heimdal:lib/krb5: verify_logonname() to handle multi component principal

FreeIPA can generate tickets with a client principal of
'host/hostname.example.com'.

verify_logonname() should just verify the principal name
in the PAC_LOGON_NAME is the same as the principal of
the client principal (without realm) of the ticket.

Samba commit b7cc8c1187ff967e44587cd0d09185330378f366
break this. We try to compare ['host']['hostname.example.com']
with ['host/hostname.example.com]' (as we interpret it as enterprise principal)
this fail if we don't compare them as strings.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11142

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

1 files changed, 20 insertions, 14 deletions

diff --git a/source4/heimdal/lib/krb5/pac.c b/source4/heimdal/lib/krb5/pac.c
index 9328647a5b3..7c8ba50e9c4 100644
--- a/source4/heimdal/lib/krb5/pac.c
+++ b/source4/heimdal/lib/krb5/pac.c
@@ -595,11 +595,12 @@ verify_logonname(krb5_context context,
 		 krb5_const_principal principal)
 {
     krb5_error_code ret;
-    krb5_principal p2;
     uint32_t time1, time2;
     krb5_storage *sp;
     uint16_t len;
-    char *s;
+    char *s = NULL;
+    char *principal_string = NULL;
+    char *logon_string = NULL;
 
     sp = krb5_storage_from_readonly_mem((const char *)data->data + logon_name->offset_lo,
 					logon_name->buffersize);
@@ -664,31 +665,36 @@ verify_logonname(krb5_context context,
 	    return ret;
 	}
 	u8len += 1; /* Add space for NUL */
-	s = malloc(u8len);
-	if (s == NULL) {
+	logon_string = malloc(u8len);
+	if (logon_string == NULL) {
 	    free(ucs2);
 	    return krb5_enomem(context);
 	}
-	ret = wind_ucs2utf8(ucs2, ucs2len, s, &u8len);
+	ret = wind_ucs2utf8(ucs2, ucs2len, logon_string, &u8len);
 	free(ucs2);
 	if (ret) {
-	    free(s);
+	    free(logon_string);
 	    krb5_set_error_message(context, ret, "Failed to convert to UTF-8");
 	    return ret;
 	}
     }
-    ret = krb5_parse_name_flags(context, s,
-				KRB5_PRINCIPAL_PARSE_NO_REALM |
-				KRB5_PRINCIPAL_PARSE_ENTERPRISE, &p2);
-    free(s);
-    if (ret)
+    ret = krb5_unparse_name_flags(context, principal,
+				  KRB5_PRINCIPAL_UNPARSE_NO_REALM |
+				  KRB5_PRINCIPAL_UNPARSE_DISPLAY,
+				  &principal_string);
+    if (ret) {
+	free(logon_string);
 	return ret;
+    }
 
-    if (krb5_principal_compare_any_realm(context, principal, p2) != TRUE) {
+    ret = strcmp(logon_string, principal_string);
+    if (ret != 0) {
 	ret = EINVAL;
-	krb5_set_error_message(context, ret, "PAC logon name mismatch");
+	krb5_set_error_message(context, ret, "PAC logon name [%s] mismatch principal name [%s]",
+			       logon_string, principal_string);
     }
-    krb5_free_principal(context, p2);
+    free(logon_string);
+    free(principal_string);
     return ret;
 out:
     return ret;