WIP: Add LayerMetadata class

pgpainless-core/src/main/java/org/pgpainless/algorithm/OpenPgpPacket.java

@@ -29,7 +29,7 @@ public enum OpenPgpPacket {
     PSK(PacketTags.PUBLIC_SUBKEY),
     UATTR(PacketTags.USER_ATTRIBUTE),
     SEIPD(PacketTags.SYM_ENC_INTEGRITY_PRO),
-    MOD(PacketTags.MOD_DETECTION_CODE),
+    MDC(PacketTags.MOD_DETECTION_CODE),
 
     EXP_1(PacketTags.EXPERIMENTAL_1),
     EXP_2(PacketTags.EXPERIMENTAL_2),

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

@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
 package org.pgpainless.decryption_verification;
 
 import org.bouncycastle.bcpg.BCPGInputStream;
@@ -27,9 +31,12 @@ 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.SymmetricKeyAlgorithm;
 import org.pgpainless.decryption_verification.automaton.InputAlphabet;
 import org.pgpainless.decryption_verification.automaton.PDA;
 import org.pgpainless.decryption_verification.automaton.StackAlphabet;
@@ -55,15 +62,22 @@ public class OpenPgpMessageInputStream extends InputStream {
 
     protected final PDA automaton = new PDA();
     protected final ConsumerOptions options;
+    protected final OpenPgpMetadata.Builder resultBuilder;
     protected final BCPGInputStream bcpgIn;
     protected InputStream in;
 
     private boolean closed = false;
 
     private Signatures signatures;
+    private LayerMetadata layerMetadata;
 
     public OpenPgpMessageInputStream(InputStream inputStream, ConsumerOptions options)
             throws IOException, PGPException {
+        this(inputStream, options, null);
+    }
+
+    OpenPgpMessageInputStream(InputStream inputStream, ConsumerOptions options, LayerMetadata layerMetadata)
+            throws PGPException, IOException {
         // TODO: Use BCPGInputStream.wrap(inputStream);
         if (inputStream instanceof BCPGInputStream) {
             this.bcpgIn = (BCPGInputStream) inputStream;
@@ -72,12 +86,35 @@ public class OpenPgpMessageInputStream extends InputStream {
         }
 
         this.options = options;
+        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;
+        }
+    }
+
     /**
      * This method consumes OpenPGP packets from the current {@link BCPGInputStream}.
      * Once it reaches a "nested" OpenPGP packet (Literal Data, Compressed Data, Encrypted Data), it sets <pre>in</pre>
@@ -92,7 +129,7 @@ public class OpenPgpMessageInputStream extends InputStream {
             throws IOException, PGPException {
         System.out.println("Walk " + automaton);
         int tag;
-        loop: while ((tag = getTag()) != -1) {
+        loop: while ((tag = nextTag()) != -1) {
             OpenPgpPacket nextPacket = OpenPgpPacket.requireFromTag(tag);
             System.out.println(nextPacket);
             switch (nextPacket) {
@@ -108,7 +145,9 @@ public class OpenPgpMessageInputStream extends InputStream {
                 case COMP:
                     automaton.next(InputAlphabet.CompressedData);
                     PGPCompressedData compressedData = new PGPCompressedData(bcpgIn);
-                    in = new OpenPgpMessageInputStream(compressedData.getDataStream(), options);
+                    LayerMetadata compressionLayer = new LayerMetadata();
+                    compressionLayer.setCompressionAlgorithm(CompressionAlgorithm.fromId(compressedData.getAlgorithm()));
+                    in = new OpenPgpMessageInputStream(compressedData.getDataStream(), options, compressionLayer);
                     break loop;
 
                 // One Pass Signatures
@@ -119,10 +158,10 @@ public class OpenPgpMessageInputStream extends InputStream {
 
                 // Signatures - either prepended to the message, or corresponding to the One Pass Signatures
                 case SIG:
-                    boolean isCorrespondingToOPS = automaton.peekStack() == StackAlphabet.ops;
+                    boolean isSigForOPS = automaton.peekStack() == StackAlphabet.ops;
                     automaton.next(InputAlphabet.Signatures);
                     PGPSignatureList signatureList = readSignatures();
-                    if (isCorrespondingToOPS) {
+                    if (isSigForOPS) {
                         signatures.addOnePassCorrespondingSignatures(signatureList);
                     } else {
                         signatures.addPrependedSignatures(signatureList);
@@ -135,6 +174,43 @@ public class OpenPgpMessageInputStream extends InputStream {
                 case SED:
                 case SEIPD:
                     automaton.next(InputAlphabet.EncryptedData);
+                    if (processEncryptedData()) {
+                        break loop;
+                    }
+
+                    throw new MissingDecryptionMethodException("No working decryption method found.");
+
+                // Marker Packets need to be skipped and ignored
+                case MARKER:
+                    bcpgIn.readPacket(); // skip
+                    break;
+
+                // Key Packets are illegal in this context
+                case SK:
+                case PK:
+                case SSK:
+                case PSK:
+                case TRUST:
+                case UID:
+                case UATTR:
+                    throw new MalformedOpenPgpMessageException("Illegal Packet in Stream: " + nextPacket);
+
+                // MDC packet is usually processed by PGPEncryptedDataList, so it is very likely we encounter this
+                //  packet out of order
+                case MDC:
+                    throw new MalformedOpenPgpMessageException("Unexpected Packet in Stream: " + nextPacket);
+
+                    // Experimental Packets are not supported
+                case EXP_1:
+                case EXP_2:
+                case EXP_3:
+                case EXP_4:
+                    throw new MalformedOpenPgpMessageException("Unsupported Packet in Stream: " + nextPacket);
+            }
+        }
+    }
+
+    private boolean processEncryptedData() throws IOException, PGPException {
         PGPEncryptedDataList encDataList = new PGPEncryptedDataList(bcpgIn);
 
         // TODO: Replace with !encDataList.isIntegrityProtected()
@@ -144,6 +220,7 @@ public class OpenPgpMessageInputStream extends InputStream {
 
         SortedESKs esks = new SortedESKs(encDataList);
 
+        // Try session key
         if (options.getSessionKey() != null) {
             SessionKeyDataDecryptorFactory decryptorFactory = ImplementationFactory.getInstance()
                     .getSessionKeyDataDecryptorFactory(options.getSessionKey());
@@ -153,11 +230,11 @@ public class OpenPgpMessageInputStream extends InputStream {
                 if (esk instanceof PGPPBEEncryptedData) {
                     PGPPBEEncryptedData skesk = (PGPPBEEncryptedData) esk;
                     in = skesk.getDataStream(decryptorFactory);
-                                break loop;
+                    return true;
                 } else if (esk instanceof PGPPublicKeyEncryptedData) {
                     PGPPublicKeyEncryptedData pkesk = (PGPPublicKeyEncryptedData) esk;
                     in = pkesk.getDataStream(decryptorFactory);
-                                break loop;
+                    return true;
                 } else {
                     throw new RuntimeException("Unknown ESK class type: " + esk.getClass().getName());
                 }
@@ -174,7 +251,7 @@ public class OpenPgpMessageInputStream extends InputStream {
                 try {
                     InputStream decrypted = skesk.getDataStream(decryptorFactory);
                     in = new OpenPgpMessageInputStream(decrypted, options);
-                                break loop;
+                    return true;
                 } catch (PGPException e) {
                     // password mismatch? Try next password
                 }
@@ -198,7 +275,7 @@ public class OpenPgpMessageInputStream extends InputStream {
             try {
                 InputStream decrypted = pkesk.getDataStream(decryptorFactory);
                 in = new OpenPgpMessageInputStream(decrypted, options);
-                            break loop;
+                return true;
             } catch (PGPException e) {
                 // hm :/
             }
@@ -215,44 +292,18 @@ public class OpenPgpMessageInputStream extends InputStream {
                 try {
                     InputStream decrypted = pkesk.getDataStream(decryptorFactory);
                     in = new OpenPgpMessageInputStream(decrypted, options);
-                                break loop;
+                    return true;
                 } catch (PGPException e) {
                     // hm :/
                 }
             }
         }
 
-                    // TODO: try interactive password callbacks
+        // we did not yet succeed in decrypting any session key :/
-
+        return false;
-                    throw new MissingDecryptionMethodException("No working decryption method found.");
-
-                case MARKER:
-                    bcpgIn.readPacket(); // skip marker packet
-                    break;
-
-                // Key Packets are illegal in this context
-                case SK:
-                case PK:
-                case SSK:
-                case PSK:
-                case TRUST:
-                case UID:
-                case UATTR:
-
-                case MOD:
-                    throw new MalformedOpenPgpMessageException("Unexpected Packet in Stream: " + nextPacket);
-
-                    // Experimental Packets are not supported
-                case EXP_1:
-                case EXP_2:
-                case EXP_3:
-                case EXP_4:
-                    throw new MalformedOpenPgpMessageException("Unsupported Packet in Stream: " + nextPacket);
-            }
-        }
     }
 
-    private int getTag() throws IOException {
+    private int nextTag() throws IOException {
         try {
             return bcpgIn.nextPacketTag();
         } catch (IOException e) {
@@ -296,7 +347,7 @@ public class OpenPgpMessageInputStream extends InputStream {
         ByteArrayOutputStream buf = new ByteArrayOutputStream();
         BCPGOutputStream bcpgOut = new BCPGOutputStream(buf);
         int tag;
-        while ((tag = getTag()) == PacketTags.ONE_PASS_SIGNATURE || tag == PacketTags.MARKER) {
+        while ((tag = nextTag()) == PacketTags.ONE_PASS_SIGNATURE || tag == PacketTags.MARKER) {
             Packet packet = bcpgIn.readPacket();
             if (tag == PacketTags.ONE_PASS_SIGNATURE) {
                 OnePassSignaturePacket sigPacket = (OnePassSignaturePacket) packet;
@@ -313,13 +364,13 @@ public class OpenPgpMessageInputStream extends InputStream {
     private PGPSignatureList readSignatures() throws IOException {
         ByteArrayOutputStream buf = new ByteArrayOutputStream();
         BCPGOutputStream bcpgOut = new BCPGOutputStream(buf);
-        int tag = getTag();
+        int tag = nextTag();
         while (tag == PacketTags.SIGNATURE || tag == PacketTags.MARKER) {
             Packet packet = bcpgIn.readPacket();
             if (tag == PacketTags.SIGNATURE) {
                 SignaturePacket sigPacket = (SignaturePacket) packet;
                 sigPacket.encode(bcpgOut);
-                tag = getTag();
+                tag = nextTag();
             }
         }
         bcpgOut.close();
@@ -356,20 +407,6 @@ public class OpenPgpMessageInputStream extends InputStream {
                 throw new RuntimeException(e);
             }
             signatures.finish();
-            /*
-            if (in instanceof OpenPgpMessageInputStream) {
-                in.close();
-                in = null;
-            } else {
-                try {
-                    System.out.println("Read consume");
-                    consumePackets();
-                    signatures.finish();
-                } catch (PGPException e) {
-                    throw new RuntimeException(e);
-                }
-            }
-             */
         }
         return r;
     }
@@ -394,18 +431,6 @@ public class OpenPgpMessageInputStream extends InputStream {
                 throw new RuntimeException(e);
             }
             signatures.finish();
-            /*
-            if (in instanceof OpenPgpMessageInputStream) {
-                in.close();
-                in = null;
-            } else {
-                try {
-                    consumePackets();
-                } catch (PGPException e) {
-                    throw new RuntimeException(e);
-                }
-            }
-             */
         }
         return r;
     }