X.509: support OSCCA certificate parse

The digital certificate format based on SM2 crypto algorithm as
specified in GM/T 0015-2012. It was published by State Encryption
Management Bureau, China.

This patch adds the OID object identifier defined by OSCCA. The
x509 certificate supports SM2-with-SM3 type certificate parsing.
It uses the standard elliptic curve public key, and the sm2
algorithm signs the hash generated by sm3.
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Tested-by: Xufeng Zhang <yunbo.xufeng@linux.alibaba.com>
Reviewed-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/asymmetric_keys/x509_cert_parser.c

@@ -234,6 +234,10 @@ int x509_note_pkey_algo(void *context, size_t hdrlen,
 	case OID_gost2012Signature512:
 		ctx->cert->sig->hash_algo = "streebog512";
 		goto ecrdsa;
+
+	case OID_SM2_with_SM3:
+		ctx->cert->sig->hash_algo = "sm3";
+		goto sm2;
 	}
 
 rsa_pkcs1:
@@ -246,6 +250,11 @@ int x509_note_pkey_algo(void *context, size_t hdrlen,
 	ctx->cert->sig->encoding = "raw";
 	ctx->algo_oid = ctx->last_oid;
 	return 0;
+sm2:
+	ctx->cert->sig->pkey_algo = "sm2";
+	ctx->cert->sig->encoding = "raw";
+	ctx->algo_oid = ctx->last_oid;
+	return 0;
 }
 
 /*
@@ -266,7 +275,8 @@ int x509_note_signature(void *context, size_t hdrlen,
 	}
 
 	if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0 ||
-	    strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0) {
+	    strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0 ||
+	    strcmp(ctx->cert->sig->pkey_algo, "sm2") == 0) {
 		/* Discard the BIT STRING metadata */
 		if (vlen < 1 || *(const u8 *)value != 0)
 			return -EBADMSG;
@@ -451,13 +461,20 @@ int x509_extract_key_data(void *context, size_t hdrlen,
 	struct x509_parse_context *ctx = context;
 
 	ctx->key_algo = ctx->last_oid;
-	if (ctx->last_oid == OID_rsaEncryption)
+	switch (ctx->last_oid) {
+	case OID_rsaEncryption:
 		ctx->cert->pub->pkey_algo = "rsa";
-	else if (ctx->last_oid == OID_gost2012PKey256 ||
-		 ctx->last_oid == OID_gost2012PKey512)
+		break;
+	case OID_gost2012PKey256:
+	case OID_gost2012PKey512:
 		ctx->cert->pub->pkey_algo = "ecrdsa";
-	else
+		break;
+	case OID_id_ecPublicKey:
+		ctx->cert->pub->pkey_algo = "sm2";
+		break;
+	default:
 		return -ENOPKG;
+	}
 
 	/* Discard the BIT STRING metadata */
 	if (vlen < 1 || *(const u8 *)value != 0)

include/linux/oid_registry.h

@@ -107,6 +107,12 @@ enum OID {
 	OID_gostTC26Sign512B,		/* 1.2.643.7.1.2.1.2.2 */
 	OID_gostTC26Sign512C,		/* 1.2.643.7.1.2.1.2.3 */
 
+	/* OSCCA */
+	OID_sm2,			/* 1.2.156.10197.1.301 */
+	OID_sm3,			/* 1.2.156.10197.1.401 */
+	OID_SM2_with_SM3,		/* 1.2.156.10197.1.501 */
+	OID_sm3WithRSAEncryption,	/* 1.2.156.10197.1.504 */
+
 	OID__NR
 };