pkcs10: Support of Microsoft CertTypeExtension

The msCertificateTypeExtension OID (1.3.6.1.4.1.311.20.2) can
be used in a PKCS#10 certificate request to define a certificate
profile. It consists of an UTF8 string.

pki: profile option

src/libstrongswan/credentials/builder.c

@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2008 Martin Willi
- * Copyright (C) 2016-2019 Andreas Steffen
+ * Copyright (C) 2016-2022 Andreas Steffen
  *
  * Copyright (C) secunet Security Networks AG
  *
@@ -59,6 +59,7 @@ ENUM(builder_part_names, BUILD_FROM_FILE, BUILD_END,
 	"BUILD_REVOKED_ENUMERATOR",
 	"BUILD_BASE_CRL",
 	"BUILD_CHALLENGE_PWD",
+	"BUILD_CERT_TYPE_EXT",
 	"BUILD_PKCS7_ATTRIBUTE",
 	"BUILD_PKCS11_MODULE",
 	"BUILD_PKCS11_SLOT",

src/libstrongswan/credentials/builder.h

@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2008 Martin Willi
- * Copyright (C) 2016-2019 Andreas Steffen
+ * Copyright (C) 2016-2022 Andreas Steffen
  *
  * Copyright (C) secunet Security Networks AG
  *
@@ -127,6 +127,8 @@ enum builder_part_t {
 	BUILD_BASE_CRL,
 	/** PKCS#10 challenge password */
 	BUILD_CHALLENGE_PWD,
+	/** PKCS#10 certificate type extension */
+	BUILD_CERT_TYPE_EXT,
 	/** PKCS#7 attribute, int oid, chunk_t with ASN1 type encoded value */
 	BUILD_PKCS7_ATTRIBUTE,
 	/** friendly name of a PKCS#11 module, null terminated char* */

src/libstrongswan/credentials/certificates/pkcs10.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009 Andreas Steffen
+ * Copyright (C) 2009-2022 Andreas Steffen
  *
  * Copyright (C) secunet Security Networks AG
  *
@@ -22,6 +22,8 @@
 #ifndef PKCS10_H_
 #define PKCS10_H_
 
+#include "x509.h"
+
 #include <collections/enumerator.h>
 #include <credentials/certificates/certificate.h>
 
@@ -47,8 +49,15 @@ struct pkcs10_t {
 	 */
 	chunk_t (*get_challengePassword)(pkcs10_t *this);
 
+    /**
+     * Get Extended Key Usage (EKU) flags
+     *
+     * @return          EKU flags
+     */
+    x509_flag_t (*get_flags)(pkcs10_t *this);
+
 	/**
-	 * Get.
+	 * Get subjectAltNames
 	 *
 	 * @return			enumerator over subjectAltNames as identification_t*
 	 */