Fix checkstyle issues

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018 Paul Schaub.
+ * Copyright 2018-2020 Paul Schaub.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,11 +18,15 @@ package org.pgpainless.decryption_verification;
 import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 import org.bouncycastle.openpgp.PGPException;
 
 public class DecryptionStream extends InputStream {
 
+    private static final Logger LOGGER = Logger.getLogger(DecryptionStream.class.getName());
+
     private final InputStream inputStream;
     private final OpenPgpMetadata.Builder resultBuilder;
     private boolean isClosed = false;
@@ -59,7 +63,7 @@ public class DecryptionStream extends InputStream {
             try {
                 s.setVerified(s.getSignature().verify());
             } catch (PGPException e) {
-                e.printStackTrace();
+                LOGGER.log(Level.WARNING, "Could not verify signature of key " + s.getFingerprint(), e);
             }
         }
     }

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

@@ -1,3 +1,18 @@
+/*
+ * Copyright 2020 Paul Schaub.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.pgpainless.decryption_verification;
 
 import org.bouncycastle.openpgp.PGPSignature;

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

@@ -1,3 +1,18 @@
+/*
+ * Copyright 2020 Paul Schaub.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.pgpainless.decryption_verification;
 
 import org.bouncycastle.openpgp.PGPException;

pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionBuilder.java

@@ -15,7 +15,6 @@
  */
 package org.pgpainless.encryption_signing;
 
-import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.HashSet;
@@ -23,6 +22,7 @@ import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import javax.annotation.Nonnull;
 
 import org.bouncycastle.openpgp.PGPException;
 import org.bouncycastle.openpgp.PGPPrivateKey;
@@ -32,7 +32,6 @@ import org.bouncycastle.openpgp.PGPPublicKeyRingCollection;
 import org.bouncycastle.openpgp.PGPSecretKey;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.bouncycastle.openpgp.PGPSecretKeyRingCollection;
-import org.jetbrains.annotations.NotNull;
 import org.pgpainless.algorithm.CompressionAlgorithm;
 import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
@@ -41,10 +40,10 @@ import org.pgpainless.key.OpenPgpV4Fingerprint;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.selection.key.PublicKeySelectionStrategy;
 import org.pgpainless.key.selection.key.SecretKeySelectionStrategy;
-import org.pgpainless.key.selection.key.util.And;
 import org.pgpainless.key.selection.key.impl.EncryptionKeySelectionStrategy;
 import org.pgpainless.key.selection.key.impl.NoRevocation;
 import org.pgpainless.key.selection.key.impl.SignatureKeySelectionStrategy;
+import org.pgpainless.key.selection.key.util.And;
 import org.pgpainless.key.selection.keyring.PublicKeyRingSelectionStrategy;
 import org.pgpainless.key.selection.keyring.SecretKeyRingSelectionStrategy;
 import org.pgpainless.util.MultiMap;

pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionStream.java

@@ -15,19 +15,16 @@
  */
 package org.pgpainless.encryption_signing;
 
-import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.io.OutputStream;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
-import java.util.HashSet;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import javax.annotation.Nonnull;
 
 import org.bouncycastle.bcpg.ArmoredOutputStream;
 import org.bouncycastle.bcpg.BCPGOutputStream;
@@ -38,10 +35,8 @@ import org.bouncycastle.openpgp.PGPLiteralData;
 import org.bouncycastle.openpgp.PGPLiteralDataGenerator;
 import org.bouncycastle.openpgp.PGPPrivateKey;
 import org.bouncycastle.openpgp.PGPPublicKey;
-import org.bouncycastle.openpgp.PGPSecretKey;
 import org.bouncycastle.openpgp.PGPSignature;
 import org.bouncycastle.openpgp.PGPSignatureGenerator;
-import org.bouncycastle.openpgp.operator.bc.BcKeyFingerprintCalculator;
 import org.bouncycastle.openpgp.operator.bc.BcPGPContentSignerBuilder;
 import org.bouncycastle.openpgp.operator.bc.BcPGPDataEncryptorBuilder;
 import org.bouncycastle.openpgp.operator.bc.BcPublicKeyKeyEncryptionMethodGenerator;

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

@@ -80,7 +80,7 @@ public class DecryptAndVerifyMessageTest {
         assertTrue(metadata.isVerified());
         assertEquals(CompressionAlgorithm.ZLIB, metadata.getCompressionAlgorithm());
         assertEquals(SymmetricKeyAlgorithm.AES_256, metadata.getSymmetricKeyAlgorithm());
-        //assertEquals(1, metadata.getSignatureKeyIDs().size());
+        assertEquals(1, metadata.getSignatures().size());
         assertEquals(1, metadata.getVerifiedSignatureKeyFingerprints().size());
         assertTrue(metadata.containsVerifiedSignatureFrom(TestKeys.JULIET_FINGERPRINT));
         assertEquals(TestKeys.JULIET_FINGERPRINT, metadata.getDecryptionFingerprint());

pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptDecryptTest.java

@@ -209,7 +209,9 @@ public class EncryptDecryptTest {
         armorOut.close();
         String armorSig = sigOut.toString();
 
+        // CHECKSTYLE:OFF
         System.out.println(armorSig);
+        // CHECKSTYLE:ON
 
         inputStream = new ByteArrayInputStream(testMessage.getBytes());
         DecryptionStream verifier = PGPainless.createDecryptor().onInputStream(inputStream)