x509: Add support for parsing x509 certs with ECDSA keys

This patch adds support for parsing of x509 certificates that contain
ECDSA keys, such as NIST P256, that have been signed by a CA using any
of the current SHA hash algorithms.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: keyrings@vger.kernel.org

crypto/asymmetric_keys/public_key.c

@@ -14,6 +14,7 @@
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 #include <linux/scatterlist.h>
+#include <linux/asn1.h>
 #include <keys/asymmetric-subtype.h>
 #include <crypto/public_key.h>
 #include <crypto/akcipher.h>
@@ -90,6 +91,24 @@ int software_key_determine_akcipher(const char *encoding,
 		return 0;
 	}
 
+	if (strcmp(encoding, "x962") == 0) {
+		enum OID oid;
+
+		if (parse_OID(pkey->params, pkey->paramlen, &oid) != 0)
+			return -EBADMSG;
+
+		switch (oid) {
+		case OID_id_prime192v1:
+			strcpy(alg_name, "ecdsa-nist-p192");
+			return 0;
+		case OID_id_prime256v1:
+			strcpy(alg_name, "ecdsa-nist-p256");
+			return 0;
+		default:
+			return -EINVAL;
+		}
+	}
+
 	return -ENOPKG;
 }
 

crypto/asymmetric_keys/x509_cert_parser.c

@@ -227,6 +227,26 @@ int x509_note_pkey_algo(void *context, size_t hdrlen,
 		ctx->cert->sig->hash_algo = "sha224";
 		goto rsa_pkcs1;
 
+	case OID_id_ecdsa_with_sha1:
+		ctx->cert->sig->hash_algo = "sha1";
+		goto ecdsa;
+
+	case OID_id_ecdsa_with_sha224:
+		ctx->cert->sig->hash_algo = "sha224";
+		goto ecdsa;
+
+	case OID_id_ecdsa_with_sha256:
+		ctx->cert->sig->hash_algo = "sha256";
+		goto ecdsa;
+
+	case OID_id_ecdsa_with_sha384:
+		ctx->cert->sig->hash_algo = "sha384";
+		goto ecdsa;
+
+	case OID_id_ecdsa_with_sha512:
+		ctx->cert->sig->hash_algo = "sha512";
+		goto ecdsa;
+
 	case OID_gost2012Signature256:
 		ctx->cert->sig->hash_algo = "streebog256";
 		goto ecrdsa;
@@ -255,6 +275,11 @@ int x509_note_pkey_algo(void *context, size_t hdrlen,
 	ctx->cert->sig->encoding = "raw";
 	ctx->algo_oid = ctx->last_oid;
 	return 0;
+ecdsa:
+	ctx->cert->sig->pkey_algo = "ecdsa";
+	ctx->cert->sig->encoding = "x962";
+	ctx->algo_oid = ctx->last_oid;
+	return 0;
 }
 
 /*
@@ -276,7 +301,8 @@ 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, "sm2") == 0) {
+	    strcmp(ctx->cert->sig->pkey_algo, "sm2") == 0 ||
+	    strcmp(ctx->cert->sig->pkey_algo, "ecdsa") == 0) {
 		/* Discard the BIT STRING metadata */
 		if (vlen < 1 || *(const u8 *)value != 0)
 			return -EBADMSG;
@@ -478,6 +504,10 @@ int x509_extract_key_data(void *context, size_t hdrlen,
 		case OID_sm2:
 			ctx->cert->pub->pkey_algo = "sm2";
 			break;
+		case OID_id_prime192v1:
+		case OID_id_prime256v1:
+			ctx->cert->pub->pkey_algo = "ecdsa";
+			break;
 		default:
 			return -ENOPKG;
 		}

include/linux/oid_registry.h

@@ -21,6 +21,8 @@ enum OID {
 	OID_id_dsa,			/* 1.2.840.10040.4.1 */
 	OID_id_ecdsa_with_sha1,		/* 1.2.840.10045.4.1 */
 	OID_id_ecPublicKey,		/* 1.2.840.10045.2.1 */
+	OID_id_prime192v1,		/* 1.2.840.10045.3.1.1 */
+	OID_id_prime256v1,		/* 1.2.840.10045.3.1.7 */
 	OID_id_ecdsa_with_sha224,	/* 1.2.840.10045.4.3.1 */
 	OID_id_ecdsa_with_sha256,	/* 1.2.840.10045.4.3.2 */
 	OID_id_ecdsa_with_sha384,	/* 1.2.840.10045.4.3.3 */