[PATCH 6/7] X.509: support OSCCA certificate parse

From: Tianjia Zhang
Date: Sun Feb 16 2020 - 04:00:08 EST


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@xxxxxxxxxxxxxxxxx>
---
crypto/asymmetric_keys/x509_cert_parser.c | 14 +++++++++++++-
include/linux/oid_registry.h | 6 ++++++
2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 26ec20ef4899..6a8aee22bfd4 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/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;
@@ -456,6 +466,8 @@ int x509_extract_key_data(void *context, size_t hdrlen,
else if (ctx->last_oid == OID_gost2012PKey256 ||
ctx->last_oid == OID_gost2012PKey512)
ctx->cert->pub->pkey_algo = "ecrdsa";
+ else if (ctx->last_oid == OID_id_ecPublicKey)
+ ctx->cert->pub->pkey_algo = "sm2";
else
return -ENOPKG;

diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
index 657d6bf2c064..48fe3133ff39 100644
--- a/include/linux/oid_registry.h
+++ b/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
};

--
2.17.1