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/*

 * AEAD: Authenticated Encryption with Associated Data

 *

 * This file provides API support for AEAD algorithms.

 *

 * Copyright (c) 2007 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/errno.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/seq_file.h>

static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,

                            unsigned int keylen)

{

        struct aead_alg *aead = crypto_aead_alg(tfm);

        unsigned long alignmask = crypto_aead_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 = aead->setkey(tfm, alignbuffer, keylen);

        memset(alignbuffer, 0, keylen);

        kfree(buffer);

        return ret;

}

static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)

{

        struct aead_alg *aead = crypto_aead_alg(tfm);

        unsigned long alignmask = crypto_aead_alignmask(tfm);

        if ((unsigned long)key & alignmask)

                return setkey_unaligned(tfm, key, keylen);

        return aead->setkey(tfm, key, keylen);

}

static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,

                                        u32 mask)

{

        return alg->cra_ctxsize;

}

static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)

{

        struct aead_alg *alg = &tfm->__crt_alg->cra_aead;

        struct aead_tfm *crt = &tfm->crt_aead;

        if (max(alg->authsize, alg->ivsize) > PAGE_SIZE / 8)

                return -EINVAL;

        crt->setkey = setkey;

        crt->encrypt = alg->encrypt;

        crt->decrypt = alg->decrypt;

        crt->ivsize = alg->ivsize;

        crt->authsize = alg->authsize;

        return 0;

}

static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)

        __attribute__ ((unused));

static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)

{

        struct aead_alg *aead = &alg->cra_aead;

        seq_printf(m, "type         : aead\n");

        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);

        seq_printf(m, "ivsize       : %u\n", aead->ivsize);

        seq_printf(m, "authsize     : %u\n", aead->authsize);

}

const struct crypto_type crypto_aead_type = {

        .ctxsize = crypto_aead_ctxsize,

        .init = crypto_init_aead_ops,

#ifdef CONFIG_PROC_FS

        .show = crypto_aead_show,

#endif

};

EXPORT_SYMBOL_GPL(crypto_aead_type);

MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");