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