src/libFLAC/md5.c - platform/external/flac - Gitiles

 /*
  * This code implements the MD5 message-digest algorithm.
  * The algorithm is due to Ron Rivest.  This code was
  * written by Colin Plumb in 1993, no copyright is claimed.
  * This code is in the public domain; do with it what you wish.
  *
  * Equivalent code is available from RSA Data Security, Inc.
  * This code has been tested against that, and is equivalent,
  * except that you don't need to include two pages of legalese
  * with every copy.
  *
  * To compute the message digest of a chunk of bytes, declare an
  * MD5Context structure, pass it to MD5Init, call MD5Update as
  * needed on buffers full of bytes, and then call MD5Final, which
  * will fill a supplied 16-byte array with the digest.
  *
  * Changed so as no longer to depend on Colin Plumb's `usual.h' header
  * definitions; now uses stuff from dpkg's config.h.
  *  - Ian Jackson <ijackson@nyx.cs.du.edu>.
  * Still in the public domain.
  *
  * Josh Coalson: made some changes to integrate with libFLAC.
  * Still in the public domain.
  */

 #include <stdlib.h>		/* for malloc() */
 #include <string.h>		/* for memcpy() */

 #include "private/md5.h"

 #ifndef FLaC__INLINE
 #define FLaC__INLINE
 #endif

 static FLAC__bool is_big_endian_host_;

 #ifndef ASM_MD5

 /* The four core functions - F1 is optimized somewhat */

 /* #define F1(x, y, z) (x & y | ~x & z) */
 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 #define F2(x, y, z) F1(z, x, y)
 #define F3(x, y, z) (x ^ y ^ z)
 #define F4(x, y, z) (y ^ (x | ~z))

 /* This is the central step in the MD5 algorithm. */
 #define MD5STEP(f,w,x,y,z,in,s) \
 	 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)

 /*
  * The core of the MD5 algorithm, this alters an existing MD5 hash to
  * reflect the addition of 16 longwords of new data.  MD5Update blocks
  * the data and converts bytes into longwords for this routine.
  */
 FLaC__INLINE
 void
 MD5Transform(FLAC__uint32 buf[4], FLAC__uint32 const in[16])
 {
 	register FLAC__uint32 a, b, c, d;

 	a = buf[0];
 	b = buf[1];
 	c = buf[2];
 	d = buf[3];

 	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);

 	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

 	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);

 	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);

 	buf[0] += a;
 	buf[1] += b;
 	buf[2] += c;
 	buf[3] += d;
 }

 #endif

 FLaC__INLINE
 void
 byteSwap(FLAC__uint32 *buf, unsigned words)
 {
 	md5byte *p = (md5byte *)buf;

 	if(!is_big_endian_host_)
 		return;
 	do {
 		*buf++ = (FLAC__uint32)((unsigned)p[3] << 8 | p[2]) << 16 | ((unsigned)p[1] << 8 | p[0]);
 		p += 4;
 	} while (--words);
 }

 /*
  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
  * initialization constants.
  */
 void
 MD5Init(struct MD5Context *ctx)
 {
 	FLAC__uint32 test = 1;

 	is_big_endian_host_ = (*((FLAC__byte*)(&test)))? false : true;

 	ctx->buf[0] = 0x67452301;
 	ctx->buf[1] = 0xefcdab89;
 	ctx->buf[2] = 0x98badcfe;
 	ctx->buf[3] = 0x10325476;

 	ctx->bytes[0] = 0;
 	ctx->bytes[1] = 0;

 	ctx->internal_buf = 0;
 	ctx->capacity = 0;
 }

 /*
  * Update context to reflect the concatenation of another buffer full
  * of bytes.
  */
 void
 MD5Update(struct MD5Context *ctx, md5byte const *buf, unsigned len)
 {
 	FLAC__uint32 t;

 	/* Update byte count */

 	t = ctx->bytes[0];
 	if ((ctx->bytes[0] = t + len) < t)
 		ctx->bytes[1]++;	/* Carry from low to high */

 	t = 64 - (t & 0x3f);	/* Space available in ctx->in (at least 1) */
 	if (t > len) {
 		memcpy((md5byte *)ctx->in + 64 - t, buf, len);
 		return;
 	}
 	/* First chunk is an odd size */
 	memcpy((md5byte *)ctx->in + 64 - t, buf, t);
 	byteSwap(ctx->in, 16);
 	MD5Transform(ctx->buf, ctx->in);
 	buf += t;
 	len -= t;

 	/* Process data in 64-byte chunks */
 	while (len >= 64) {
 		memcpy(ctx->in, buf, 64);
 		byteSwap(ctx->in, 16);
 		MD5Transform(ctx->buf, ctx->in);
 		buf += 64;
 		len -= 64;
 	}

 	/* Handle any remaining bytes of data. */
 	memcpy(ctx->in, buf, len);
 }

 /*
  * Convert the incoming audio signal to a byte stream and MD5Update it.
  */
 FLAC__bool
 FLAC__MD5Accumulate(struct MD5Context *ctx, const FLAC__int32 * const signal[], unsigned channels, unsigned samples, unsigned bytes_per_sample)
 {
 	unsigned channel, sample, a_byte;
 	FLAC__int32 a_word;
 	FLAC__byte *buf_;
 	const unsigned bytes_needed = channels * samples * bytes_per_sample;

 	if(ctx->capacity < bytes_needed) {
 		FLAC__byte *tmp = realloc(ctx->internal_buf, bytes_needed);
 		if(0 == tmp) {
 			free(ctx->internal_buf);
 			if(0 == (ctx->internal_buf = malloc(bytes_needed)))
 				return false;
 		}
 		ctx->internal_buf = tmp;
 		ctx->capacity = bytes_needed;
 	}

 	buf_ = ctx->internal_buf;

 #ifdef FLAC__CPU_IA32
 	if(channels == 2 && bytes_per_sample == 2) {
 		memcpy(buf_, signal[0], sizeof(FLAC__int32) * samples);
 		buf_ += sizeof(FLAC__int16);
 		for(sample = 0; sample < samples; sample++)
 			((FLAC__int16 *)buf_)[2 * sample] = (FLAC__int16)signal[1][sample];
 	}
 	else if(channels == 1 && bytes_per_sample == 2) {
 		for(sample = 0; sample < samples; sample++)
 			((FLAC__int16 *)buf_)[sample] = (FLAC__int16)signal[0][sample];
 	}
 	else
 #endif
 	for(sample = 0; sample < samples; sample++) {
 		for(channel = 0; channel < channels; channel++) {
 			a_word = signal[channel][sample];
 			for(a_byte = 0; a_byte < bytes_per_sample; a_byte++) {
 				*buf_++ = (FLAC__byte)(a_word & 0xff);
 				a_word >>= 8;
 			}
 		}
 	}

 	MD5Update(ctx, ctx->internal_buf, bytes_needed);

 	return true;
 }

 /*
  * Final wrapup - pad to 64-byte boundary with the bit pattern
  * 1 0* (64-bit count of bits processed, MSB-first)
  */
 void
 MD5Final(md5byte digest[16], struct MD5Context *ctx)
 {
 	int count = ctx->bytes[0] & 0x3f;	/* Number of bytes in ctx->in */
 	md5byte *p = (md5byte *)ctx->in + count;

 	/* Set the first char of padding to 0x80.  There is always room. */
 	*p++ = 0x80;

 	/* Bytes of padding needed to make 56 bytes (-8..55) */
 	count = 56 - 1 - count;

 	if (count < 0) {	/* Padding forces an extra block */
 		memset(p, 0, count + 8);
 		byteSwap(ctx->in, 16);
 		MD5Transform(ctx->buf, ctx->in);
 		p = (md5byte *)ctx->in;
 		count = 56;
 	}
 	memset(p, 0, count);
 	byteSwap(ctx->in, 14);

 	/* Append length in bits and transform */
 	ctx->in[14] = ctx->bytes[0] << 3;
 	ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
 	MD5Transform(ctx->buf, ctx->in);

 	byteSwap(ctx->buf, 4);
 	memcpy(digest, ctx->buf, 16);
 	memset(ctx, 0, sizeof(ctx));	/* In case it's sensitive */
 	if(0 != ctx->internal_buf) {
 		free(ctx->internal_buf);
 		ctx->internal_buf = 0;
 		ctx->capacity = 0;
 	}
 }
	/*
	* This code implements the MD5 message-digest algorithm.
	* The algorithm is due to Ron Rivest. This code was
	* written by Colin Plumb in 1993, no copyright is claimed.
	* This code is in the public domain; do with it what you wish.
	*
	* Equivalent code is available from RSA Data Security, Inc.
	* This code has been tested against that, and is equivalent,
	* except that you don't need to include two pages of legalese
	* with every copy.
	*
	* To compute the message digest of a chunk of bytes, declare an
	* MD5Context structure, pass it to MD5Init, call MD5Update as
	* needed on buffers full of bytes, and then call MD5Final, which
	* will fill a supplied 16-byte array with the digest.
	*
	* Changed so as no longer to depend on Colin Plumb's `usual.h' header
	* definitions; now uses stuff from dpkg's config.h.
	* - Ian Jackson <ijackson@nyx.cs.du.edu>.
	* Still in the public domain.
	*
	* Josh Coalson: made some changes to integrate with libFLAC.
	* Still in the public domain.
	*/

	#include <stdlib.h> /* for malloc() */
	#include <string.h> /* for memcpy() */

	#include "private/md5.h"

	#ifndef FLaC__INLINE
	#define FLaC__INLINE
	#endif

	static FLAC__bool is_big_endian_host_;

	#ifndef ASM_MD5

	/* The four core functions - F1 is optimized somewhat */

	/* #define F1(x, y, z) (x & y \| ~x & z) */
	#define F1(x, y, z) (z ^ (x & (y ^ z)))
	#define F2(x, y, z) F1(z, x, y)
	#define F3(x, y, z) (x ^ y ^ z)
	#define F4(x, y, z) (y ^ (x \| ~z))

	/* This is the central step in the MD5 algorithm. */
	#define MD5STEP(f,w,x,y,z,in,s) \
	(w += f(x,y,z) + in, w = (w<<s \| w>>(32-s)) + x)

	/*
	* The core of the MD5 algorithm, this alters an existing MD5 hash to
	* reflect the addition of 16 longwords of new data. MD5Update blocks
	* the data and converts bytes into longwords for this routine.
	*/
	FLaC__INLINE
	void
	MD5Transform(FLAC__uint32 buf[4], FLAC__uint32 const in[16])
	{
	register FLAC__uint32 a, b, c, d;

	a = buf[0];
	b = buf[1];
	c = buf[2];
	d = buf[3];

	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);

	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);

	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);

	buf[0] += a;
	buf[1] += b;
	buf[2] += c;
	buf[3] += d;
	}

	#endif

	FLaC__INLINE
	void
	byteSwap(FLAC__uint32 *buf, unsigned words)
	{
	md5byte p = (md5byte )buf;

	if(!is_big_endian_host_)
	return;
	do {
	*buf++ = (FLAC__uint32)((unsigned)p[3] << 8 \| p[2]) << 16 \| ((unsigned)p[1] << 8 \| p[0]);
	p += 4;
	} while (--words);
	}

	/*
	* Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
	* initialization constants.
	*/
	void
	MD5Init(struct MD5Context *ctx)
	{
	FLAC__uint32 test = 1;

	is_big_endian_host_ = (((FLAC__byte)(&test)))? false : true;

	ctx->buf[0] = 0x67452301;
	ctx->buf[1] = 0xefcdab89;
	ctx->buf[2] = 0x98badcfe;
	ctx->buf[3] = 0x10325476;

	ctx->bytes[0] = 0;
	ctx->bytes[1] = 0;

	ctx->internal_buf = 0;
	ctx->capacity = 0;
	}

	/*
	* Update context to reflect the concatenation of another buffer full
	* of bytes.
	*/
	void
	MD5Update(struct MD5Context ctx, md5byte const buf, unsigned len)
	{
	FLAC__uint32 t;

	/* Update byte count */

	t = ctx->bytes[0];
	if ((ctx->bytes[0] = t + len) < t)
	ctx->bytes[1]++; /* Carry from low to high */

	t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
	if (t > len) {
	memcpy((md5byte *)ctx->in + 64 - t, buf, len);
	return;
	}
	/* First chunk is an odd size */
	memcpy((md5byte *)ctx->in + 64 - t, buf, t);
	byteSwap(ctx->in, 16);
	MD5Transform(ctx->buf, ctx->in);
	buf += t;
	len -= t;

	/* Process data in 64-byte chunks */
	while (len >= 64) {
	memcpy(ctx->in, buf, 64);
	byteSwap(ctx->in, 16);
	MD5Transform(ctx->buf, ctx->in);
	buf += 64;
	len -= 64;
	}

	/* Handle any remaining bytes of data. */
	memcpy(ctx->in, buf, len);
	}

	/*
	* Convert the incoming audio signal to a byte stream and MD5Update it.
	*/
	FLAC__bool
	FLAC__MD5Accumulate(struct MD5Context ctx, const FLAC__int32 const signal[], unsigned channels, unsigned samples, unsigned bytes_per_sample)
	{
	unsigned channel, sample, a_byte;
	FLAC__int32 a_word;
	FLAC__byte *buf_;
	const unsigned bytes_needed = channels * samples * bytes_per_sample;

	if(ctx->capacity < bytes_needed) {
	FLAC__byte *tmp = realloc(ctx->internal_buf, bytes_needed);
	if(0 == tmp) {
	free(ctx->internal_buf);
	if(0 == (ctx->internal_buf = malloc(bytes_needed)))
	return false;
	}
	ctx->internal_buf = tmp;
	ctx->capacity = bytes_needed;
	}

	buf_ = ctx->internal_buf;

	#ifdef FLAC__CPU_IA32
	if(channels == 2 && bytes_per_sample == 2) {
	memcpy(buf_, signal[0], sizeof(FLAC__int32) * samples);
	buf_ += sizeof(FLAC__int16);
	for(sample = 0; sample < samples; sample++)
	((FLAC__int16 )buf_)[2 sample] = (FLAC__int16)signal[1][sample];
	}
	else if(channels == 1 && bytes_per_sample == 2) {
	for(sample = 0; sample < samples; sample++)
	((FLAC__int16 *)buf_)[sample] = (FLAC__int16)signal[0][sample];
	}
	else
	#endif
	for(sample = 0; sample < samples; sample++) {
	for(channel = 0; channel < channels; channel++) {
	a_word = signal[channel][sample];
	for(a_byte = 0; a_byte < bytes_per_sample; a_byte++) {
	*buf_++ = (FLAC__byte)(a_word & 0xff);
	a_word >>= 8;
	}
	}
	}

	MD5Update(ctx, ctx->internal_buf, bytes_needed);

	return true;
	}

	/*
	* Final wrapup - pad to 64-byte boundary with the bit pattern
	* 1 0* (64-bit count of bits processed, MSB-first)
	*/
	void
	MD5Final(md5byte digest[16], struct MD5Context *ctx)
	{
	int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */
	md5byte p = (md5byte )ctx->in + count;

	/* Set the first char of padding to 0x80. There is always room. */
	*p++ = 0x80;

	/* Bytes of padding needed to make 56 bytes (-8..55) */
	count = 56 - 1 - count;

	if (count < 0) { /* Padding forces an extra block */
	memset(p, 0, count + 8);
	byteSwap(ctx->in, 16);
	MD5Transform(ctx->buf, ctx->in);
	p = (md5byte *)ctx->in;
	count = 56;
	}
	memset(p, 0, count);
	byteSwap(ctx->in, 14);

	/* Append length in bits and transform */
	ctx->in[14] = ctx->bytes[0] << 3;
	ctx->in[15] = ctx->bytes[1] << 3 \| ctx->bytes[0] >> 29;
	MD5Transform(ctx->buf, ctx->in);

	byteSwap(ctx->buf, 4);
	memcpy(digest, ctx->buf, 16);
	memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */
	if(0 != ctx->internal_buf) {
	free(ctx->internal_buf);
	ctx->internal_buf = 0;
	ctx->capacity = 0;
	}
	}