crypto: arc4 - improve performance by adding ecb(arc4) (ce6dd368) · Commits · 戴 / test

crypto/arc4.c

+87 −22

Original line number	Diff line number	Diff line
		@@ -11,9 +11,11 @@
		* (at your option) any later version.
		*
		*/

		#include <linux/module.h>
		#include <linux/init.h>
		#include <linux/crypto.h>
		#include <crypto/algapi.h>

		#define ARC4_MIN_KEY_SIZE 1
		#define ARC4_MAX_KEY_SIZE 256
		@@ -48,51 +50,114 @@ static int arc4_set_key(struct crypto_tfm tfm, const u8 in_key,
		return 0;
		}

		static void arc4_crypt(struct crypto_tfm tfm, u8 out, const u8 *in)
		static void arc4_crypt(struct arc4_ctx ctx, u8 out, const u8 *in,
		unsigned int len)
		{
		struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);

		u8 *const S = ctx->S;
		u8 x = ctx->x;
		u8 y = ctx->y;
		u8 a, b;
		u8 x, y, a, b;
		u8 ty, ta, tb;

		if (len == 0)
		return;

		x = ctx->x;
		y = ctx->y;

		a = S[x];
		y = (y + a) & 0xff;
		b = S[y];
		S[x] = b;

		do {
		S[y] = a;
		a = (a + b) & 0xff;
		S[x] = b;
		x = (x + 1) & 0xff;
		out++ = in ^ S[(a + b) & 0xff];
		ta = S[x];
		ty = (y + ta) & 0xff;
		tb = S[ty];
		out++ = in++ ^ S[a];
		if (--len == 0)
		break;
		y = ty;
		a = ta;
		b = tb;
		} while (true);

		ctx->x = x;
		ctx->y = y;
		}

		static struct crypto_alg arc4_alg = {
		static void arc4_crypt_one(struct crypto_tfm tfm, u8 out, const u8 *in)
		{
		arc4_crypt(crypto_tfm_ctx(tfm), out, in, 1);
		}

		static int ecb_arc4_crypt(struct blkcipher_desc desc, struct scatterlist dst,
		struct scatterlist *src, unsigned int nbytes)
		{
		struct arc4_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
		struct blkcipher_walk walk;
		int err;

		blkcipher_walk_init(&walk, dst, src, nbytes);

		err = blkcipher_walk_virt(desc, &walk);

		while (walk.nbytes > 0) {
		u8 *wsrc = walk.src.virt.addr;
		u8 *wdst = walk.dst.virt.addr;

		arc4_crypt(ctx, wdst, wsrc, walk.nbytes);

		err = blkcipher_walk_done(desc, &walk, 0);
		}

		return err;
		}

		static struct crypto_alg arc4_algs[2] = { {
		.cra_name = "arc4",
		.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
		.cra_blocksize = ARC4_BLOCK_SIZE,
		.cra_ctxsize = sizeof(struct arc4_ctx),
		.cra_module = THIS_MODULE,
		.cra_list = LIST_HEAD_INIT(arc4_alg.cra_list),
		.cra_u = { .cipher = {
		.cra_u = {
		.cipher = {
		.cia_min_keysize = ARC4_MIN_KEY_SIZE,
		.cia_max_keysize = ARC4_MAX_KEY_SIZE,
		.cia_setkey = arc4_set_key,
		.cia_encrypt = arc4_crypt,
		.cia_decrypt = arc4_crypt } }
		};
		.cia_encrypt = arc4_crypt_one,
		.cia_decrypt = arc4_crypt_one,
		},
		},
		}, {
		.cra_name = "ecb(arc4)",
		.cra_priority = 100,
		.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
		.cra_blocksize = ARC4_BLOCK_SIZE,
		.cra_ctxsize = sizeof(struct arc4_ctx),
		.cra_alignmask = 0,
		.cra_type = &crypto_blkcipher_type,
		.cra_module = THIS_MODULE,
		.cra_u = {
		.blkcipher = {
		.min_keysize = ARC4_MIN_KEY_SIZE,
		.max_keysize = ARC4_MAX_KEY_SIZE,
		.setkey = arc4_set_key,
		.encrypt = ecb_arc4_crypt,
		.decrypt = ecb_arc4_crypt,
		},
		},
		} };

		static int __init arc4_init(void)
		{
		return crypto_register_alg(&arc4_alg);
		return crypto_register_algs(arc4_algs, ARRAY_SIZE(arc4_algs));
		}


		static void __exit arc4_exit(void)
		{
		crypto_unregister_alg(&arc4_alg);
		crypto_unregister_algs(arc4_algs, ARRAY_SIZE(arc4_algs));
		}

		module_init(arc4_init);

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