
272 /*
273  * Convert the incoming audio signal to a byte stream
274  */
format_input_(FLAC__multibyte * mbuf,const FLAC__int32 * const signal[],uint32_t channels,uint32_t samples,uint32_t bytes_per_sample)275 static void format_input_(FLAC__multibyte *mbuf, const FLAC__int32 * const signal[], uint32_t channels, uint32_t samples, uint32_t bytes_per_sample)
276 {
277 	FLAC__byte *buf_ = mbuf->p8;
278 	FLAC__int16 *buf16 = mbuf->p16;
279 	FLAC__int32 *buf32 = mbuf->p32;
280 	FLAC__int32 a_word;
281 	uint32_t channel, sample;
282 
283 	/* Storage in the output buffer, buf, is little endian. */
284 
285 #define BYTES_CHANNEL_SELECTOR(bytes, channels)   (bytes * 100 + channels)
286 
287 	/* First do the most commonly used combinations. */
288 	switch (BYTES_CHANNEL_SELECTOR (bytes_per_sample, channels)) {
289 		/* One byte per sample. */
290 		case (BYTES_CHANNEL_SELECTOR (1, 1)):
291 			for (sample = 0; sample < samples; sample++)
292 				*buf_++ = signal[0][sample];
293 			return;
294 
295 		case (BYTES_CHANNEL_SELECTOR (1, 2)):
296 			for (sample = 0; sample < samples; sample++) {
297 				*buf_++ = signal[0][sample];
298 				*buf_++ = signal[1][sample];
299 			}
300 			return;
301 
302 		case (BYTES_CHANNEL_SELECTOR (1, 4)):
303 			for (sample = 0; sample < samples; sample++) {
304 				*buf_++ = signal[0][sample];
305 				*buf_++ = signal[1][sample];
306 				*buf_++ = signal[2][sample];
307 				*buf_++ = signal[3][sample];
308 			}
309 			return;
310 
311 		case (BYTES_CHANNEL_SELECTOR (1, 6)):
312 			for (sample = 0; sample < samples; sample++) {
313 				*buf_++ = signal[0][sample];
314 				*buf_++ = signal[1][sample];
315 				*buf_++ = signal[2][sample];
316 				*buf_++ = signal[3][sample];
317 				*buf_++ = signal[4][sample];
318 				*buf_++ = signal[5][sample];
319 			}
320 			return;
321 
322 		case (BYTES_CHANNEL_SELECTOR (1, 8)):
323 			for (sample = 0; sample < samples; sample++) {
324 				*buf_++ = signal[0][sample];
325 				*buf_++ = signal[1][sample];
326 				*buf_++ = signal[2][sample];
327 				*buf_++ = signal[3][sample];
328 				*buf_++ = signal[4][sample];
329 				*buf_++ = signal[5][sample];
330 				*buf_++ = signal[6][sample];
331 				*buf_++ = signal[7][sample];
332 			}
333 			return;
334 
335 		/* Two bytes per sample. */
336 		case (BYTES_CHANNEL_SELECTOR (2, 1)):
337 			for (sample = 0; sample < samples; sample++)
338 				*buf16++ = H2LE_16(signal[0][sample]);
339 			return;
340 
341 		case (BYTES_CHANNEL_SELECTOR (2, 2)):
342 			for (sample = 0; sample < samples; sample++) {
343 				*buf16++ = H2LE_16(signal[0][sample]);
344 				*buf16++ = H2LE_16(signal[1][sample]);
345 			}
346 			return;
347 
348 		case (BYTES_CHANNEL_SELECTOR (2, 4)):
349 			for (sample = 0; sample < samples; sample++) {
350 				*buf16++ = H2LE_16(signal[0][sample]);
351 				*buf16++ = H2LE_16(signal[1][sample]);
352 				*buf16++ = H2LE_16(signal[2][sample]);
353 				*buf16++ = H2LE_16(signal[3][sample]);
354 			}
355 			return;
356 
357 		case (BYTES_CHANNEL_SELECTOR (2, 6)):
358 			for (sample = 0; sample < samples; sample++) {
359 				*buf16++ = H2LE_16(signal[0][sample]);
360 				*buf16++ = H2LE_16(signal[1][sample]);
361 				*buf16++ = H2LE_16(signal[2][sample]);
362 				*buf16++ = H2LE_16(signal[3][sample]);
363 				*buf16++ = H2LE_16(signal[4][sample]);
364 				*buf16++ = H2LE_16(signal[5][sample]);
365 			}
366 			return;
367 
368 		case (BYTES_CHANNEL_SELECTOR (2, 8)):
369 			for (sample = 0; sample < samples; sample++) {
370 				*buf16++ = H2LE_16(signal[0][sample]);
371 				*buf16++ = H2LE_16(signal[1][sample]);
372 				*buf16++ = H2LE_16(signal[2][sample]);
373 				*buf16++ = H2LE_16(signal[3][sample]);
374 				*buf16++ = H2LE_16(signal[4][sample]);
375 				*buf16++ = H2LE_16(signal[5][sample]);
376 				*buf16++ = H2LE_16(signal[6][sample]);
377 				*buf16++ = H2LE_16(signal[7][sample]);
378 			}
379 			return;
380 
381 		/* Three bytes per sample. */
382 		case (BYTES_CHANNEL_SELECTOR (3, 1)):
383 			for (sample = 0; sample < samples; sample++) {
384 				a_word = signal[0][sample];
385 				*buf_++ = (FLAC__byte)a_word; a_word >>= 8;
386 				*buf_++ = (FLAC__byte)a_word; a_word >>= 8;
387 				*buf_++ = (FLAC__byte)a_word;
388 			}
389 			return;
390 
391 		case (BYTES_CHANNEL_SELECTOR (3, 2)):
392 			for (sample = 0; sample < samples; sample++) {
393 				a_word = signal[0][sample];
394 				*buf_++ = (FLAC__byte)a_word; a_word >>= 8;
395 				*buf_++ = (FLAC__byte)a_word; a_word >>= 8;
396 				*buf_++ = (FLAC__byte)a_word;
397 				a_word = signal[1][sample];
398 				*buf_++ = (FLAC__byte)a_word; a_word >>= 8;
399 				*buf_++ = (FLAC__byte)a_word; a_word >>= 8;
400 				*buf_++ = (FLAC__byte)a_word;
401 			}
402 			return;
403 
404 		/* Four bytes per sample. */
405 		case (BYTES_CHANNEL_SELECTOR (4, 1)):
406 			for (sample = 0; sample < samples; sample++)
407 				*buf32++ = H2LE_32(signal[0][sample]);
408 			return;
409 
410 		case (BYTES_CHANNEL_SELECTOR (4, 2)):
411 			for (sample = 0; sample < samples; sample++) {
412 				*buf32++ = H2LE_32(signal[0][sample]);
413 				*buf32++ = H2LE_32(signal[1][sample]);
414 			}
415 			return;
416 
417 		case (BYTES_CHANNEL_SELECTOR (4, 4)):
418 			for (sample = 0; sample < samples; sample++) {
419 				*buf32++ = H2LE_32(signal[0][sample]);
420 				*buf32++ = H2LE_32(signal[1][sample]);
421 				*buf32++ = H2LE_32(signal[2][sample]);
422 				*buf32++ = H2LE_32(signal[3][sample]);
423 			}
424 			return;
425 
426 		case (BYTES_CHANNEL_SELECTOR (4, 6)):
427 			for (sample = 0; sample < samples; sample++) {
428 				*buf32++ = H2LE_32(signal[0][sample]);
429 				*buf32++ = H2LE_32(signal[1][sample]);
430 				*buf32++ = H2LE_32(signal[2][sample]);
431 				*buf32++ = H2LE_32(signal[3][sample]);
432 				*buf32++ = H2LE_32(signal[4][sample]);
433 				*buf32++ = H2LE_32(signal[5][sample]);
434 			}
435 			return;
436 
437 		case (BYTES_CHANNEL_SELECTOR (4, 8)):
438 			for (sample = 0; sample < samples; sample++) {
439 				*buf32++ = H2LE_32(signal[0][sample]);
440 				*buf32++ = H2LE_32(signal[1][sample]);
441 				*buf32++ = H2LE_32(signal[2][sample]);
442 				*buf32++ = H2LE_32(signal[3][sample]);
443 				*buf32++ = H2LE_32(signal[4][sample]);
444 				*buf32++ = H2LE_32(signal[5][sample]);
445 				*buf32++ = H2LE_32(signal[6][sample]);
446 				*buf32++ = H2LE_32(signal[7][sample]);
447 			}
448 			return;
449 
450 		default:
451 			break;
452 	}
453 
454 	/* General version. */
455 	switch (bytes_per_sample) {
456 		case 1:
457 			for (sample = 0; sample < samples; sample++)
458 				for (channel = 0; channel < channels; channel++)
459 					*buf_++ = signal[channel][sample];
460 			return;
461 
462 		case 2:
463 			for (sample = 0; sample < samples; sample++)
464 				for (channel = 0; channel < channels; channel++)
465 					*buf16++ = H2LE_16(signal[channel][sample]);
466 			return;
467 
468 		case 3:
469 			for (sample = 0; sample < samples; sample++)
470 				for (channel = 0; channel < channels; channel++) {
471 					a_word = signal[channel][sample];
472 					*buf_++ = (FLAC__byte)a_word; a_word >>= 8;
473 					*buf_++ = (FLAC__byte)a_word; a_word >>= 8;
474 					*buf_++ = (FLAC__byte)a_word;
475 				}
476 			return;
477 
478 		case 4:
479 			for (sample = 0; sample < samples; sample++)
480 				for (channel = 0; channel < channels; channel++)
481 					*buf32++ = H2LE_32(signal[channel][sample]);
482 			return;
483 
484 		default:
485 			break;
486 	}
487 }
488 
489 /*
490  * Convert the incoming audio signal to a byte stream and FLAC__MD5Update it.
491  */
FLAC__MD5Accumulate(FLAC__MD5Context * ctx,const FLAC__int32 * const signal[],uint32_t channels,uint32_t samples,uint32_t bytes_per_sample)492 FLAC__bool FLAC__MD5Accumulate(FLAC__MD5Context *ctx, const FLAC__int32 * const signal[], uint32_t channels, uint32_t samples, uint32_t bytes_per_sample)
493 {
494 	const size_t bytes_needed = (size_t)channels * (size_t)samples * (size_t)bytes_per_sample;
495 
496 	/* overflow check */
497 	if ((size_t)channels > SIZE_MAX / (size_t)bytes_per_sample)
498 		return false;
499 	if ((size_t)channels * (size_t)bytes_per_sample > SIZE_MAX / (size_t)samples)
500 		return false;
501 
502 	if (ctx->capacity < bytes_needed) {
503 		if (0 == (ctx->internal_buf.p8 = safe_realloc_(ctx->internal_buf.p8, bytes_needed))) {
504 			if (0 == (ctx->internal_buf.p8 = safe_malloc_(bytes_needed))) {
505 				ctx->capacity = 0;
506 				return false;
507 			}
508 		}
509 		ctx->capacity = bytes_needed;
510 	}
511 
512 	format_input_(&ctx->internal_buf, signal, channels, samples, bytes_per_sample);
513 
514 	FLAC__MD5Update(ctx, ctx->internal_buf.p8, bytes_needed);
515 
516 	return true;
517 }
518