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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/internal/aead.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/seq_file.h>

#include "internal.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)
{
struct aead_tfm *crt = crypto_aead_crt(tfm);
int err;

if (authsize > crypto_aead_alg(tfm)->maxauthsize)
return -EINVAL;

if (crypto_aead_alg(tfm)->setauthsize) {
err = crypto_aead_alg(tfm)->setauthsize(crt->base, authsize);
if (err)
return err;
}

crypto_aead_crt(crt->base)->authsize = authsize;
crt->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_givcrypt(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 = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
alg->setkey : setkey;
crt->encrypt = alg->encrypt;
crt->decrypt = alg->decrypt;
crt->givencrypt = alg->givencrypt ?: no_givcrypt;
crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
crt->base = __crypto_aead_cast(tfm);
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, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
"yes" : "no");
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);
seq_printf(m, "geniv : %s\n", aead->geniv ?: "<built-in>");
}

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);

static int aead_null_givencrypt(struct aead_givcrypt_request *req)
{
return crypto_aead_encrypt(&req->areq);
}

static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
{
return crypto_aead_decrypt(&req->areq);
}

static int crypto_init_nivaead_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;
if (!alg->ivsize) {
crt->givencrypt = aead_null_givencrypt;
crt->givdecrypt = aead_null_givdecrypt;
}
crt->base = __crypto_aead_cast(tfm);
crt->ivsize = alg->ivsize;
crt->authsize = alg->maxauthsize;

return 0;
}

static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
{
struct aead_alg *aead = &alg->cra_aead;

seq_printf(m, "type : nivaead\n");
seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
"yes" : "no");
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);
seq_printf(m, "geniv : %s\n", aead->geniv);
}

const struct crypto_type crypto_nivaead_type = {
.ctxsize = crypto_aead_ctxsize,
.init = crypto_init_nivaead_ops,
#ifdef CONFIG_PROC_FS
.show = crypto_nivaead_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_nivaead_type);

static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
const char *name, u32 type, u32 mask)
{
struct crypto_alg *alg;
int err;

type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
type |= CRYPTO_ALG_TYPE_AEAD;
mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;

alg = crypto_alg_mod_lookup(name, type, mask);
if (IS_ERR(alg))
return PTR_ERR(alg);

err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
crypto_mod_put(alg);
return err;
}

struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
struct rtattr **tb, u32 type,
u32 mask)
{
const char *name;
struct crypto_aead_spawn *spawn;
struct crypto_attr_type *algt;
struct crypto_instance *inst;
struct crypto_alg *alg;
int err;

algt = crypto_get_attr_type(tb);
err = PTR_ERR(algt);
if (IS_ERR(algt))
return ERR_PTR(err);

if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
algt->mask)
return ERR_PTR(-EINVAL);

name = crypto_attr_alg_name(tb[1]);
err = PTR_ERR(name);
if (IS_ERR(name))
return ERR_PTR(err);

inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return ERR_PTR(-ENOMEM);

spawn = crypto_instance_ctx(inst);

/* Ignore async algorithms if necessary. */
mask |= crypto_requires_sync(algt->type, algt->mask);

crypto_set_aead_spawn(spawn, inst);
err = crypto_grab_nivaead(spawn, name, type, mask);
if (err)
goto err_free_inst;

alg = crypto_aead_spawn_alg(spawn);

err = -EINVAL;
if (!alg->cra_aead.ivsize)
goto err_drop_alg;

/*
* This is only true if we're constructing an algorithm with its
* default IV generator. For the default generator we elide the
* template name and double-check the IV generator.
*/
if (algt->mask & CRYPTO_ALG_GENIV) {
if (strcmp(tmpl->name, alg->cra_aead.geniv))
goto err_drop_alg;

memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
CRYPTO_MAX_ALG_NAME);
} else {
err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
"%s(%s)", tmpl->name, alg->cra_name) >=
CRYPTO_MAX_ALG_NAME)
goto err_drop_alg;
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"%s(%s)", tmpl->name, alg->cra_driver_name) >=
CRYPTO_MAX_ALG_NAME)
goto err_drop_alg;
}

inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.cra_priority = alg->cra_priority;
inst->alg.cra_blocksize = alg->cra_blocksize;
inst->alg.cra_alignmask = alg->cra_alignmask;
inst->alg.cra_type = &crypto_aead_type;

inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
inst->alg.cra_aead.geniv = alg->cra_aead.geniv;

inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;

out:
return inst;

err_drop_alg:
crypto_drop_aead(spawn);
err_free_inst:
kfree(inst);
inst = ERR_PTR(err);
goto out;
}
EXPORT_SYMBOL_GPL(aead_geniv_alloc);

void aead_geniv_free(struct crypto_instance *inst)
{
crypto_drop_aead(crypto_instance_ctx(inst));
kfree(inst);
}
EXPORT_SYMBOL_GPL(aead_geniv_free);

int aead_geniv_init(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct crypto_aead *aead;

aead = crypto_spawn_aead(crypto_instance_ctx(inst));
if (IS_ERR(aead))
return PTR_ERR(aead);

tfm->crt_aead.base = aead;
tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);

return 0;
}
EXPORT_SYMBOL_GPL(aead_geniv_init);

void aead_geniv_exit(struct crypto_tfm *tfm)
{
crypto_free_aead(tfm->crt_aead.base);
}
EXPORT_SYMBOL_GPL(aead_geniv_exit);

static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
{
struct rtattr *tb[3];
struct {
struct rtattr attr;
struct crypto_attr_type data;
} ptype;
struct {
struct rtattr attr;
struct crypto_attr_alg data;
} palg;
struct crypto_template *tmpl;
struct crypto_instance *inst;
struct crypto_alg *larval;
const char *geniv;
int err;

larval = crypto_larval_lookup(alg->cra_driver_name,
CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
err = PTR_ERR(larval);
if (IS_ERR(larval))
goto out;

err = -EAGAIN;
if (!crypto_is_larval(larval))
goto drop_larval;

ptype.attr.rta_len = sizeof(ptype);
ptype.attr.rta_type = CRYPTOA_TYPE;
ptype.data.type = type | CRYPTO_ALG_GENIV;
/* GENIV tells the template that we're making a default geniv. */
ptype.data.mask = mask | CRYPTO_ALG_GENIV;
tb[0] = &ptype.attr;

palg.attr.rta_len = sizeof(palg);
palg.attr.rta_type = CRYPTOA_ALG;
/* Must use the exact name to locate ourselves. */
memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
tb[1] = &palg.attr;

tb[2] = NULL;

geniv = alg->cra_aead.geniv;

tmpl = crypto_lookup_template(geniv);
err = -ENOENT;
if (!tmpl)
goto kill_larval;

inst = tmpl->alloc(tb);
err = PTR_ERR(inst);
if (IS_ERR(inst))
goto put_tmpl;

if ((err = crypto_register_instance(tmpl, inst))) {
tmpl->free(inst);
goto put_tmpl;
}

/* Redo the lookup to use the instance we just registered. */
err = -EAGAIN;

put_tmpl:
crypto_tmpl_put(tmpl);
kill_larval:
crypto_larval_kill(larval);
drop_larval:
crypto_mod_put(larval);
out:
crypto_mod_put(alg);
return err;
}

static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
u32 mask)
{
struct crypto_alg *alg;

alg = crypto_alg_mod_lookup(name, type, mask);
if (IS_ERR(alg))
return alg;

if (alg->cra_type == &crypto_aead_type)
return alg;

if (!alg->cra_aead.ivsize)
return alg;

crypto_mod_put(alg);
alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
mask & ~CRYPTO_ALG_TESTED);
if (IS_ERR(alg))
return alg;

if (alg->cra_type == &crypto_aead_type) {
if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
crypto_mod_put(alg);
alg = ERR_PTR(-ENOENT);
}
return alg;
}

BUG_ON(!alg->cra_aead.ivsize);

return ERR_PTR(crypto_nivaead_default(alg, type, mask));
}

int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
u32 type, u32 mask)
{
struct crypto_alg *alg;
int err;

type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
type |= CRYPTO_ALG_TYPE_AEAD;
mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
mask |= CRYPTO_ALG_TYPE_MASK;

alg = crypto_lookup_aead(name, type, mask);
if (IS_ERR(alg))
return PTR_ERR(alg);

err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
crypto_mod_put(alg);
return err;
}
EXPORT_SYMBOL_GPL(crypto_grab_aead);

struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
{
struct crypto_tfm *tfm;
int err;

type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
type |= CRYPTO_ALG_TYPE_AEAD;
mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
mask |= CRYPTO_ALG_TYPE_MASK;

for (;;) {
struct crypto_alg *alg;

alg = crypto_lookup_aead(alg_name, type, mask);
if (IS_ERR(alg)) {
err = PTR_ERR(alg);
goto err;
}

tfm = __crypto_alloc_tfm(alg, type, mask);
if (!IS_ERR(tfm))
return __crypto_aead_cast(tfm);

crypto_mod_put(alg);
err = PTR_ERR(tfm);

err:
if (err != -EAGAIN)
break;
if (signal_pending(current)) {
err = -EINTR;
break;
}
}

return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_aead);

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