commands/xnu_uuid.c - chromiumos/third_party/grub2 - Git at Google

 /* xnu_uuid.c - transform 64-bit serial number
    to 128-bit uuid suitable for xnu. */
 /*
  *  GRUB  --  GRand Unified Bootloader
  *  Copyright (C) 1995,1996,1998,1999,2001,2002,
  *                2003, 2009  Free Software Foundation, Inc.
  *
  *  GRUB is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation, either version 3 of the License, or
  *  (at your option) any later version.
  *
  *  GRUB is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include <grub/types.h>
 #include <grub/misc.h>
 #include <grub/mm.h>
 #include <grub/err.h>
 #include <grub/dl.h>
 #include <grub/device.h>
 #include <grub/disk.h>
 #include <grub/fs.h>
 #include <grub/file.h>
 #include <grub/misc.h>
 #include <grub/env.h>
 #include <grub/command.h>

 struct tohash
 {
   grub_uint8_t prefix[16];
   grub_uint64_t serial;
 } __attribute__ ((packed));

 /* This prefix is used by xnu and boot-132 to hash
    together with volume serial. */
 static grub_uint8_t hash_prefix[16]
   = {0xB3, 0xE2, 0x0F, 0x39, 0xF2, 0x92, 0x11, 0xD6,
      0x97, 0xA4, 0x00, 0x30, 0x65, 0x43, 0xEC, 0xAC};

 #define rol(x,n) ( ((x) << (n)) | ((x) >> (32-(n))) )
 #define ror(x,n) ( ((x) >> (n)) | ((x) << (32-(n))) )

 typedef struct {
   grub_uint32_t A,B,C,D;	  /* chaining variables */
   grub_uint32_t  nblocks;
   grub_uint8_t buf[64];
   int  count;
 } MD5_CONTEXT;

 static void
 md5_init( void *context )
 {
   MD5_CONTEXT *ctx = context;

   ctx->A = 0x67452301;
   ctx->B = 0xefcdab89;
   ctx->C = 0x98badcfe;
   ctx->D = 0x10325476;

   ctx->nblocks = 0;
   ctx->count = 0;
 }

 /* These are the four functions used in the four steps of the MD5 algorithm
    and defined in the RFC 1321.  The first function is a little bit optimized
    (as found in Colin Plumbs public domain implementation).  */
 /* #define FF(b, c, d) ((b & c) | (~b & d)) */
 #define FF(b, c, d) (d ^ (b & (c ^ d)))
 #define FG(b, c, d) FF (d, b, c)
 #define FH(b, c, d) (b ^ c ^ d)
 #define FI(b, c, d) (c ^ (b | ~d))


 /****************
  * transform n*64 grub_uint8_ts
  */
 static void
 transform ( MD5_CONTEXT *ctx, const unsigned char *data )
 {
   grub_uint32_t correct_words[16];
   register grub_uint32_t A = ctx->A;
   register grub_uint32_t B = ctx->B;
   register grub_uint32_t C = ctx->C;
   register grub_uint32_t D = ctx->D;
   grub_uint32_t *cwp = correct_words;

 #ifdef GRUB_CPU_WORDS_BIGENDIAN
   {
     int i;
     const grub_uint32_t *p = (const grub_uint32_t *) data;

     for (i = 0; i < 16; i++)
       correct_words[i] = grub_le_to_cpu32 (p[i]);
   }
 #else
   grub_memcpy (correct_words, data, 64);
 #endif

 #define OP(a, b, c, d, s, T) \
   do			         	   \
   {					   \
     a += FF (b, c, d) + (*cwp++) + T;    \
     a = rol(a, s);			   \
     a += b;				   \
   }					   \
   while (0)

   /* Before we start, one word about the strange constants.
      They are defined in RFC 1321 as

      T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
      */

   /* Round 1.  */
   OP (A, B, C, D,  7, 0xd76aa478);
   OP (D, A, B, C, 12, 0xe8c7b756);
   OP (C, D, A, B, 17, 0x242070db);
   OP (B, C, D, A, 22, 0xc1bdceee);
   OP (A, B, C, D,  7, 0xf57c0faf);
   OP (D, A, B, C, 12, 0x4787c62a);
   OP (C, D, A, B, 17, 0xa8304613);
   OP (B, C, D, A, 22, 0xfd469501);
   OP (A, B, C, D,  7, 0x698098d8);
   OP (D, A, B, C, 12, 0x8b44f7af);
   OP (C, D, A, B, 17, 0xffff5bb1);
   OP (B, C, D, A, 22, 0x895cd7be);
   OP (A, B, C, D,  7, 0x6b901122);
   OP (D, A, B, C, 12, 0xfd987193);
   OP (C, D, A, B, 17, 0xa679438e);
   OP (B, C, D, A, 22, 0x49b40821);

 #undef OP
 #define OP(f, a, b, c, d, k, s, T)  \
   do								      \
   { 							      \
     a += f (b, c, d) + correct_words[k] + T;		      \
     a = rol(a, s);						      \
     a += b; 						      \
   } 							      \
   while (0)

   /* Round 2.  */
   OP (FG, A, B, C, D,  1,  5, 0xf61e2562);
   OP (FG, D, A, B, C,  6,  9, 0xc040b340);
   OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
   OP (FG, B, C, D, A,  0, 20, 0xe9b6c7aa);
   OP (FG, A, B, C, D,  5,  5, 0xd62f105d);
   OP (FG, D, A, B, C, 10,  9, 0x02441453);
   OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
   OP (FG, B, C, D, A,  4, 20, 0xe7d3fbc8);
   OP (FG, A, B, C, D,  9,  5, 0x21e1cde6);
   OP (FG, D, A, B, C, 14,  9, 0xc33707d6);
   OP (FG, C, D, A, B,  3, 14, 0xf4d50d87);
   OP (FG, B, C, D, A,  8, 20, 0x455a14ed);
   OP (FG, A, B, C, D, 13,  5, 0xa9e3e905);
   OP (FG, D, A, B, C,  2,  9, 0xfcefa3f8);
   OP (FG, C, D, A, B,  7, 14, 0x676f02d9);
   OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);

   /* Round 3.  */
   OP (FH, A, B, C, D,  5,  4, 0xfffa3942);
   OP (FH, D, A, B, C,  8, 11, 0x8771f681);
   OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
   OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
   OP (FH, A, B, C, D,  1,  4, 0xa4beea44);
   OP (FH, D, A, B, C,  4, 11, 0x4bdecfa9);
   OP (FH, C, D, A, B,  7, 16, 0xf6bb4b60);
   OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
   OP (FH, A, B, C, D, 13,  4, 0x289b7ec6);
   OP (FH, D, A, B, C,  0, 11, 0xeaa127fa);
   OP (FH, C, D, A, B,  3, 16, 0xd4ef3085);
   OP (FH, B, C, D, A,  6, 23, 0x04881d05);
   OP (FH, A, B, C, D,  9,  4, 0xd9d4d039);
   OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
   OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
   OP (FH, B, C, D, A,  2, 23, 0xc4ac5665);

   /* Round 4.  */
   OP (FI, A, B, C, D,  0,  6, 0xf4292244);
   OP (FI, D, A, B, C,  7, 10, 0x432aff97);
   OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
   OP (FI, B, C, D, A,  5, 21, 0xfc93a039);
   OP (FI, A, B, C, D, 12,  6, 0x655b59c3);
   OP (FI, D, A, B, C,  3, 10, 0x8f0ccc92);
   OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
   OP (FI, B, C, D, A,  1, 21, 0x85845dd1);
   OP (FI, A, B, C, D,  8,  6, 0x6fa87e4f);
   OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
   OP (FI, C, D, A, B,  6, 15, 0xa3014314);
   OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
   OP (FI, A, B, C, D,  4,  6, 0xf7537e82);
   OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
   OP (FI, C, D, A, B,  2, 15, 0x2ad7d2bb);
   OP (FI, B, C, D, A,  9, 21, 0xeb86d391);

   /* Put checksum in context given as argument.  */
   ctx->A += A;
   ctx->B += B;
   ctx->C += C;
   ctx->D += D;
 }

 /* The routine updates the message-digest context to
  * account for the presence of each of the characters inBuf[0..inLen-1]
  * in the message whose digest is being computed.
  */
 static void
 md5_write( void *context, const void *inbuf_arg , grub_size_t inlen)
 {
   const unsigned char *inbuf = inbuf_arg;
   MD5_CONTEXT *hd = context;

   if( hd->count == 64 )  /* flush the buffer */
   {
     transform( hd, hd->buf );
     //      _gcry_burn_stack (80+6*sizeof(void*));
     hd->count = 0;
     hd->nblocks++;
   }
   if( !inbuf )
     return;

   if( hd->count )
   {
     for( ; inlen && hd->count < 64; inlen-- )
       hd->buf[hd->count++] = *inbuf++;
     md5_write( hd, NULL, 0 );
     if( !inlen )
       return;
   }
   //  _gcry_burn_stack (80+6*sizeof(void*));

   while( inlen >= 64 )
   {
     transform( hd, inbuf );
     hd->count = 0;
     hd->nblocks++;
     inlen -= 64;
     inbuf += 64;
   }
   for( ; inlen && hd->count < 64; inlen-- )
     hd->buf[hd->count++] = *inbuf++;

 }


 /* The routine final terminates the message-digest computation and
  * ends with the desired message digest in mdContext->digest[0...15].
  * The handle is prepared for a new MD5 cycle.
  * Returns 16 grub_uint8_ts representing the digest.
  */
 static void
 md5_final( void *context)
 {
   MD5_CONTEXT *hd = context;
   grub_uint32_t t, msb, lsb;
   grub_uint32_t *p;

   md5_write(hd, NULL, 0); /* flush */;

   t = hd->nblocks;
   /* multiply by 64 to make a grub_uint8_t count */
   lsb = t << 6;
   msb = t >> 26;
   /* add the count */
   t = lsb;
   if( (lsb += hd->count) < t )
     msb++;
   /* multiply by 8 to make a bit count */
   t = lsb;
   lsb <<= 3;
   msb <<= 3;
   msb |= t >> 29;

   if( hd->count < 56 )  /* enough room */
   {
     hd->buf[hd->count++] = 0x80; /* pad */
     while( hd->count < 56 )
       hd->buf[hd->count++] = 0;  /* pad */
   }
   else  /* need one extra block */
   {
     hd->buf[hd->count++] = 0x80; /* pad character */
     while( hd->count < 64 )
       hd->buf[hd->count++] = 0;
     md5_write(hd, NULL, 0);  /* flush */;
     grub_memset(hd->buf, 0, 56 ); /* fill next block with zeroes */
   }
   /* append the 64 bit count */
   hd->buf[56] = lsb	   ;
   hd->buf[57] = lsb >>  8;
   hd->buf[58] = lsb >> 16;
   hd->buf[59] = lsb >> 24;
   hd->buf[60] = msb	   ;
   hd->buf[61] = msb >>  8;
   hd->buf[62] = msb >> 16;
   hd->buf[63] = msb >> 24;
   transform( hd, hd->buf );
   //  _gcry_burn_stack (80+6*sizeof(void*));

   p = (grub_uint32_t *) hd->buf;
 #define X(a) do { *p = grub_le_to_cpu32 (hd->a); p++; } while (0)
   X(A);
   X(B);
   X(C);
   X(D);
 #undef X

 }

 /**
  * GRUB2 Crypto Interface
  * Written by Michael Gorven
  */
 static grub_err_t
 md5 (const char *in, grub_size_t insize, char *out)
 {
   MD5_CONTEXT hd;

   md5_init (&hd);
   md5_write (&hd, in, insize);
   md5_final (&hd);
   grub_memcpy (out, hd.buf, 16);

   return GRUB_ERR_NONE;
 }

 static grub_err_t
 grub_cmd_xnu_uuid (grub_command_t cmd __attribute__ ((unused)),
 		   int argc, char **args)
 {
   struct tohash hashme;
   grub_uint8_t xnu_uuid[16];
   char uuid_string[sizeof ("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
   char *ptr;

   if (argc < 1)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, "UUID required");

   hashme.serial = grub_cpu_to_be64 (grub_strtoull (args[0], 0, 16));
   grub_memcpy (hashme.prefix, hash_prefix, sizeof (hashme.prefix));

   md5 ((char *) &hashme, sizeof (hashme), (char *) xnu_uuid);
   grub_sprintf (uuid_string,
 		"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 		(unsigned int) xnu_uuid[0], (unsigned int) xnu_uuid[1],
 		(unsigned int) xnu_uuid[2], (unsigned int) xnu_uuid[3],
 		(unsigned int) xnu_uuid[4], (unsigned int) xnu_uuid[5],
 		(unsigned int) ((xnu_uuid[6] & 0xf) | 0x30),
 		(unsigned int) xnu_uuid[7],
 		(unsigned int) ((xnu_uuid[8] & 0x3f) | 0x80),
 		(unsigned int) xnu_uuid[9],
 		(unsigned int) xnu_uuid[10], (unsigned int) xnu_uuid[11],
 		(unsigned int) xnu_uuid[12], (unsigned int) xnu_uuid[13],
 		(unsigned int) xnu_uuid[14], (unsigned int) xnu_uuid[15]);
   for (ptr = uuid_string; *ptr; ptr++)
     *ptr = grub_toupper (*ptr);
   if (argc == 1)
     grub_printf ("%s", uuid_string);
   if (argc > 1)
     grub_env_set (args[1], uuid_string);

   return GRUB_ERR_NONE;
 }

 static grub_command_t cmd;


 GRUB_MOD_INIT (xnu_uuid)
 {
   cmd = grub_register_command ("xnu_uuid", grub_cmd_xnu_uuid,
 			       "xnu_uuid GRUBUUID [VARNAME]",
 			       "Transform 64-bit UUID to format "
 			       "suitable for xnu.");
 }

 GRUB_MOD_FINI (xnu_uuid)
 {
   grub_unregister_command (cmd);
 }
	/* xnu_uuid.c - transform 64-bit serial number
	to 128-bit uuid suitable for xnu. */
	/*
	* GRUB -- GRand Unified Bootloader
	* Copyright (C) 1995,1996,1998,1999,2001,2002,
	* 2003, 2009 Free Software Foundation, Inc.
	*
	* GRUB is free software: you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation, either version 3 of the License, or
	* (at your option) any later version.
	*
	* GRUB is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include <grub/types.h>
	#include <grub/misc.h>
	#include <grub/mm.h>
	#include <grub/err.h>
	#include <grub/dl.h>
	#include <grub/device.h>
	#include <grub/disk.h>
	#include <grub/fs.h>
	#include <grub/file.h>
	#include <grub/misc.h>
	#include <grub/env.h>
	#include <grub/command.h>

	struct tohash
	{
	grub_uint8_t prefix[16];
	grub_uint64_t serial;
	} __attribute__ ((packed));

	/* This prefix is used by xnu and boot-132 to hash
	together with volume serial. */
	static grub_uint8_t hash_prefix[16]
	= {0xB3, 0xE2, 0x0F, 0x39, 0xF2, 0x92, 0x11, 0xD6,
	0x97, 0xA4, 0x00, 0x30, 0x65, 0x43, 0xEC, 0xAC};

	#define rol(x,n) ( ((x) << (n)) \| ((x) >> (32-(n))) )
	#define ror(x,n) ( ((x) >> (n)) \| ((x) << (32-(n))) )

	typedef struct {
	grub_uint32_t A,B,C,D; /* chaining variables */
	grub_uint32_t nblocks;
	grub_uint8_t buf[64];
	int count;
	} MD5_CONTEXT;

	static void
	md5_init( void *context )
	{
	MD5_CONTEXT *ctx = context;

	ctx->A = 0x67452301;
	ctx->B = 0xefcdab89;
	ctx->C = 0x98badcfe;
	ctx->D = 0x10325476;

	ctx->nblocks = 0;
	ctx->count = 0;
	}

	/* These are the four functions used in the four steps of the MD5 algorithm
	and defined in the RFC 1321. The first function is a little bit optimized
	(as found in Colin Plumbs public domain implementation). */
	/* #define FF(b, c, d) ((b & c) \| (~b & d)) */
	#define FF(b, c, d) (d ^ (b & (c ^ d)))
	#define FG(b, c, d) FF (d, b, c)
	#define FH(b, c, d) (b ^ c ^ d)
	#define FI(b, c, d) (c ^ (b \| ~d))


	/****************
	* transform n*64 grub_uint8_ts
	*/
	static void
	transform ( MD5_CONTEXT ctx, const unsigned char data )
	{
	grub_uint32_t correct_words[16];
	register grub_uint32_t A = ctx->A;
	register grub_uint32_t B = ctx->B;
	register grub_uint32_t C = ctx->C;
	register grub_uint32_t D = ctx->D;
	grub_uint32_t *cwp = correct_words;

	#ifdef GRUB_CPU_WORDS_BIGENDIAN
	{
	int i;
	const grub_uint32_t p = (const grub_uint32_t ) data;

	for (i = 0; i < 16; i++)
	correct_words[i] = grub_le_to_cpu32 (p[i]);
	}
	#else
	grub_memcpy (correct_words, data, 64);
	#endif

	#define OP(a, b, c, d, s, T) \
	do \
	{ \
	a += FF (b, c, d) + (*cwp++) + T; \
	a = rol(a, s); \
	a += b; \
	} \
	while (0)

	/* Before we start, one word about the strange constants.
	They are defined in RFC 1321 as

	T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
	*/

	/* Round 1. */
	OP (A, B, C, D, 7, 0xd76aa478);
	OP (D, A, B, C, 12, 0xe8c7b756);
	OP (C, D, A, B, 17, 0x242070db);
	OP (B, C, D, A, 22, 0xc1bdceee);
	OP (A, B, C, D, 7, 0xf57c0faf);
	OP (D, A, B, C, 12, 0x4787c62a);
	OP (C, D, A, B, 17, 0xa8304613);
	OP (B, C, D, A, 22, 0xfd469501);
	OP (A, B, C, D, 7, 0x698098d8);
	OP (D, A, B, C, 12, 0x8b44f7af);
	OP (C, D, A, B, 17, 0xffff5bb1);
	OP (B, C, D, A, 22, 0x895cd7be);
	OP (A, B, C, D, 7, 0x6b901122);
	OP (D, A, B, C, 12, 0xfd987193);
	OP (C, D, A, B, 17, 0xa679438e);
	OP (B, C, D, A, 22, 0x49b40821);

	#undef OP
	#define OP(f, a, b, c, d, k, s, T) \
	do \
	{ \
	a += f (b, c, d) + correct_words[k] + T; \
	a = rol(a, s); \
	a += b; \
	} \
	while (0)

	/* Round 2. */
	OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
	OP (FG, D, A, B, C, 6, 9, 0xc040b340);
	OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
	OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
	OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
	OP (FG, D, A, B, C, 10, 9, 0x02441453);
	OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
	OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
	OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
	OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
	OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
	OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
	OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
	OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
	OP (FG, C, D, A, B, 7, 14, 0x676f02d9);
	OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);

	/* Round 3. */
	OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
	OP (FH, D, A, B, C, 8, 11, 0x8771f681);
	OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
	OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
	OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
	OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
	OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);
	OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
	OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
	OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
	OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
	OP (FH, B, C, D, A, 6, 23, 0x04881d05);
	OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);
	OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
	OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
	OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);

	/* Round 4. */
	OP (FI, A, B, C, D, 0, 6, 0xf4292244);
	OP (FI, D, A, B, C, 7, 10, 0x432aff97);
	OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
	OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
	OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
	OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);
	OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
	OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
	OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);
	OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
	OP (FI, C, D, A, B, 6, 15, 0xa3014314);
	OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
	OP (FI, A, B, C, D, 4, 6, 0xf7537e82);
	OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
	OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
	OP (FI, B, C, D, A, 9, 21, 0xeb86d391);

	/* Put checksum in context given as argument. */
	ctx->A += A;
	ctx->B += B;
	ctx->C += C;
	ctx->D += D;
	}

	/* The routine updates the message-digest context to
	* account for the presence of each of the characters inBuf[0..inLen-1]
	* in the message whose digest is being computed.
	*/
	static void
	md5_write( void context, const void inbuf_arg , grub_size_t inlen)
	{
	const unsigned char *inbuf = inbuf_arg;
	MD5_CONTEXT *hd = context;

	if( hd->count == 64 ) /* flush the buffer */
	{
	transform( hd, hd->buf );
	// _gcry_burn_stack (80+6sizeof(void));
	hd->count = 0;
	hd->nblocks++;
	}
	if( !inbuf )
	return;

	if( hd->count )
	{
	for( ; inlen && hd->count < 64; inlen-- )
	hd->buf[hd->count++] = *inbuf++;
	md5_write( hd, NULL, 0 );
	if( !inlen )
	return;
	}
	// _gcry_burn_stack (80+6sizeof(void));

	while( inlen >= 64 )
	{
	transform( hd, inbuf );
	hd->count = 0;
	hd->nblocks++;
	inlen -= 64;
	inbuf += 64;
	}
	for( ; inlen && hd->count < 64; inlen-- )
	hd->buf[hd->count++] = *inbuf++;

	}



	/* The routine final terminates the message-digest computation and
	* ends with the desired message digest in mdContext->digest[0...15].
	* The handle is prepared for a new MD5 cycle.
	* Returns 16 grub_uint8_ts representing the digest.
	*/
	static void
	md5_final( void *context)
	{
	MD5_CONTEXT *hd = context;
	grub_uint32_t t, msb, lsb;
	grub_uint32_t *p;

	md5_write(hd, NULL, 0); /* flush */;

	t = hd->nblocks;
	/* multiply by 64 to make a grub_uint8_t count */
	lsb = t << 6;
	msb = t >> 26;
	/* add the count */
	t = lsb;
	if( (lsb += hd->count) < t )
	msb++;
	/* multiply by 8 to make a bit count */
	t = lsb;
	lsb <<= 3;
	msb <<= 3;
	msb \|= t >> 29;

	if( hd->count < 56 ) /* enough room */
	{
	hd->buf[hd->count++] = 0x80; /* pad */
	while( hd->count < 56 )
	hd->buf[hd->count++] = 0; /* pad */
	}
	else /* need one extra block */
	{
	hd->buf[hd->count++] = 0x80; /* pad character */
	while( hd->count < 64 )
	hd->buf[hd->count++] = 0;
	md5_write(hd, NULL, 0); /* flush */;
	grub_memset(hd->buf, 0, 56 ); /* fill next block with zeroes */
	}
	/* append the 64 bit count */
	hd->buf[56] = lsb ;
	hd->buf[57] = lsb >> 8;
	hd->buf[58] = lsb >> 16;
	hd->buf[59] = lsb >> 24;
	hd->buf[60] = msb ;
	hd->buf[61] = msb >> 8;
	hd->buf[62] = msb >> 16;
	hd->buf[63] = msb >> 24;
	transform( hd, hd->buf );
	// _gcry_burn_stack (80+6sizeof(void));

	p = (grub_uint32_t *) hd->buf;
	#define X(a) do { *p = grub_le_to_cpu32 (hd->a); p++; } while (0)
	X(A);
	X(B);
	X(C);
	X(D);
	#undef X

	}

	/**
	* GRUB2 Crypto Interface
	* Written by Michael Gorven
	*/
	static grub_err_t
	md5 (const char in, grub_size_t insize, char out)
	{
	MD5_CONTEXT hd;

	md5_init (&hd);
	md5_write (&hd, in, insize);
	md5_final (&hd);
	grub_memcpy (out, hd.buf, 16);

	return GRUB_ERR_NONE;
	}

	static grub_err_t
	grub_cmd_xnu_uuid (grub_command_t cmd __attribute__ ((unused)),
	int argc, char **args)
	{
	struct tohash hashme;
	grub_uint8_t xnu_uuid[16];
	char uuid_string[sizeof ("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
	char *ptr;

	if (argc < 1)
	return grub_error (GRUB_ERR_BAD_ARGUMENT, "UUID required");

	hashme.serial = grub_cpu_to_be64 (grub_strtoull (args[0], 0, 16));
	grub_memcpy (hashme.prefix, hash_prefix, sizeof (hashme.prefix));

	md5 ((char ) &hashme, sizeof (hashme), (char ) xnu_uuid);
	grub_sprintf (uuid_string,
	"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
	(unsigned int) xnu_uuid[0], (unsigned int) xnu_uuid[1],
	(unsigned int) xnu_uuid[2], (unsigned int) xnu_uuid[3],
	(unsigned int) xnu_uuid[4], (unsigned int) xnu_uuid[5],
	(unsigned int) ((xnu_uuid[6] & 0xf) \| 0x30),
	(unsigned int) xnu_uuid[7],
	(unsigned int) ((xnu_uuid[8] & 0x3f) \| 0x80),
	(unsigned int) xnu_uuid[9],
	(unsigned int) xnu_uuid[10], (unsigned int) xnu_uuid[11],
	(unsigned int) xnu_uuid[12], (unsigned int) xnu_uuid[13],
	(unsigned int) xnu_uuid[14], (unsigned int) xnu_uuid[15]);
	for (ptr = uuid_string; *ptr; ptr++)
	ptr = grub_toupper (ptr);
	if (argc == 1)
	grub_printf ("%s", uuid_string);
	if (argc > 1)
	grub_env_set (args[1], uuid_string);

	return GRUB_ERR_NONE;
	}

	static grub_command_t cmd;


	GRUB_MOD_INIT (xnu_uuid)
	{
	cmd = grub_register_command ("xnu_uuid", grub_cmd_xnu_uuid,
	"xnu_uuid GRUBUUID [VARNAME]",
	"Transform 64-bit UUID to format "
	"suitable for xnu.");
	}

	GRUB_MOD_FINI (xnu_uuid)
	{
	grub_unregister_command (cmd);
	}