Commit 16cb0d95 authored by Andy Polyakov's avatar Andy Polyakov
Browse files

xts128.c: minor optimization.

parent 0ab8fd58

crypto/modes/xts128.c

+55 −56
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, u64 secno, 
{

	const union { long one; char little; } is_endian = {1};

	union { u64 u[2]; u32 d[4]; u8 c[16]; } tweak, scratch;

	unsigned int i;



	if (len<16) return -1;
@@ -84,7 +85,7 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, u64 secno, 


	(*ctx->block2)(tweak.c,tweak.c,ctx->key2);



	if (!enc && len%16) len-=16;

	if (!enc && (len%16)) len-=16;



	while (len>=16) {

#if defined(STRICT_ALIGNMENT)
@@ -103,6 +104,8 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, u64 secno, 
		out += 16;

		len -= 16;



		if (len==0)	return 0;



		if (is_endian.little) {

			unsigned int carry,res;
@@ -112,7 +115,7 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, u64 secno, 
			tweak.u[1] = (tweak.u[1]<<1)|carry;

		}

		else {

			unsigned int carry,c,i;

			unsigned int carry,c;



			for (carry=0,i=0;i<16;++i) {

				c = tweak.c[i];
@@ -122,9 +125,6 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, u64 secno, 
			tweak.c[0] ^= 0x87&(0-carry);

		}

	}

	if (len) {

		unsigned int i;



	if (enc) {

		for (i=0;i<len;++i) {

			u8 c = inp[i];
@@ -183,7 +183,6 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, u64 secno, 
		scratch.u[1] ^= tweak.u[1];

		memcpy (out,scratch.c,16);

	}

	}



	return 0;

}