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26 7u83 1 
#include "os.h"
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#include <libsec.h>
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/* little-endian data order */
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#define	GET4(p)		((p)[0]|((p)[1]<<8)|((p)[2]<<16)|((p)[3]<<24))
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#define	PUT4(p,v)	(p)[0]=(v);(p)[1]=(v)>>8;(p)[2]=(v)>>16;(p)[3]=(v)>>24
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static void
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gf_mulx(uchar *x)
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{
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	ulong t0, t1, t2, t3, t4;
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	t0 = GET4(x);
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	t1 = GET4(x+4);
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	t2 = GET4(x+8);
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	t3 = GET4(x+12);
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	t4 =             (t3 >> 31);
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	t3 = (t3 << 1) | (t2 >> 31);
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	t2 = (t2 << 1) | (t1 >> 31);
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	t1 = (t1 << 1) | (t0 >> 31);
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	t0 = (t0 << 1) ^ (t4*135);
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	PUT4(x, t0);
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	PUT4(x+4, t1);
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	PUT4(x+8, t2);
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	PUT4(x+12, t3);
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}
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static void
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xor128(uchar *o, uchar *i1, uchar *i2)
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{
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	int i;
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	for(i=0; i<16; i++)
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		o[i] = i1[i] ^ i2[i];
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}
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static void
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setupT(AESstate *tweak, uvlong sectorNumber, uchar T[AESbsize])
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{
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	PUT4(T+0, (ulong)sectorNumber), sectorNumber >>= 32;
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	PUT4(T+4, (ulong)sectorNumber);
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	PUT4(T+8, 0);
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	PUT4(T+12, 0);
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	aes_encrypt(tweak->ekey, tweak->rounds, T, T);
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}
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void
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aes_xts_encrypt(AESstate *tweak, AESstate *ecb,
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	uvlong sectorNumber, uchar *input, uchar *output, ulong len)
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{
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	uchar T[AESbsize], x[AESbsize];
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	if(len % AESbsize)
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		abort();
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	setupT(tweak, sectorNumber, T);
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	for (; len > 0; len -= AESbsize, input += AESbsize, output += AESbsize) {
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		xor128(x, input, T);
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		aes_encrypt(ecb->ekey, ecb->rounds, x, x);
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		xor128(output, x, T);
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		gf_mulx(T);
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	}
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}
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void
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aes_xts_decrypt(AESstate *tweak, AESstate *ecb,
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	uvlong sectorNumber, uchar *input, uchar *output, ulong len)
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{
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	uchar T[AESbsize], x[AESbsize];
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	if(len % AESbsize)
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		abort();
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	setupT(tweak, sectorNumber, T);
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	for (; len > 0; len -= AESbsize, input += AESbsize, output += AESbsize) {
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		xor128(x, input, T);
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		aes_decrypt(ecb->dkey, ecb->rounds, x, x);
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		xor128(output, x, T);
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		gf_mulx(T);
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	}
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}