diff --git a/src/wscutil.c b/src/wscutil.c
index e940bbe8..49c27acc 100644
--- a/src/wscutil.c
+++ b/src/wscutil.c
@@ -546,6 +546,8 @@ static attr_handler handler_for_type(enum wsc_attr type)
 	case WSC_ATTR_R_HASH1:
 	case WSC_ATTR_R_HASH2:
 		return extract_hash;
+	case WSC_ATTR_R_SNONCE1:
+		return extract_nonce;
 	case WSC_ATTR_SELECTED_REGISTRAR:
 		return extract_bool;
 	case WSC_ATTR_SELECTED_REGISTRAR_CONFIGURATION_METHODS:
@@ -1148,6 +1150,17 @@ int wsc_parse_m4(const uint8_t *pdu, uint32_t len, struct wsc_m4 *out,
 	return 0;
 }
 
+int wsc_parse_m4_encrypted_settings(const uint8_t *pdu, uint32_t len,
+					struct wsc_m4_encrypted_settings *out)
+{
+	memset(out, 0, sizeof(*out));
+
+	return wsc_parse_attrs(pdu, len, NULL, NULL,
+			WSC_ATTR_KEY_WRAP_AUTHENTICATOR, out->authenticator,
+			REQUIRED(R_SNONCE1, out->r_snonce1),
+			WSC_ATTR_INVALID);
+}
+
 int wsc_parse_m5(const uint8_t *pdu, uint32_t len, struct wsc_m5 *out,
 						struct iovec *out_encrypted)
 {
diff --git a/src/wscutil.h b/src/wscutil.h
index ca78f74a..632cba13 100644
--- a/src/wscutil.h
+++ b/src/wscutil.h
@@ -454,6 +454,11 @@ struct wsc_m4 {
 	uint8_t authenticator[8];
 };
 
+struct wsc_m4_encrypted_settings {
+	uint8_t r_snonce1[16];
+	uint8_t authenticator[8];
+};
+
 struct wsc_m5 {
 	bool version2;
 	uint8_t registrar_nonce[16];
@@ -479,6 +484,8 @@ int wsc_parse_m2(const uint8_t *pdu, uint32_t len, struct wsc_m2 *out);
 int wsc_parse_m3(const uint8_t *pdu, uint32_t len, struct wsc_m3 *out);
 int wsc_parse_m4(const uint8_t *pdu, uint32_t len, struct wsc_m4 *out,
 						struct iovec *out_encrypted);
+int wsc_parse_m4_encrypted_settings(const uint8_t *pdu, uint32_t len,
+					struct wsc_m4_encrypted_settings *out);
 int wsc_parse_m5(const uint8_t *pdu, uint32_t len, struct wsc_m5 *out,
 						struct iovec *out_encrypted);