From 892f452da86657de0b6f44cd2f167ed530ce52f7 Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Sat, 8 May 2021 14:02:44 +0200
Subject: [PATCH] Print fingerprint+user-id in comment headers of Armor

---
 .../java/org/pgpainless/util/ArmorUtils.java  | 39 +++++++++++++++++--
 .../java/org/pgpainless/util/MultiMap.java    |  6 +--
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/ArmorUtils.java b/pgpainless-core/src/main/java/org/pgpainless/util/ArmorUtils.java
index 6807e37f..02d5892d 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/ArmorUtils.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/util/ArmorUtils.java
@@ -19,30 +19,61 @@ import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.Iterator;
 
 import org.bouncycastle.bcpg.ArmoredOutputStream;
+import org.bouncycastle.openpgp.PGPKeyRing;
 import org.bouncycastle.openpgp.PGPPublicKeyRing;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.bouncycastle.util.io.Streams;
+import org.pgpainless.key.OpenPgpV4Fingerprint;
 
 public class ArmorUtils {
 
     public static String toAsciiArmoredString(PGPSecretKeyRing secretKeys) throws IOException {
-        return toAsciiArmoredString(secretKeys.getEncoded());
+        MultiMap<String, String> header = keyToHeader(secretKeys);
+        return toAsciiArmoredString(secretKeys.getEncoded(), header);
     }
 
     public static String toAsciiArmoredString(PGPPublicKeyRing publicKeys) throws IOException {
-        return toAsciiArmoredString(publicKeys.getEncoded());
+        MultiMap<String, String> header = keyToHeader(publicKeys);
+        return toAsciiArmoredString(publicKeys.getEncoded(), header);
+    }
+
+    private static MultiMap<String, String> keyToHeader(PGPKeyRing keyRing) {
+        MultiMap<String, String> header = new MultiMap<>();
+        OpenPgpV4Fingerprint fingerprint = new OpenPgpV4Fingerprint(keyRing);
+        Iterator<String> userIds = keyRing.getPublicKey().getUserIDs();
+
+        header.put("Comment", fingerprint.prettyPrint());
+        if (userIds.hasNext()) {
+            header.put("Comment", userIds.next());
+        }
+        return header;
     }
 
     public static String toAsciiArmoredString(byte[] bytes) throws IOException {
-        return toAsciiArmoredString(new ByteArrayInputStream(bytes));
+        return toAsciiArmoredString(bytes, null);
+    }
+
+    public static String toAsciiArmoredString(byte[] bytes, MultiMap<String, String> additionalHeaderValues) throws IOException {
+        return toAsciiArmoredString(new ByteArrayInputStream(bytes), additionalHeaderValues);
     }
 
     public static String toAsciiArmoredString(InputStream inputStream) throws IOException {
+        return toAsciiArmoredString(inputStream, null);
+    }
+
+    public static String toAsciiArmoredString(InputStream inputStream, MultiMap<String, String> additionalHeaderValues) throws IOException {
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         ArmoredOutputStream armor = ArmoredOutputStreamFactory.get(out);
-
+        if (additionalHeaderValues != null) {
+            for (String header : additionalHeaderValues.keySet()) {
+                for (String value : additionalHeaderValues.get(header)) {
+                    armor.addHeader(header, value);
+                }
+            }
+        }
         Streams.pipeAll(inputStream, armor);
         armor.close();
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/MultiMap.java b/pgpainless-core/src/main/java/org/pgpainless/util/MultiMap.java
index d9b7c584..45c5000b 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/MultiMap.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/util/MultiMap.java
@@ -18,7 +18,7 @@ package org.pgpainless.util;
 import javax.annotation.Nonnull;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
 
@@ -33,7 +33,7 @@ public class MultiMap<K, V> {
     public MultiMap(@Nonnull MultiMap<K, V> other) {
         this.map = new HashMap<>();
         for (K k : other.map.keySet()) {
-            map.put(k, new HashSet<>(other.map.get(k)));
+            map.put(k, new LinkedHashSet<>(other.map.get(k)));
         }
     }
 
@@ -67,7 +67,7 @@ public class MultiMap<K, V> {
     public void put(K k, V v) {
         Set<V> values = map.get(k);
         if (values == null) {
-            values = new HashSet<>();
+            values = new LinkedHashSet<>();
             map.put(k, values);
         }
         values.add(v);