From 616bc539e7054f7e561ca66672019f7990759811 Mon Sep 17 00:00:00 2001
From: Fraser Tweedale <ftweedal@redhat.com>
Date: Thu, 17 Aug 2017 18:10:37 +1000
Subject: [PATCH] MS cert template: add template extension to CSR

Add the MS V2 certificate template extension to the CSR, when the
attribute is set.  Failure to parse the value (as stored) merely
causes the extension to be skipped.

Part of: https://pagure.io/certmonger/issue/78
---
 src/certext.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 84 insertions(+), 2 deletions(-)

diff --git a/src/certext.c b/src/certext.c
index 64ae05a..5f8a743 100644
--- a/src/certext.c
+++ b/src/certext.c
@@ -69,7 +69,7 @@ struct kerberos_principal_name {
 struct ms_template {
 	SECItem id;
 	SECItem major;
-	SECItem *minor;
+	SECItem minor;
 };
 
 /* KerberosString: RFC 4120, 5.2.1 */
@@ -180,7 +180,7 @@ cm_ms_template_template[] = {
 	.kind = SEC_ASN1_SEQUENCE,
 	.offset = 0,
 	.sub = NULL,
-	.size = sizeof(struct kerberos_principal_name),
+	.size = sizeof(struct ms_template),
 	},
 	{
 	.kind = SEC_ASN1_OBJECT_ID,
@@ -1593,6 +1593,76 @@ cm_certext_build_profile(struct cm_store_entry *entry,
 	return item;
 }
 
+/* Build a Microsoft certificate template extension value. */
+static SECItem *
+cm_certext_build_certificate_template(
+	PLArenaPool *arena,
+	char *template_spec)
+{
+	struct ms_template template_data;
+	memset(&template_data, 0, sizeof(struct ms_template));
+
+	if (NULL == template_spec || *template_spec == '\0')
+		return NULL;
+
+	/* strtok overwrites delimiters with null bytes;
+	 * therefore duplicate the input string */
+	char *template_spec_dup = PORT_ArenaStrdup(arena, template_spec);
+	if (NULL == template_spec_dup)
+		return NULL;
+
+	int i = 0;
+	char *saveptr, *endptr;
+	for (
+		char *part = strtok_r(template_spec_dup, ":", &saveptr);
+		part != NULL;
+		part = strtok_r(NULL, ":", &saveptr)
+	) {
+		if (i == 0) {
+			// parse OID
+			if (SECSuccess != SEC_StringToOID(arena, &template_data.id, part, 0))
+				return NULL;
+		}
+		else if (i == 1) {
+			// parse major version
+			long x = strtol(part, &endptr, 10);
+			if (*part == '\0' || *endptr != '\0') {
+				// string was empty or contained non-digits
+				return NULL;
+			}
+			if (SEC_ASN1EncodeInteger(arena, &template_data.major, x)
+					!= &template_data.major)
+				return NULL;
+		}
+		else if (i == 2) {
+			// parse minor version
+			long x = strtol(part, &endptr, 10);
+			if (*part == '\0' || *endptr != '\0') {
+				// string was empty or contained non-digits
+				return NULL;
+			}
+			if (SEC_ASN1EncodeInteger(arena, &template_data.minor, x)
+					!= &template_data.minor)
+				return NULL;
+		}
+		else {
+			// there are too many parts!
+			return NULL;
+		}
+		i++;
+	}
+	if (i < 2) {
+		// there are too few parts! (OID and major version are required)
+		return NULL;
+	}
+
+	SECItem encoded;
+	if (SEC_ASN1EncodeItem(arena, &encoded, &template_data,
+			       cm_ms_template_template) != &encoded)
+		return NULL;
+	return SECITEM_ArenaDupItem(arena, &encoded);
+}
+
 /* Build a Netscape certtype extension value. */
 static SECItem *
 cm_certext_build_ns_certtype(struct cm_store_entry *entry,
@@ -1840,6 +1910,18 @@ cm_certext_build_csr_extensions(struct cm_store_entry *entry,
 			i++;
 		}
 	}
+	if (entry->cm_template_certificate_template != NULL) {
+		oid = (SECOidData *) &oid_microsoft_certificate_template;
+		item = cm_certext_build_certificate_template(
+			arena, entry->cm_template_certificate_template);
+		if ((item != NULL) && (oid != NULL)) {
+			ext[i].id = oid->oid;
+			ext[i].critical = der_false;
+			ext[i].value = *item;
+			exts[i] = &ext[i];
+			i++;
+		}
+	}
 	if (entry->cm_template_ns_certtype != NULL) {
 		oid = SECOID_FindOIDByTag(SEC_OID_NS_CERT_EXT_CERT_TYPE);
 		item = cm_certext_build_ns_certtype(entry, arena,
-- 
2.14.4