diff options
Diffstat (limited to 'drivers/staging/rtl8192e/ieee80211/arc4.c')
-rw-r--r-- | drivers/staging/rtl8192e/ieee80211/arc4.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/staging/rtl8192e/ieee80211/arc4.c b/drivers/staging/rtl8192e/ieee80211/arc4.c new file mode 100644 index 00000000000..e408472af30 --- /dev/null +++ b/drivers/staging/rtl8192e/ieee80211/arc4.c @@ -0,0 +1,103 @@ +/* + * Cryptographic API + * + * ARC4 Cipher Algorithm + * + * Jon Oberheide <jon@oberheide.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ +#include <linux/module.h> +#include <linux/init.h> +#include "rtl_crypto.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; +}; + +static int arc4_set_key(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags) +{ + struct arc4_ctx *ctx = ctx_arg; + 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++) + { + u8 a = ctx->S[i]; + j = (j + in_key[k] + a) & 0xff; + ctx->S[i] = ctx->S[j]; + ctx->S[j] = a; + if((unsigned int)++k >= key_len) + k = 0; + } + + return 0; +} + +static void arc4_crypt(void *ctx_arg, u8 *out, const u8 *in) +{ + struct arc4_ctx *ctx = ctx_arg; + + u8 *const S = ctx->S; + u8 x = ctx->x; + u8 y = ctx->y; + u8 a, b; + + 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]; + + ctx->x = x; + ctx->y = y; +} + +static struct crypto_alg arc4_alg = { + .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 } } +}; + +static int __init arc4_init(void) +{ + return crypto_register_alg(&arc4_alg); +} + + +static void __exit arc4_exit(void) +{ + crypto_unregister_alg(&arc4_alg); +} + +module_init(arc4_init); +module_exit(arc4_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("ARC4 Cipher Algorithm"); +MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>"); |