Add methods to control direct-key sigs and add unfinished test for primaryUserId test

pgpainless-core/src/main/kotlin/org/pgpainless/key/generation/GenerateOpenPgpKey.kt

@@ -103,6 +103,7 @@ open class GenerateOpenPgpKey(
         private val primaryKey =
             OpenPgpComponentKeyBuilder.V4PrimaryKeyBuilder(primaryKeyType, referenceTime, policy)
         private val subkeys = mutableListOf<OpenPgpComponentKeyBuilder.V4SubkeyBuilder>()
+        private var addDirectKeySignature = true
 
         private val preferencesCallback =
             SelfSignatureSubpackets.applyHashed {
@@ -113,6 +114,16 @@ open class GenerateOpenPgpKey(
                 primaryFlags?.let { setKeyFlags(*it.toTypedArray()) }
             }
 
+        fun directKeySignature(
+            subpacketsCallback: SelfSignatureSubpackets.Callback = SelfSignatureSubpackets.nop()
+        ) = apply {
+            addDirectKeySignature = false
+            primaryKey.directKeySignature(
+                subpacketsCallback = preferencesCallback.then(subpacketsCallback))
+        }
+
+        fun noDirectKeySignature() = apply { addDirectKeySignature = false }
+
         /**
          * Add a user-id to the key. The subpackets of the binding signature are prepopulated,
          * setting algorithm preferences and features. However, the subpackets can still be modified
@@ -259,7 +270,9 @@ open class GenerateOpenPgpKey(
         ): PGPSecretKeyRing {
 
             // add a direct key sig with preferences
-            primaryKey.directKeySignature(subpacketsCallback = preferencesCallback)
+            if (addDirectKeySignature) {
+                primaryKey.directKeySignature(subpacketsCallback = preferencesCallback)
+            }
 
             return PGPSecretKeyRing(
                 mutableListOf(

pgpainless-core/src/test/kotlin/org/pgpainless/key/generation/MalformedKeyGenerationTest.kt

@@ -7,10 +7,14 @@ package org.pgpainless.key.generation
 import org.bouncycastle.bcpg.sig.Exportable
 import org.bouncycastle.bcpg.sig.PrimaryUserID
 import org.bouncycastle.bcpg.sig.Revocable
+import org.bouncycastle.extensions.toAsciiArmor
 import org.junit.jupiter.api.Test
 import org.pgpainless.PGPainless
+import org.pgpainless.algorithm.HashAlgorithm
+import org.pgpainless.algorithm.KeyFlag
 import org.pgpainless.key.generation.type.KeyType
 import org.pgpainless.key.generation.type.eddsa.EdDSACurve
+import org.pgpainless.key.generation.type.xdh.XDHSpec
 import org.pgpainless.policy.Policy
 import org.pgpainless.signature.subpackets.SelfSignatureSubpackets
 
@@ -70,4 +74,38 @@ class MalformedKeyGenerationTest {
         PGPainless.readKeyRing().secretKeyRing(key.encoded)!!
         // TODO: Check interpretation of faulty packet
     }
+
+    @Test
+    fun primaryUserIdOnDirectKeySig() {
+        val policy = Policy.getInstance()
+        val key =
+            GenerateOpenPgpKey(policy)
+                .buildV4Key(
+                    KeyType.EDDSA(EdDSACurve._Ed25519),
+                    listOf(KeyFlag.CERTIFY_OTHER, KeyFlag.SIGN_DATA))
+                .directKeySignature(
+                    SelfSignatureSubpackets.applyHashed {
+                        setPrimaryUserId()
+                        setPreferredHashAlgorithms(HashAlgorithm.SHA224)
+                    })
+                .addUserId(
+                    "Alice <alice@pgpainless.org>",
+                    SelfSignatureSubpackets.applyHashed {
+                        setPrimaryUserId(null)
+                        setPreferredHashAlgorithms(HashAlgorithm.SHA256)
+                    })
+                .addUserId(
+                    "Bob <bob@pgpainless.org>",
+                    SelfSignatureSubpackets.applyHashed {
+                        setPrimaryUserId()
+                        setPreferredHashAlgorithms(HashAlgorithm.SHA384)
+                    })
+                .addEncryptionSubkey(KeyType.XDH(XDHSpec._X25519))
+                .build()
+        println(key.toAsciiArmor())
+
+        // TODO: Test, which hash algo is used when we encrypt+sign a message for this key.
+        //  Correct would be SHA384, since this is the primary user-id.
+        //  PrimaryUserID packets on the DK sig shall be ignored.
+    }
 }