From b40476c9652758453a01ce0eb1022ee37158e673 Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Mon, 24 Oct 2022 17:49:30 +0200
Subject: [PATCH] Only check message integrity once

---
 .../IntegrityProtectedInputStream.java                | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.java b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.java
index 4da52d0f..286160e8 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.java
@@ -11,12 +11,17 @@ import javax.annotation.Nonnull;
 import org.bouncycastle.openpgp.PGPEncryptedData;
 import org.bouncycastle.openpgp.PGPException;
 import org.pgpainless.exception.ModificationDetectionException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class IntegrityProtectedInputStream extends InputStream {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(IntegrityProtectedInputStream.class);
+
     private final InputStream inputStream;
     private final PGPEncryptedData encryptedData;
     private final ConsumerOptions options;
+    private boolean closed = false;
 
     public IntegrityProtectedInputStream(InputStream inputStream, PGPEncryptedData encryptedData, ConsumerOptions options) {
         this.inputStream = inputStream;
@@ -36,11 +41,17 @@ public class IntegrityProtectedInputStream extends InputStream {
 
     @Override
     public void close() throws IOException {
+        if (closed) {
+            return;
+        }
+        closed = true;
+
         if (encryptedData.isIntegrityProtected() && !options.isIgnoreMDCErrors()) {
             try {
                 if (!encryptedData.verify()) {
                     throw new ModificationDetectionException();
                 }
+                LOGGER.debug("Integrity Protection check passed");
             } catch (PGPException e) {
                 throw new IOException("Failed to verify integrity protection", e);
             }