diff options
Diffstat (limited to 'drivers/staging/rtl8192e/ieee80211/cipher.c')
-rw-r--r-- | drivers/staging/rtl8192e/ieee80211/cipher.c | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/drivers/staging/rtl8192e/ieee80211/cipher.c b/drivers/staging/rtl8192e/ieee80211/cipher.c new file mode 100644 index 00000000000..1968acfe32b --- /dev/null +++ b/drivers/staging/rtl8192e/ieee80211/cipher.c @@ -0,0 +1,299 @@ +/* + * Cryptographic API. + * + * Cipher operations. + * + * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> + * + * 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/kernel.h> +//#include <linux/crypto.h> +#include "rtl_crypto.h" +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <asm/scatterlist.h> +#include "internal.h" +#include "scatterwalk.h" + +typedef void (cryptfn_t)(void *, u8 *, const u8 *); +typedef void (procfn_t)(struct crypto_tfm *, u8 *, + u8*, cryptfn_t, int enc, void *, int); + +static inline void xor_64(u8 *a, const u8 *b) +{ + ((u32 *)a)[0] ^= ((u32 *)b)[0]; + ((u32 *)a)[1] ^= ((u32 *)b)[1]; +} + +static inline void xor_128(u8 *a, const u8 *b) +{ + ((u32 *)a)[0] ^= ((u32 *)b)[0]; + ((u32 *)a)[1] ^= ((u32 *)b)[1]; + ((u32 *)a)[2] ^= ((u32 *)b)[2]; + ((u32 *)a)[3] ^= ((u32 *)b)[3]; +} + + +/* + * Generic encrypt/decrypt wrapper for ciphers, handles operations across + * multiple page boundaries by using temporary blocks. In user context, + * the kernel is given a chance to schedule us once per block. + */ +static int crypt(struct crypto_tfm *tfm, + struct scatterlist *dst, + struct scatterlist *src, + unsigned int nbytes, cryptfn_t crfn, + procfn_t prfn, int enc, void *info) +{ + struct scatter_walk walk_in, walk_out; + const unsigned int bsize = crypto_tfm_alg_blocksize(tfm); + u8 tmp_src[bsize]; + u8 tmp_dst[bsize]; + + if (!nbytes) + return 0; + + if (nbytes % bsize) { + tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN; + return -EINVAL; + } + + scatterwalk_start(&walk_in, src); + scatterwalk_start(&walk_out, dst); + + for(;;) { + u8 *src_p, *dst_p; + int in_place; + + scatterwalk_map(&walk_in, 0); + scatterwalk_map(&walk_out, 1); + src_p = scatterwalk_whichbuf(&walk_in, bsize, tmp_src); + dst_p = scatterwalk_whichbuf(&walk_out, bsize, tmp_dst); + in_place = scatterwalk_samebuf(&walk_in, &walk_out, + src_p, dst_p); + + nbytes -= bsize; + + scatterwalk_copychunks(src_p, &walk_in, bsize, 0); + + prfn(tfm, dst_p, src_p, crfn, enc, info, in_place); + + scatterwalk_done(&walk_in, 0, nbytes); + + scatterwalk_copychunks(dst_p, &walk_out, bsize, 1); + scatterwalk_done(&walk_out, 1, nbytes); + + if (!nbytes) + return 0; + + crypto_yield(tfm); + } +} + +static void cbc_process(struct crypto_tfm *tfm, u8 *dst, u8 *src, + cryptfn_t fn, int enc, void *info, int in_place) +{ + u8 *iv = info; + + /* Null encryption */ + if (!iv) + return; + + if (enc) { + tfm->crt_u.cipher.cit_xor_block(iv, src); + fn(crypto_tfm_ctx(tfm), dst, iv); + memcpy(iv, dst, crypto_tfm_alg_blocksize(tfm)); + } else { + u8 stack[in_place ? crypto_tfm_alg_blocksize(tfm) : 0]; + u8 *buf = in_place ? stack : dst; + + fn(crypto_tfm_ctx(tfm), buf, src); + tfm->crt_u.cipher.cit_xor_block(buf, iv); + memcpy(iv, src, crypto_tfm_alg_blocksize(tfm)); + if (buf != dst) + memcpy(dst, buf, crypto_tfm_alg_blocksize(tfm)); + } +} + +static void ecb_process(struct crypto_tfm *tfm, u8 *dst, u8 *src, + cryptfn_t fn, int enc, void *info, int in_place) +{ + fn(crypto_tfm_ctx(tfm), dst, src); +} + +static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) +{ + struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; + + if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) { + tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } else + return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen, + &tfm->crt_flags); +} + +static int ecb_encrypt(struct crypto_tfm *tfm, + struct scatterlist *dst, + struct scatterlist *src, unsigned int nbytes) +{ + return crypt(tfm, dst, src, nbytes, + tfm->__crt_alg->cra_cipher.cia_encrypt, + ecb_process, 1, NULL); +} + +static int ecb_decrypt(struct crypto_tfm *tfm, + struct scatterlist *dst, + struct scatterlist *src, + unsigned int nbytes) +{ + return crypt(tfm, dst, src, nbytes, + tfm->__crt_alg->cra_cipher.cia_decrypt, + ecb_process, 1, NULL); +} + +static int cbc_encrypt(struct crypto_tfm *tfm, + struct scatterlist *dst, + struct scatterlist *src, + unsigned int nbytes) +{ + return crypt(tfm, dst, src, nbytes, + tfm->__crt_alg->cra_cipher.cia_encrypt, + cbc_process, 1, tfm->crt_cipher.cit_iv); +} + +static int cbc_encrypt_iv(struct crypto_tfm *tfm, + struct scatterlist *dst, + struct scatterlist *src, + unsigned int nbytes, u8 *iv) +{ + return crypt(tfm, dst, src, nbytes, + tfm->__crt_alg->cra_cipher.cia_encrypt, + cbc_process, 1, iv); +} + +static int cbc_decrypt(struct crypto_tfm *tfm, + struct scatterlist *dst, + struct scatterlist *src, + unsigned int nbytes) +{ + return crypt(tfm, dst, src, nbytes, + tfm->__crt_alg->cra_cipher.cia_decrypt, + cbc_process, 0, tfm->crt_cipher.cit_iv); +} + +static int cbc_decrypt_iv(struct crypto_tfm *tfm, + struct scatterlist *dst, + struct scatterlist *src, + unsigned int nbytes, u8 *iv) +{ + return crypt(tfm, dst, src, nbytes, + tfm->__crt_alg->cra_cipher.cia_decrypt, + cbc_process, 0, iv); +} + +static int nocrypt(struct crypto_tfm *tfm, + struct scatterlist *dst, + struct scatterlist *src, + unsigned int nbytes) +{ + return -ENOSYS; +} + +static int nocrypt_iv(struct crypto_tfm *tfm, + struct scatterlist *dst, + struct scatterlist *src, + unsigned int nbytes, u8 *iv) +{ + return -ENOSYS; +} + +int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags) +{ + u32 mode = flags & CRYPTO_TFM_MODE_MASK; + + tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB; + if (flags & CRYPTO_TFM_REQ_WEAK_KEY) + tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY; + + return 0; +} + +int crypto_init_cipher_ops(struct crypto_tfm *tfm) +{ + int ret = 0; + struct cipher_tfm *ops = &tfm->crt_cipher; + + ops->cit_setkey = setkey; + + switch (tfm->crt_cipher.cit_mode) { + case CRYPTO_TFM_MODE_ECB: + ops->cit_encrypt = ecb_encrypt; + ops->cit_decrypt = ecb_decrypt; + break; + + case CRYPTO_TFM_MODE_CBC: + ops->cit_encrypt = cbc_encrypt; + ops->cit_decrypt = cbc_decrypt; + ops->cit_encrypt_iv = cbc_encrypt_iv; + ops->cit_decrypt_iv = cbc_decrypt_iv; + break; + + case CRYPTO_TFM_MODE_CFB: + ops->cit_encrypt = nocrypt; + ops->cit_decrypt = nocrypt; + ops->cit_encrypt_iv = nocrypt_iv; + ops->cit_decrypt_iv = nocrypt_iv; + break; + + case CRYPTO_TFM_MODE_CTR: + ops->cit_encrypt = nocrypt; + ops->cit_decrypt = nocrypt; + ops->cit_encrypt_iv = nocrypt_iv; + ops->cit_decrypt_iv = nocrypt_iv; + break; + + default: + BUG(); + } + + if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) { + + switch (crypto_tfm_alg_blocksize(tfm)) { + case 8: + ops->cit_xor_block = xor_64; + break; + + case 16: + ops->cit_xor_block = xor_128; + break; + + default: + printk(KERN_WARNING "%s: block size %u not supported\n", + crypto_tfm_alg_name(tfm), + crypto_tfm_alg_blocksize(tfm)); + ret = -EINVAL; + goto out; + } + + ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm); + ops->cit_iv = kmalloc(ops->cit_ivsize, GFP_KERNEL); + if (ops->cit_iv == NULL) + ret = -ENOMEM; + } + +out: + return ret; +} + +void crypto_exit_cipher_ops(struct crypto_tfm *tfm) +{ + if (tfm->crt_cipher.cit_iv) + kfree(tfm->crt_cipher.cit_iv); +} |