crypto: gcm - helper functions for assoclen/authsize check

Added inline helper functions to check authsize and assoclen for
gcm, rfc4106 and rfc4543.
These are used in the generic implementation of gcm, rfc4106 and
rfc4543.

Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/gcm.c b/crypto/gcm.c
index f254e2d4c206aacc341548dd40744f02459956ab..2f3b50f8f3e0166105b2f22f2175ca2197395d55 100644 (file)
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -152,20 +152,7 @@ out:
 static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
                                  unsigned int authsize)
 {
-       switch (authsize) {
-       case 4:
-       case 8:
-       case 12:
-       case 13:
-       case 14:
-       case 15:
-       case 16:
-               break;
-       default:
-               return -EINVAL;
-       }
-
-       return 0;
+       return crypto_gcm_check_authsize(authsize);
 }
 
 static void crypto_gcm_init_common(struct aead_request *req)
@@ -762,15 +749,11 @@ static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
                                      unsigned int authsize)
 {
        struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
+       int err;
 
-       switch (authsize) {
-       case 8:
-       case 12:
-       case 16:
-               break;
-       default:
-               return -EINVAL;
-       }
+       err = crypto_rfc4106_check_authsize(authsize);
+       if (err)
+               return err;
 
        return crypto_aead_setauthsize(ctx->child, authsize);
 }
@@ -818,8 +801,11 @@ static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
 
 static int crypto_rfc4106_encrypt(struct aead_request *req)
 {
-       if (req->assoclen != 16 && req->assoclen != 20)
-               return -EINVAL;
+       int err;
+
+       err = crypto_ipsec_check_assoclen(req->assoclen);
+       if (err)
+               return err;
 
        req = crypto_rfc4106_crypt(req);
 
@@ -828,8 +814,11 @@ static int crypto_rfc4106_encrypt(struct aead_request *req)
 
 static int crypto_rfc4106_decrypt(struct aead_request *req)
 {
-       if (req->assoclen != 16 && req->assoclen != 20)
-               return -EINVAL;
+       int err;
+
+       err = crypto_ipsec_check_assoclen(req->assoclen);
+       if (err)
+               return err;
 
        req = crypto_rfc4106_crypt(req);
 

diff --git a/include/crypto/gcm.h b/include/crypto/gcm.h
index c50e057ea17e30ce4c17081eae10b6fb10fb2cc1..9d7eff04f22441e08f7c748333e302f83887ebe8 100644 (file)
--- a/include/crypto/gcm.h
+++ b/include/crypto/gcm.h
@@ -1,8 +1,63 @@
 #ifndef _CRYPTO_GCM_H
 #define _CRYPTO_GCM_H
 
+#include <linux/errno.h>
+
 #define GCM_AES_IV_SIZE 12
 #define GCM_RFC4106_IV_SIZE 8
 #define GCM_RFC4543_IV_SIZE 8
 
+/*
+ * validate authentication tag for GCM
+ */
+static inline int crypto_gcm_check_authsize(unsigned int authsize)
+{
+       switch (authsize) {
+       case 4:
+       case 8:
+       case 12:
+       case 13:
+       case 14:
+       case 15:
+       case 16:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+/*
+ * validate authentication tag for RFC4106
+ */
+static inline int crypto_rfc4106_check_authsize(unsigned int authsize)
+{
+       switch (authsize) {
+       case 8:
+       case 12:
+       case 16:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+/*
+ * validate assoclen for RFC4106/RFC4543
+ */
+static inline int crypto_ipsec_check_assoclen(unsigned int assoclen)
+{
+       switch (assoclen) {
+       case 16:
+       case 20:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
 #endif