pkcs7, x509: Add ML-DSA support

Add support for ML-DSA keys and signatures to the CMS/PKCS#7 and X.509
implementations.  ML-DSA-44, -65 and -87 are all supported.  For X.509
certificates, the TBSCertificate is required to be signed directly; for
CMS, direct signing of the data is preferred, though use of SHA512 (and
only that) as an intermediate hash of the content is permitted with
signedAttrs.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Lukas Wunner <lukas@wunner.de>
cc: Ignat Korchagin <ignat@cloudflare.com>
cc: Stephan Mueller <smueller@chronox.de>
cc: Eric Biggers <ebiggers@kernel.org>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org

crypto/asymmetric_keys/pkcs7_parser.c

@@ -95,11 +95,18 @@ static int pkcs7_check_authattrs(struct pkcs7_message *msg)
 	if (sinfo->authattrs) {
 		want = true;
 		msg->have_authattrs = true;
+	} else if (sinfo->sig->algo_takes_data) {
+		sinfo->sig->hash_algo = "none";
 	}
 
-	for (sinfo = sinfo->next; sinfo; sinfo = sinfo->next)
+	for (sinfo = sinfo->next; sinfo; sinfo = sinfo->next) {
 		if (!!sinfo->authattrs != want)
 			goto inconsistent;
+
+		if (!sinfo->authattrs &&
+		    sinfo->sig->algo_takes_data)
+			sinfo->sig->hash_algo = "none";
+	}
 	return 0;
 
 inconsistent:
@@ -297,6 +304,21 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
 		ctx->sinfo->sig->pkey_algo = "ecrdsa";
 		ctx->sinfo->sig->encoding = "raw";
 		break;
+	case OID_id_ml_dsa_44:
+		ctx->sinfo->sig->pkey_algo = "mldsa44";
+		ctx->sinfo->sig->encoding = "raw";
+		ctx->sinfo->sig->algo_takes_data = true;
+		break;
+	case OID_id_ml_dsa_65:
+		ctx->sinfo->sig->pkey_algo = "mldsa65";
+		ctx->sinfo->sig->encoding = "raw";
+		ctx->sinfo->sig->algo_takes_data = true;
+		break;
+	case OID_id_ml_dsa_87:
+		ctx->sinfo->sig->pkey_algo = "mldsa87";
+		ctx->sinfo->sig->encoding = "raw";
+		ctx->sinfo->sig->algo_takes_data = true;
+		break;
 	default:
 		printk("Unsupported pkey algo: %u\n", ctx->last_oid);
 		return -ENOPKG;

crypto/asymmetric_keys/public_key.c

@@ -142,6 +142,16 @@ software_key_determine_akcipher(const struct public_key *pkey,
 		if (strcmp(hash_algo, "streebog256") != 0 &&
 		    strcmp(hash_algo, "streebog512") != 0)
 			return -EINVAL;
+	} else if (strcmp(pkey->pkey_algo, "mldsa44") == 0 ||
+		   strcmp(pkey->pkey_algo, "mldsa65") == 0 ||
+		   strcmp(pkey->pkey_algo, "mldsa87") == 0) {
+		if (strcmp(encoding, "raw") != 0)
+			return -EINVAL;
+		if (!hash_algo)
+			return -EINVAL;
+		if (strcmp(hash_algo, "none") != 0 &&
+		    strcmp(hash_algo, "sha512") != 0)
+			return -EINVAL;
 	} else {
 		/* Unknown public key algorithm */
 		return -ENOPKG;

crypto/asymmetric_keys/x509_cert_parser.c

@@ -257,6 +257,15 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
 	case OID_gost2012Signature512:
 		ctx->cert->sig->hash_algo = "streebog512";
 		goto ecrdsa;
+	case OID_id_ml_dsa_44:
+		ctx->cert->sig->pkey_algo = "mldsa44";
+		goto ml_dsa;
+	case OID_id_ml_dsa_65:
+		ctx->cert->sig->pkey_algo = "mldsa65";
+		goto ml_dsa;
+	case OID_id_ml_dsa_87:
+		ctx->cert->sig->pkey_algo = "mldsa87";
+		goto ml_dsa;
 	}
 
 rsa_pkcs1:
@@ -274,6 +283,12 @@ ecdsa:
 	ctx->cert->sig->encoding = "x962";
 	ctx->sig_algo = ctx->last_oid;
 	return 0;
+ml_dsa:
+	ctx->cert->sig->algo_takes_data = true;
+	ctx->cert->sig->hash_algo = "none";
+	ctx->cert->sig->encoding = "raw";
+	ctx->sig_algo = ctx->last_oid;
+	return 0;
 }
 
 /*
@@ -300,7 +315,8 @@ 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, "ecdsa") == 0) {
+	    strcmp(ctx->cert->sig->pkey_algo, "ecdsa") == 0 ||
+	    strncmp(ctx->cert->sig->pkey_algo, "mldsa", 5) == 0) {
 		/* Discard the BIT STRING metadata */
 		if (vlen < 1 || *(const u8 *)value != 0)
 			return -EBADMSG;
@@ -524,6 +540,15 @@ int x509_extract_key_data(void *context, size_t hdrlen,
 			return -ENOPKG;
 		}
 		break;
+	case OID_id_ml_dsa_44:
+		ctx->cert->pub->pkey_algo = "mldsa44";
+		break;
+	case OID_id_ml_dsa_65:
+		ctx->cert->pub->pkey_algo = "mldsa65";
+		break;
+	case OID_id_ml_dsa_87:
+		ctx->cert->pub->pkey_algo = "mldsa87";
+		break;
 	default:
 		return -ENOPKG;
 	}

include/linux/oid_registry.h

@@ -145,6 +145,11 @@ enum OID {
 	OID_id_rsassa_pkcs1_v1_5_with_sha3_384, /* 2.16.840.1.101.3.4.3.15 */
 	OID_id_rsassa_pkcs1_v1_5_with_sha3_512, /* 2.16.840.1.101.3.4.3.16 */
 
+	/* NIST FIPS-204 ML-DSA */
+	OID_id_ml_dsa_44,			/* 2.16.840.1.101.3.4.3.17 */
+	OID_id_ml_dsa_65,			/* 2.16.840.1.101.3.4.3.18 */
+	OID_id_ml_dsa_87,			/* 2.16.840.1.101.3.4.3.19 */
+
 	OID__NR
 };