static int crypto_ofb_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct skcipher_instance *inst;
struct crypto_alg *alg;
int err;
inst = skcipher_alloc_instance_simple(tmpl, tb, &alg);
if (IS_ERR(inst))
return PTR_ERR(inst);
/* OFB mode is a stream cipher. */
inst->alg.base.cra_blocksize = 1;
/*
* To simplify the implementation, configure the skcipher walk to only
* give a partial block at the very end, never earlier.
*/
inst->alg.chunksize = alg->cra_blocksize;
inst->alg.encrypt = crypto_ofb_crypt;
inst->alg.decrypt = crypto_ofb_crypt;
err = skcipher_register_instance(tmpl, inst);
if (err)
inst->free(inst);
crypto_mod_put(alg);
return err;
}
static int crypto_ctr_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct skcipher_instance *inst;
struct crypto_alg *alg;
int err;
inst = skcipher_alloc_instance_simple(tmpl, tb, &alg);
if (IS_ERR(inst))
return PTR_ERR(inst);
/* Block size must be >= 4 bytes. */
err = -EINVAL;
if (alg->cra_blocksize < 4)
goto out_free_inst;
/* If this is false we'd fail the alignment of crypto_inc. */
if (alg->cra_blocksize % 4)
goto out_free_inst;
/* CTR mode is a stream cipher. */
inst->alg.base.cra_blocksize = 1;
/*
* To simplify the implementation, configure the skcipher walk to only
* give a partial block at the very end, never earlier.
*/
inst->alg.chunksize = alg->cra_blocksize;
inst->alg.encrypt = crypto_ctr_crypt;
inst->alg.decrypt = crypto_ctr_crypt;
err = skcipher_register_instance(tmpl, inst);
if (err)
goto out_free_inst;
goto out_put_alg;
out_free_inst:
inst->free(inst);
out_put_alg:
crypto_mod_put(alg);
return err;
}
