Kotlin conversion: CRLFGeneratorStream

pgpainless-core/src/main/kotlin/org/pgpainless/encryption_signing/CRLFGeneratorStream.kt

@@ -0,0 +1,52 @@
+// SPDX-FileCopyrightText: 2021 David Hook <dgh@cryptoworkshop.com>
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.encryption_signing
+
+import org.pgpainless.algorithm.StreamEncoding
+import java.io.OutputStream
+
+/**
+ * [OutputStream] which applies CR-LF encoding of its input data, based on the desired [StreamEncoding].
+ * This implementation originates from the Bouncy Castle library.
+ */
+class CRLFGeneratorStream(
+        private val crlfOut: OutputStream,
+        encoding: StreamEncoding
+) : OutputStream() {
+
+    private val isBinary: Boolean
+    private var lastB = 0
+
+    init {
+        isBinary = encoding == StreamEncoding.BINARY
+    }
+
+    override fun write(b: Int) {
+        if (!isBinary) {
+            if (b == '\n'.code && lastB != '\r'.code) {     // Unix
+                crlfOut.write('\r'.code)
+            } else if (lastB == '\r'.code) {                // MAC
+                if (b != '\n'.code) {
+                    crlfOut.write('\n'.code)
+                }
+            }
+            lastB = b
+        }
+        crlfOut.write(b)
+    }
+
+    override fun close() {
+        if (!isBinary && lastB == 'r'.code) {
+            crlfOut.write('\n'.code)
+        }
+        crlfOut.close()
+    }
+
+    override fun flush() {
+        super.flush()
+        crlfOut.flush()
+    }
+}