Add StreamGeneratorWrapper which uses new PGPCanonicalizedDataGenerator if required

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

@@ -15,7 +15,6 @@ import org.bouncycastle.bcpg.BCPGOutputStream;
 import org.bouncycastle.openpgp.PGPCompressedDataGenerator;
 import org.bouncycastle.openpgp.PGPEncryptedDataGenerator;
 import org.bouncycastle.openpgp.PGPException;
-import org.bouncycastle.openpgp.PGPLiteralDataGenerator;
 import org.bouncycastle.openpgp.PGPSignature;
 import org.bouncycastle.openpgp.PGPSignatureGenerator;
 import org.bouncycastle.openpgp.operator.PGPDataEncryptorBuilder;
@@ -25,6 +24,7 @@ import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.implementation.ImplementationFactory;
 import org.pgpainless.key.SubkeyIdentifier;
 import org.pgpainless.util.ArmoredOutputStreamFactory;
+import org.pgpainless.util.StreamGeneratorWrapper;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -50,7 +50,7 @@ public final class EncryptionStream extends OutputStream {
     private OutputStream publicKeyEncryptedStream = null;
     private PGPCompressedDataGenerator compressedDataGenerator;
     private BCPGOutputStream basicCompressionStream;
-    private PGPLiteralDataGenerator literalDataGenerator;
+    private StreamGeneratorWrapper streamGeneratorWrapper;
     private OutputStream literalDataStream;
 
     EncryptionStream(@Nonnull OutputStream targetOutputStream,
@@ -147,12 +147,10 @@ public final class EncryptionStream extends OutputStream {
             armorOutputStream.beginClearText(firstMethod.getHashAlgorithm().getAlgorithmId());
             return;
         }
-        literalDataGenerator = new PGPLiteralDataGenerator();
+
-        literalDataStream = literalDataGenerator.open(outermostStream,
+        streamGeneratorWrapper = StreamGeneratorWrapper.forStreamEncoding(options.getEncoding());
-                options.getEncoding().getCode(),
+        literalDataStream = streamGeneratorWrapper.open(outermostStream,
-                options.getFileName(),
+                options.getFileName(), options.getModificationDate(), new byte[BUFFER_SIZE]);
-                options.getModificationDate(),
-                new byte[BUFFER_SIZE]);
         outermostStream = literalDataStream;
 
         resultBuilder.setFileName(options.getFileName())
@@ -212,8 +210,8 @@ public final class EncryptionStream extends OutputStream {
             literalDataStream.flush();
             literalDataStream.close();
         }
-        if (literalDataGenerator != null) {
+        if (streamGeneratorWrapper != null) {
-            literalDataGenerator.close();
+            streamGeneratorWrapper.close();
         }
 
         if (options.isCleartextSigned()) {

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

@@ -0,0 +1,94 @@
+// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.util;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.Date;
+
+import javax.annotation.Nonnull;
+
+import org.bouncycastle.openpgp.PGPCanonicalizedDataGenerator;
+import org.bouncycastle.openpgp.PGPLiteralDataGenerator;
+import org.pgpainless.algorithm.StreamEncoding;
+
+/**
+ * Literal Data can be encoded in different ways.
+ * BINARY encoding leaves the data as is and is generated through the {@link PGPLiteralDataGenerator}.
+ * However, if the data is encoded in TEXT or UTF8 encoding, we need to use the {@link PGPCanonicalizedDataGenerator}
+ * instead.
+ *
+ * This wrapper class acts as a handle for both options and provides a unified interface for them.
+ */
+public final class StreamGeneratorWrapper {
+
+    private final StreamEncoding encoding;
+    private final PGPLiteralDataGenerator literalDataGenerator;
+    private final PGPCanonicalizedDataGenerator canonicalizedDataGenerator;
+
+    /**
+     * Create a new instance for the given encoding.
+     *
+     * @param encoding stream encoding
+     * @return wrapper
+     */
+    public static StreamGeneratorWrapper forStreamEncoding(@Nonnull StreamEncoding encoding) {
+        if (encoding == StreamEncoding.BINARY) {
+            return new StreamGeneratorWrapper(encoding, new PGPLiteralDataGenerator());
+        } else {
+            return new StreamGeneratorWrapper(encoding, new PGPCanonicalizedDataGenerator());
+        }
+    }
+
+    private StreamGeneratorWrapper(@Nonnull StreamEncoding encoding, @Nonnull PGPLiteralDataGenerator literalDataGenerator) {
+        if (encoding != StreamEncoding.BINARY) {
+            throw new IllegalArgumentException("PGPLiteralDataGenerator can only be used with BINARY encoding.");
+        }
+        this.encoding = encoding;
+        this.literalDataGenerator = literalDataGenerator;
+        this.canonicalizedDataGenerator = null;
+    }
+
+    private StreamGeneratorWrapper(@Nonnull StreamEncoding encoding, @Nonnull PGPCanonicalizedDataGenerator canonicalizedDataGenerator) {
+        if (encoding != StreamEncoding.TEXT && encoding != StreamEncoding.UTF8) {
+            throw new IllegalArgumentException("PGPCanonicalizedDataGenerator can only be used with TEXT or UTF8 encoding.");
+        }
+        this.encoding = encoding;
+        this.canonicalizedDataGenerator = canonicalizedDataGenerator;
+        this.literalDataGenerator = null;
+    }
+
+    /**
+     * Open a new encoding stream.
+     *
+     * @param outputStream wrapped output stream
+     * @param filename file name
+     * @param modificationDate modification date
+     * @param buffer buffer
+     * @return encoding stream
+     * @throws IOException
+     */
+    public OutputStream open(OutputStream outputStream, String filename, Date modificationDate, byte[] buffer) throws IOException {
+        if (literalDataGenerator != null) {
+            return literalDataGenerator.open(outputStream, encoding.getCode(), filename, modificationDate, buffer);
+        } else {
+            return canonicalizedDataGenerator.open(outputStream, encoding.getCode(), filename, modificationDate, buffer);
+        }
+    }
+
+    /**
+     * Close all encoding streams opened by this generator wrapper.
+     *
+     * @throws IOException
+     */
+    public void close() throws IOException {
+        if (literalDataGenerator != null) {
+            literalDataGenerator.close();
+        }
+        if (canonicalizedDataGenerator != null) {
+            canonicalizedDataGenerator.close();
+        }
+    }
+}

pgpainless-core/src/test/java/org/bouncycastle/LiteralDataCRLFEncodingTest.java

@@ -23,7 +23,7 @@ public class LiteralDataCRLFEncodingTest {
     public void testCanonicalization() throws IOException {
         PGPCanonicalizedDataGenerator generator = new PGPCanonicalizedDataGenerator();
         ByteArrayOutputStream out = new ByteArrayOutputStream();
-        OutputStream canonicalizer = generator.open(out, PGPCanonicalizedDataGenerator.UTF8, "", new Date(), new byte[1<<9]);
+        OutputStream canonicalizer = generator.open(out, PGPCanonicalizedDataGenerator.UTF8, "", new Date(), new byte[1 << 9]);
 
         ByteArrayInputStream in = new ByteArrayInputStream("Foo\nBar\n".getBytes(StandardCharsets.UTF_8));
         Streams.pipeAll(in, canonicalizer);