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[CRYPTO] gcm: Allow block cipher parameter

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This patch adds the gcm_base template which takes a block cipher
parameter instead of cipher.  This allows the user to specify a
specific CTR implementation.

This also fixes a leak of the cipher algorithm that was previously
looked up but never freed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2007-12-07 20:31:10 +08:00
parent 9ffde35a8e
commit d00aa19b50
1 changed files with 89 additions and 24 deletions
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113
crypto/gcm.c
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@ -413,30 +413,23 @@ static void crypto_gcm_exit_tfm(struct crypto_tfm *tfm)
crypto_free_ablkcipher(ctx->ctr);
}
static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb,
const char *full_name,
const char *ctr_name)
{
struct crypto_attr_type *algt;
struct crypto_instance *inst;
struct crypto_alg *ctr;
struct crypto_alg *cipher;
struct gcm_instance_ctx *ctx;
int err;
char ctr_name[CRYPTO_MAX_ALG_NAME];
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD);
if (err)
algt = crypto_get_attr_type(tb);
err = PTR_ERR(algt);
if (IS_ERR(algt))
return ERR_PTR(err);
cipher = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
CRYPTO_ALG_TYPE_MASK);
inst = ERR_PTR(PTR_ERR(cipher));
if (IS_ERR(cipher))
return inst;
inst = ERR_PTR(ENAMETOOLONG);
if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
cipher->cra_name) >= CRYPTO_MAX_ALG_NAME)
return inst;
if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
return ERR_PTR(-EINVAL);
ctr = crypto_alg_mod_lookup(ctr_name, CRYPTO_ALG_TYPE_BLKCIPHER,
CRYPTO_ALG_TYPE_MASK);
@ -444,7 +437,14 @@ static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
if (IS_ERR(ctr))
return ERR_PTR(PTR_ERR(ctr));
if (cipher->cra_blocksize != 16)
/* We only support 16-byte blocks. */
if ((ctr->cra_type == &crypto_blkcipher_type ?
ctr->cra_blkcipher.ivsize : ctr->cra_ablkcipher.ivsize) != 16)
goto out_put_ctr;
/* Not a stream cipher? */
err = -EINVAL;
if (ctr->cra_blocksize != 1)
goto out_put_ctr;
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
@ -453,21 +453,21 @@ static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
goto out_put_ctr;
err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
"gcm(%s)", cipher->cra_name) >= CRYPTO_MAX_ALG_NAME ||
snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"gcm(%s)", cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"gcm_base(%s)", ctr->cra_driver_name) >=
CRYPTO_MAX_ALG_NAME)
goto err_free_inst;
ctx = crypto_instance_ctx(inst);
err = crypto_init_spawn(&ctx->ctr, ctr, inst, CRYPTO_ALG_TYPE_MASK);
if (err)
goto err_free_inst;
memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC;
inst->alg.cra_priority = ctr->cra_priority;
inst->alg.cra_blocksize = 16;
inst->alg.cra_blocksize = 1;
inst->alg.cra_alignmask = ctr->cra_alignmask | (__alignof__(u64) - 1);
inst->alg.cra_type = &crypto_aead_type;
inst->alg.cra_aead.ivsize = 16;
@ -489,6 +489,29 @@ out_put_ctr:
goto out;
}
static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
{
int err;
const char *cipher_name;
char ctr_name[CRYPTO_MAX_ALG_NAME];
char full_name[CRYPTO_MAX_ALG_NAME];
cipher_name = crypto_attr_alg_name(tb[1]);
err = PTR_ERR(cipher_name);
if (IS_ERR(cipher_name))
return ERR_PTR(err);
if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
CRYPTO_MAX_ALG_NAME)
return ERR_PTR(-ENAMETOOLONG);
if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >=
CRYPTO_MAX_ALG_NAME)
return ERR_PTR(-ENAMETOOLONG);
return crypto_gcm_alloc_common(tb, full_name, ctr_name);
}
static void crypto_gcm_free(struct crypto_instance *inst)
{
struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst);
@ -504,14 +527,55 @@ static struct crypto_template crypto_gcm_tmpl = {
.module = THIS_MODULE,
};
static struct crypto_instance *crypto_gcm_base_alloc(struct rtattr **tb)
{
int err;
const char *ctr_name;
char full_name[CRYPTO_MAX_ALG_NAME];
ctr_name = crypto_attr_alg_name(tb[1]);
err = PTR_ERR(ctr_name);
if (IS_ERR(ctr_name))
return ERR_PTR(err);
if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s)",
ctr_name) >= CRYPTO_MAX_ALG_NAME)
return ERR_PTR(-ENAMETOOLONG);
return crypto_gcm_alloc_common(tb, full_name, ctr_name);
}
static struct crypto_template crypto_gcm_base_tmpl = {
.name = "gcm_base",
.alloc = crypto_gcm_base_alloc,
.free = crypto_gcm_free,
.module = THIS_MODULE,
};
static int __init crypto_gcm_module_init(void)
{
return crypto_register_template(&crypto_gcm_tmpl);
int err;
err = crypto_register_template(&crypto_gcm_base_tmpl);
if (err)
goto out;
err = crypto_register_template(&crypto_gcm_tmpl);
if (err)
goto out_undo_base;
out:
return err;
out_undo_base:
crypto_unregister_template(&crypto_gcm_base_tmpl);
goto out;
}
static void __exit crypto_gcm_module_exit(void)
{
crypto_unregister_template(&crypto_gcm_tmpl);
crypto_unregister_template(&crypto_gcm_base_tmpl);
}
module_init(crypto_gcm_module_init);
@ -520,3 +584,4 @@ module_exit(crypto_gcm_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Galois/Counter Mode");
MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
MODULE_ALIAS("gcm_base");