Add getPrimaryUserId()

pgpainless-core/src/main/java/org/pgpainless/key/info/KeyRingInfo.java

@@ -82,11 +82,8 @@ public class KeyRingInfo {
      * @return list of public keys
      */
     public List<PGPPublicKey> getPublicKeys() {
-        List<PGPPublicKey> list = new ArrayList<>();
         Iterator<PGPPublicKey> iterator = keys.getPublicKeys();
-        while (iterator.hasNext()) {
-            list.add(iterator.next());
-        }
+        List<PGPPublicKey> list = iteratorToList(iterator);
         return Collections.unmodifiableList(list);
     }
 
@@ -122,15 +119,12 @@ public class KeyRingInfo {
      * @return list of secret keys
      */
     public List<PGPSecretKey> getSecretKeys() {
-        List<PGPSecretKey> list = new ArrayList<>();
         if (keys instanceof PGPSecretKeyRing) {
             PGPSecretKeyRing secretKeys = (PGPSecretKeyRing) keys;
             Iterator<PGPSecretKey> iterator = secretKeys.getSecretKeys();
-            while (iterator.hasNext()) {
-                list.add(iterator.next());
-            }
+            return Collections.unmodifiableList(iteratorToList(iterator));
         }
-        return Collections.unmodifiableList(list);
+        return Collections.emptyList();
     }
 
     /**
@@ -151,17 +145,25 @@ public class KeyRingInfo {
         return new OpenPgpV4Fingerprint(getPublicKey());
     }
 
+    public String getPrimaryUserId() throws PGPException {
+        List<String> userIds = getValidUserIds();
+        for (String userId : userIds) {
+            PGPSignature signature = getLatestValidSignatureOnUserId(userId);
+            if (signature.getHashedSubPackets().isPrimaryUserID()) {
+                return userId;
+            }
+        }
+        return null;
+    }
+
     /**
      * Return a list of all user-ids of the primary key.
      *
      * @return list of user-ids
      */
     public List<String> getUserIds() {
-        List<String> userIds = new ArrayList<>();
         Iterator<String> iterator = getPublicKey().getUserIDs();
-        while (iterator.hasNext()) {
-            userIds.add(iterator.next());
-        }
+        List<String> userIds = iteratorToList(iterator);
         return userIds;
     }
 
@@ -315,10 +317,7 @@ public class KeyRingInfo {
     public List<PGPSignature> getSelfSignaturesOnKey(long subkeyId) {
         PGPPublicKey publicKey = KeyRingUtils.requirePublicKeyFrom(keys, subkeyId);
         Iterator<PGPSignature> it = publicKey.getSignaturesForKeyID(keys.getPublicKey().getKeyID());
-        List<PGPSignature> signatures = new ArrayList<>();
-        while (it.hasNext()) {
-            signatures.add(it.next());
-        }
+        List<PGPSignature> signatures = iteratorToList(it);
         sortByCreationTimeAscending(signatures);
         return signatures;
     }
@@ -337,6 +336,13 @@ public class KeyRingInfo {
         return getLatestValidSignature(publicKey, signatures, keys);
     }
 
+    public PGPSignature getLatestValidSignatureOnUserId(String userId) throws PGPException {
+        PGPPublicKey publicKey = KeyRingUtils.requirePrimaryPublicKeyFrom(keys);
+        Iterator<PGPSignature> iterator = publicKey.getSignaturesForID(userId);
+        List<PGPSignature> signatures = iteratorToList(iterator);
+        return getLatestValidSignature(publicKey, signatures, keys);
+    }
+
     public List<PGPSignature> getBindingSignaturesOnKey(OpenPgpV4Fingerprint fingerprint) {
         return getBindingSignaturesOnKey(fingerprint.getKeyId());
     }
@@ -371,5 +377,12 @@ public class KeyRingInfo {
         return self.getCreationTime().after(binding.getCreationTime()) ? self : binding;
     }
 
-
+    private static <I> List<I> iteratorToList(Iterator<I> iterator) {
+        List<I> items = new ArrayList<>();
+        while (iterator.hasNext()) {
+            Object o = iterator.next();
+            items.add((I) o);
+        }
+        return items;
+    }
 }

pgpainless-core/src/test/java/org/pgpainless/key/info/PrimaryUserIdTest.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2021 Paul Schaub.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.pgpainless.key.info;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.security.InvalidAlgorithmParameterException;
+import java.security.NoSuchAlgorithmException;
+
+import org.bouncycastle.openpgp.PGPException;
+import org.bouncycastle.openpgp.PGPSecretKeyRing;
+import org.junit.jupiter.api.Test;
+import org.pgpainless.PGPainless;
+import org.pgpainless.key.protection.SecretKeyRingProtector;
+
+public class PrimaryUserIdTest {
+
+    @Test
+    public void testGetPrimaryUserId() throws InvalidAlgorithmParameterException, NoSuchAlgorithmException, PGPException {
+        PGPSecretKeyRing secretKeys = PGPainless.generateKeyRing().simpleEcKeyRing("alice@wonderland.lit");
+        secretKeys = PGPainless.modifyKeyRing(secretKeys)
+                .addUserId("mad_alice@wonderland.lit", SecretKeyRingProtector.unprotectedKeys())
+                .done();
+
+        KeyRingInfo info = PGPainless.inspectKeyRing(secretKeys);
+        assertEquals("alice@wonderland.lit", info.getPrimaryUserId());
+    }
+}