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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);
}
int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
{
int err;
if (authsize > crypto_aead_alg(tfm)->maxauthsize)
return -EINVAL;
if (crypto_aead_alg(tfm)->setauthsize) {
err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
if (err)
return err;
}
crypto_aead_crt(tfm)->authsize = authsize;
return 0;
}
EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
u32 mask)
{
return alg->cra_ctxsize;
}
static int no_givdecrypt(struct aead_givcrypt_request *req)
{
return -ENOSYS;
}
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->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
return -EINVAL;
crt->setkey = setkey;
crt->encrypt = alg->encrypt;
crt->decrypt = alg->decrypt;
crt->givencrypt = alg->givencrypt;
crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
crt->ivsize = alg->ivsize;
crt->authsize = alg->maxauthsize;
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, "maxauthsize : %u\n", aead->maxauthsize);
}
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)");
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