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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/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 (at) 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  */
     54 static 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
    139 static 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 }
    148 static 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  */
    178 static 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  */
    217 void 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  */
    235 void 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  */
    274 static 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  */
    491 FLAC__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