Wip: Introduce MessageMetadata class

pgpainless-core/src/main/java/org/pgpainless/decryption_verification/MessageMetadata.java

@@ -0,0 +1,249 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.decryption_verification;
+
+import org.pgpainless.algorithm.CompressionAlgorithm;
+import org.pgpainless.algorithm.StreamEncoding;
+import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
+import org.pgpainless.util.SessionKey;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.Iterator;
+import java.util.List;
+import java.util.NoSuchElementException;
+
+public class MessageMetadata {
+
+    protected Message message;
+
+    public MessageMetadata(@Nonnull Message message) {
+        this.message = message;
+    }
+
+    public @Nullable SymmetricKeyAlgorithm getEncryptionAlgorithm() {
+        Iterator<SymmetricKeyAlgorithm> algorithms = getEncryptionAlgorithms();
+        if (algorithms.hasNext()) {
+            return algorithms.next();
+        }
+        return null;
+    }
+
+    public @Nonnull Iterator<SymmetricKeyAlgorithm> getEncryptionAlgorithms() {
+        return new LayerIterator<SymmetricKeyAlgorithm>(message) {
+            @Override
+            public boolean matches(Nested layer) {
+                return layer instanceof EncryptedData;
+            }
+
+            @Override
+            public SymmetricKeyAlgorithm getProperty(Layer last) {
+                return ((EncryptedData) last).algorithm;
+            }
+        };
+    }
+
+    public @Nullable CompressionAlgorithm getCompressionAlgorithm() {
+        Iterator<CompressionAlgorithm> algorithms = getCompressionAlgorithms();
+        if (algorithms.hasNext()) {
+            return algorithms.next();
+        }
+        return null;
+    }
+
+    public @Nonnull Iterator<CompressionAlgorithm> getCompressionAlgorithms() {
+        return new LayerIterator<CompressionAlgorithm>(message) {
+            @Override
+            public boolean matches(Nested layer) {
+                return layer instanceof CompressedData;
+            }
+
+            @Override
+            public CompressionAlgorithm getProperty(Layer last) {
+                return ((CompressedData) last).algorithm;
+            }
+        };
+    }
+
+    public String getFilename() {
+        return findLiteralData().getFileName();
+    }
+
+    public Date getModificationDate() {
+        return findLiteralData().getModificationDate();
+    }
+
+    public StreamEncoding getFormat() {
+        return findLiteralData().getFormat();
+    }
+
+    private LiteralData findLiteralData() {
+        Nested nested = message.child;
+        while (nested.hasNestedChild()) {
+            Layer layer = (Layer) nested;
+            nested = layer.child;
+        }
+        return (LiteralData) nested;
+    }
+
+    public static abstract class Layer {
+        protected final List<SignatureVerification> verifiedSignatures = new ArrayList<>();
+        protected final List<SignatureVerification.Failure> failedSignatures = new ArrayList<>();
+        protected Nested child;
+
+        public Nested getChild() {
+            return child;
+        }
+
+        public void setChild(Nested child) {
+            this.child = child;
+        }
+
+        public List<SignatureVerification> getVerifiedSignatures() {
+            return new ArrayList<>(verifiedSignatures);
+        }
+
+        public List<SignatureVerification.Failure> getFailedSignatures() {
+            return new ArrayList<>(failedSignatures);
+        }
+    }
+
+    public interface Nested {
+        boolean hasNestedChild();
+    }
+
+    public static class Message extends Layer {
+
+    }
+
+    public static class LiteralData implements Nested {
+        protected String fileName;
+        protected Date modificationDate;
+        protected StreamEncoding format;
+
+        public LiteralData() {
+            this("", new Date(0L), StreamEncoding.BINARY);
+        }
+
+        public LiteralData(String fileName, Date modificationDate, StreamEncoding format) {
+            this.fileName = fileName;
+            this.modificationDate = modificationDate;
+            this.format = format;
+        }
+
+        public String getFileName() {
+            return fileName;
+        }
+
+        public Date getModificationDate() {
+            return modificationDate;
+        }
+
+        public StreamEncoding getFormat() {
+            return format;
+        }
+
+        @Override
+        public boolean hasNestedChild() {
+            return false;
+        }
+    }
+
+    public static class CompressedData extends Layer implements Nested {
+        protected final CompressionAlgorithm algorithm;
+
+        public CompressedData(CompressionAlgorithm zip) {
+            this.algorithm = zip;
+        }
+
+        public CompressionAlgorithm getAlgorithm() {
+            return algorithm;
+        }
+
+        @Override
+        public boolean hasNestedChild() {
+            return true;
+        }
+    }
+
+    public static class EncryptedData extends Layer implements Nested {
+        protected final SymmetricKeyAlgorithm algorithm;
+        protected SessionKey sessionKey;
+        protected List<Long> recipients;
+
+        public EncryptedData(SymmetricKeyAlgorithm algorithm) {
+            this.algorithm = algorithm;
+        }
+
+        public SymmetricKeyAlgorithm getAlgorithm() {
+            return algorithm;
+        }
+
+        public SessionKey getSessionKey() {
+            return sessionKey;
+        }
+
+        public List<Long> getRecipients() {
+            return new ArrayList<>(recipients);
+        }
+
+        @Override
+        public boolean hasNestedChild() {
+            return true;
+        }
+    }
+
+
+    private static abstract class LayerIterator<O> implements Iterator<O> {
+        private Nested current;
+        Layer last = null;
+
+        public LayerIterator(Message message) {
+            super();
+            this.current = message.child;
+            if (matches(current)) {
+                last = (Layer) current;
+            }
+        }
+
+        @Override
+        public boolean hasNext() {
+            if (last == null) {
+                findNext();
+            }
+            return last != null;
+        }
+
+        @Override
+        public O next() {
+            if (last == null) {
+                findNext();
+            }
+            if (last != null) {
+                O property = getProperty(last);
+                last = null;
+                return property;
+            }
+            throw new NoSuchElementException();
+        }
+
+        private void findNext() {
+            while (current instanceof Layer) {
+                current = ((Layer) current).child;
+                if (matches(current)) {
+                    last = (Layer) current;
+                    break;
+                }
+            }
+        }
+
+        abstract boolean matches(Nested layer);
+
+        abstract O getProperty(Layer last);
+    }
+
+}

pgpainless-core/src/main/java/org/pgpainless/decryption_verification/OpenPgpMessageInputStream.java

@@ -31,11 +31,11 @@ import org.bouncycastle.openpgp.operator.PBEDataDecryptorFactory;
 import org.bouncycastle.openpgp.operator.PGPContentVerifierBuilderProvider;
 import org.bouncycastle.openpgp.operator.PublicKeyDataDecryptorFactory;
 import org.bouncycastle.openpgp.operator.SessionKeyDataDecryptorFactory;
-import org.bouncycastle.pqc.crypto.rainbow.Layer;
 import org.pgpainless.PGPainless;
 import org.pgpainless.algorithm.CompressionAlgorithm;
 import org.pgpainless.algorithm.EncryptionPurpose;
 import org.pgpainless.algorithm.OpenPgpPacket;
+import org.pgpainless.algorithm.StreamEncoding;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.decryption_verification.automaton.InputAlphabet;
 import org.pgpainless.decryption_verification.automaton.PDA;
@@ -69,14 +69,14 @@ public class OpenPgpMessageInputStream extends InputStream {
     private boolean closed = false;
 
     private Signatures signatures;
-    private LayerMetadata layerMetadata;
+    private MessageMetadata.Layer metadata;
 
     public OpenPgpMessageInputStream(InputStream inputStream, ConsumerOptions options)
             throws IOException, PGPException {
-        this(inputStream, options, null);
+        this(inputStream, options, new MessageMetadata.Message());
     }
 
-    OpenPgpMessageInputStream(InputStream inputStream, ConsumerOptions options, LayerMetadata layerMetadata)
+    OpenPgpMessageInputStream(InputStream inputStream, ConsumerOptions options, MessageMetadata.Layer metadata)
             throws PGPException, IOException {
         // TODO: Use BCPGInputStream.wrap(inputStream);
         if (inputStream instanceof BCPGInputStream) {
@@ -86,33 +86,12 @@ public class OpenPgpMessageInputStream extends InputStream {
         }
 
         this.options = options;
+        this.metadata = metadata;
         this.resultBuilder = OpenPgpMetadata.getBuilder();
         this.signatures = new Signatures(options);
         this.signatures.addDetachedSignatures(options.getDetachedSignatures());
 
-        consumePackets();
-    }
-
-    static class LayerMetadata {
-
-        private CompressionAlgorithm compressionAlgorithm;
-        private SymmetricKeyAlgorithm symmetricKeyAlgorithm;
-        private LayerMetadata child;
-
-        public LayerMetadata setCompressionAlgorithm(CompressionAlgorithm algorithm) {
-            this.compressionAlgorithm = algorithm;
-            return this;
-        }
-
-        public LayerMetadata setSymmetricEncryptionAlgorithm(SymmetricKeyAlgorithm algorithm) {
-            this.symmetricKeyAlgorithm = algorithm;
-            return this;
-        }
-
-        public LayerMetadata setChild(LayerMetadata child) {
-            this.child = child;
-            return this;
-        }
+        consumePackets(); // nom nom nom
     }
 
     /**
@@ -127,27 +106,21 @@ public class OpenPgpMessageInputStream extends InputStream {
      */
     private void consumePackets()
             throws IOException, PGPException {
-        System.out.println("Walk " + automaton);
         int tag;
         loop: while ((tag = nextTag()) != -1) {
             OpenPgpPacket nextPacket = OpenPgpPacket.requireFromTag(tag);
-            System.out.println(nextPacket);
             switch (nextPacket) {
 
                 // Literal Data - the literal data content is the new input stream
                 case LIT:
                     automaton.next(InputAlphabet.LiteralData);
-                    PGPLiteralData literalData = new PGPLiteralData(bcpgIn);
-                    in = literalData.getDataStream();
+                    processLiteralData();
                     break loop;
 
                 // Compressed Data - the content contains another OpenPGP message
                 case COMP:
                     automaton.next(InputAlphabet.CompressedData);
-                    PGPCompressedData compressedData = new PGPCompressedData(bcpgIn);
-                    LayerMetadata compressionLayer = new LayerMetadata();
-                    compressionLayer.setCompressionAlgorithm(CompressionAlgorithm.fromId(compressedData.getAlgorithm()));
-                    in = new OpenPgpMessageInputStream(compressedData.getDataStream(), options, compressionLayer);
+                    processCompressedData();
                     break loop;
 
                 // One Pass Signatures
@@ -160,12 +133,7 @@ public class OpenPgpMessageInputStream extends InputStream {
                 case SIG:
                     boolean isSigForOPS = automaton.peekStack() == StackAlphabet.ops;
                     automaton.next(InputAlphabet.Signatures);
-                    PGPSignatureList signatureList = readSignatures();
-                    if (isSigForOPS) {
-                        signatures.addOnePassCorrespondingSignatures(signatureList);
-                    } else {
-                        signatures.addPrependedSignatures(signatureList);
-                    }
+                    processSignature(isSigForOPS);
                     break;
 
                 // Encrypted Data (ESKs and SED/SEIPD are parsed the same by BC)
@@ -210,6 +178,29 @@ public class OpenPgpMessageInputStream extends InputStream {
         }
     }
 
+    private void processSignature(boolean isSigForOPS) throws IOException {
+        PGPSignatureList signatureList = readSignatures();
+        if (isSigForOPS) {
+            signatures.addOnePassCorrespondingSignatures(signatureList);
+        } else {
+            signatures.addPrependedSignatures(signatureList);
+        }
+    }
+
+    private void processCompressedData() throws IOException, PGPException {
+        PGPCompressedData compressedData = new PGPCompressedData(bcpgIn);
+        MessageMetadata.CompressedData compressionLayer = new MessageMetadata.CompressedData(
+                CompressionAlgorithm.fromId(compressedData.getAlgorithm()));
+        in = new OpenPgpMessageInputStream(compressedData.getDataStream(), options, compressionLayer);
+    }
+
+    private void processLiteralData() throws IOException {
+        PGPLiteralData literalData = new PGPLiteralData(bcpgIn);
+        this.metadata.setChild(new MessageMetadata.LiteralData(literalData.getFileName(), literalData.getModificationTime(),
+                StreamEncoding.requireFromCode(literalData.getFormat())));
+        in = literalData.getDataStream();
+    }
+
     private boolean processEncryptedData() throws IOException, PGPException {
         PGPEncryptedDataList encDataList = new PGPEncryptedDataList(bcpgIn);
 
@@ -227,13 +218,14 @@ public class OpenPgpMessageInputStream extends InputStream {
             // TODO: Replace with encDataList.addSessionKeyDecryptionMethod(sessionKey)
             PGPEncryptedData esk = esks.all().get(0);
             try {
+                MessageMetadata.EncryptedData encryptedData = new MessageMetadata.EncryptedData(options.getSessionKey().getAlgorithm());
                 if (esk instanceof PGPPBEEncryptedData) {
                     PGPPBEEncryptedData skesk = (PGPPBEEncryptedData) esk;
-                    in = skesk.getDataStream(decryptorFactory);
+                    in = new OpenPgpMessageInputStream(skesk.getDataStream(decryptorFactory), options, encryptedData);
                     return true;
                 } else if (esk instanceof PGPPublicKeyEncryptedData) {
                     PGPPublicKeyEncryptedData pkesk = (PGPPublicKeyEncryptedData) esk;
-                    in = pkesk.getDataStream(decryptorFactory);
+                    in = new OpenPgpMessageInputStream(pkesk.getDataStream(decryptorFactory), options, encryptedData);
                     return true;
                 } else {
                     throw new RuntimeException("Unknown ESK class type: " + esk.getClass().getName());
@@ -250,7 +242,9 @@ public class OpenPgpMessageInputStream extends InputStream {
                         .getPBEDataDecryptorFactory(passphrase);
                 try {
                     InputStream decrypted = skesk.getDataStream(decryptorFactory);
-                    in = new OpenPgpMessageInputStream(decrypted, options);
+                    MessageMetadata.EncryptedData encryptedData = new MessageMetadata.EncryptedData(
+                            SymmetricKeyAlgorithm.requireFromId(skesk.getSymmetricAlgorithm(decryptorFactory)));
+                    in = new OpenPgpMessageInputStream(decrypted, options, encryptedData);
                     return true;
                 } catch (PGPException e) {
                     // password mismatch? Try next password
@@ -274,7 +268,9 @@ public class OpenPgpMessageInputStream extends InputStream {
                     .getPublicKeyDataDecryptorFactory(privateKey);
             try {
                 InputStream decrypted = pkesk.getDataStream(decryptorFactory);
-                in = new OpenPgpMessageInputStream(decrypted, options);
+                MessageMetadata.EncryptedData encryptedData = new MessageMetadata.EncryptedData(
+                        SymmetricKeyAlgorithm.requireFromId(pkesk.getSymmetricAlgorithm(decryptorFactory)));
+                in = new OpenPgpMessageInputStream(decrypted, options, encryptedData);
                 return true;
             } catch (PGPException e) {
                 // hm :/
@@ -291,7 +287,9 @@ public class OpenPgpMessageInputStream extends InputStream {
 
                 try {
                     InputStream decrypted = pkesk.getDataStream(decryptorFactory);
-                    in = new OpenPgpMessageInputStream(decrypted, options);
+                    MessageMetadata.EncryptedData encryptedData = new MessageMetadata.EncryptedData(
+                            SymmetricKeyAlgorithm.requireFromId(pkesk.getSymmetricAlgorithm(decryptorFactory)));
+                    in = new OpenPgpMessageInputStream(decrypted, options, encryptedData);
                     return true;
                 } catch (PGPException e) {
                     // hm :/
@@ -402,6 +400,7 @@ public class OpenPgpMessageInputStream extends InputStream {
             signatures.update(b);
         } else {
             in.close();
+            collectMetadata();
             in = null;
 
             try {
@@ -426,6 +425,7 @@ public class OpenPgpMessageInputStream extends InputStream {
         int r = in.read(b, off, len);
         if (r == -1) {
             in.close();
+            collectMetadata();
             in = null;
 
             try {
@@ -447,6 +447,7 @@ public class OpenPgpMessageInputStream extends InputStream {
 
         if (in != null) {
             in.close();
+            collectMetadata();
             in = null;
         }
 
@@ -461,6 +462,21 @@ public class OpenPgpMessageInputStream extends InputStream {
         closed = true;
     }
 
+    private void collectMetadata() {
+        if (in instanceof OpenPgpMessageInputStream) {
+            OpenPgpMessageInputStream child = (OpenPgpMessageInputStream) in;
+            MessageMetadata.Layer childLayer = child.metadata;
+            this.metadata.setChild((MessageMetadata.Nested) childLayer);
+        }
+    }
+
+    public MessageMetadata getMetadata() {
+        if (!closed) {
+            throw new IllegalStateException("Stream must be closed before access to metadata can be granted.");
+        }
+        return new MessageMetadata((MessageMetadata.Message) metadata);
+    }
+
     private static class SortedESKs {
 
         private List<PGPPBEEncryptedData> skesks = new ArrayList<>();

pgpainless-core/src/main/java/org/pgpainless/decryption_verification/automaton/PDA.java

@@ -187,10 +187,7 @@ public class PDA {
     }
 
     public void next(InputAlphabet input) throws MalformedOpenPgpMessageException {
-        State old = state;
-        StackAlphabet stackItem = stack.isEmpty() ? null : stack.peek();
         state = state.transition(input, this);
-        System.out.println(id + ": Transition from " + old + " to " + state + " via " + input + " with stack " + stackItem);
     }
 
     /**

pgpainless-core/src/test/java/org/pgpainless/decryption_verification/MessageMetadataTest.java

@@ -0,0 +1,84 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.decryption_verification;
+
+import org.junit.JUtils;
+import org.junit.jupiter.api.Test;
+import org.pgpainless.algorithm.CompressionAlgorithm;
+import org.pgpainless.algorithm.StreamEncoding;
+import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
+import org.pgpainless.util.DateUtil;
+
+import java.util.Date;
+import java.util.Iterator;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class MessageMetadataTest {
+
+    @Test
+    public void processTestMessage_COMP_ENC_ENC_LIT() {
+        // Note: COMP of ENC does not make sense, since ENC is indistinguishable from randomness
+        //  and randomness cannot be encrypted.
+        //  For the sake of testing though, this is okay.
+        MessageMetadata.Message message = new MessageMetadata.Message();
+
+        MessageMetadata.CompressedData compressedData = new MessageMetadata.CompressedData(CompressionAlgorithm.ZIP);
+        MessageMetadata.EncryptedData encryptedData = new MessageMetadata.EncryptedData(SymmetricKeyAlgorithm.AES_128);
+        MessageMetadata.EncryptedData encryptedData1 = new MessageMetadata.EncryptedData(SymmetricKeyAlgorithm.AES_256);
+        MessageMetadata.LiteralData literalData = new MessageMetadata.LiteralData();
+
+        message.setChild(compressedData);
+        compressedData.setChild(encryptedData);
+        encryptedData.setChild(encryptedData1);
+        encryptedData1.setChild(literalData);
+
+        MessageMetadata metadata = new MessageMetadata(message);
+
+        // Check encryption algs
+        assertEquals(SymmetricKeyAlgorithm.AES_128, metadata.getEncryptionAlgorithm(), "getEncryptionAlgorithm() returns alg of outermost EncryptedData");
+        Iterator<SymmetricKeyAlgorithm> encryptionAlgs = metadata.getEncryptionAlgorithms();
+        assertTrue(encryptionAlgs.hasNext(), "There is at least one EncryptedData child");
+        assertTrue(encryptionAlgs.hasNext(), "The child is still there");
+        assertEquals(SymmetricKeyAlgorithm.AES_128, encryptionAlgs.next(), "The first algo is AES128");
+        assertTrue(encryptionAlgs.hasNext(), "There is another EncryptedData");
+        assertTrue(encryptionAlgs.hasNext(), "There is *still* another EncryptedData");
+        assertEquals(SymmetricKeyAlgorithm.AES_256, encryptionAlgs.next(), "The second algo is AES256");
+        assertFalse(encryptionAlgs.hasNext(), "There is no more EncryptedData");
+        assertFalse(encryptionAlgs.hasNext(), "There *still* is no more EncryptedData");
+
+        assertEquals(CompressionAlgorithm.ZIP, metadata.getCompressionAlgorithm(), "getCompressionAlgorithm() returns alg of outermost CompressedData");
+        Iterator<CompressionAlgorithm> compAlgs = metadata.getCompressionAlgorithms();
+        assertTrue(compAlgs.hasNext());
+        assertTrue(compAlgs.hasNext());
+        assertEquals(CompressionAlgorithm.ZIP, compAlgs.next());
+        assertFalse(compAlgs.hasNext());
+        assertFalse(compAlgs.hasNext());
+
+        assertEquals("", metadata.getFilename());
+        JUtils.assertDateEquals(new Date(0L), metadata.getModificationDate());
+        assertEquals(StreamEncoding.BINARY, metadata.getFormat());
+    }
+
+    @Test
+    public void testProcessLiteralDataMessage() {
+        MessageMetadata.LiteralData literalData = new MessageMetadata.LiteralData(
+                "collateral_murder.zip",
+                DateUtil.parseUTCDate("2010-04-05 10:12:03 UTC"),
+                StreamEncoding.BINARY);
+        MessageMetadata.Message message = new MessageMetadata.Message();
+        message.setChild(literalData);
+
+        MessageMetadata metadata = new MessageMetadata(message);
+        assertNull(metadata.getCompressionAlgorithm());
+        assertNull(metadata.getEncryptionAlgorithm());
+        assertEquals("collateral_murder.zip", metadata.getFilename());
+        assertEquals(DateUtil.parseUTCDate("2010-04-05 10:12:03 UTC"), metadata.getModificationDate());
+        assertEquals(StreamEncoding.BINARY, metadata.getFormat());
+    }
+}

pgpainless-core/src/test/java/org/pgpainless/decryption_verification/OpenPgpMessageInputStreamTest.java

@@ -1,5 +1,21 @@
 package org.pgpainless.decryption_verification;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.NoSuchAlgorithmException;
+import java.util.Date;
+import java.util.Iterator;
+import java.util.stream.Stream;
+
 import org.bouncycastle.bcpg.ArmoredInputStream;
 import org.bouncycastle.bcpg.ArmoredOutputStream;
 import org.bouncycastle.bcpg.CompressionAlgorithmTags;
@@ -11,9 +27,14 @@ import org.bouncycastle.openpgp.PGPPublicKeyRing;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.bouncycastle.openpgp.PGPSignature;
 import org.bouncycastle.util.io.Streams;
-import org.junit.jupiter.api.Test;
+import org.junit.JUtils;
+import org.junit.jupiter.api.Named;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 import org.pgpainless.PGPainless;
 import org.pgpainless.algorithm.CompressionAlgorithm;
+import org.pgpainless.algorithm.StreamEncoding;
 import org.pgpainless.encryption_signing.EncryptionOptions;
 import org.pgpainless.encryption_signing.EncryptionResult;
 import org.pgpainless.encryption_signing.EncryptionStream;
@@ -23,17 +44,7 @@ import org.pgpainless.exception.MalformedOpenPgpMessageException;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.util.ArmoredInputStreamFactory;
 import org.pgpainless.util.Passphrase;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.OutputStream;
-import java.nio.charset.StandardCharsets;
-import java.security.InvalidAlgorithmParameterException;
-import java.security.NoSuchAlgorithmException;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import org.pgpainless.util.Tuple;
 
 public class OpenPgpMessageInputStreamTest {
 
@@ -304,107 +315,119 @@ public class OpenPgpMessageInputStreamTest {
         System.out.println(out);
     }
 
-    @Test
-    public void testProcessLIT() throws IOException, PGPException {
-        String plain = processReadBuffered(LIT, ConsumerOptions.get());
-        assertEquals(PLAINTEXT, plain);
-
-        plain = processReadSequential(LIT, ConsumerOptions.get());
-        assertEquals(PLAINTEXT, plain);
+    interface Processor {
+        Tuple<String, MessageMetadata> process(String armoredMessage, ConsumerOptions options) throws PGPException, IOException;
     }
 
-    @Test
-    public void testProcessLIT_LIT_fails() {
+    private static Stream<Arguments> provideMessageProcessors() {
+        return Stream.of(
+                Arguments.of(Named.of("read(buf,off,len)", (Processor) OpenPgpMessageInputStreamTest::processReadBuffered)),
+                Arguments.of(Named.of("read()", (Processor) OpenPgpMessageInputStreamTest::processReadSequential)));
+    }
+
+    @ParameterizedTest(name = "Process LIT using {0}")
+    @MethodSource("provideMessageProcessors")
+    public void testProcessLIT(Processor processor) throws IOException, PGPException {
+        Tuple<String, MessageMetadata> result = processor.process(LIT, ConsumerOptions.get());
+        String plain = result.getA();
+        assertEquals(PLAINTEXT, plain);
+
+        MessageMetadata metadata = result.getB();
+        assertNull(metadata.getCompressionAlgorithm());
+        assertNull(metadata.getEncryptionAlgorithm());
+        assertEquals("", metadata.getFilename());
+        JUtils.assertDateEquals(new Date(0L), metadata.getModificationDate());
+        assertEquals(StreamEncoding.BINARY, metadata.getFormat());
+    }
+
+    @ParameterizedTest(name = "Process LIT LIT using {0}")
+    @MethodSource("provideMessageProcessors")
+    public void testProcessLIT_LIT_fails(Processor processor) {
         assertThrows(MalformedOpenPgpMessageException.class,
-                () -> processReadBuffered(LIT_LIT, ConsumerOptions.get()));
+                () -> processor.process(LIT_LIT, ConsumerOptions.get()));
+    }
 
+    @ParameterizedTest(name = "Process COMP(LIT) using {0}")
+    @MethodSource("provideMessageProcessors")
+    public void testProcessCOMP_LIT(Processor processor) throws PGPException, IOException {
+        Tuple<String, MessageMetadata> result = processor.process(COMP_LIT, ConsumerOptions.get());
+        String plain = result.getA();
+        assertEquals(PLAINTEXT, plain);
+        MessageMetadata metadata = result.getB();
+        assertEquals(CompressionAlgorithm.ZIP, metadata.getCompressionAlgorithm());
+    }
+
+    @ParameterizedTest(name = "Process COMP using {0}")
+    @MethodSource("provideMessageProcessors")
+    public void testProcessCOMP_fails(Processor processor) {
         assertThrows(MalformedOpenPgpMessageException.class,
-                () -> processReadSequential(LIT_LIT, ConsumerOptions.get()));
+                () -> processor.process(COMP, ConsumerOptions.get()));
     }
 
-    @Test
-    public void testProcessCOMP_LIT() throws PGPException, IOException {
-        String plain = processReadBuffered(COMP_LIT, ConsumerOptions.get());
-        assertEquals(PLAINTEXT, plain);
-
-        plain = processReadSequential(COMP_LIT, ConsumerOptions.get());
+    @ParameterizedTest(name = "Process COMP(COMP(LIT)) using {0}")
+    @MethodSource("provideMessageProcessors")
+    public void testProcessCOMP_COMP_LIT(Processor processor) throws PGPException, IOException {
+        Tuple<String, MessageMetadata> result = processor.process(COMP_COMP_LIT, ConsumerOptions.get());
+        String plain = result.getA();
         assertEquals(PLAINTEXT, plain);
+        MessageMetadata metadata = result.getB();
+        assertEquals(CompressionAlgorithm.ZIP, metadata.getCompressionAlgorithm());
+        Iterator<CompressionAlgorithm> compressionAlgorithms = metadata.getCompressionAlgorithms();
+        assertEquals(CompressionAlgorithm.ZIP, compressionAlgorithms.next());
+        assertEquals(CompressionAlgorithm.BZIP2, compressionAlgorithms.next());
+        assertFalse(compressionAlgorithms.hasNext());
     }
 
-    @Test
-    public void testProcessCOMP_fails() {
-        assertThrows(MalformedOpenPgpMessageException.class,
-                () -> processReadBuffered(COMP, ConsumerOptions.get()));
-
-        assertThrows(MalformedOpenPgpMessageException.class,
-                () -> processReadSequential(COMP, ConsumerOptions.get()));
-    }
-
-    @Test
-    public void testProcessCOMP_COMP_LIT() throws PGPException, IOException {
-        String plain = processReadBuffered(COMP_COMP_LIT, ConsumerOptions.get());
-        assertEquals(PLAINTEXT, plain);
-
-        plain = processReadSequential(COMP_COMP_LIT, ConsumerOptions.get());
-        assertEquals(PLAINTEXT, plain);
-    }
-
-    @Test
-    public void testProcessSIG_LIT() throws PGPException, IOException {
+    @ParameterizedTest(name = "Process SIG LIT using {0}")
+    @MethodSource("provideMessageProcessors")
+    public void testProcessSIG_LIT(Processor processor) throws PGPException, IOException {
         PGPPublicKeyRing cert = PGPainless.extractCertificate(
                 PGPainless.readKeyRing().secretKeyRing(KEY));
 
-        String plain = processReadBuffered(SIG_LIT, ConsumerOptions.get()
-                .addVerificationCert(cert));
-        assertEquals(PLAINTEXT, plain);
-
-        plain = processReadSequential(SIG_LIT, ConsumerOptions.get()
+        Tuple<String, MessageMetadata> result = processor.process(SIG_LIT, ConsumerOptions.get()
                 .addVerificationCert(cert));
+        String plain = result.getA();
         assertEquals(PLAINTEXT, plain);
     }
 
-    @Test
-    public void testProcessSENC_LIT() throws PGPException, IOException {
-        String plain = processReadBuffered(SENC_LIT, ConsumerOptions.get().addDecryptionPassphrase(Passphrase.fromPassword(PASSPHRASE)));
-        assertEquals(PLAINTEXT, plain);
-
-        plain = processReadSequential(SENC_LIT, ConsumerOptions.get().addDecryptionPassphrase(Passphrase.fromPassword(PASSPHRASE)));
+    @ParameterizedTest(name = "Process SENC(LIT) using {0}")
+    @MethodSource("provideMessageProcessors")
+    public void testProcessSENC_LIT(Processor processor) throws PGPException, IOException {
+        Tuple<String, MessageMetadata> result = processor.process(SENC_LIT, ConsumerOptions.get().addDecryptionPassphrase(Passphrase.fromPassword(PASSPHRASE)));
+        String plain = result.getA();
         assertEquals(PLAINTEXT, plain);
     }
 
-    @Test
-    public void testProcessPENC_COMP_LIT() throws IOException, PGPException {
+    @ParameterizedTest(name = "Process PENC(LIT) using {0}")
+    @MethodSource("provideMessageProcessors")
+    public void testProcessPENC_COMP_LIT(Processor processor) throws IOException, PGPException {
         PGPSecretKeyRing secretKeys = PGPainless.readKeyRing().secretKeyRing(KEY);
-        String plain = processReadBuffered(PENC_COMP_LIT, ConsumerOptions.get()
-                .addDecryptionKey(secretKeys));
-        assertEquals(PLAINTEXT, plain);
-
-        plain = processReadSequential(PENC_COMP_LIT, ConsumerOptions.get()
+        Tuple<String, MessageMetadata> result = processor.process(PENC_COMP_LIT, ConsumerOptions.get()
                 .addDecryptionKey(secretKeys));
+        String plain = result.getA();
         assertEquals(PLAINTEXT, plain);
     }
 
-    @Test
-    public void testProcessOPS_LIT_SIG() throws IOException, PGPException {
+    @ParameterizedTest(name = "Process OPS LIT SIG using {0}")
+    @MethodSource("provideMessageProcessors")
+    public void testProcessOPS_LIT_SIG(Processor processor) throws IOException, PGPException {
         PGPPublicKeyRing cert = PGPainless.extractCertificate(PGPainless.readKeyRing().secretKeyRing(KEY));
-        String plain = processReadBuffered(OPS_LIT_SIG, ConsumerOptions.get()
-                .addVerificationCert(cert));
-        assertEquals(PLAINTEXT, plain);
-
-        plain = processReadSequential(OPS_LIT_SIG, ConsumerOptions.get()
+        Tuple<String, MessageMetadata> result = processor.process(OPS_LIT_SIG, ConsumerOptions.get()
                 .addVerificationCert(cert));
+        String plain = result.getA();
         assertEquals(PLAINTEXT, plain);
     }
 
-    private String processReadBuffered(String armoredMessage, ConsumerOptions options) throws PGPException, IOException {
+    private static Tuple<String, MessageMetadata> processReadBuffered(String armoredMessage, ConsumerOptions options) throws PGPException, IOException {
         OpenPgpMessageInputStream in = get(armoredMessage, options);
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         Streams.pipeAll(in, out);
         in.close();
-        return out.toString();
+        MessageMetadata metadata = in.getMetadata();
+        return new Tuple<>(out.toString(), metadata);
     }
 
-    private String processReadSequential(String armoredMessage, ConsumerOptions options) throws PGPException, IOException {
+    private static Tuple<String, MessageMetadata> processReadSequential(String armoredMessage, ConsumerOptions options) throws PGPException, IOException {
         OpenPgpMessageInputStream in = get(armoredMessage, options);
         ByteArrayOutputStream out = new ByteArrayOutputStream();
 
@@ -414,10 +437,11 @@ public class OpenPgpMessageInputStreamTest {
         }
 
         in.close();
-        return out.toString();
+        MessageMetadata metadata = in.getMetadata();
+        return new Tuple<>(out.toString(), metadata);
     }
 
-    private OpenPgpMessageInputStream get(String armored, ConsumerOptions options) throws IOException, PGPException {
+    private static OpenPgpMessageInputStream get(String armored, ConsumerOptions options) throws IOException, PGPException {
         ByteArrayInputStream bytesIn = new ByteArrayInputStream(armored.getBytes(StandardCharsets.UTF_8));
         ArmoredInputStream armorIn = ArmoredInputStreamFactory.get(bytesIn);
         OpenPgpMessageInputStream pgpIn = new OpenPgpMessageInputStream(armorIn, options);