Add a payload.get_header_length() method, remove header length definitions

41 files changed, 196 insertions, 164 deletions

diff --git a/src/libcharon/encoding/payloads/auth_payload.c b/src/libcharon/encoding/payloads/auth_payload.c
index 3825244e2..57dc58f2a 100644
--- a/src/libcharon/encoding/payloads/auth_payload.c
+++ b/src/libcharon/encoding/payloads/auth_payload.c
@@ -126,6 +126,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_auth_payload_t *this)
+{
+	return 8;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_auth_payload_t *this)
 {
@@ -167,7 +173,7 @@ METHOD(auth_payload_t, set_data, void,
 {
 	free(this->auth_data.ptr);
 	this->auth_data = chunk_clone(data);
-	this->payload_length = AUTH_PAYLOAD_HEADER_LENGTH + this->auth_data.len;
+	this->payload_length = get_header_length(this) + this->auth_data.len;
 }
 
 METHOD(auth_payload_t, get_data, chunk_t,
@@ -195,6 +201,7 @@ auth_payload_t *auth_payload_create()
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -208,7 +215,7 @@ auth_payload_t *auth_payload_create()
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = AUTH_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 	);
 	return &this->public;
 }
diff --git a/src/libcharon/encoding/payloads/auth_payload.h b/src/libcharon/encoding/payloads/auth_payload.h
index e4c4e6ae3..521fe1d19 100644
--- a/src/libcharon/encoding/payloads/auth_payload.h
+++ b/src/libcharon/encoding/payloads/auth_payload.h
@@ -29,11 +29,6 @@ typedef struct auth_payload_t auth_payload_t;
 #include <sa/authenticators/authenticator.h>
 
 /**
- * Length of a auth payload without the auth data in bytes.
- */
-#define AUTH_PAYLOAD_HEADER_LENGTH 8
-
-/**
  * Class representing an IKEv2 AUTH payload.
  *
  * The AUTH payload format is described in RFC section 3.8.
diff --git a/src/libcharon/encoding/payloads/cert_payload.c b/src/libcharon/encoding/payloads/cert_payload.c
index 8f6deb89c..565be7f34 100644
--- a/src/libcharon/encoding/payloads/cert_payload.c
+++ b/src/libcharon/encoding/payloads/cert_payload.c
@@ -173,6 +173,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_cert_payload_t *this)
+{
+	return 5;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_cert_payload_t *this)
 {
@@ -270,6 +276,7 @@ cert_payload_t *cert_payload_create()
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -283,7 +290,7 @@ cert_payload_t *cert_payload_create()
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = CERT_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 	);
 	return &this->public;
 }
@@ -312,7 +319,7 @@ cert_payload_t *cert_payload_create_from_cert(certificate_t *cert)
 		free(this);
 		return NULL;
 	}
-	this->payload_length = CERT_PAYLOAD_HEADER_LENGTH + this->data.len;
+	this->payload_length = get_header_length(this) + this->data.len;
 	return &this->public;
 }
 
@@ -325,7 +332,7 @@ cert_payload_t *cert_payload_create_from_hash_and_url(chunk_t hash, char *url)
 
 	this->encoding = ENC_X509_HASH_AND_URL;
 	this->data = chunk_cat("cc", hash, chunk_create(url, strlen(url)));
-	this->payload_length = CERT_PAYLOAD_HEADER_LENGTH + this->data.len;
+	this->payload_length = get_header_length(this) + this->data.len;
 	return &this->public;
 }
 
@@ -338,6 +345,6 @@ cert_payload_t *cert_payload_create_custom(cert_encoding_t type, chunk_t data)
 
 	this->encoding = type;
 	this->data = data;
-	this->payload_length = CERT_PAYLOAD_HEADER_LENGTH + this->data.len;
+	this->payload_length = get_header_length(this) + this->data.len;
 	return &this->public;
 }
diff --git a/src/libcharon/encoding/payloads/cert_payload.h b/src/libcharon/encoding/payloads/cert_payload.h
index 21b503a40..6eb79c8ed 100644
--- a/src/libcharon/encoding/payloads/cert_payload.h
+++ b/src/libcharon/encoding/payloads/cert_payload.h
@@ -31,11 +31,6 @@ typedef enum cert_encoding_t cert_encoding_t;
 #include <encoding/payloads/payload.h>
 
 /**
- * Length of a cert payload without the cert data in bytes.
- */
-#define CERT_PAYLOAD_HEADER_LENGTH 5
-
-/**
  * Certifcate encodings, as in RFC4306
  */
 enum cert_encoding_t {
diff --git a/src/libcharon/encoding/payloads/certreq_payload.c b/src/libcharon/encoding/payloads/certreq_payload.c
index ec46e9277..dc685e651 100644
--- a/src/libcharon/encoding/payloads/certreq_payload.c
+++ b/src/libcharon/encoding/payloads/certreq_payload.c
@@ -129,6 +129,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_certreq_payload_t *this)
+{
+	return 5;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_certreq_payload_t *this)
 {
@@ -241,6 +247,7 @@ certreq_payload_t *certreq_payload_create()
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -253,7 +260,7 @@ certreq_payload_t *certreq_payload_create()
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = CERTREQ_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 	);
 	return &this->public;
 }
diff --git a/src/libcharon/encoding/payloads/certreq_payload.h b/src/libcharon/encoding/payloads/certreq_payload.h
index 914063628..421ad6d58 100644
--- a/src/libcharon/encoding/payloads/certreq_payload.h
+++ b/src/libcharon/encoding/payloads/certreq_payload.h
@@ -29,11 +29,6 @@ typedef struct certreq_payload_t certreq_payload_t;
 #include <encoding/payloads/cert_payload.h>
 
 /**
- * Length of a CERTREQ payload without the CERTREQ data in bytes.
- */
-#define CERTREQ_PAYLOAD_HEADER_LENGTH 5
-
-/**
  * Class representing an IKEv2 CERTREQ payload.
  *
  * The CERTREQ payload format is described in RFC section 3.7.
diff --git a/src/libcharon/encoding/payloads/configuration_attribute.c b/src/libcharon/encoding/payloads/configuration_attribute.c
index a657ef13a..8746b9b9e 100644
--- a/src/libcharon/encoding/payloads/configuration_attribute.c
+++ b/src/libcharon/encoding/payloads/configuration_attribute.c
@@ -161,6 +161,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_configuration_attribute_t *this)
+{
+	return 4;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_configuration_attribute_t *this)
 {
@@ -181,7 +187,7 @@ METHOD(payload_t, set_next_type, void,
 METHOD(payload_t, get_length, size_t,
 	private_configuration_attribute_t *this)
 {
-	return this->value.len + CONFIGURATION_ATTRIBUTE_HEADER_LENGTH;
+	return get_header_length(this) + this->value.len;
 }
 
 METHOD(configuration_attribute_t, get_cattr_type, configuration_attribute_type_t,
@@ -215,6 +221,7 @@ configuration_attribute_t *configuration_attribute_create()
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
diff --git a/src/libcharon/encoding/payloads/configuration_attribute.h b/src/libcharon/encoding/payloads/configuration_attribute.h
index 6e4b018bb..e216ee366 100644
--- a/src/libcharon/encoding/payloads/configuration_attribute.h
+++ b/src/libcharon/encoding/payloads/configuration_attribute.h
@@ -29,11 +29,6 @@ typedef struct configuration_attribute_t configuration_attribute_t;
 #include <encoding/payloads/payload.h>
 
 /**
- * Configuration attribute header length in bytes.
- */
-#define CONFIGURATION_ATTRIBUTE_HEADER_LENGTH 4
-
-/**
  * Class representing an IKEv2-CONFIGURATION Attribute.
  *
  * The CONFIGURATION ATTRIBUTE format is described in RFC section 3.15.1.
diff --git a/src/libcharon/encoding/payloads/cp_payload.c b/src/libcharon/encoding/payloads/cp_payload.c
index 4e782dd88..05f16c33f 100644
--- a/src/libcharon/encoding/payloads/cp_payload.c
+++ b/src/libcharon/encoding/payloads/cp_payload.c
@@ -149,6 +149,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_cp_payload_t *this)
+{
+	return 8;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_cp_payload_t *this)
 {
@@ -175,7 +181,7 @@ static void compute_length(private_cp_payload_t *this)
 	enumerator_t *enumerator;
 	payload_t *attribute;
 
-	this->payload_length = CP_PAYLOAD_HEADER_LENGTH;
+	this->payload_length = get_header_length(this);
 
 	enumerator = this->attributes->create_enumerator(this->attributes);
 	while (enumerator->enumerate(enumerator, &attribute))
@@ -230,6 +236,7 @@ cp_payload_t *cp_payload_create_type(config_type_t type)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -242,7 +249,7 @@ cp_payload_t *cp_payload_create_type(config_type_t type)
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = CP_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 		.attributes = linked_list_create(),
 		.type = type,
 	);
diff --git a/src/libcharon/encoding/payloads/cp_payload.h b/src/libcharon/encoding/payloads/cp_payload.h
index afae6091a..bc6bdee50 100644
--- a/src/libcharon/encoding/payloads/cp_payload.h
+++ b/src/libcharon/encoding/payloads/cp_payload.h
@@ -31,11 +31,6 @@ typedef struct cp_payload_t cp_payload_t;
 #include <utils/enumerator.h>
 
 /**
- * CP_PAYLOAD length in bytes without any proposal substructure.
- */
-#define CP_PAYLOAD_HEADER_LENGTH 8
-
-/**
  * Config Type of an Configuration Payload.
  */
 enum config_type_t {
diff --git a/src/libcharon/encoding/payloads/delete_payload.c b/src/libcharon/encoding/payloads/delete_payload.c
index b396135be..5f0af8c86 100644
--- a/src/libcharon/encoding/payloads/delete_payload.c
+++ b/src/libcharon/encoding/payloads/delete_payload.c
@@ -152,6 +152,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_delete_payload_t *this)
+{
+	return 8;
+}
+
 METHOD(payload_t, get_payload_type, payload_type_t,
 	private_delete_payload_t *this)
 {
@@ -258,6 +264,7 @@ delete_payload_t *delete_payload_create(protocol_id_t protocol_id)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -270,7 +277,7 @@ delete_payload_t *delete_payload_create(protocol_id_t protocol_id)
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = DELETE_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 		.protocol_id = protocol_id,
 		.spi_size = protocol_id == PROTO_AH || protocol_id == PROTO_ESP ? 4 : 0,
 	);
diff --git a/src/libcharon/encoding/payloads/delete_payload.h b/src/libcharon/encoding/payloads/delete_payload.h
index 026829f97..ebafe04fb 100644
--- a/src/libcharon/encoding/payloads/delete_payload.h
+++ b/src/libcharon/encoding/payloads/delete_payload.h
@@ -29,11 +29,6 @@ typedef struct delete_payload_t delete_payload_t;
 #include <encoding/payloads/proposal_substructure.h>
 
 /**
- * Length of a delete payload without the SPI in bytes.
- */
-#define DELETE_PAYLOAD_HEADER_LENGTH 8
-
-/**
  * Class representing an IKEv2 DELETE payload.
  *
  * The DELETE payload format is described in RFC section 3.11.
diff --git a/src/libcharon/encoding/payloads/eap_payload.c b/src/libcharon/encoding/payloads/eap_payload.c
index 581547499..47a9b1673 100644
--- a/src/libcharon/encoding/payloads/eap_payload.c
+++ b/src/libcharon/encoding/payloads/eap_payload.c
@@ -150,6 +150,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_eap_payload_t *this)
+{
+	return 4;
+}
+
 METHOD(payload_t, get_payload_type, payload_type_t,
 	private_eap_payload_t *this)
 {
@@ -251,6 +257,7 @@ eap_payload_t *eap_payload_create()
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -265,7 +272,7 @@ eap_payload_t *eap_payload_create()
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = EAP_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 	);
 	return &this->public;
 }
diff --git a/src/libcharon/encoding/payloads/eap_payload.h b/src/libcharon/encoding/payloads/eap_payload.h
index 60d9c99d2..e63db7d88 100644
--- a/src/libcharon/encoding/payloads/eap_payload.h
+++ b/src/libcharon/encoding/payloads/eap_payload.h
@@ -29,11 +29,6 @@ typedef struct eap_payload_t eap_payload_t;
 #include <sa/authenticators/eap/eap_method.h>
 
 /**
- * Length of a EAP payload without the EAP Message in bytes.
- */
-#define EAP_PAYLOAD_HEADER_LENGTH 4
-
-/**
  * Class representing an IKEv2 EAP payload.
  *
  * The EAP payload format is described in RFC section 3.16.
diff --git a/src/libcharon/encoding/payloads/encryption_payload.c b/src/libcharon/encoding/payloads/encryption_payload.c
index b0b863b36..08c64fb51 100644
--- a/src/libcharon/encoding/payloads/encryption_payload.c
+++ b/src/libcharon/encoding/payloads/encryption_payload.c
@@ -122,6 +122,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_encryption_payload_t *this)
+{
+	return 4;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_encryption_payload_t *this)
 {
@@ -173,7 +179,7 @@ static void compute_length(private_encryption_payload_t *this)
 			length += this->aead->get_icv_size(this->aead);
 		}
 	}
-	length += ENCRYPTION_PAYLOAD_HEADER_LENGTH;
+	length += get_header_length(this);
 	this->payload_length = length;
 }
 
@@ -463,6 +469,7 @@ encryption_payload_t *encryption_payload_create()
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -478,7 +485,7 @@ encryption_payload_t *encryption_payload_create()
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = ENCRYPTION_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 		.payloads = linked_list_create(),
 	);
 
diff --git a/src/libcharon/encoding/payloads/encryption_payload.h b/src/libcharon/encoding/payloads/encryption_payload.h
index e99c42fb7..3cdc54b37 100644
--- a/src/libcharon/encoding/payloads/encryption_payload.h
+++ b/src/libcharon/encoding/payloads/encryption_payload.h
@@ -30,11 +30,6 @@ typedef struct encryption_payload_t encryption_payload_t;
 #include <encoding/payloads/payload.h>
 
 /**
- * Encrpytion payload length in bytes without IV and following data.
- */
-#define ENCRYPTION_PAYLOAD_HEADER_LENGTH 4
-
-/**
  * The encryption payload as described in RFC section 3.14.
  */
 struct encryption_payload_t {
diff --git a/src/libcharon/encoding/payloads/id_payload.c b/src/libcharon/encoding/payloads/id_payload.c
index 1d42f1595..b94c72b60 100644
--- a/src/libcharon/encoding/payloads/id_payload.c
+++ b/src/libcharon/encoding/payloads/id_payload.c
@@ -141,6 +141,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_id_payload_t *this)
+{
+	return 8;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_id_payload_t *this)
 {
@@ -190,6 +196,7 @@ id_payload_t *id_payload_create(payload_type_t payload_type)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -200,7 +207,7 @@ id_payload_t *id_payload_create(payload_type_t payload_type)
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = ID_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 		.payload_type = payload_type,
 	);
 	return &this->public;
diff --git a/src/libcharon/encoding/payloads/id_payload.h b/src/libcharon/encoding/payloads/id_payload.h
index 99831f85f..c24b8ffc6 100644
--- a/src/libcharon/encoding/payloads/id_payload.h
+++ b/src/libcharon/encoding/payloads/id_payload.h
@@ -30,11 +30,6 @@ typedef struct id_payload_t id_payload_t;
 #include <encoding/payloads/payload.h>
 
 /**
- * Length of a id payload without the data in bytes.
- */
-#define ID_PAYLOAD_HEADER_LENGTH 8
-
-/**
  * Object representing an IKEv2 ID payload.
  *
  * The ID payload format is described in RFC section 3.5.
diff --git a/src/libcharon/encoding/payloads/ike_header.c b/src/libcharon/encoding/payloads/ike_header.c
index 97c6d8c26..54e04658c 100644
--- a/src/libcharon/encoding/payloads/ike_header.c
+++ b/src/libcharon/encoding/payloads/ike_header.c
@@ -251,6 +251,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_ike_header_t *this)
+{
+	return IKE_HEADER_LENGTH;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_ike_header_t *this)
 {
@@ -438,6 +444,7 @@ ike_header_t *ike_header_create()
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
diff --git a/src/libcharon/encoding/payloads/ke_payload.c b/src/libcharon/encoding/payloads/ke_payload.c
index 183e722a2..a6e5217aa 100644
--- a/src/libcharon/encoding/payloads/ke_payload.c
+++ b/src/libcharon/encoding/payloads/ke_payload.c
@@ -157,6 +157,16 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings_v1);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_ke_payload_t *this)
+{
+	if (this->type == KEY_EXCHANGE)
+	{
+		return 8;
+	}
+	return 4;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_ke_payload_t *this)
 {
@@ -212,6 +222,7 @@ ke_payload_t *ke_payload_create(payload_type_t type)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -223,14 +234,10 @@ ke_payload_t *ke_payload_create(payload_type_t type)
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = KE_PAYLOAD_HEADER_LENGTH,
 		.dh_group_number = MODP_NONE,
 		.type = type,
 	);
-	if (type == KEY_EXCHANGE_V1)
-	{
-		this->payload_length = KE_PAYLOAD_V1_HEADER_LENGTH;
-	}
+	this->payload_length = get_header_length(this);
 	return &this->public;
 }
 
diff --git a/src/libcharon/encoding/payloads/ke_payload.h b/src/libcharon/encoding/payloads/ke_payload.h
index c448ceff6..5942954d9 100644
--- a/src/libcharon/encoding/payloads/ke_payload.h
+++ b/src/libcharon/encoding/payloads/ke_payload.h
@@ -31,16 +31,6 @@ typedef struct ke_payload_t ke_payload_t;
 #include <crypto/diffie_hellman.h>
 
 /**
- * KE payload length in bytes without any key exchange data (IKEv2).
- */
-#define KE_PAYLOAD_HEADER_LENGTH 8
-
-/**
- * KE payload length in bytes without any key exchange data (IKEv1).
- */
-#define KE_PAYLOAD_V1_HEADER_LENGTH 4
-
-/**
  * Class representing an IKEv1 or IKEv2 key exchange payload.
  */
 struct ke_payload_t {
diff --git a/src/libcharon/encoding/payloads/nonce_payload.c b/src/libcharon/encoding/payloads/nonce_payload.c
index 86222c13a..1e0cf5579 100644
--- a/src/libcharon/encoding/payloads/nonce_payload.c
+++ b/src/libcharon/encoding/payloads/nonce_payload.c
@@ -117,6 +117,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_nonce_payload_t *this)
+{
+	return 4;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_nonce_payload_t *this)
 {
@@ -145,7 +151,7 @@ METHOD(nonce_payload_t, set_nonce, void,
 	 private_nonce_payload_t *this, chunk_t nonce)
 {
 	this->nonce = chunk_clone(nonce);
-	this->payload_length = NONCE_PAYLOAD_HEADER_LENGTH + nonce.len;
+	this->payload_length = get_header_length(this) + nonce.len;
 }
 
 METHOD(nonce_payload_t, get_nonce, chunk_t,
@@ -173,6 +179,7 @@ nonce_payload_t *nonce_payload_create(payload_type_t type)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -184,7 +191,7 @@ nonce_payload_t *nonce_payload_create(payload_type_t type)
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = NONCE_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 		.type = type,
 	);
 	return &this->public;
diff --git a/src/libcharon/encoding/payloads/nonce_payload.h b/src/libcharon/encoding/payloads/nonce_payload.h
index 3be2e2e13..5c47f5f9f 100644
--- a/src/libcharon/encoding/payloads/nonce_payload.h
+++ b/src/libcharon/encoding/payloads/nonce_payload.h
@@ -33,11 +33,6 @@ typedef struct nonce_payload_t nonce_payload_t;
 #define NONCE_SIZE 32
 
 /**
- * Length of a nonce payload without a nonce in bytes.
- */
-#define NONCE_PAYLOAD_HEADER_LENGTH 4
-
-/**
  * Object representing an IKEv1/IKEv2 Nonce payload.
  */
 struct nonce_payload_t {
diff --git a/src/libcharon/encoding/payloads/notify_payload.c b/src/libcharon/encoding/payloads/notify_payload.c
index d8f45b9b4..f2e1267c6 100644
--- a/src/libcharon/encoding/payloads/notify_payload.c
+++ b/src/libcharon/encoding/payloads/notify_payload.c
@@ -430,6 +430,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_notify_payload_t *this)
+{
+	return 8 + this->spi_size;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_notify_payload_t *this)
 {
@@ -451,19 +457,9 @@ METHOD(payload_t, set_next_type, void,
 /**
  * recompute the payloads length.
  */
-static void compute_length (private_notify_payload_t *this)
+static void compute_length(private_notify_payload_t *this)
 {
-	size_t length = NOTIFY_PAYLOAD_HEADER_LENGTH;
-
-	if (this->notification_data.ptr != NULL)
-	{
-		length += this->notification_data.len;
-	}
-	if (this->spi.ptr != NULL)
-	{
-		length += this->spi.len;
-	}
-	this->payload_length = length;
+	this->payload_length = get_header_length(this) + this->notification_data.len;
 }
 
 METHOD(payload_t, get_length, size_t,
@@ -565,6 +561,7 @@ notify_payload_t *notify_payload_create()
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -582,8 +579,8 @@ notify_payload_t *notify_payload_create()
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = NOTIFY_PAYLOAD_HEADER_LENGTH,
 	);
+	compute_length(this);
 	return &this->public;
 }
 
diff --git a/src/libcharon/encoding/payloads/notify_payload.h b/src/libcharon/encoding/payloads/notify_payload.h
index 35feb4871..91a3cac0f 100644
--- a/src/libcharon/encoding/payloads/notify_payload.h
+++ b/src/libcharon/encoding/payloads/notify_payload.h
@@ -33,11 +33,6 @@ typedef struct notify_payload_t notify_payload_t;
 #include <utils/linked_list.h>
 
 /**
- * Notify payload length in bytes without any spi and notification data.
- */
-#define NOTIFY_PAYLOAD_HEADER_LENGTH 8
-
-/**
  * Notify message types.
  *
  * See IKEv2 RFC 3.10.1.
diff --git a/src/libcharon/encoding/payloads/payload.h b/src/libcharon/encoding/payloads/payload.h
index 963c5f090..0060e3730 100644
--- a/src/libcharon/encoding/payloads/payload.h
+++ b/src/libcharon/encoding/payloads/payload.h
@@ -277,6 +277,13 @@ struct payload_t {
 	int (*get_encoding_rules) (payload_t *this, encoding_rule_t **rules);
 
 	/**
+	 * Get non-variable header length for a variable length payload.
+	 *
+	 * @return				fixed length of the payload
+	 */
+	int (*get_header_length)(payload_t *this);
+
+	/**
 	 * Get type of payload.
 	 *
 	 * @return 				type of this payload
diff --git a/src/libcharon/encoding/payloads/proposal_substructure.c b/src/libcharon/encoding/payloads/proposal_substructure.c
index 3b663da86..16d5794ae 100644
--- a/src/libcharon/encoding/payloads/proposal_substructure.c
+++ b/src/libcharon/encoding/payloads/proposal_substructure.c
@@ -308,6 +308,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings_v1);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_proposal_substructure_t *this)
+{
+	return 8 + this->spi_size;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_proposal_substructure_t *this)
 {
@@ -334,7 +340,7 @@ static void compute_length(private_proposal_substructure_t *this)
 	payload_t *transform;
 
 	this->transforms_count = 0;
-	this->proposal_length = PROPOSAL_SUBSTRUCTURE_HEADER_LENGTH + this->spi.len;
+	this->proposal_length = get_header_length(this);
 	enumerator = this->transforms->create_enumerator(this->transforms);
 	while (enumerator->enumerate(enumerator, &transform))
 	{
@@ -692,6 +698,7 @@ proposal_substructure_t *proposal_substructure_create(payload_type_t type)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -710,10 +717,10 @@ proposal_substructure_t *proposal_substructure_create(payload_type_t type)
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.proposal_length = PROPOSAL_SUBSTRUCTURE_HEADER_LENGTH,
 		.transforms = linked_list_create(),
 		.type = type,
 	);
+	compute_length(this);
 
 	return &this->public;
 }
diff --git a/src/libcharon/encoding/payloads/proposal_substructure.h b/src/libcharon/encoding/payloads/proposal_substructure.h
index 86ccd5b8b..72bbdd64f 100644
--- a/src/libcharon/encoding/payloads/proposal_substructure.h
+++ b/src/libcharon/encoding/payloads/proposal_substructure.h
@@ -30,12 +30,6 @@ typedef struct proposal_substructure_t proposal_substructure_t;
 #include <config/proposal.h>
 #include <utils/linked_list.h>
 
-
-/**
- * Length of the proposal substructure header (without spi).
- */
-#define PROPOSAL_SUBSTRUCTURE_HEADER_LENGTH 8
-
 /**
  * Class representing an IKEv1/IKEv2 proposal substructure.
  */
diff --git a/src/libcharon/encoding/payloads/sa_payload.c b/src/libcharon/encoding/payloads/sa_payload.c
index 32251e28b..66e994b43 100644
--- a/src/libcharon/encoding/payloads/sa_payload.c
+++ b/src/libcharon/encoding/payloads/sa_payload.c
@@ -214,6 +214,16 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings_v2);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_sa_payload_t *this)
+{
+	if (this->type == SECURITY_ASSOCIATION_V1)
+	{
+		return 12;
+	}
+	return 4;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_sa_payload_t *this)
 {
@@ -239,21 +249,15 @@ static void compute_length(private_sa_payload_t *this)
 {
 	enumerator_t *enumerator;
 	payload_t *current;
-	size_t length = SA_PAYLOAD_HEADER_LENGTH;
 
-	if (this->type == SECURITY_ASSOCIATION_V1)
-	{
-		length = SA_PAYLOAD_V1_HEADER_LENGTH;
-	}
+	this->payload_length = get_header_length(this);
 
 	enumerator = this->proposals->create_enumerator(this->proposals);
 	while (enumerator->enumerate(enumerator, (void **)&current))
 	{
-		length += current->get_length(current);
+		this->payload_length += current->get_length(current);
 	}
 	enumerator->destroy(enumerator);
-
-	this->payload_length = length;
 }
 
 METHOD(payload_t, get_length, size_t,
@@ -367,6 +371,7 @@ sa_payload_t *sa_payload_create(payload_type_t type)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
diff --git a/src/libcharon/encoding/payloads/sa_payload.h b/src/libcharon/encoding/payloads/sa_payload.h
index 11fc774e5..16d462e65 100644
--- a/src/libcharon/encoding/payloads/sa_payload.h
+++ b/src/libcharon/encoding/payloads/sa_payload.h
@@ -30,16 +30,6 @@ typedef struct sa_payload_t sa_payload_t;
 #include <utils/linked_list.h>
 
 /**
- * SECURITY_ASSOCIATION length in bytes without any proposal substructure.
- */
-#define SA_PAYLOAD_HEADER_LENGTH 4
-
-/**
- * SECURITY_ASSOCIATION_V1 length in bytes without any proposal substructure.
- */
-#define SA_PAYLOAD_V1_HEADER_LENGTH 12
-
-/**
  * Class representing an IKEv1 or IKEv2 SA Payload.
  *
  * The SA Payload format is described in RFC section 3.3.
diff --git a/src/libcharon/encoding/payloads/traffic_selector_substructure.c b/src/libcharon/encoding/payloads/traffic_selector_substructure.c
index c213441ab..378f5bbc3 100644
--- a/src/libcharon/encoding/payloads/traffic_selector_substructure.c
+++ b/src/libcharon/encoding/payloads/traffic_selector_substructure.c
@@ -155,6 +155,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_traffic_selector_substructure_t *this)
+{
+	return 8;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_traffic_selector_substructure_t *this)
 {
@@ -207,6 +213,7 @@ traffic_selector_substructure_t *traffic_selector_substructure_create()
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -216,7 +223,7 @@ traffic_selector_substructure_t *traffic_selector_substructure_create()
 			.get_traffic_selector = _get_traffic_selector,
 			.destroy = _destroy,
 		},
-		.payload_length = TRAFFIC_SELECTOR_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 		/* must be set to be valid */
 		.ts_type = TS_IPV4_ADDR_RANGE,
 	);
@@ -238,7 +245,7 @@ traffic_selector_substructure_t *traffic_selector_substructure_create_from_traff
 	this->end_port = ts->get_to_port(ts);
 	this->starting_address = chunk_clone(ts->get_from_address(ts));
 	this->ending_address = chunk_clone(ts->get_to_address(ts));
-	this->payload_length = TRAFFIC_SELECTOR_HEADER_LENGTH +
+	this->payload_length = get_header_length(this) +
 						this->ending_address.len + this->starting_address.len;
 
 	return &this->public;
diff --git a/src/libcharon/encoding/payloads/traffic_selector_substructure.h b/src/libcharon/encoding/payloads/traffic_selector_substructure.h
index 0109fd7f5..1ad5fb526 100644
--- a/src/libcharon/encoding/payloads/traffic_selector_substructure.h
+++ b/src/libcharon/encoding/payloads/traffic_selector_substructure.h
@@ -30,11 +30,6 @@ typedef struct traffic_selector_substructure_t traffic_selector_substructure_t;
 #include <encoding/payloads/payload.h>
 
 /**
- * Length of a TRAFFIC SELECTOR SUBSTRUCTURE without start and end address.
- */
-#define TRAFFIC_SELECTOR_HEADER_LENGTH 8
-
-/**
  * Class representing an IKEv2 TRAFFIC SELECTOR.
  *
  * The TRAFFIC SELECTOR format is described in RFC section 3.13.1.
diff --git a/src/libcharon/encoding/payloads/transform_attribute.c b/src/libcharon/encoding/payloads/transform_attribute.c
index fa344019b..474362fca 100644
--- a/src/libcharon/encoding/payloads/transform_attribute.c
+++ b/src/libcharon/encoding/payloads/transform_attribute.c
@@ -141,6 +141,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_transform_attribute_t *this)
+{
+	return 0;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_transform_attribute_t *this)
 {
@@ -258,6 +264,7 @@ transform_attribute_t *transform_attribute_create(payload_type_t type)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
diff --git a/src/libcharon/encoding/payloads/transform_substructure.c b/src/libcharon/encoding/payloads/transform_substructure.c
index da022ca75..63464e9f3 100644
--- a/src/libcharon/encoding/payloads/transform_substructure.c
+++ b/src/libcharon/encoding/payloads/transform_substructure.c
@@ -174,6 +174,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings_v1);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_transform_substructure_t *this)
+{
+	return 8;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_transform_substructure_t *this)
 {
@@ -194,7 +200,7 @@ static void compute_length(private_transform_substructure_t *this)
 	enumerator_t *enumerator;
 	payload_t *attribute;
 
-	this->transform_length = TRANSFORM_SUBSTRUCTURE_HEADER_LENGTH;
+	this->transform_length = get_header_length(this);
 	enumerator = this->attributes->create_enumerator(this->attributes);
 	while (enumerator->enumerate(enumerator, &attribute))
 	{
@@ -269,6 +275,7 @@ transform_substructure_t *transform_substructure_create(payload_type_t type)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -283,7 +290,7 @@ transform_substructure_t *transform_substructure_create(payload_type_t type)
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.transform_length = TRANSFORM_SUBSTRUCTURE_HEADER_LENGTH,
+		.transform_length = get_header_length(this),
 		.attributes = linked_list_create(),
 		.type = type,
 	);
diff --git a/src/libcharon/encoding/payloads/transform_substructure.h b/src/libcharon/encoding/payloads/transform_substructure.h
index 7b1071275..947df24f9 100644
--- a/src/libcharon/encoding/payloads/transform_substructure.h
+++ b/src/libcharon/encoding/payloads/transform_substructure.h
@@ -40,11 +40,6 @@ typedef struct transform_substructure_t transform_substructure_t;
 #define TRANSFORM_TYPE_VALUE 3
 
 /**
- * Length of the transform substructure header in bytes.
- */
-#define TRANSFORM_SUBSTRUCTURE_HEADER_LENGTH 8
-
-/**
  * Class representing an IKEv1/IKEv2 transform substructure.
  */
 struct transform_substructure_t {
diff --git a/src/libcharon/encoding/payloads/ts_payload.c b/src/libcharon/encoding/payloads/ts_payload.c
index 8f4508a9c..df47b8892 100644
--- a/src/libcharon/encoding/payloads/ts_payload.c
+++ b/src/libcharon/encoding/payloads/ts_payload.c
@@ -152,6 +152,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_ts_payload_t *this)
+{
+	return 8;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_ts_payload_t *this)
 {
@@ -182,7 +188,7 @@ static void compute_length(private_ts_payload_t *this)
 	enumerator_t *enumerator;
 	payload_t *subst;
 
-	this->payload_length = TS_PAYLOAD_HEADER_LENGTH;
+	this->payload_length = get_header_length(this);
 	this->ts_num = 0;
 	enumerator = this->substrs->create_enumerator(this->substrs);
 	while (enumerator->enumerate(enumerator, &subst))
@@ -250,6 +256,7 @@ ts_payload_t *ts_payload_create(bool is_initiator)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -262,7 +269,7 @@ ts_payload_t *ts_payload_create(bool is_initiator)
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = TS_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 		.is_initiator = is_initiator,
 		.substrs = linked_list_create(),
 	);
diff --git a/src/libcharon/encoding/payloads/ts_payload.h b/src/libcharon/encoding/payloads/ts_payload.h
index 88ca00bc9..5a92655dc 100644
--- a/src/libcharon/encoding/payloads/ts_payload.h
+++ b/src/libcharon/encoding/payloads/ts_payload.h
@@ -31,11 +31,6 @@ typedef struct ts_payload_t ts_payload_t;
 #include <encoding/payloads/traffic_selector_substructure.h>
 
 /**
- * Length of a TS payload without the Traffic selectors.
- */
-#define TS_PAYLOAD_HEADER_LENGTH 8
-
-/**
  * Class representing an IKEv2 TS payload.
  *
  * The TS payload format is described in RFC section 3.13.
diff --git a/src/libcharon/encoding/payloads/unknown_payload.c b/src/libcharon/encoding/payloads/unknown_payload.c
index 9f5c6ef98..29dfa9da4 100644
--- a/src/libcharon/encoding/payloads/unknown_payload.c
+++ b/src/libcharon/encoding/payloads/unknown_payload.c
@@ -102,10 +102,6 @@ static encoding_rule_t encodings[] = {
 METHOD(payload_t, verify, status_t,
 	private_unknown_payload_t *this)
 {
-	if (this->payload_length != UNKNOWN_PAYLOAD_HEADER_LENGTH + this->data.len)
-	{
-		return FAILED;
-	}
 	return SUCCESS;
 }
 
@@ -116,6 +112,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_unknown_payload_t *this)
+{
+	return 4;
+}
+
 METHOD(payload_t, get_payload_type, payload_type_t,
 	private_unknown_payload_t *this)
 {
@@ -171,6 +173,7 @@ unknown_payload_t *unknown_payload_create(payload_type_t type)
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -182,7 +185,7 @@ unknown_payload_t *unknown_payload_create(payload_type_t type)
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = UNKNOWN_PAYLOAD_HEADER_LENGTH,
+		.payload_length = get_header_length(this),
 		.type = type,
 	);
 
@@ -201,7 +204,7 @@ unknown_payload_t *unknown_payload_create_data(payload_type_t type,
 	this = (private_unknown_payload_t*)unknown_payload_create(type);
 	this->data = data;
 	this->critical = critical;
-	this->payload_length = UNKNOWN_PAYLOAD_HEADER_LENGTH + data.len;
+	this->payload_length = get_header_length(this) + data.len;
 
 	return &this->public;
 }
diff --git a/src/libcharon/encoding/payloads/unknown_payload.h b/src/libcharon/encoding/payloads/unknown_payload.h
index 5ae85331b..326b550cd 100644
--- a/src/libcharon/encoding/payloads/unknown_payload.h
+++ b/src/libcharon/encoding/payloads/unknown_payload.h
@@ -28,11 +28,6 @@ typedef struct unknown_payload_t unknown_payload_t;
 #include <encoding/payloads/payload.h>
 
 /**
- * Header length of the unknown payload.
- */
-#define UNKNOWN_PAYLOAD_HEADER_LENGTH 4
-
-/**
  * Payload which can't be processed further.
  *
  * When the parser finds an unknown payload, he builds an instance of
diff --git a/src/libcharon/encoding/payloads/vendor_id_payload.c b/src/libcharon/encoding/payloads/vendor_id_payload.c
index 45669879b..8a1d9970d 100644
--- a/src/libcharon/encoding/payloads/vendor_id_payload.c
+++ b/src/libcharon/encoding/payloads/vendor_id_payload.c
@@ -112,6 +112,12 @@ METHOD(payload_t, get_encoding_rules, int,
 	return countof(encodings);
 }
 
+METHOD(payload_t, get_header_length, int,
+	private_vendor_id_payload_t *this)
+{
+	return 4;
+}
+
 METHOD(payload_t, get_type, payload_type_t,
 	private_vendor_id_payload_t *this)
 {
@@ -162,6 +168,7 @@ vendor_id_payload_t *vendor_id_payload_create_data(payload_type_t type,
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
@@ -172,7 +179,7 @@ vendor_id_payload_t *vendor_id_payload_create_data(payload_type_t type,
 			.destroy = _destroy,
 		},
 		.next_payload = NO_PAYLOAD,
-		.payload_length = VENDOR_ID_PAYLOAD_HEADER_LENGTH + data.len,
+		.payload_length = get_header_length(this) + data.len,
 		.data = data,
 		.type = type,
 	);
diff --git a/src/libcharon/encoding/payloads/vendor_id_payload.h b/src/libcharon/encoding/payloads/vendor_id_payload.h
index 4943af436..9a814777b 100644
--- a/src/libcharon/encoding/payloads/vendor_id_payload.h
+++ b/src/libcharon/encoding/payloads/vendor_id_payload.h
@@ -28,11 +28,6 @@ typedef struct vendor_id_payload_t vendor_id_payload_t;
 #include <encoding/payloads/payload.h>
 
 /**
- * Length of a VENDOR ID payload without the VID data in bytes.
- */
-#define VENDOR_ID_PAYLOAD_HEADER_LENGTH 4
-
-/**
  * Class representing an IKEv1/IKEv2 VENDOR ID payload.
  *
  * The VENDOR ID payload format is described in RFC section 3.12.