diff options
| -rw-r--r-- | crypto/arc4.c | 109 |
1 files changed, 87 insertions, 22 deletions
diff --git a/crypto/arc4.c b/crypto/arc4.c index 0d12a96..07913fc5 100644 --- a/crypto/arc4.c +++ b/crypto/arc4.c @@ -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; - S[y] = a; - x = (x + 1) & 0xff; - *out++ = *in ^ S[(a + b) & 0xff]; + + do { + S[y] = a; + a = (a + b) & 0xff; + S[x] = b; + x = (x + 1) & 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 = { - .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 } } -}; + .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_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); |
