x509: Add support for signature schemes with parameters

Also adds support for specifying the hash algorithm for attribute
certificate signatures.

5 files changed, 220 insertions, 143 deletions

diff --git a/src/libstrongswan/plugins/x509/x509_ac.c b/src/libstrongswan/plugins/x509/x509_ac.c
index c0a64fc5d..8e2b4c1e3 100644
--- a/src/libstrongswan/plugins/x509/x509_ac.c
+++ b/src/libstrongswan/plugins/x509/x509_ac.c
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2017 Tobias Brunner
  * Copyright (C) 2002 Ueli Galizzi, Ariane Seiler
  * Copyright (C) 2003 Martin Berner, Lukas Suter
  * Copyright (C) 2002-2017 Andreas Steffen
@@ -116,9 +117,9 @@ struct private_x509_ac_t {
 	bool noRevAvail;
 
 	/**
-	 * Signature algorithm
+	 * Signature scheme
 	 */
-	int algorithm;
+	signature_params_t *scheme;
 
 	/**
 	 * Signature
@@ -425,7 +426,7 @@ static bool parse_certificate(private_x509_ac_t *this)
 	int objectID;
 	int type     = OID_UNKNOWN;
 	int extn_oid = OID_UNKNOWN;
-	int sig_alg  = OID_UNKNOWN;
+	signature_params_t sig_alg;
 	bool success = FALSE;
 	bool critical;
 
@@ -476,7 +477,11 @@ static bool parse_certificate(private_x509_ac_t *this)
 				}
 				break;
 			case AC_OBJ_SIG_ALG:
-				sig_alg = asn1_parse_algorithmIdentifier(object, level, NULL);
+				if (!signature_params_parse(object, level, &sig_alg))
+				{
+					DBG1(DBG_ASN, "  unable to parse signature algorithm");
+					goto end;
+				}
 				break;
 			case AC_OBJ_SERIAL_NUMBER:
 				this->serialNumber = chunk_clone(object);
@@ -550,12 +555,15 @@ static bool parse_certificate(private_x509_ac_t *this)
 				break;
 			}
 			case AC_OBJ_ALGORITHM:
-				this->algorithm = asn1_parse_algorithmIdentifier(object, level,
-																 NULL);
-				if (this->algorithm != sig_alg)
+				INIT(this->scheme);
+				if (!signature_params_parse(object, level, this->scheme))
+				{
+					DBG1(DBG_ASN, "  unable to parse signature algorithm");
+					goto end;
+				}
+				if (!signature_params_equal(this->scheme, &sig_alg))
 				{
 					DBG1(DBG_ASN, "  signature algorithms do not agree");
-					success = FALSE;
 					goto end;
 				}
 				break;
@@ -570,6 +578,7 @@ static bool parse_certificate(private_x509_ac_t *this)
 
 end:
 	parser->destroy(parser);
+	signature_params_clear(&sig_alg);
 	return success;
 }
 
@@ -742,13 +751,13 @@ static chunk_t build_extensions(private_x509_ac_t *this)
 /**
  * build attributeCertificateInfo
  */
-static chunk_t build_attr_cert_info(private_x509_ac_t *this)
+static chunk_t build_attr_cert_info(private_x509_ac_t *this, chunk_t sig_scheme)
 {
-	return asn1_wrap(ASN1_SEQUENCE, "cmmmmmmm",
+	return asn1_wrap(ASN1_SEQUENCE, "cmmcmmmm",
 				ASN1_INTEGER_1,
 				build_holder(this),
 				build_v2_form(this),
-				asn1_algorithmIdentifier(OID_SHA1_WITH_RSA),
+				sig_scheme,
 				asn1_simple_object(ASN1_INTEGER, this->serialNumber),
 				build_attr_cert_validity(this),
 				build_attributes(this),
@@ -758,20 +767,39 @@ static chunk_t build_attr_cert_info(private_x509_ac_t *this)
 /**
  * build an X.509 attribute certificate
  */
-static bool build_ac(private_x509_ac_t *this)
+static bool build_ac(private_x509_ac_t *this, hash_algorithm_t digest_alg)
 {
-	chunk_t signatureValue, attributeCertificateInfo;
+	chunk_t signatureValue, attributeCertificateInfo, sig_scheme;
+	private_key_t *key = this->signerKey;
+
+	if (!this->scheme)
+	{
+		INIT(this->scheme,
+			.scheme = signature_scheme_from_oid(
+								hasher_signature_algorithm_to_oid(digest_alg,
+												key->get_type(key))),
+		);
+	}
+	if (this->scheme->scheme == SIGN_UNKNOWN)
+	{
+		return FALSE;
+	}
+	if (!signature_params_build(this->scheme, &sig_scheme))
+	{
+		return FALSE;
+	}
 
-	attributeCertificateInfo = build_attr_cert_info(this);
-	if (!this->signerKey->sign(this->signerKey, SIGN_RSA_EMSA_PKCS1_SHA1, NULL,
-							   attributeCertificateInfo, &signatureValue))
+	attributeCertificateInfo = build_attr_cert_info(this, sig_scheme);
+	if (!key->sign(key, this->scheme->scheme, this->scheme->params,
+				   attributeCertificateInfo, &signatureValue))
 	{
 		free(attributeCertificateInfo.ptr);
+		free(sig_scheme.ptr);
 		return FALSE;
 	}
 	this->encoding = asn1_wrap(ASN1_SEQUENCE, "mmm",
 						attributeCertificateInfo,
-						asn1_algorithmIdentifier(OID_SHA1_WITH_RSA),
+						sig_scheme,
 						asn1_bitstring("m", signatureValue));
 	return TRUE;
 }
@@ -887,10 +915,9 @@ METHOD(certificate_t, has_issuer, id_match_t,
 
 METHOD(certificate_t, issued_by, bool,
 	private_x509_ac_t *this, certificate_t *issuer,
-	signature_params_t **schemep)
+	signature_params_t **scheme)
 {
 	public_key_t *key;
-	signature_scheme_t scheme;
 	bool valid;
 	x509_t *x509 = (x509_t*)issuer;
 
@@ -927,21 +954,16 @@ METHOD(certificate_t, issued_by, bool,
 		}
 	}
 
-	/* determine signature scheme */
-	scheme = signature_scheme_from_oid(this->algorithm);
-
-	if (scheme == SIGN_UNKNOWN || key == NULL)
+	if (!key)
 	{
 		return FALSE;
 	}
-	valid = key->verify(key, scheme, NULL, this->certificateInfo,
-						this->signature);
+	valid = key->verify(key, this->scheme->scheme, this->scheme->params,
+						this->certificateInfo, this->signature);
 	key->destroy(key);
-	if (valid && schemep)
+	if (valid && scheme)
 	{
-		INIT(*schemep,
-			.scheme = scheme,
-		);
+		*scheme = signature_params_clone(this->scheme);
 	}
 	return valid;
 }
@@ -1024,6 +1046,7 @@ METHOD(certificate_t, destroy, void,
 		DESTROY_IF(this->signerCert);
 		DESTROY_IF(this->signerKey);
 		this->groups->destroy_function(this->groups, (void*)group_destroy);
+		signature_params_destroy(this->scheme);
 		free(this->serialNumber.ptr);
 		free(this->authKeyIdentifier.ptr);
 		free(this->encoding.ptr);
@@ -1130,6 +1153,7 @@ static void add_groups_from_list(private_x509_ac_t *this, linked_list_t *list)
  */
 x509_ac_t *x509_ac_gen(certificate_type_t type, va_list args)
 {
+	hash_algorithm_t digest_alg = HASH_SHA1;
 	private_x509_ac_t *ac;
 
 	ac = create_empty();
@@ -1161,6 +1185,13 @@ x509_ac_t *x509_ac_gen(certificate_type_t type, va_list args)
 				ac->signerKey = va_arg(args, private_key_t*);
 				ac->signerKey->get_ref(ac->signerKey);
 				continue;
+			case BUILD_SIGNATURE_SCHEME:
+				ac->scheme = va_arg(args, signature_params_t*);
+				ac->scheme = signature_params_clone(ac->scheme);
+				continue;
+			case BUILD_DIGEST_ALG:
+				digest_alg = va_arg(args, int);
+				continue;
 			case BUILD_END:
 				break;
 			default:
@@ -1174,7 +1205,7 @@ x509_ac_t *x509_ac_gen(certificate_type_t type, va_list args)
 		ac->holderCert->get_type(ac->holderCert) == CERT_X509 &&
 		ac->signerCert->get_type(ac->signerCert) == CERT_X509)
 	{
-		if (build_ac(ac))
+		if (build_ac(ac, digest_alg))
 		{
 			return &ac->public;
 		}
diff --git a/src/libstrongswan/plugins/x509/x509_cert.c b/src/libstrongswan/plugins/x509/x509_cert.c
index 9bb272a4f..d1f9d9aac 100644
--- a/src/libstrongswan/plugins/x509/x509_cert.c
+++ b/src/libstrongswan/plugins/x509/x509_cert.c
@@ -4,7 +4,7 @@
  * Copyright (C) 2002 Mario Strasser
  * Copyright (C) 2000-2017 Andreas Steffen
  * Copyright (C) 2006-2009 Martin Willi
- * Copyright (C) 2008 Tobias Brunner
+ * Copyright (C) 2008-2017 Tobias Brunner
  * HSR Hochschule fuer Technik Rapperswil
  *
  * This program is free software; you can redistribute it and/or modify it
@@ -197,9 +197,9 @@ struct private_x509_cert_t {
 	x509_flag_t flags;
 
 	/**
-	 * Signature algorithm
+	 * Signature scheme
 	 */
-	int algorithm;
+	signature_params_t *scheme;
 
 	/**
 	 * Signature
@@ -1375,7 +1375,7 @@ static bool parse_certificate(private_x509_cert_t *this)
 	chunk_t object;
 	int objectID;
 	int extn_oid = OID_UNKNOWN;
-	int sig_alg  = OID_UNKNOWN;
+	signature_params_t sig_alg = {};
 	bool success = FALSE;
 	bool critical = FALSE;
 
@@ -1406,7 +1406,11 @@ static bool parse_certificate(private_x509_cert_t *this)
 				this->serialNumber = object;
 				break;
 			case X509_OBJ_SIG_ALG:
-				sig_alg = asn1_parse_algorithmIdentifier(object, level, NULL);
+				if (!signature_params_parse(object, level, &sig_alg))
+				{
+					DBG1(DBG_ASN, "  unable to parse signature algorithm");
+					goto end;
+				}
 				break;
 			case X509_OBJ_ISSUER:
 				this->issuer = identification_create_from_encoding(ID_DER_ASN1_DN, object);
@@ -1560,8 +1564,13 @@ static bool parse_certificate(private_x509_cert_t *this)
 				break;
 			}
 			case X509_OBJ_ALGORITHM:
-				this->algorithm = asn1_parse_algorithmIdentifier(object, level, NULL);
-				if (this->algorithm != sig_alg)
+				INIT(this->scheme);
+				if (!signature_params_parse(object, level, this->scheme))
+				{
+					DBG1(DBG_ASN, "  unable to parse signature algorithm");
+					goto end;
+				}
+				if (!signature_params_equal(this->scheme, &sig_alg))
 				{
 					DBG1(DBG_ASN, "  signature algorithms do not agree");
 					goto end;
@@ -1578,6 +1587,7 @@ static bool parse_certificate(private_x509_cert_t *this)
 
 end:
 	parser->destroy(parser);
+	signature_params_clear(&sig_alg);
 	if (success)
 	{
 		hasher_t *hasher;
@@ -1677,26 +1687,21 @@ METHOD(certificate_t, has_issuer, id_match_t,
 
 METHOD(certificate_t, issued_by, bool,
 	private_x509_cert_t *this, certificate_t *issuer,
-	signature_params_t **schemep)
+	signature_params_t **scheme)
 {
 	public_key_t *key;
-	signature_scheme_t scheme;
 	bool valid;
 	x509_t *x509 = (x509_t*)issuer;
 
-	/* determine signature scheme */
-	scheme = signature_scheme_from_oid(this->algorithm);
-	if (scheme == SIGN_UNKNOWN)
-	{
-		return FALSE;
-	}
-
 	if (&this->public.interface.interface == issuer)
 	{
 		if (this->flags & X509_SELF_SIGNED)
 		{
-			valid = TRUE;
-			goto out;
+			if (scheme)
+			{
+				*scheme = signature_params_clone(this->scheme);
+			}
+			return TRUE;
 		}
 	}
 	else
@@ -1721,16 +1726,12 @@ METHOD(certificate_t, issued_by, bool,
 	{
 		return FALSE;
 	}
-	valid = key->verify(key, scheme, NULL, this->tbsCertificate,
-						this->signature);
+	valid = key->verify(key, this->scheme->scheme, this->scheme->params,
+						this->tbsCertificate, this->signature);
 	key->destroy(key);
-
-out:
-	if (valid && schemep)
+	if (valid && scheme)
 	{
-		INIT(*schemep,
-			.scheme = scheme,
-		);
+		*scheme = signature_params_clone(this->scheme);
 	}
 	return valid;
 }
@@ -1930,6 +1931,7 @@ METHOD(certificate_t, destroy, void,
 											  (void*)cert_policy_destroy);
 		this->policy_mappings->destroy_function(this->policy_mappings,
 											  (void*)policy_mapping_destroy);
+		signature_params_destroy(this->scheme);
 		DESTROY_IF(this->issuer);
 		DESTROY_IF(this->subject);
 		DESTROY_IF(this->public_key);
@@ -2185,10 +2187,9 @@ static bool generate(private_x509_cert_t *cert, certificate_t *sign_cert,
 	chunk_t crlDistributionPoints = chunk_empty, authorityInfoAccess = chunk_empty;
 	chunk_t policyConstraints = chunk_empty, inhibitAnyPolicy = chunk_empty;
 	chunk_t ikeIntermediate = chunk_empty, msSmartcardLogon = chunk_empty;
-	chunk_t ipAddrBlocks = chunk_empty;
+	chunk_t ipAddrBlocks = chunk_empty, sig_scheme = chunk_empty;
 	identification_t *issuer, *subject;
 	chunk_t key_info;
-	signature_scheme_t scheme;
 	hasher_t *hasher;
 	enumerator_t *enumerator;
 	char *uri;
@@ -2221,18 +2222,28 @@ static bool generate(private_x509_cert_t *cert, certificate_t *sign_cert,
 		cert->notAfter = cert->notBefore + 60 * 60 * 24 * 365;
 	}
 
-	/* select signature scheme */
-	cert->algorithm = hasher_signature_algorithm_to_oid(digest_alg,
-								sign_key->get_type(sign_key));
-	if (cert->algorithm == OID_UNKNOWN)
+	/* select signature scheme, if not already specified */
+	if (!cert->scheme)
+	{
+		INIT(cert->scheme,
+			.scheme = signature_scheme_from_oid(
+								hasher_signature_algorithm_to_oid(digest_alg,
+												sign_key->get_type(sign_key))),
+		);
+	}
+	if (cert->scheme->scheme == SIGN_UNKNOWN)
+	{
+		return FALSE;
+	}
+	if (!signature_params_build(cert->scheme, &sig_scheme))
 	{
 		return FALSE;
 	}
-	scheme = signature_scheme_from_oid(cert->algorithm);
 
 	if (!cert->public_key->get_encoding(cert->public_key,
 										PUBKEY_SPKI_ASN1_DER, &key_info))
 	{
+		chunk_free(&sig_scheme);
 		return FALSE;
 	}
 
@@ -2557,10 +2568,10 @@ static bool generate(private_x509_cert_t *cert, certificate_t *sign_cert,
 							ipAddrBlocks));
 	}
 
-	cert->tbsCertificate = asn1_wrap(ASN1_SEQUENCE, "mmmcmcmm",
+	cert->tbsCertificate = asn1_wrap(ASN1_SEQUENCE, "mmccmcmm",
 		asn1_simple_object(ASN1_CONTEXT_C_0, ASN1_INTEGER_2),
 		asn1_integer("c", cert->serialNumber),
-		asn1_algorithmIdentifier(cert->algorithm),
+		sig_scheme,
 		issuer->get_encoding(issuer),
 		asn1_wrap(ASN1_SEQUENCE, "mm",
 			asn1_from_time(&cert->notBefore, ASN1_UTCTIME),
@@ -2568,13 +2579,14 @@ static bool generate(private_x509_cert_t *cert, certificate_t *sign_cert,
 		subject->get_encoding(subject),
 		key_info, extensions);
 
-	if (!sign_key->sign(sign_key, scheme, NULL, cert->tbsCertificate,
-						&cert->signature))
+	if (!sign_key->sign(sign_key, cert->scheme->scheme, cert->scheme->params,
+						cert->tbsCertificate, &cert->signature))
 	{
+		chunk_free(&sig_scheme);
 		return FALSE;
 	}
 	cert->encoding = asn1_wrap(ASN1_SEQUENCE, "cmm", cert->tbsCertificate,
-							   asn1_algorithmIdentifier(cert->algorithm),
+							   sig_scheme,
 							   asn1_bitstring("c", cert->signature));
 
 	hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
@@ -2638,7 +2650,7 @@ x509_cert_t *x509_cert_gen(certificate_type_t type, va_list args)
 	private_x509_cert_t *cert;
 	certificate_t *sign_cert = NULL;
 	private_key_t *sign_key = NULL;
-	hash_algorithm_t digest_alg = HASH_SHA1;
+	hash_algorithm_t digest_alg = HASH_SHA256;
 	u_int constraint;
 
 	cert = create_empty();
@@ -2830,6 +2842,10 @@ x509_cert_t *x509_cert_gen(certificate_type_t type, va_list args)
 			case BUILD_SERIAL:
 				cert->serialNumber = chunk_clone(va_arg(args, chunk_t));
 				continue;
+			case BUILD_SIGNATURE_SCHEME:
+				cert->scheme = va_arg(args, signature_params_t*);
+				cert->scheme = signature_params_clone(cert->scheme);
+				continue;
 			case BUILD_DIGEST_ALG:
 				digest_alg = va_arg(args, int);
 				continue;
diff --git a/src/libstrongswan/plugins/x509/x509_crl.c b/src/libstrongswan/plugins/x509/x509_crl.c
index 2712ad83e..699ac5a39 100644
--- a/src/libstrongswan/plugins/x509/x509_crl.c
+++ b/src/libstrongswan/plugins/x509/x509_crl.c
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2014-2017 Tobias Brunner
  * Copyright (C) 2008-2009 Martin Willi
  * Copyright (C) 2017 Andreas Steffen
  * HSR Hochschule fuer Technik Rapperswil
@@ -121,9 +122,9 @@ struct private_x509_crl_t {
 	chunk_t baseCrlNumber;
 
 	/**
-	 * Signature algorithm
+	 * Signature scheme
 	 */
-	int algorithm;
+	signature_params_t *scheme;
 
 	/**
 	 * Signature
@@ -225,7 +226,7 @@ static bool parse(private_x509_crl_t *this)
 	chunk_t extnID = chunk_empty;
 	chunk_t userCertificate = chunk_empty;
 	int objectID;
-	int sig_alg = OID_UNKNOWN;
+	signature_params_t sig_alg = {};
 	bool success = FALSE;
 	bool critical = FALSE;
 	revoked_t *revoked = NULL;
@@ -246,7 +247,11 @@ static bool parse(private_x509_crl_t *this)
 				DBG2(DBG_ASN, "  v%d", this->version);
 				break;
 			case CRL_OBJ_SIG_ALG:
-				sig_alg = asn1_parse_algorithmIdentifier(object, level, NULL);
+				if (!signature_params_parse(object, level, &sig_alg))
+				{
+					DBG1(DBG_ASN, "  unable to parse signature algorithm");
+					goto end;
+				}
 				break;
 			case CRL_OBJ_ISSUER:
 				this->issuer = identification_create_from_encoding(ID_DER_ASN1_DN, object);
@@ -342,8 +347,13 @@ static bool parse(private_x509_crl_t *this)
 			}
 			case CRL_OBJ_ALGORITHM:
 			{
-				this->algorithm = asn1_parse_algorithmIdentifier(object, level, NULL);
-				if (this->algorithm != sig_alg)
+				INIT(this->scheme);
+				if (!signature_params_parse(object, level, this->scheme))
+				{
+					DBG1(DBG_ASN, "  unable to parse signature algorithm");
+					goto end;
+				}
+				if (!signature_params_equal(this->scheme, &sig_alg))
 				{
 					DBG1(DBG_ASN, "  signature algorithms do not agree");
 					goto end;
@@ -361,6 +371,7 @@ static bool parse(private_x509_crl_t *this)
 
 end:
 	parser->destroy(parser);
+	signature_params_clear(&sig_alg);
 	return success;
 }
 
@@ -458,10 +469,9 @@ METHOD(certificate_t, has_issuer, id_match_t,
 
 METHOD(certificate_t, issued_by, bool,
 	private_x509_crl_t *this, certificate_t *issuer,
-	signature_params_t **schemep)
+	signature_params_t **scheme)
 {
 	public_key_t *key;
-	signature_scheme_t scheme;
 	bool valid;
 	x509_t *x509 = (x509_t*)issuer;
 	chunk_t keyid = chunk_empty;
@@ -493,23 +503,17 @@ METHOD(certificate_t, issued_by, bool,
 		}
 	}
 
-	scheme = signature_scheme_from_oid(this->algorithm);
-	if (scheme == SIGN_UNKNOWN)
-	{
-		return FALSE;
-	}
 	key = issuer->get_public_key(issuer);
 	if (!key)
 	{
 		return FALSE;
 	}
-	valid = key->verify(key, scheme, NULL, this->tbsCertList, this->signature);
+	valid = key->verify(key, this->scheme->scheme, this->scheme->params,
+						this->tbsCertList, this->signature);
 	key->destroy(key);
-	if (valid && schemep)
+	if (valid && scheme)
 	{
-		INIT(*schemep,
-			.scheme = scheme,
-		);
+		*scheme = signature_params_clone(this->scheme);
 	}
 	return valid;
 }
@@ -596,6 +600,7 @@ METHOD(certificate_t, destroy, void,
 		this->revoked->destroy_function(this->revoked, (void*)revoked_destroy);
 		this->crl_uris->destroy_function(this->crl_uris,
 										 (void*)x509_cdp_destroy);
+		signature_params_destroy(this->scheme);
 		DESTROY_IF(this->issuer);
 		free(this->authKeyIdentifier.ptr);
 		free(this->encoding.ptr);
@@ -712,6 +717,7 @@ static bool generate(private_x509_crl_t *this, certificate_t *cert,
 {
 	chunk_t extensions = chunk_empty, certList = chunk_empty, serial;
 	chunk_t crlDistributionPoints = chunk_empty, baseCrlNumber = chunk_empty;
+	chunk_t sig_scheme = chunk_empty;
 	enumerator_t *enumerator;
 	crl_reason_t reason;
 	time_t date;
@@ -724,10 +730,20 @@ static bool generate(private_x509_crl_t *this, certificate_t *cert,
 
 	this->authKeyIdentifier = chunk_clone(x509->get_subjectKeyIdentifier(x509));
 
-	/* select signature scheme */
-	this->algorithm = hasher_signature_algorithm_to_oid(digest_alg,
-														key->get_type(key));
-	if (this->algorithm == OID_UNKNOWN)
+	/* select signature scheme, if not already specified */
+	if (!this->scheme)
+	{
+		INIT(this->scheme,
+			.scheme = signature_scheme_from_oid(
+								hasher_signature_algorithm_to_oid(digest_alg,
+												key->get_type(key))),
+		);
+	}
+	if (this->scheme->scheme == SIGN_UNKNOWN)
+	{
+		return FALSE;
+	}
+	if (!signature_params_build(this->scheme, &sig_scheme))
 	{
 		return FALSE;
 	}
@@ -781,23 +797,24 @@ static bool generate(private_x509_crl_t *this, certificate_t *cert,
 								asn1_integer("c", this->crlNumber))),
 						crlDistributionPoints, baseCrlNumber));
 
-	this->tbsCertList = asn1_wrap(ASN1_SEQUENCE, "cmcmmmm",
+	this->tbsCertList = asn1_wrap(ASN1_SEQUENCE, "cccmmmm",
 							ASN1_INTEGER_1,
-							asn1_algorithmIdentifier(this->algorithm),
+							sig_scheme,
 							this->issuer->get_encoding(this->issuer),
 							asn1_from_time(&this->thisUpdate, ASN1_UTCTIME),
 							asn1_from_time(&this->nextUpdate, ASN1_UTCTIME),
 							asn1_wrap(ASN1_SEQUENCE, "m", certList),
 							extensions);
 
-	if (!key->sign(key, signature_scheme_from_oid(this->algorithm), NULL,
+	if (!key->sign(key, this->scheme->scheme, this->scheme->params,
 				   this->tbsCertList, &this->signature))
 	{
+		chunk_free(&sig_scheme);
 		return FALSE;
 	}
 	this->encoding = asn1_wrap(ASN1_SEQUENCE, "cmm",
 							this->tbsCertList,
-							asn1_algorithmIdentifier(this->algorithm),
+							sig_scheme,
 							asn1_bitstring("c", this->signature));
 	return TRUE;
 }
@@ -836,6 +853,10 @@ x509_crl_t *x509_crl_gen(certificate_type_t type, va_list args)
 				crl->crlNumber = va_arg(args, chunk_t);
 				crl->crlNumber = chunk_clone(crl->crlNumber);
 				continue;
+			case BUILD_SIGNATURE_SCHEME:
+				crl->scheme = va_arg(args, signature_params_t*);
+				crl->scheme = signature_params_clone(crl->scheme);
+				continue;
 			case BUILD_DIGEST_ALG:
 				digest_alg = va_arg(args, int);
 				continue;
diff --git a/src/libstrongswan/plugins/x509/x509_ocsp_response.c b/src/libstrongswan/plugins/x509/x509_ocsp_response.c
index e803c185c..aa4999cbd 100644
--- a/src/libstrongswan/plugins/x509/x509_ocsp_response.c
+++ b/src/libstrongswan/plugins/x509/x509_ocsp_response.c
@@ -1,4 +1,5 @@
-/**
+/*
+ * Copyright (C) 2017 Tobias Brunner
  * Copyright (C) 2008-2009 Martin Willi
  * Copyright (C) 2007-2015 Andreas Steffen
  * HSR Hochschule fuer Technik Rapperswil
@@ -63,9 +64,9 @@ struct private_x509_ocsp_response_t {
 	chunk_t tbsResponseData;
 
 	/**
-	 * signature algorithm (OID)
+	 * signature scheme
 	 */
-	int signatureAlgorithm;
+	signature_params_t *scheme;
 
 	/**
 	 * signature
@@ -576,8 +577,13 @@ static bool parse_basicOCSPResponse(private_x509_ocsp_response_t *this,
 				}
 				break;
 			case BASIC_RESPONSE_ALGORITHM:
-				this->signatureAlgorithm = asn1_parse_algorithmIdentifier(object,
-												parser->get_level(parser)+1, NULL);
+				INIT(this->scheme);
+				if (!signature_params_parse(object, parser->get_level(parser)+1,
+											this->scheme))
+				{
+					DBG1(DBG_ASN, "  unable to parse signature algorithm");
+					goto end;
+				}
 				break;
 			case BASIC_RESPONSE_SIGNATURE:
 				this->signature = chunk_skip(object, 1);
@@ -703,10 +709,9 @@ METHOD(certificate_t, has_issuer, id_match_t,
 
 METHOD(certificate_t, issued_by, bool,
 	private_x509_ocsp_response_t *this, certificate_t *issuer,
-	signature_params_t **schemep)
+	signature_params_t **scheme)
 {
 	public_key_t *key;
-	signature_scheme_t scheme;
 	bool valid;
 	x509_t *x509 = (x509_t*)issuer;
 
@@ -743,24 +748,17 @@ METHOD(certificate_t, issued_by, bool,
 		return FALSE;
 	}
 
-	/* get the public key of the issuer */
 	key = issuer->get_public_key(issuer);
-
-	/* determine signature scheme */
-	scheme = signature_scheme_from_oid(this->signatureAlgorithm);
-
-	if (scheme == SIGN_UNKNOWN || key == NULL)
+	if (!key)
 	{
 		return FALSE;
 	}
-	valid = key->verify(key, scheme, NULL, this->tbsResponseData,
-						this->signature);
+	valid = key->verify(key, this->scheme->scheme, this->scheme->params,
+						this->tbsResponseData, this->signature);
 	key->destroy(key);
-	if (valid && schemep)
+	if (valid && scheme)
 	{
-		INIT(*schemep,
-			.scheme = scheme,
-		);
+		*scheme = signature_params_clone(this->scheme);
 	}
 	return valid;
 }
@@ -842,6 +840,7 @@ METHOD(certificate_t, destroy, void,
 	{
 		this->certs->destroy_offset(this->certs, offsetof(certificate_t, destroy));
 		this->responses->destroy_function(this->responses, free);
+		signature_params_destroy(this->scheme);
 		DESTROY_IF(this->responderId);
 		free(this->encoding.ptr);
 		free(this);
@@ -882,7 +881,6 @@ static x509_ocsp_response_t *load(chunk_t blob)
 		.producedAt = UNDEFINED_TIME,
 		.usableUntil = UNDEFINED_TIME,
 		.responses = linked_list_create(),
-		.signatureAlgorithm = OID_UNKNOWN,
 		.certs = linked_list_create(),
 	);
 
diff --git a/src/libstrongswan/plugins/x509/x509_pkcs10.c b/src/libstrongswan/plugins/x509/x509_pkcs10.c
index 019ccf7c1..587fbd5d6 100644
--- a/src/libstrongswan/plugins/x509/x509_pkcs10.c
+++ b/src/libstrongswan/plugins/x509/x509_pkcs10.c
@@ -72,9 +72,9 @@ struct private_x509_pkcs10_t {
 	chunk_t challengePassword;
 
 	/**
-	 * Signature algorithm
+	 * Signature scheme
 	 */
-	int algorithm;
+	signature_params_t *scheme;
 
 	/**
 	 * Signature
@@ -124,22 +124,15 @@ METHOD(certificate_t, has_subject, id_match_t,
 
 METHOD(certificate_t, issued_by, bool,
 	private_x509_pkcs10_t *this, certificate_t *issuer,
-	signature_params_t **schemep)
+	signature_params_t **scheme)
 {
 	public_key_t *key;
-	signature_scheme_t scheme;
 	bool valid;
 
 	if (&this->public.interface.interface != issuer)
 	{
 		return FALSE;
 	}
-	/* determine signature scheme */
-	scheme = signature_scheme_from_oid(this->algorithm);
-	if (scheme == SIGN_UNKNOWN)
-	{
-		return FALSE;
-	}
 	if (this->self_signed)
 	{
 		valid = TRUE;
@@ -152,14 +145,12 @@ METHOD(certificate_t, issued_by, bool,
 		{
 			return FALSE;
 		}
-		valid = key->verify(key, scheme, NULL, this->certificationRequestInfo,
-							this->signature);
+		valid = key->verify(key, this->scheme->scheme, this->scheme->params,
+							this->certificationRequestInfo, this->signature);
 	}
-	if (valid && schemep)
+	if (valid && scheme)
 	{
-		INIT(*schemep,
-			.scheme = scheme,
-		);
+		*scheme = signature_params_clone(this->scheme);
 	}
 	return valid;
 }
@@ -413,7 +404,7 @@ static bool parse_certificate_request(private_x509_pkcs10_t *this)
 			case PKCS10_SUBJECT_PUBLIC_KEY_INFO:
 				this->public_key = lib->creds->create(lib->creds, CRED_PUBLIC_KEY,
 						KEY_ANY, BUILD_BLOB_ASN1_DER, object, BUILD_END);
-				if (this->public_key == NULL)
+				if (!this->public_key)
 				{
 					goto end;
 				}
@@ -441,7 +432,12 @@ static bool parse_certificate_request(private_x509_pkcs10_t *this)
 				}
 				break;
 			case PKCS10_ALGORITHM:
-				this->algorithm = asn1_parse_algorithmIdentifier(object, level, NULL);
+				INIT(this->scheme);
+				if (!signature_params_parse(object, level, this->scheme))
+				{
+					DBG1(DBG_ASN, "  unable to parse signature algorithm");
+					goto end;
+				}
 				break;
 			case PKCS10_SIGNATURE:
 				this->signature = chunk_skip(object, 1);
@@ -477,6 +473,7 @@ METHOD(certificate_t, destroy, void,
 	{
 		this->subjectAltNames->destroy_offset(this->subjectAltNames,
 									offsetof(identification_t, destroy));
+		signature_params_destroy(this->scheme);
 		DESTROY_IF(this->subject);
 		DESTROY_IF(this->public_key);
 		chunk_free(&this->encoding);
@@ -533,25 +530,34 @@ static bool generate(private_x509_pkcs10_t *cert, private_key_t *sign_key,
 {
 	chunk_t key_info, subjectAltNames, attributes;
 	chunk_t extensionRequest  = chunk_empty;
-	chunk_t challengePassword = chunk_empty;
-	signature_scheme_t scheme;
+	chunk_t challengePassword = chunk_empty, sig_scheme = chunk_empty;
 	identification_t *subject;
 
 	subject = cert->subject;
 	cert->public_key = sign_key->get_public_key(sign_key);
 
-	/* select signature scheme */
-	cert->algorithm = hasher_signature_algorithm_to_oid(digest_alg,
-									sign_key->get_type(sign_key));
-	if (cert->algorithm == OID_UNKNOWN)
+	/* select signature scheme, if not already specified */
+	if (!cert->scheme)
+	{
+		INIT(cert->scheme,
+			.scheme = signature_scheme_from_oid(
+								hasher_signature_algorithm_to_oid(digest_alg,
+												sign_key->get_type(sign_key))),
+		);
+	}
+	if (cert->scheme->scheme == SIGN_UNKNOWN)
+	{
+		return FALSE;
+	}
+	if (!signature_params_build(cert->scheme, &sig_scheme))
 	{
 		return FALSE;
 	}
-	scheme = signature_scheme_from_oid(cert->algorithm);
 
 	if (!cert->public_key->get_encoding(cert->public_key,
 										PUBKEY_SPKI_ASN1_DER, &key_info))
 	{
+		chunk_free(&sig_scheme);
 		return FALSE;
 	}
 
@@ -587,15 +593,16 @@ static bool generate(private_x509_pkcs10_t *cert, private_key_t *sign_key,
 							key_info,
 							attributes);
 
-	if (!sign_key->sign(sign_key, scheme, NULL, cert->certificationRequestInfo,
-						&cert->signature))
+	if (!sign_key->sign(sign_key, cert->scheme->scheme, cert->scheme->params,
+						cert->certificationRequestInfo, &cert->signature))
 	{
+		chunk_free(&sig_scheme);
 		return FALSE;
 	}
 
 	cert->encoding = asn1_wrap(ASN1_SEQUENCE, "cmm",
 							   cert->certificationRequestInfo,
-							   asn1_algorithmIdentifier(cert->algorithm),
+							   sig_scheme,
 							   asn1_bitstring("c", cert->signature));
 	return TRUE;
 }
@@ -677,6 +684,10 @@ x509_pkcs10_t *x509_pkcs10_gen(certificate_type_t type, va_list args)
 			case BUILD_CHALLENGE_PWD:
 				cert->challengePassword = chunk_clone(va_arg(args, chunk_t));
 				continue;
+			case BUILD_SIGNATURE_SCHEME:
+				cert->scheme = va_arg(args, signature_params_t*);
+				cert->scheme = signature_params_clone(cert->scheme);
+				continue;
 			case BUILD_DIGEST_ALG:
 				digest_alg = va_arg(args, int);
 				continue;