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/*

 * 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 <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[size + 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;

}

void crypto_exit_cipher_ops(struct crypto_tfm *tfm)

{

}