Commit 7660b1fb authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: chacha20 - use rol32() macro from bitops.h 



For chacha20_block(), use the existing 32-bit left-rotate function
instead of defining one ourselves.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 75d68369

lib/chacha20.c

+32 −37
Original line number Diff line number Diff line
@@ -16,11 +16,6 @@ 
#include <asm/unaligned.h>

#include <crypto/chacha20.h>



static inline u32 rotl32(u32 v, u8 n)

{

	return (v << n) | (v >> (sizeof(v) * 8 - n));

}



void chacha20_block(u32 *state, u32 *stream)

{

	u32 x[16], *out = stream;
@@ -30,45 +25,45 @@ void chacha20_block(u32 *state, u32 *stream) 
		x[i] = state[i];



	for (i = 0; i < 20; i += 2) {

		x[0]  += x[4];    x[12] = rotl32(x[12] ^ x[0],  16);

		x[1]  += x[5];    x[13] = rotl32(x[13] ^ x[1],  16);

		x[2]  += x[6];    x[14] = rotl32(x[14] ^ x[2],  16);

		x[3]  += x[7];    x[15] = rotl32(x[15] ^ x[3],  16);

		x[0]  += x[4];    x[12] = rol32(x[12] ^ x[0],  16);

		x[1]  += x[5];    x[13] = rol32(x[13] ^ x[1],  16);

		x[2]  += x[6];    x[14] = rol32(x[14] ^ x[2],  16);

		x[3]  += x[7];    x[15] = rol32(x[15] ^ x[3],  16);



		x[8]  += x[12];   x[4]  = rotl32(x[4]  ^ x[8],  12);

		x[9]  += x[13];   x[5]  = rotl32(x[5]  ^ x[9],  12);

		x[10] += x[14];   x[6]  = rotl32(x[6]  ^ x[10], 12);

		x[11] += x[15];   x[7]  = rotl32(x[7]  ^ x[11], 12);

		x[8]  += x[12];   x[4]  = rol32(x[4]  ^ x[8],  12);

		x[9]  += x[13];   x[5]  = rol32(x[5]  ^ x[9],  12);

		x[10] += x[14];   x[6]  = rol32(x[6]  ^ x[10], 12);

		x[11] += x[15];   x[7]  = rol32(x[7]  ^ x[11], 12);



		x[0]  += x[4];    x[12] = rotl32(x[12] ^ x[0],   8);

		x[1]  += x[5];    x[13] = rotl32(x[13] ^ x[1],   8);

		x[2]  += x[6];    x[14] = rotl32(x[14] ^ x[2],   8);

		x[3]  += x[7];    x[15] = rotl32(x[15] ^ x[3],   8);

		x[0]  += x[4];    x[12] = rol32(x[12] ^ x[0],   8);

		x[1]  += x[5];    x[13] = rol32(x[13] ^ x[1],   8);

		x[2]  += x[6];    x[14] = rol32(x[14] ^ x[2],   8);

		x[3]  += x[7];    x[15] = rol32(x[15] ^ x[3],   8);



		x[8]  += x[12];   x[4]  = rotl32(x[4]  ^ x[8],   7);

		x[9]  += x[13];   x[5]  = rotl32(x[5]  ^ x[9],   7);

		x[10] += x[14];   x[6]  = rotl32(x[6]  ^ x[10],  7);

		x[11] += x[15];   x[7]  = rotl32(x[7]  ^ x[11],  7);

		x[8]  += x[12];   x[4]  = rol32(x[4]  ^ x[8],   7);

		x[9]  += x[13];   x[5]  = rol32(x[5]  ^ x[9],   7);

		x[10] += x[14];   x[6]  = rol32(x[6]  ^ x[10],  7);

		x[11] += x[15];   x[7]  = rol32(x[7]  ^ x[11],  7);



		x[0]  += x[5];    x[15] = rotl32(x[15] ^ x[0],  16);

		x[1]  += x[6];    x[12] = rotl32(x[12] ^ x[1],  16);

		x[2]  += x[7];    x[13] = rotl32(x[13] ^ x[2],  16);

		x[3]  += x[4];    x[14] = rotl32(x[14] ^ x[3],  16);

		x[0]  += x[5];    x[15] = rol32(x[15] ^ x[0],  16);

		x[1]  += x[6];    x[12] = rol32(x[12] ^ x[1],  16);

		x[2]  += x[7];    x[13] = rol32(x[13] ^ x[2],  16);

		x[3]  += x[4];    x[14] = rol32(x[14] ^ x[3],  16);



		x[10] += x[15];   x[5]  = rotl32(x[5]  ^ x[10], 12);

		x[11] += x[12];   x[6]  = rotl32(x[6]  ^ x[11], 12);

		x[8]  += x[13];   x[7]  = rotl32(x[7]  ^ x[8],  12);

		x[9]  += x[14];   x[4]  = rotl32(x[4]  ^ x[9],  12);

		x[10] += x[15];   x[5]  = rol32(x[5]  ^ x[10], 12);

		x[11] += x[12];   x[6]  = rol32(x[6]  ^ x[11], 12);

		x[8]  += x[13];   x[7]  = rol32(x[7]  ^ x[8],  12);

		x[9]  += x[14];   x[4]  = rol32(x[4]  ^ x[9],  12);



		x[0]  += x[5];    x[15] = rotl32(x[15] ^ x[0],   8);

		x[1]  += x[6];    x[12] = rotl32(x[12] ^ x[1],   8);

		x[2]  += x[7];    x[13] = rotl32(x[13] ^ x[2],   8);

		x[3]  += x[4];    x[14] = rotl32(x[14] ^ x[3],   8);

		x[0]  += x[5];    x[15] = rol32(x[15] ^ x[0],   8);

		x[1]  += x[6];    x[12] = rol32(x[12] ^ x[1],   8);

		x[2]  += x[7];    x[13] = rol32(x[13] ^ x[2],   8);

		x[3]  += x[4];    x[14] = rol32(x[14] ^ x[3],   8);



		x[10] += x[15];   x[5]  = rotl32(x[5]  ^ x[10],  7);

		x[11] += x[12];   x[6]  = rotl32(x[6]  ^ x[11],  7);

		x[8]  += x[13];   x[7]  = rotl32(x[7]  ^ x[8],   7);

		x[9]  += x[14];   x[4]  = rotl32(x[4]  ^ x[9],   7);

		x[10] += x[15];   x[5]  = rol32(x[5]  ^ x[10],  7);

		x[11] += x[12];   x[6]  = rol32(x[6]  ^ x[11],  7);

		x[8]  += x[13];   x[7]  = rol32(x[7]  ^ x[8],   7);

		x[9]  += x[14];   x[4]  = rol32(x[4]  ^ x[9],   7);

	}



	for (i = 0; i < ARRAY_SIZE(x); i++)