1 files changed, 18 insertions, 26 deletions

diff --git a/crypto/ccm.c b/crypto/ccm.c
index 3d036df0f4d4..c1ef9d0b4271 100644
--- a/crypto/ccm.c
+++ b/crypto/ccm.c
@@ -458,7 +458,6 @@ static void crypto_ccm_free(struct aead_instance *inst)
 
 static int crypto_ccm_create_common(struct crypto_template *tmpl,
 				    struct rtattr **tb,
-				    const char *full_name,
 				    const char *ctr_name,
 				    const char *mac_name)
 {
@@ -486,7 +485,8 @@ static int crypto_ccm_create_common(struct crypto_template *tmpl,
 
 	mac = __crypto_hash_alg_common(mac_alg);
 	err = -EINVAL;
-	if (mac->digestsize != 16)
+	if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
+	    mac->digestsize != 16)
 		goto out_put_mac;
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
@@ -509,23 +509,27 @@ static int crypto_ccm_create_common(struct crypto_template *tmpl,
 
 	ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
 
-	/* Not a stream cipher? */
+	/* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
 	err = -EINVAL;
-	if (ctr->base.cra_blocksize != 1)
+	if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
+	    crypto_skcipher_alg_ivsize(ctr) != 16 ||
+	    ctr->base.cra_blocksize != 1)
 		goto err_drop_ctr;
 
-	/* We want the real thing! */
-	if (crypto_skcipher_alg_ivsize(ctr) != 16)
+	/* ctr and cbcmac must use the same underlying block cipher. */
+	if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
 		goto err_drop_ctr;
 
 	err = -ENAMETOOLONG;
+	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
+		     "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
+		goto err_drop_ctr;
+
 	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 		     "ccm_base(%s,%s)", ctr->base.cra_driver_name,
 		     mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 		goto err_drop_ctr;
 
-	memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
-
 	inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
 	inst->alg.base.cra_priority = (mac->base.cra_priority +
 				       ctr->base.cra_priority) / 2;
@@ -567,7 +571,6 @@ static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
 	const char *cipher_name;
 	char ctr_name[CRYPTO_MAX_ALG_NAME];
 	char mac_name[CRYPTO_MAX_ALG_NAME];
-	char full_name[CRYPTO_MAX_ALG_NAME];
 
 	cipher_name = crypto_attr_alg_name(tb[1]);
 	if (IS_ERR(cipher_name))
@@ -581,35 +584,24 @@ static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
 		     cipher_name) >= CRYPTO_MAX_ALG_NAME)
 		return -ENAMETOOLONG;
 
-	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
-	    CRYPTO_MAX_ALG_NAME)
-		return -ENAMETOOLONG;
-
-	return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
-					mac_name);
+	return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
 }
 
 static int crypto_ccm_base_create(struct crypto_template *tmpl,
 				  struct rtattr **tb)
 {
 	const char *ctr_name;
-	const char *cipher_name;
-	char full_name[CRYPTO_MAX_ALG_NAME];
+	const char *mac_name;
 
 	ctr_name = crypto_attr_alg_name(tb[1]);
 	if (IS_ERR(ctr_name))
 		return PTR_ERR(ctr_name);
 
-	cipher_name = crypto_attr_alg_name(tb[2]);
-	if (IS_ERR(cipher_name))
-		return PTR_ERR(cipher_name);
-
-	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
-		     ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
-		return -ENAMETOOLONG;
+	mac_name = crypto_attr_alg_name(tb[2]);
+	if (IS_ERR(mac_name))
+		return PTR_ERR(mac_name);
 
-	return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
-					cipher_name);
+	return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
 }
 
 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,