[PATCH 3/3] x509: Detect sm2 keys by their parameters OID

[Stefan Berger]

From: Stefan Berger <stef...@linux.ibm.com>

Detect whether a key is a sm2 type of key by its OID in the parameters
array.

Signed-off-by: Stefan Berger <stef...@linux.ibm.com>
---
 crypto/asymmetric_keys/x509_cert_parser.c | 27 +++++++++++++----------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/crypto/asymmetric_keys/x509_cert_parser.c 
b/crypto/asymmetric_keys/x509_cert_parser.c
index 720cc7977077..82e331da5041 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -485,6 +485,7 @@ int x509_extract_key_data(void *context, size_t hdrlen,
                          const void *value, size_t vlen)
 {
        struct x509_parse_context *ctx = context;
+       enum OID oid;
 
        ctx->key_algo = ctx->last_oid;
        switch (ctx->last_oid) {
@@ -496,18 +497,20 @@ int x509_extract_key_data(void *context, size_t hdrlen,
                ctx->cert->pub->pkey_algo = "ecrdsa";
                break;
        case OID_id_ecPublicKey:
-               ctx->cert->pub->pkey_algo = "sm2";
-               if (ctx->params_size > 2) {
-                       enum OID oid = look_up_OID(ctx->params + 2,
-                                                  ctx->params_size - 2);
-                       switch (oid) {
-                       case OID_id_prime192v1:
-                       case OID_id_prime256v1:
-                               ctx->cert->pub->pkey_algo = "ecdsa";
-                               break;
-                       default:
-                               break;
-                       }
+               if (ctx->params_size < 2)
+                       return -ENOPKG;
+
+               oid = look_up_OID(ctx->params + 2, ctx->params_size - 2);
+               switch (oid) {
+               case OID_id_prime192v1:
+               case OID_id_prime256v1:
+                       ctx->cert->pub->pkey_algo = "ecdsa";
+                       break;
+               case OID_sm2:
+                       ctx->cert->pub->pkey_algo = "sm2";
+                       break;
+               default:
+                       return -ENOPKG;
                }
                break;
        default:
-- 
2.25.4