Remove workaround for publicKey.getBitStrength() == -1 in BC

see https://github.com/bcgit/bc-java/issues/972

pgpainless-core/src/main/java/org/pgpainless/key/modification/secretkeyring/SecretKeyRingEditor.java

@@ -64,7 +64,6 @@ import org.pgpainless.signature.subpackets.SelfSignatureSubpackets;
 import org.pgpainless.signature.subpackets.SignatureSubpackets;
 import org.pgpainless.signature.subpackets.SignatureSubpacketsHelper;
 import org.pgpainless.signature.subpackets.SignatureSubpacketsUtil;
-import org.pgpainless.util.BCUtil;
 import org.pgpainless.util.CollectionUtils;
 import org.pgpainless.util.Passphrase;
 import org.pgpainless.util.selection.userid.SelectUserId;
@@ -278,7 +277,7 @@ public class SecretKeyRingEditor implements SecretKeyRingEditorInterface {
 
         // check key against public key algorithm policy
         PublicKeyAlgorithm publicKeyAlgorithm = PublicKeyAlgorithm.fromId(subkey.getPublicKey().getAlgorithm());
-        int bitStrength = BCUtil.getBitStrength(subkey.getPublicKey());
+        int bitStrength = subkey.getPublicKey().getBitStrength();
         if (!PGPainless.getPolicy().getPublicKeyAlgorithmPolicy().isAcceptable(publicKeyAlgorithm, bitStrength)) {
             throw new IllegalArgumentException("Public key algorithm policy violation: " +
                     publicKeyAlgorithm + " with bit strength " + bitStrength + " is not acceptable.");

pgpainless-core/src/main/java/org/pgpainless/signature/consumer/SignatureValidator.java

@@ -4,7 +4,6 @@
 
 package org.pgpainless.signature.consumer;
 
-import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
 import java.util.Date;
 import java.util.Iterator;
@@ -32,7 +31,6 @@ import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.policy.Policy;
 import org.pgpainless.signature.SignatureUtils;
 import org.pgpainless.signature.subpackets.SignatureSubpacketsUtil;
-import org.pgpainless.util.BCUtil;
 import org.pgpainless.util.DateUtil;
 import org.pgpainless.util.NotationRegistry;
 
@@ -171,15 +169,14 @@ public abstract class SignatureValidator {
             @Override
             public void verify(PGPSignature signature) throws SignatureValidationException {
                 PublicKeyAlgorithm algorithm = PublicKeyAlgorithm.fromId(signingKey.getAlgorithm());
-                try {
+                    int bitStrength = signingKey.getBitStrength();
-                    int bitStrength = BCUtil.getBitStrength(signingKey);
+                    if (bitStrength == -1) {
+                        throw new SignatureValidationException("Cannot determine bit strength of signing key.");
+                    }
                     if (!policy.getPublicKeyAlgorithmPolicy().isAcceptable(algorithm, bitStrength)) {
                         throw new SignatureValidationException("Signature was made using unacceptable key. " +
                                 algorithm + " (" + bitStrength + " bits) is not acceptable according to the public key algorithm policy.");
                     }
-                } catch (NoSuchAlgorithmException e) {
-                    throw new SignatureValidationException("Cannot determine bit strength of signing key.", e);
-                }
             }
         };
     }

pgpainless-core/src/main/java/org/pgpainless/util/BCUtil.java

@@ -4,50 +4,12 @@
 
 package org.pgpainless.util;
 
-import java.security.NoSuchAlgorithmException;
-
-import org.bouncycastle.asn1.ASN1ObjectIdentifier;
-import org.bouncycastle.bcpg.ECPublicBCPGKey;
-import org.bouncycastle.openpgp.PGPPublicKey;
-
 public final class BCUtil {
 
     private BCUtil() {
 
     }
 
-    /**
-     * Utility method to get the bit strength of OpenPGP keys.
-     * Bouncycastle is lacking support for some keys (eg. EdDSA, X25519), so this method
-     * manually derives the bit strength from the keys curves OID.
-     *
-     * @param key key
-     * @return bit strength
-     */
-    public static int getBitStrength(PGPPublicKey key) throws NoSuchAlgorithmException {
-        int bitStrength = key.getBitStrength();
-
-        if (bitStrength == -1) {
-            // BC's PGPPublicKey.getBitStrength() does fail for some keys (EdDSA, X25519)
-            // therefore we manually set the bit strength.
-            // see https://github.com/bcgit/bc-java/issues/972
-
-            ASN1ObjectIdentifier oid = ((ECPublicBCPGKey) key.getPublicKeyPacket().getKey()).getCurveOID();
-            if (oid.getId().equals("1.3.6.1.4.1.11591.15.1")) {
-                // ed25519 is 256 bits
-                bitStrength = 256;
-            } else if (oid.getId().equals("1.3.6.1.4.1.3029.1.5.1")) {
-                // curvey25519 is 256 bits
-                bitStrength = 256;
-            } else {
-                throw new NoSuchAlgorithmException("Unknown curve: " + oid.getId());
-            }
-
-        }
-        return bitStrength;
-    }
-
-
     /**
      * A constant time equals comparison - does not terminate early if
      * test will fail. For best results always pass the expected value

pgpainless-core/src/test/java/org/pgpainless/key/generation/BrainpoolKeyGenerationTest.java

@@ -29,9 +29,8 @@ import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.key.generation.type.xdh.XDHSpec;
 import org.pgpainless.key.info.KeyInfo;
 import org.pgpainless.key.util.UserId;
-import org.pgpainless.util.BCUtil;
-import org.pgpainless.util.TestAllImplementations;
 import org.pgpainless.util.Passphrase;
+import org.pgpainless.util.TestAllImplementations;
 
 public class BrainpoolKeyGenerationTest {
 
@@ -96,22 +95,22 @@ public class BrainpoolKeyGenerationTest {
         PGPSecretKey ecdsaPrim = iterator.next();
         KeyInfo ecdsaInfo = new KeyInfo(ecdsaPrim);
         assertEquals(EllipticCurve._BRAINPOOLP384R1.getName(), ecdsaInfo.getCurveName());
-        assertEquals(384, BCUtil.getBitStrength(ecdsaPrim.getPublicKey()));
+        assertEquals(384, ecdsaPrim.getPublicKey().getBitStrength());
 
         PGPSecretKey eddsaSub = iterator.next();
         KeyInfo eddsaInfo = new KeyInfo(eddsaSub);
         assertEquals(EdDSACurve._Ed25519.getName(), eddsaInfo.getCurveName());
-        assertEquals(256, BCUtil.getBitStrength(eddsaSub.getPublicKey()));
+        assertEquals(256, eddsaSub.getPublicKey().getBitStrength());
 
         PGPSecretKey xdhSub = iterator.next();
         KeyInfo xdhInfo = new KeyInfo(xdhSub);
         assertEquals(XDHSpec._X25519.getCurveName(), xdhInfo.getCurveName());
-        assertEquals(256, BCUtil.getBitStrength(xdhSub.getPublicKey()));
+        assertEquals(256, xdhSub.getPublicKey().getBitStrength());
 
         PGPSecretKey rsaSub = iterator.next();
         KeyInfo rsaInfo = new KeyInfo(rsaSub);
         assertThrows(IllegalArgumentException.class, rsaInfo::getCurveName, "RSA is not a curve-based encryption system");
-        assertEquals(3072, BCUtil.getBitStrength(rsaSub.getPublicKey()));
+        assertEquals(3072, rsaSub.getPublicKey().getBitStrength());
     }
 
     public PGPSecretKeyRing generateKey(KeySpec primaryKey, KeySpec subKey, String userId) throws InvalidAlgorithmParameterException, NoSuchAlgorithmException, PGPException {