From 09ba8d1e1794432e520c189cad2a7bf2feac37b9 Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Fri, 21 Oct 2022 00:40:40 +0200
Subject: [PATCH] Add more direct PDA tests

---
 .../syntax_check/PDATest.java                 | 86 ++++++++++++++-----
 1 file changed, 63 insertions(+), 23 deletions(-)

diff --git a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/syntax_check/PDATest.java b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/syntax_check/PDATest.java
index 346e1f3b..e4877d94 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/syntax_check/PDATest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/syntax_check/PDATest.java
@@ -1,10 +1,11 @@
 package org.pgpainless.decryption_verification.syntax_check;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import org.junit.jupiter.api.Test;
 import org.pgpainless.exception.MalformedOpenPgpMessageException;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 public class PDATest {
 
 
@@ -15,11 +16,11 @@ public class PDATest {
      */
     @Test
     public void testSimpleLiteralMessageIsValid() throws MalformedOpenPgpMessageException {
-        PDA automaton = new PDA();
-        automaton.next(InputAlphabet.LiteralData);
-        automaton.next(InputAlphabet.EndOfSequence);
+        PDA check = new PDA();
+        check.next(InputAlphabet.LiteralData);
+        check.next(InputAlphabet.EndOfSequence);
 
-        assertTrue(automaton.isValid());
+        assertTrue(check.isValid());
     }
 
     /**
@@ -29,13 +30,13 @@ public class PDATest {
      */
     @Test
     public void testSimpleOpsSignedMesssageIsValid() throws MalformedOpenPgpMessageException {
-        PDA automaton = new PDA();
-        automaton.next(InputAlphabet.OnePassSignature);
-        automaton.next(InputAlphabet.LiteralData);
-        automaton.next(InputAlphabet.Signature);
-        automaton.next(InputAlphabet.EndOfSequence);
+        PDA check = new PDA();
+        check.next(InputAlphabet.OnePassSignature);
+        check.next(InputAlphabet.LiteralData);
+        check.next(InputAlphabet.Signature);
+        check.next(InputAlphabet.EndOfSequence);
 
-        assertTrue(automaton.isValid());
+        assertTrue(check.isValid());
     }
 
 
@@ -46,12 +47,12 @@ public class PDATest {
      */
     @Test
     public void testSimplePrependSignedMessageIsValid() throws MalformedOpenPgpMessageException {
-        PDA automaton = new PDA();
-        automaton.next(InputAlphabet.Signature);
-        automaton.next(InputAlphabet.LiteralData);
-        automaton.next(InputAlphabet.EndOfSequence);
+        PDA check = new PDA();
+        check.next(InputAlphabet.Signature);
+        check.next(InputAlphabet.LiteralData);
+        check.next(InputAlphabet.EndOfSequence);
 
-        assertTrue(automaton.isValid());
+        assertTrue(check.isValid());
     }
 
 
@@ -62,14 +63,53 @@ public class PDATest {
      */
     @Test
     public void testOPSSignedCompressedMessageIsValid() throws MalformedOpenPgpMessageException {
-        PDA automaton = new PDA();
-        automaton.next(InputAlphabet.OnePassSignature);
-        automaton.next(InputAlphabet.CompressedData);
+        PDA check = new PDA();
+        check.next(InputAlphabet.OnePassSignature);
+        check.next(InputAlphabet.CompressedData);
         // Here would be a nested PDA for the LiteralData packet
-        automaton.next(InputAlphabet.Signature);
-        automaton.next(InputAlphabet.EndOfSequence);
+        check.next(InputAlphabet.Signature);
+        check.next(InputAlphabet.EndOfSequence);
 
-        assertTrue(automaton.isValid());
+        assertTrue(check.isValid());
     }
 
+    @Test
+    public void testTwoLiteralDataIsNotValid() {
+        PDA check = new PDA();
+        check.next(InputAlphabet.LiteralData);
+        assertThrows(MalformedOpenPgpMessageException.class,
+                () -> check.next(InputAlphabet.LiteralData));
+    }
+
+    @Test
+    public void testTrailingSigIsNotValid() {
+        PDA check = new PDA();
+        check.next(InputAlphabet.LiteralData);
+        assertThrows(MalformedOpenPgpMessageException.class,
+                () -> check.next(InputAlphabet.Signature));
+    }
+
+    @Test
+    public void testOPSWithPrependedSigIsValid() {
+        PDA check = new PDA();
+        check.next(InputAlphabet.Signature);
+        check.next(InputAlphabet.OnePassSignature);
+        check.next(InputAlphabet.LiteralData);
+        check.next(InputAlphabet.Signature);
+        check.next(InputAlphabet.EndOfSequence);
+
+        assertTrue(check.isValid());
+    }
+
+    @Test
+    public void testPrependedSigInsideOPSSignedMessageIsValid() {
+        PDA check = new PDA();
+        check.next(InputAlphabet.OnePassSignature);
+        check.next(InputAlphabet.Signature);
+        check.next(InputAlphabet.LiteralData);
+        check.next(InputAlphabet.Signature);
+        check.next(InputAlphabet.EndOfSequence);
+
+        assertTrue(check.isValid());
+    }
 }