Kotlin conversion: IntegrityProtectedInputStream

pgpainless-core/src/main/kotlin/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.kt

@@ -0,0 +1,42 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.decryption_verification
+
+import org.bouncycastle.openpgp.PGPEncryptedData
+import org.bouncycastle.openpgp.PGPException
+import org.pgpainless.exception.ModificationDetectionException
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
+import java.io.IOException
+import java.io.InputStream
+
+class IntegrityProtectedInputStream(
+        private val inputStream: InputStream,
+        private val encryptedData: PGPEncryptedData,
+        private val options: ConsumerOptions
+) : InputStream() {
+    private var closed: Boolean = false
+
+    override fun read() = inputStream.read()
+    override fun read(b: ByteArray, off: Int, len: Int) = inputStream.read(b, off, len)
+    override fun close() {
+        if (closed) return
+
+        closed = true
+        if (encryptedData.isIntegrityProtected && !options.isIgnoreMDCErrors()) {
+            try {
+                if (!encryptedData.verify()) throw ModificationDetectionException()
+                LOGGER.debug("Integrity Protection check passed.")
+            } catch (e : PGPException) {
+                throw IOException("Data appears to not be integrity protected.", e)
+            }
+        }
+    }
+
+    companion object {
+        @JvmStatic
+        val LOGGER: Logger = LoggerFactory.getLogger(IntegrityProtectedInputStream::class.java)
+    }
+}