Add support for PolicyURI subpackets (fixes #248)

pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/BaseSignatureSubpackets.java

@@ -5,6 +5,7 @@
 package org.pgpainless.signature.subpackets;
 
 import java.io.IOException;
+import java.net.URL;
 import java.util.Date;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -15,6 +16,7 @@ import org.bouncycastle.bcpg.sig.IntendedRecipientFingerprint;
 import org.bouncycastle.bcpg.sig.IssuerFingerprint;
 import org.bouncycastle.bcpg.sig.IssuerKeyID;
 import org.bouncycastle.bcpg.sig.NotationData;
+import org.bouncycastle.bcpg.sig.PolicyURI;
 import org.bouncycastle.bcpg.sig.Revocable;
 import org.bouncycastle.bcpg.sig.SignatureCreationTime;
 import org.bouncycastle.bcpg.sig.SignatureExpirationTime;
@@ -88,6 +90,12 @@ public interface BaseSignatureSubpackets {
 
     BaseSignatureSubpackets setExportable(@Nullable Exportable exportable);
 
+    BaseSignatureSubpackets setPolicyUrl(@Nullable URL policyUrl);
+
+    BaseSignatureSubpackets setPolicyUrl(boolean isCritical, @Nonnull URL policyUrl);
+
+    BaseSignatureSubpackets setPolicyUrl(@Nullable PolicyURI policyUrl);
+
     BaseSignatureSubpackets setRevocable(boolean revocable);
 
     BaseSignatureSubpackets setRevocable(boolean isCritical, boolean isRevocable);

pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpackets.java

@@ -5,6 +5,7 @@
 package org.pgpainless.signature.subpackets;
 
 import java.io.IOException;
+import java.net.URL;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
@@ -26,6 +27,7 @@ import org.bouncycastle.bcpg.sig.IssuerKeyID;
 import org.bouncycastle.bcpg.sig.KeyExpirationTime;
 import org.bouncycastle.bcpg.sig.KeyFlags;
 import org.bouncycastle.bcpg.sig.NotationData;
+import org.bouncycastle.bcpg.sig.PolicyURI;
 import org.bouncycastle.bcpg.sig.PreferredAlgorithms;
 import org.bouncycastle.bcpg.sig.PrimaryUserID;
 import org.bouncycastle.bcpg.sig.Revocable;
@@ -68,6 +70,7 @@ public class SignatureSubpackets
     private final List<EmbeddedSignature> embeddedSignatureList = new ArrayList<>();
     private SignerUserID signerUserId;
     private KeyExpirationTime keyExpirationTime;
+    private PolicyURI policyURI;
     private PrimaryUserID primaryUserId;
     private Revocable revocable;
     private RevocationReason revocationReason;
@@ -485,6 +488,26 @@ public class SignatureSubpackets
         return exportable;
     }
 
+    @Override
+    public BaseSignatureSubpackets setPolicyUrl(@Nullable URL policyUrl) {
+        return policyUrl == null ? setPolicyUrl((PolicyURI) null) : setPolicyUrl(false, policyUrl);
+    }
+
+    @Override
+    public BaseSignatureSubpackets setPolicyUrl(boolean isCritical, @Nonnull URL policyUrl) {
+        return setPolicyUrl(new PolicyURI(isCritical, policyUrl.toString()));
+    }
+
+    @Override
+    public BaseSignatureSubpackets setPolicyUrl(@Nullable PolicyURI policyUrl) {
+        this.policyURI = policyUrl;
+        return this;
+    }
+
+    public PolicyURI getPolicyURI() {
+        return policyURI;
+    }
+
     @Override
     public SignatureSubpackets setRevocable(boolean revocable) {
         return setRevocable(true, revocable);

pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpacketsHelper.java

@@ -12,6 +12,7 @@ import org.bouncycastle.bcpg.sig.IntendedRecipientFingerprint;
 import org.bouncycastle.bcpg.sig.KeyExpirationTime;
 import org.bouncycastle.bcpg.sig.KeyFlags;
 import org.bouncycastle.bcpg.sig.NotationData;
+import org.bouncycastle.bcpg.sig.PolicyURI;
 import org.bouncycastle.bcpg.sig.PreferredAlgorithms;
 import org.bouncycastle.bcpg.sig.PrimaryUserID;
 import org.bouncycastle.bcpg.sig.Revocable;
@@ -114,11 +115,14 @@ public class SignatureSubpacketsHelper {
                     IntendedRecipientFingerprint intendedRecipientFingerprint = (IntendedRecipientFingerprint) subpacket;
                     subpackets.addIntendedRecipientFingerprint(intendedRecipientFingerprint);
                     break;
+                case policyUrl:
+                    PolicyURI policyURI = (PolicyURI) subpacket;
+                    subpackets.setPolicyUrl(policyURI);
+                    break;
 
                 case regularExpression:
                 case keyServerPreferences:
                 case preferredKeyServers:
-                case policyUrl:
                 case placeholder:
                 case preferredAEADAlgorithms:
                 case attestedCertification:
@@ -135,6 +139,7 @@ public class SignatureSubpacketsHelper {
         addSubpacket(generator, subpackets.getSignatureCreationTimeSubpacket());
         addSubpacket(generator, subpackets.getSignatureExpirationTimeSubpacket());
         addSubpacket(generator, subpackets.getExportableSubpacket());
+        addSubpacket(generator, subpackets.getPolicyURI());
         for (NotationData notationData : subpackets.getNotationDataSubpackets()) {
             addSubpacket(generator, notationData);
         }