Fix detection of unarmored data in detached signature verification

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

@@ -46,6 +46,7 @@ import org.pgpainless.algorithm.CompressionAlgorithm;
 import org.pgpainless.algorithm.EncryptionPurpose;
 import org.pgpainless.algorithm.StreamEncoding;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
+import org.pgpainless.exception.FinalIOException;
 import org.pgpainless.exception.MessageNotIntegrityProtectedException;
 import org.pgpainless.exception.MissingDecryptionMethodException;
 import org.pgpainless.exception.MissingLiteralDataException;
@@ -154,7 +155,7 @@ public final class DecryptionStreamFactory {
             objectFactory = ImplementationFactory.getInstance().getPGPObjectFactory(decoderStream);
             // Parse OpenPGP message
             inputStream = processPGPPackets(objectFactory, 1);
-        } catch (EOFException e) {
+        } catch (EOFException | FinalIOException e) {
             throw e;
         } catch (MissingLiteralDataException e) {
             // Not an OpenPGP message.
@@ -174,7 +175,7 @@ public final class DecryptionStreamFactory {
                 objectFactory = ImplementationFactory.getInstance().getPGPObjectFactory(decoderStream);
                 inputStream = wrapInVerifySignatureStream(bufferedIn, objectFactory);
             } else {
-                throw e;
+                throw new FinalIOException(e);
             }
         }
 
@@ -195,6 +196,7 @@ public final class DecryptionStreamFactory {
             throw new PGPException("Maximum depth of nested packages exceeded.");
         }
         Object nextPgpObject;
+        try {
             while ((nextPgpObject = objectFactory.nextObject()) != null) {
                 if (nextPgpObject instanceof PGPEncryptedDataList) {
                     return processPGPEncryptedDataList((PGPEncryptedDataList) nextPgpObject, depth);
@@ -209,6 +211,15 @@ public final class DecryptionStreamFactory {
                     return processPGPLiteralData(objectFactory, (PGPLiteralData) nextPgpObject, depth);
                 }
             }
+        } catch (FinalIOException e) {
+            throw e;
+        } catch (IOException e) {
+            if (depth == 1 && e.getMessage().contains("unknown object in stream:")) {
+                throw new MissingLiteralDataException("No Literal Data Packet found.");
+            } else {
+                throw new FinalIOException(e);
+            }
+        }
 
         throw new MissingLiteralDataException("No Literal Data Packet found");
     }

pgpainless-core/src/main/java/org/pgpainless/exception/FinalIOException.java

@@ -0,0 +1,17 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.exception;
+
+import java.io.IOException;
+
+/**
+ * Wrapper for {@link IOException} indicating that we need to throw this exception up.
+ */
+public class FinalIOException extends IOException {
+
+    public FinalIOException(IOException e) {
+        super(e);
+    }
+}

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

@@ -0,0 +1,71 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.decryption_verification;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+
+import org.bouncycastle.openpgp.PGPException;
+import org.bouncycastle.util.io.Streams;
+import org.junit.jupiter.api.Test;
+import org.pgpainless.PGPainless;
+import org.pgpainless.decryption_verification.cleartext_signatures.InMemoryMultiPassStrategy;
+
+public class VerifyDetachedSignatureTest {
+
+    @Test
+    public void verify() throws PGPException, IOException {
+        String signedContent = "Content-Type: multipart/mixed; boundary=\"OSR6TONWKJD9dgyc2XH5AQPNnAs7pdg1t\"\n" +
+                "\n" +
+                "--OSR6TONWKJD9dgyc2XH5AQPNnAs7pdg1t\n" +
+                "Content-Type: text/plain; charset=utf-8\n" +
+                "Content-Transfer-Encoding: quoted-printable\n" +
+                "Content-Language: en-US\n" +
+                "\n" +
+                "NOT encrypted + signed(detached)\n" +
+                "\n" +
+                "\n" +
+                "\n" +
+                "--OSR6TONWKJD9dgyc2XH5AQPNnAs7pdg1t--\n";
+        String signature = "-----BEGIN PGP SIGNATURE-----\n" +
+                "\n" +
+                "iHUEARYIAB0WIQTBZCjWAcs5N4nPYdTDIInNavjWzgUCYgKPzAAKCRDDIInNavjW\n" +
+                "zmdoAP0TdFt1OWqosHhXxt2hNYqZQMc6bgQRpJNL029nRyzkPAD/SoYJ4T+aYEhw\n" +
+                "11qrbXloqkr0G3QaA6/zk31RPMI/bgI=\n" +
+                "=o5Ze\n" +
+                "-----END PGP SIGNATURE-----\n";
+        String pubkey = "-----BEGIN PGP PUBLIC KEY BLOCK-----\n" +
+                "Version: PGPainless\n" +
+                "\n" +
+                "mDMEYIucWBYJKwYBBAHaRw8BAQdAew+8mzMWyf3+Pfy49qa60uKV6e5os7de4TdZ\n" +
+                "ceAWUq+0F2RlbmJvbmQ3QGZsb3djcnlwdC50ZXN0iHgEExYKACAFAmCLnFgCGwMF\n" +
+                "FgIDAQAECwkIBwUVCgkICwIeAQIZAQAKCRDDIInNavjWzm3JAQCgFgCEyD58iEa/\n" +
+                "Rw/DYNoQNoZC1lhw1bxBiOcIbtkdBgEAsDFZu3TBavOMKI7KW+vfMBHtRVbkMNpv\n" +
+                "unaAldoabgO4OARgi5xYEgorBgEEAZdVAQUBAQdAB1/Mrq5JGYim4KqGTSK4OESQ\n" +
+                "UwPgK56q0yrkiU9WgyYDAQgHiHUEGBYKAB0FAmCLnFgCGwwFFgIDAQAECwkIBwUV\n" +
+                "CgkICwIeAQAKCRDDIInNavjWzjMgAQCU+R1fItqdY6lt9jXUqipmXuqVaEFPwNA8\n" +
+                "YJ1rIwDwVQEAyUc8162KWzA2iQB5akwLwNr/pLDDtOWwhLUkrBb3mAc=\n" +
+                "=pXF6\n" +
+                "-----END PGP PUBLIC KEY BLOCK-----\n";
+
+
+        DecryptionStream verifier = PGPainless.decryptAndOrVerify()
+                .onInputStream(new ByteArrayInputStream(signedContent.getBytes(StandardCharsets.UTF_8)))
+                .withOptions(
+                        new ConsumerOptions()
+                                .addVerificationOfDetachedSignatures(new ByteArrayInputStream(signature.getBytes(StandardCharsets.UTF_8)))
+                                .addVerificationCerts(PGPainless.readKeyRing().keyRingCollection(pubkey, true).getPgpPublicKeyRingCollection())
+                                .setMultiPassStrategy(new InMemoryMultiPassStrategy())
+                );
+
+        Streams.drain(verifier);
+        verifier.close();
+        OpenPgpMetadata metadata = verifier.getResult();
+        assertTrue(metadata.isVerified());
+    }
+}