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-rw-r--r--crypto/arc4.c115
1 files changed, 90 insertions, 25 deletions
diff --git a/crypto/arc4.c b/crypto/arc4.c
index 0d12a96..5a772c3 100644
--- a/crypto/arc4.c
+++ b/crypto/arc4.c
@@ -11,17 +11,19 @@
* (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
#define ARC4_BLOCK_SIZE 1
struct arc4_ctx {
- u8 S[256];
- u8 x, y;
+ u32 S[256];
+ u32 x, y;
};
static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
@@ -37,7 +39,7 @@ static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
ctx->S[i] = i;
for (i = 0; i < 256; i++) {
- u8 a = ctx->S[i];
+ u32 a = ctx->S[i];
j = (j + in_key[k] + a) & 0xff;
ctx->S[i] = ctx->S[j];
ctx->S[j] = a;
@@ -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);
+ u32 *const S = ctx->S;
+ u32 x, y, a, b;
+ u32 ty, ta, tb;
+
+ if (len == 0)
+ return;
- u8 *const S = ctx->S;
- u8 x = ctx->x;
- u8 y = ctx->y;
- u8 a, b;
+ 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);