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author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2019-06-12 18:19:53 +0200 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-06-20 14:18:33 +0800 |
commit | dc51f25752bfcb5f1edbac1ca4ce16af7b3bd507 (patch) | |
tree | 063eb09177d3abc17deaaae732dd011592f5f573 /crypto/arc4.c | |
parent | 192125ed5ce62afba24312d8e7a0314577565b4a (diff) | |
download | linux-dc51f25752bfcb5f1edbac1ca4ce16af7b3bd507.tar.bz2 |
crypto: arc4 - refactor arc4 core code into separate library
Refactor the core rc4 handling so we can move most users to a library
interface, permitting us to drop the cipher interface entirely in a
future patch. This is part of an effort to simplify the crypto API
and improve its robustness against incorrect use.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/arc4.c')
-rw-r--r-- | crypto/arc4.c | 60 |
1 files changed, 1 insertions, 59 deletions
diff --git a/crypto/arc4.c b/crypto/arc4.c index b78dcb390a7e..d303b7ff1fed 100644 --- a/crypto/arc4.c +++ b/crypto/arc4.c @@ -18,33 +18,12 @@ #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; + return arc4_setkey(ctx, in_key, key_len); } static int arc4_set_key_skcipher(struct crypto_skcipher *tfm, const u8 *in_key, @@ -53,43 +32,6 @@ static int arc4_set_key_skcipher(struct crypto_skcipher *tfm, const u8 *in_key, 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; -} - static void arc4_crypt_one(struct crypto_tfm *tfm, u8 *out, const u8 *in) { arc4_crypt(crypto_tfm_ctx(tfm), out, in, 1); |