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-rw-r--r--crypto/arc4.c125
1 files changed, 17 insertions, 108 deletions
diff --git a/crypto/arc4.c b/crypto/arc4.c
index a2120e06bf84..aa79571dbd49 100644
--- a/crypto/arc4.c
+++ b/crypto/arc4.c
@@ -13,84 +13,15 @@
#include <linux/init.h>
#include <linux/module.h>
-struct arc4_ctx {
- u32 S[256];
- u32 x, y;
-};
-
-static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
- unsigned int key_len)
-{
- struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);
- int i, j = 0, k = 0;
-
- ctx->x = 1;
- ctx->y = 0;
-
- for (i = 0; i < 256; i++)
- ctx->S[i] = i;
-
- for (i = 0; i < 256; i++) {
- u32 a = ctx->S[i];
- j = (j + in_key[k] + a) & 0xff;
- ctx->S[i] = ctx->S[j];
- ctx->S[j] = a;
- if (++k >= key_len)
- k = 0;
- }
-
- return 0;
-}
-
-static int arc4_set_key_skcipher(struct crypto_skcipher *tfm, const u8 *in_key,
- unsigned int key_len)
+static int crypto_arc4_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
+ unsigned int key_len)
{
- return arc4_set_key(&tfm->base, in_key, key_len);
-}
-
-static void arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in,
- unsigned int len)
-{
- u32 *const S = ctx->S;
- u32 x, y, a, b;
- u32 ty, ta, tb;
-
- if (len == 0)
- return;
-
- x = ctx->x;
- y = ctx->y;
-
- a = S[x];
- y = (y + a) & 0xff;
- b = S[y];
-
- 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;
-}
+ struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
-static void arc4_crypt_one(struct crypto_tfm *tfm, u8 *out, const u8 *in)
-{
- arc4_crypt(crypto_tfm_ctx(tfm), out, in, 1);
+ return arc4_setkey(ctx, in_key, key_len);
}
-static int ecb_arc4_crypt(struct skcipher_request *req)
+static int crypto_arc4_crypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
@@ -108,54 +39,32 @@ static int ecb_arc4_crypt(struct skcipher_request *req)
return err;
}
-static struct crypto_alg arc4_cipher = {
- .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_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,
- },
- },
-};
-
-static struct skcipher_alg arc4_skcipher = {
+static struct skcipher_alg arc4_alg = {
+ /*
+ * For legacy reasons, this is named "ecb(arc4)", not "arc4".
+ * Nevertheless it's actually a stream cipher, not a block cipher.
+ */
.base.cra_name = "ecb(arc4)",
+ .base.cra_driver_name = "ecb(arc4)-generic",
.base.cra_priority = 100,
.base.cra_blocksize = ARC4_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct arc4_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = ARC4_MIN_KEY_SIZE,
.max_keysize = ARC4_MAX_KEY_SIZE,
- .setkey = arc4_set_key_skcipher,
- .encrypt = ecb_arc4_crypt,
- .decrypt = ecb_arc4_crypt,
+ .setkey = crypto_arc4_setkey,
+ .encrypt = crypto_arc4_crypt,
+ .decrypt = crypto_arc4_crypt,
};
static int __init arc4_init(void)
{
- int err;
-
- err = crypto_register_alg(&arc4_cipher);
- if (err)
- return err;
-
- err = crypto_register_skcipher(&arc4_skcipher);
- if (err)
- crypto_unregister_alg(&arc4_cipher);
- return err;
+ return crypto_register_skcipher(&arc4_alg);
}
static void __exit arc4_exit(void)
{
- crypto_unregister_alg(&arc4_cipher);
- crypto_unregister_skcipher(&arc4_skcipher);
+ crypto_unregister_skcipher(&arc4_alg);
}
subsys_initcall(arc4_init);
@@ -164,4 +73,4 @@ module_exit(arc4_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
-MODULE_ALIAS_CRYPTO("arc4");
+MODULE_ALIAS_CRYPTO("ecb(arc4)");