omnisessio: accept tabs in config file

Motivation:
Admins like to format config files with tabs, however omnisessio config
parser accepts only strings.

Modification:
Update omnisessio config passer to split files by any whitespace
characters, including tabs.

Result:
omnisessio config can use tabs as a field separator

Fixes: #7881
Acked-by: Marina Sahakyan
Acked-by: Dmitry Litvintsev
Target: master
Require-book: no
Require-notes: yes

Author: kofemann

modules/gplazma2-omnisession/src/main/java/org/dcache/gplazma/omnisession/ConfigurationParser.java

@@ -1,6 +1,6 @@
 /* dCache - http://www.dcache.org/
  *
- * Copyright (C) 2021-2025 Deutsches Elektronen-Synchrotron
+ * Copyright (C) 2021 - 2025 Deutsches Elektronen-Synchrotron
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -22,6 +22,7 @@
 import static org.dcache.util.ByteSizeParser.Whitespace.NOT_ALLOWED;
 import static org.dcache.util.Exceptions.genericCheck;
 
+import com.google.common.base.CharMatcher;
 import com.google.common.base.Splitter;
 import diskCacheV111.util.FsPath;
 import java.util.ArrayList;
@@ -89,7 +90,7 @@ public void accept(String rawLine) throws UnrecoverableParsingException {
         }
 
         try {
-            if (line.startsWith("DEFAULT ")) {
+            if (line.startsWith("DEFAULT")) {
                 checkBadLine(defaultAttributes.isEmpty(), "\"DEFAULT\" is already defined.");
                 List<LoginAttribute> attributes = parseAttributes(line.substring(8));
                 defaultAttributes = Optional.of(attributes);
@@ -125,7 +126,7 @@ private List<LoginAttribute> parseAttributes(String description) throws BadLineE
         boolean isReadOnly = false;
         Set<Class<? extends LoginAttribute>> addedAttributes = new HashSet<>();
 
-        for (String attr : Splitter.on(' ').omitEmptyStrings().split(description)) {
+        for (String attr : Splitter.on(CharMatcher.whitespace()).trimResults().omitEmptyStrings().split(description)) {
             try {
                 if (attr.equals("read-only")) {
                     checkBadLine(!isReadOnly, "already defined 'read-only'");

modules/gplazma2-omnisession/src/main/java/org/dcache/gplazma/omnisession/PrincipalPredicates.java

@@ -1,6 +1,6 @@
 /* dCache - http://www.dcache.org/
  *
- * Copyright (C) 2021 Deutsches Elektronen-Synchrotron
+ * Copyright (C) 2021 - 2025 Deutsches Elektronen-Synchrotron
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -45,7 +45,7 @@
 public class PrincipalPredicates {
 
     private static final Pattern PRINCIPAL_PREDICATE =
-          Pattern.compile("^(?<type>[^:]+):(?<value>([^\"][^ ]*)|(\"[^\"]*\"?)) *");
+          Pattern.compile("^(?<type>[^:]+):(?<value>([^\"][^ \t]*)|(\"[^\"]*\"?)) *");
     private static final Map<String, TestablePrincipal> TESTABLE_PRINCIPAL_BY_LABEL;
 
     static {

modules/gplazma2-omnisession/src/test/java/org/dcache/gplazma/omnisession/ConfigurationParserTest.java

@@ -1,6 +1,6 @@
 /* dCache - http://www.dcache.org/
  *
- * Copyright (C) 2021 Deutsches Elektronen-Synchrotron
+ * Copyright (C) 2021 - 2025 Deutsches Elektronen-Synchrotron
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -82,6 +82,17 @@ public void shouldAcceptEmptyLine() throws Exception {
               new HomeDirectory("/")));
     }
 
+    @Test
+    public void shouldAcceptTabs() throws Exception {
+        // line with tabs
+        givenConfig("username:paul	root:/	home:/");
+
+        var loginAttributes = attributesFor(aSetOfPrincipals().withUsername("paul"));
+
+        assertThat(loginAttributes, containsInAnyOrder(new RootDirectory("/"),
+                new HomeDirectory("/")));
+    }
+
     @Test(expected = AuthenticationException.class)
     public void shouldNotMatchWithWrongUsername() throws Exception {
         givenConfig("username:paul root:/ home:/");