diff options
Diffstat (limited to 'crypto/cipher.c')
-rw-r--r-- | crypto/cipher.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/crypto/cipher.c b/crypto/cipher.c new file mode 100644 index 000000000..57836c30a --- /dev/null +++ b/crypto/cipher.c @@ -0,0 +1,119 @@ +/* + * Cryptographic API. + * + * Cipher operations. + * + * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> + * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.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 <crypto/algapi.h> +#include <linux/kernel.h> +#include <linux/crypto.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/string.h> +#include "internal.h" + +static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key, + unsigned int keylen) +{ + struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; + unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); + int ret; + u8 *buffer, *alignbuffer; + unsigned long absize; + + absize = keylen + alignmask; + buffer = kmalloc(absize, GFP_ATOMIC); + if (!buffer) + return -ENOMEM; + + alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); + memcpy(alignbuffer, key, keylen); + ret = cia->cia_setkey(tfm, alignbuffer, keylen); + memset(alignbuffer, 0, keylen); + kfree(buffer); + return ret; + +} + +static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) +{ + struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; + unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); + + tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; + if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) { + tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } + + if ((unsigned long)key & alignmask) + return setkey_unaligned(tfm, key, keylen); + + return cia->cia_setkey(tfm, key, keylen); +} + +static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *, + const u8 *), + struct crypto_tfm *tfm, + u8 *dst, const u8 *src) +{ + unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); + unsigned int size = crypto_tfm_alg_blocksize(tfm); + u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK]; + u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); + + memcpy(tmp, src, size); + fn(tfm, tmp, tmp); + memcpy(dst, tmp, size); +} + +static void cipher_encrypt_unaligned(struct crypto_tfm *tfm, + u8 *dst, const u8 *src) +{ + unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); + struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; + + if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { + cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src); + return; + } + + cipher->cia_encrypt(tfm, dst, src); +} + +static void cipher_decrypt_unaligned(struct crypto_tfm *tfm, + u8 *dst, const u8 *src) +{ + unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); + struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; + + if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { + cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src); + return; + } + + cipher->cia_decrypt(tfm, dst, src); +} + +int crypto_init_cipher_ops(struct crypto_tfm *tfm) +{ + struct cipher_tfm *ops = &tfm->crt_cipher; + struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; + + ops->cit_setkey = setkey; + ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ? + cipher_encrypt_unaligned : cipher->cia_encrypt; + ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ? + cipher_decrypt_unaligned : cipher->cia_decrypt; + + return 0; +} |