Use ArmoredOutputStreamFactory to hide version string in ascii armor

Partially fixes #82

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

@@ -51,6 +51,7 @@ import org.pgpainless.decryption_verification.DetachedSignature;
 import org.pgpainless.decryption_verification.OpenPgpMetadata;
 import org.pgpainless.implementation.ImplementationFactory;
 import org.pgpainless.key.OpenPgpV4Fingerprint;
+import org.pgpainless.util.ArmoredOutputStreamFactory;
 import org.pgpainless.util.Passphrase;
 
 /**
@@ -146,7 +147,7 @@ public final class EncryptionStream extends OutputStream {
         }
 
         LOGGER.log(LEVEL, "Wrap encryption output in ASCII armor");
-        armorOutputStream = new ArmoredOutputStream(outermostStream);
+        armorOutputStream = ArmoredOutputStreamFactory.get(outermostStream);
         outermostStream = armorOutputStream;
     }
 

pgpainless-core/src/main/java/org/pgpainless/util/ArmorUtils.java

@@ -41,7 +41,7 @@ public class ArmorUtils {
 
     public static String toAsciiArmoredString(InputStream inputStream) throws IOException {
         ByteArrayOutputStream out = new ByteArrayOutputStream();
-        ArmoredOutputStream armor = new ArmoredOutputStream(out);
+        ArmoredOutputStream armor = ArmoredOutputStreamFactory.get(out);
 
         Streams.pipeAll(inputStream, armor);
         armor.close();

pgpainless-core/src/main/java/org/pgpainless/util/ArmoredOutputStreamFactory.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2021 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.util;
+
+import java.io.OutputStream;
+
+import org.bouncycastle.bcpg.ArmoredOutputStream;
+
+/**
+ * Factory to create configured {@link ArmoredOutputStream ArmoredOutputStreams}.
+ */
+public class ArmoredOutputStreamFactory {
+
+    public static final String VERSION = "PGPainless";
+
+    public static ArmoredOutputStream get(OutputStream outputStream) {
+        ArmoredOutputStream armoredOutputStream = new ArmoredOutputStream(outputStream);
+        armoredOutputStream.setHeader(ArmoredOutputStream.VERSION_HDR, VERSION);
+        return armoredOutputStream;
+    }
+}

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

@@ -52,6 +52,7 @@ import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnprotectedKeysProtector;
 import org.pgpainless.key.util.KeyRingUtils;
+import org.pgpainless.util.ArmoredOutputStreamFactory;
 import org.pgpainless.util.BCUtil;
 
 public class EncryptDecryptTest {
@@ -205,7 +206,7 @@ public class EncryptDecryptTest {
 
         Set<PGPSignature> signatureSet = metadata.getSignatures();
         ByteArrayOutputStream sigOut = new ByteArrayOutputStream();
-        ArmoredOutputStream armorOut = new ArmoredOutputStream(sigOut);
+        ArmoredOutputStream armorOut = ArmoredOutputStreamFactory.get(sigOut);
         signatureSet.iterator().next().encode(armorOut);
         armorOut.close();
         String armorSig = sigOut.toString();

pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateKeyTest.java

@@ -30,6 +30,7 @@ import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.OpenPgpV4Fingerprint;
 import org.pgpainless.key.util.KeyRingUtils;
+import org.pgpainless.util.ArmoredOutputStreamFactory;
 
 public class GenerateKeyTest {
 
@@ -41,13 +42,13 @@ public class GenerateKeyTest {
         PGPPublicKeyRing publicKeys = KeyRingUtils.publicKeyRingFrom(secretKeys);
 
         ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-        ArmoredOutputStream armor = new ArmoredOutputStream(bytes);
+        ArmoredOutputStream armor = ArmoredOutputStreamFactory.get(bytes);
         secretKeys.encode(armor);
         armor.close();
         String publicKey = new String(bytes.toByteArray());
 
         bytes = new ByteArrayOutputStream();
-        armor = new ArmoredOutputStream(bytes);
+        armor = ArmoredOutputStreamFactory.get(bytes);
         secretKeys.encode(armor);
         armor.close();
         String privateKey = new String(bytes.toByteArray());

pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateKeyWithAdditionalUserIdTest.java

@@ -35,6 +35,7 @@ import org.pgpainless.algorithm.KeyFlag;
 import org.pgpainless.key.generation.type.KeyType;
 import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.key.util.KeyRingUtils;
+import org.pgpainless.util.ArmoredOutputStreamFactory;
 
 public class GenerateKeyWithAdditionalUserIdTest {
 
@@ -65,7 +66,7 @@ public class GenerateKeyWithAdditionalUserIdTest {
         assertFalse(userIds.hasNext());
 
         ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
-        ArmoredOutputStream armor = new ArmoredOutputStream(byteOut);
+        ArmoredOutputStream armor = ArmoredOutputStreamFactory.get(byteOut);
         secretKeys.encode(armor);
         armor.close();
 

pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeKeyWithGenericCertificationSignatureTest.java

@@ -28,6 +28,7 @@ import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.protection.UnprotectedKeysProtector;
+import org.pgpainless.util.ArmoredOutputStreamFactory;
 
 /**
  * Test that makes sure that PGPainless can deal with keys that carry a key
@@ -88,14 +89,14 @@ public class RevokeKeyWithGenericCertificationSignatureTest {
 
         PGPPublicKey pkr = secretKeyRing.getPublicKeys().next();
         ByteArrayOutputStream pubOutBytes = new ByteArrayOutputStream();
-        try (ArmoredOutputStream pubOut = new ArmoredOutputStream(pubOutBytes)) {
+        try (ArmoredOutputStream pubOut = ArmoredOutputStreamFactory.get(pubOutBytes)) {
             pkr.encode(pubOut);
         }
         pubOutBytes.close();
 
         PGPSecretKey skr = secretKeyRing.getSecretKeys().next();
         ByteArrayOutputStream secOutBytes = new ByteArrayOutputStream();
-        try (ArmoredOutputStream privOut = new ArmoredOutputStream(secOutBytes)) {
+        try (ArmoredOutputStream privOut = ArmoredOutputStreamFactory.get(secOutBytes)) {
             skr.encode(privOut);
         }
         secOutBytes.close();

pgpainless-core/src/test/java/org/pgpainless/symmetric_encryption/LegacySymmetricEncryptionTest.java

@@ -27,6 +27,7 @@ import org.bouncycastle.openpgp.PGPException;
 import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
+import org.pgpainless.util.ArmoredOutputStreamFactory;
 import org.pgpainless.util.Passphrase;
 
 public class LegacySymmetricEncryptionTest {
@@ -52,7 +53,7 @@ public class LegacySymmetricEncryptionTest {
         Passphrase passphrase = new Passphrase(password.toCharArray());
         byte[] enc = PGPainless.encryptWithPassword(plain, passphrase, SymmetricKeyAlgorithm.AES_128);
         ByteArrayOutputStream out = new ByteArrayOutputStream();
-        ArmoredOutputStream armor = new ArmoredOutputStream(out);
+        ArmoredOutputStream armor = ArmoredOutputStreamFactory.get(out);
         armor.write(enc);
         armor.flush();
         armor.close();

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Armor.java

@@ -17,6 +17,7 @@ package org.pgpainless.sop.commands;
 
 import org.bouncycastle.bcpg.ArmoredOutputStream;
 import org.bouncycastle.util.io.Streams;
+import org.pgpainless.util.ArmoredOutputStreamFactory;
 import picocli.CommandLine;
 
 import java.io.IOException;
@@ -49,7 +50,7 @@ public class Armor implements Runnable {
     @Override
     public void run() {
 
-        try (PushbackInputStream pbIn = new PushbackInputStream(System.in); ArmoredOutputStream armoredOutputStream = new ArmoredOutputStream(System.out)) {
+        try (PushbackInputStream pbIn = new PushbackInputStream(System.in); ArmoredOutputStream armoredOutputStream = ArmoredOutputStreamFactory.get(System.out)) {
             byte[] start = new byte[14];
             int read = pbIn.read(start);
             pbIn.unread(read);