KeyRingInfo.isUsableFor*(): Check if primary key is revoked

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

@@ -1048,10 +1048,14 @@ public class KeyRingInfo {
      * @return true if usable for encryption
      */
     public boolean isUsableForEncryption(@Nonnull EncryptionPurpose purpose) {
-        return !getEncryptionSubkeys(purpose).isEmpty();
+        return isKeyValidlyBound(getKeyId()) && !getEncryptionSubkeys(purpose).isEmpty();
     }
 
     public boolean isUsableForSigning() {
+        if (!isKeyValidlyBound(getKeyId())) {
+            return false;
+        }
+
         List<PGPPublicKey> signingKeys = getSigningSubkeys();
         for (PGPPublicKey pk : signingKeys) {
             PGPSecretKey sk = getSecretKey(pk.getKeyID());

pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokedKeyTest.java

@@ -0,0 +1,44 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.key.modification;
+
+import org.bouncycastle.openpgp.PGPPublicKeyRing;
+import org.junit.jupiter.api.Test;
+import org.pgpainless.PGPainless;
+import org.pgpainless.key.info.KeyRingInfo;
+
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+public class RevokedKeyTest {
+
+    private static final String REVOKED = "-----BEGIN PGP PUBLIC KEY BLOCK-----\n" +
+            "\n" +
+            "xjMEYumXWhYJKwYBBAHaRw8BAQdAsesa7C2dtchG2LDYRPVgNiyXDDltTIW0\n" +
+            "7hbPKuklr+LCeAQgFgoACQUCYume7wIdAAAhCRARRbJWkH7x7hYhBCHmM1W/\n" +
+            "k8Vt/xDX4xFFslaQfvHusjoBAKeMumYgtr1uwbcNobWhojRjik+Uq7jER1Ph\n" +
+            "zrZPPwyaAP9NpV4//AB5BbwUgHMhCErD8L6GZEBOpCWYDgS00eKmCc0kVGVz\n" +
+            "dCBVc2VyIDx0ZXN0LnVzZXJAZmxvd2NyeXB0LnRlc3Q+wqcEExYIADgWIQQh\n" +
+            "5jNVv5PFbf8Q1+MRRbJWkH7x7gUCYumXWgIbAwULCQgHAgYVCgkICwIEFgID\n" +
+            "AQIeAQIXgAAhCRARRbJWkH7x7hYhBCHmM1W/k8Vt/xDX4xFFslaQfvHu0GUB\n" +
+            "AJ/FAi0K0YQ/gv9fO2EwSLH9imrXSxtfkzAyCQS32A/IAQDdqUfbABEoQvo2\n" +
+            "n1ktpVXroW3XPe3HlYFwSQzpVSHADc44BGLpl1oSCisGAQQBl1UBBQEBB0DJ\n" +
+            "8e0hG6v64O4P3qa9n8FxrkNoKS+J+fAW1Vzpf5tBUQMBCAfCjwQYFggAIBYh\n" +
+            "BCHmM1W/k8Vt/xDX4xFFslaQfvHuBQJi6ZdaAhsMACEJEBFFslaQfvHuFiEE\n" +
+            "IeYzVb+TxW3/ENfjEUWyVpB+8e51yAD/ewAe43L4bXYehVAKq+/CSfXEpYxU\n" +
+            "8kZv/mfA6nRfvOIA/iTx2uNw5NzC6TM5ZCBrXVxVGPmR9SwjnBHRmzVAmT8B\n" +
+            "=pY9e\n" +
+            "-----END PGP PUBLIC KEY BLOCK-----";
+
+    @Test
+    public void test() throws IOException {
+        PGPPublicKeyRing cert = PGPainless.readKeyRing().publicKeyRing(REVOKED);
+        KeyRingInfo info = PGPainless.inspectKeyRing(cert);
+
+        assertFalse(info.isUsableForSigning());
+        assertFalse(info.isUsableForEncryption());
+    }
+}