ft2-clone

Fasttracker 2 clone
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md5.c (15609B)


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