[CRYPTO] gcm: Allow block cipher parameter
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 <[email protected]>
---
crypto/gcm.c | 122 ++++++++++++++++++++++++++++++++++++++++++++++-------------
1 files changed, 96 insertions(+), 26 deletions(-)
diff --git a/crypto/gcm.c b/crypto/gcm.c
index 1624301..9c29765 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -381,30 +381,24 @@ 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,
+ const char *cipher_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, "rfc3686(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);
@@ -412,29 +406,34 @@ static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
if (IS_ERR(ctr))
return ERR_PTR(PTR_ERR(ctr));
+ /* Not a stream cipher? */
+ err = -EINVAL;
+ if (ctr->cra_blocksize != 1)
+ goto out_put_ctr;
+
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
err = -ENOMEM;
if (!inst)
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)
- goto err_free_inst;
-
+ if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+ "gcm_base(%s,%s)", ctr->cra_driver_name, cipher_name) >=
+ CRYPTO_MAX_ALG_NAME)
+ goto out_put_ctr;
ctx = crypto_instance_ctx(inst);
err = crypto_init_spawn(&ctx->ctr, ctr, inst, CRYPTO_ALG_TYPE_MASK);
if (err)
goto err_free_inst;
- memcpy(ctx->cipher_name, cipher->cra_driver_name, CRYPTO_MAX_ALG_NAME);
+ memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
+ memcpy(ctx->cipher_name, cipher_name, CRYPTO_MAX_ALG_NAME);
- inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC;
+ inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
+ inst->alg.cra_flags |= ctr->cra_flags & 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 = 12;
@@ -456,6 +455,29 @@ 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, "rfc3686(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, cipher_name);
+}
+
static void crypto_gcm_free(struct crypto_instance *inst)
{
struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst);
@@ -471,14 +493,61 @@ 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;
+ const char *cipher_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);
+
+ cipher_name = crypto_attr_alg_name(tb[2]);
+ err = PTR_ERR(cipher_name);
+ if (IS_ERR(cipher_name))
+ return ERR_PTR(err);
+
+ if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s,%s)",
+ ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ return crypto_gcm_alloc_common(tb, full_name, ctr_name, cipher_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);
@@ -487,3 +556,4 @@ module_exit(crypto_gcm_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Galois/Counter Mode");
MODULE_AUTHOR("Mikko Herranen <[email protected]>");
+MODULE_ALIAS("gcm_base");