Introduce AEADAlgorithmCombination class

pgpainless-core/src/main/java/org/pgpainless/algorithm/AEADAlgorithmCombination.java

@@ -0,0 +1,73 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.algorithm;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import org.bouncycastle.bcpg.sig.PreferredAEADCiphersuites;
+
+public final class AEADAlgorithmCombination {
+
+    private final AEADAlgorithm aeadAlgorithm;
+    private final SymmetricKeyAlgorithm symmetricKeyAlgorithm;
+
+    /**
+     * AES-128 + OCB is a MUST implement and is therefore implicitly supported.
+     *
+     * @see <a href="https://openpgp-wg.gitlab.io/rfc4880bis/#name-preferred-aead-ciphersuites">
+     * Crypto-Refresh § 5.2.3.15. Preferred AEAD Ciphersuites</a>
+     */
+    public static AEADAlgorithmCombination AES_128_OCB = AEADAlgorithmCombination.from(
+            SymmetricKeyAlgorithm.AES_128, AEADAlgorithm.OCB);
+
+    private AEADAlgorithmCombination(@Nonnull SymmetricKeyAlgorithm symmetricKeyAlgorithm,
+                                    @Nonnull AEADAlgorithm aeadAlgorithm) {
+        this.aeadAlgorithm = aeadAlgorithm;
+        this.symmetricKeyAlgorithm = symmetricKeyAlgorithm;
+    }
+
+    @Nonnull
+    public AEADAlgorithm getAeadAlgorithm() {
+        return aeadAlgorithm;
+    }
+
+    @Nonnull
+    public SymmetricKeyAlgorithm getSymmetricKeyAlgorithm() {
+        return symmetricKeyAlgorithm;
+    }
+
+    public static AEADAlgorithmCombination from(@Nonnull SymmetricKeyAlgorithm symmetricKeyAlgorithm,
+                                                @Nonnull AEADAlgorithm aeadAlgorithm) {
+        return new AEADAlgorithmCombination(symmetricKeyAlgorithm, aeadAlgorithm);
+    }
+
+    @Nullable
+    public static AEADAlgorithmCombination from(PreferredAEADCiphersuites.Combination combination) {
+        return fromIds(combination.getSymmetricAlgorithm(), combination.getAeadAlgorithm());
+    }
+
+    @Nonnull
+    public static AEADAlgorithmCombination requireFrom(PreferredAEADCiphersuites.Combination combination) {
+        return requireFromIds(combination.getSymmetricAlgorithm(), combination.getAeadAlgorithm());
+    }
+
+    @Nullable
+    public static AEADAlgorithmCombination fromIds(int symmetricAlgorithmId, int aeadAlgorithmId) {
+        SymmetricKeyAlgorithm symmetric = SymmetricKeyAlgorithm.fromId(symmetricAlgorithmId);
+        AEADAlgorithm aead = AEADAlgorithm.fromId(aeadAlgorithmId);
+
+        if (symmetric == null || aead == null) {
+            return null;
+        }
+
+        return new AEADAlgorithmCombination(symmetric, aead);
+    }
+
+    @Nonnull
+    public static AEADAlgorithmCombination requireFromIds(int symmetricAlgorithmId, int aeadAlgorithmId) {
+        return from(SymmetricKeyAlgorithm.requireFromId(symmetricAlgorithmId), AEADAlgorithm.requireFromId(aeadAlgorithmId));
+    }
+}

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

@@ -18,13 +18,12 @@ import org.bouncycastle.bcpg.sig.PreferredAlgorithms;
 import org.bouncycastle.bcpg.sig.PrimaryUserID;
 import org.bouncycastle.bcpg.sig.RevocationKey;
 import org.bouncycastle.openpgp.PGPPublicKey;
-import org.pgpainless.algorithm.AEADAlgorithm;
+import org.pgpainless.algorithm.AEADAlgorithmCombination;
 import org.pgpainless.algorithm.CompressionAlgorithm;
 import org.pgpainless.algorithm.Feature;
 import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.KeyFlag;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
-import org.pgpainless.util.Tuple;
 
 public interface SelfSignatureSubpackets extends BaseSignatureSubpackets {
 
@@ -59,11 +58,11 @@ public interface SelfSignatureSubpackets extends BaseSignatureSubpackets {
 
     SelfSignatureSubpackets setKeyExpirationTime(@Nullable KeyExpirationTime keyExpirationTime);
 
-    SelfSignatureSubpackets setPreferredAEADCiphersuites(Tuple<SymmetricKeyAlgorithm, AEADAlgorithm>... algorithms);
+    SelfSignatureSubpackets setPreferredAEADCiphersuites(AEADAlgorithmCombination... algorithms);
 
-    SelfSignatureSubpackets setPreferredAEADCiphersuites(Set<Tuple<SymmetricKeyAlgorithm, AEADAlgorithm>> algorithms);
+    SelfSignatureSubpackets setPreferredAEADCiphersuites(Set<AEADAlgorithmCombination> algorithms);
 
-    SelfSignatureSubpackets setPreferredAEADCiphersuites(boolean isCritical, Set<Tuple<SymmetricKeyAlgorithm, AEADAlgorithm>> algorithms);
+    SelfSignatureSubpackets setPreferredAEADCiphersuites(boolean isCritical, Set<AEADAlgorithmCombination> algorithms);
 
     SelfSignatureSubpackets setPreferredAEADCiphersuites(@Nullable PreferredAEADCiphersuites algorithms);
 

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

@@ -43,7 +43,7 @@ import org.bouncycastle.bcpg.sig.TrustSignature;
 import org.bouncycastle.openpgp.PGPPublicKey;
 import org.bouncycastle.openpgp.PGPSignature;
 import org.bouncycastle.openpgp.PGPSignatureSubpacketVector;
-import org.pgpainless.algorithm.AEADAlgorithm;
+import org.pgpainless.algorithm.AEADAlgorithmCombination;
 import org.pgpainless.algorithm.CompressionAlgorithm;
 import org.pgpainless.algorithm.Feature;
 import org.pgpainless.algorithm.HashAlgorithm;
@@ -51,7 +51,6 @@ import org.pgpainless.algorithm.KeyFlag;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.key.util.RevocationAttributes;
-import org.pgpainless.util.Tuple;
 
 public class SignatureSubpackets
         implements BaseSignatureSubpackets, SelfSignatureSubpackets, CertificationSubpackets, RevocationSignatureSubpackets {
@@ -318,23 +317,24 @@ public class SignatureSubpackets
     }
 
     @Override
-    public SelfSignatureSubpackets setPreferredAEADCiphersuites(Tuple<SymmetricKeyAlgorithm, AEADAlgorithm>... algorithms) {
+    public SelfSignatureSubpackets setPreferredAEADCiphersuites(AEADAlgorithmCombination... algorithms) {
         return setPreferredAEADCiphersuites(new LinkedHashSet<>(Arrays.asList(algorithms)));
     }
 
     @Override
-    public SelfSignatureSubpackets setPreferredAEADCiphersuites(Set<Tuple<SymmetricKeyAlgorithm, AEADAlgorithm>> algorithms) {
+    public SelfSignatureSubpackets setPreferredAEADCiphersuites(Set<AEADAlgorithmCombination> algorithms) {
         return setPreferredAEADCiphersuites(false, algorithms);
     }
 
     @Override
-    public SelfSignatureSubpackets setPreferredAEADCiphersuites(boolean isCritical, Set<Tuple<SymmetricKeyAlgorithm, AEADAlgorithm>> algorithms) {
+    public SelfSignatureSubpackets setPreferredAEADCiphersuites(boolean isCritical, Set<AEADAlgorithmCombination> algorithms) {
         List<PreferredAEADCiphersuites.Combination> combinations = new ArrayList<>();
-        Iterator<Tuple<SymmetricKeyAlgorithm, AEADAlgorithm>> iterator = algorithms.iterator();
+        Iterator<AEADAlgorithmCombination> iterator = algorithms.iterator();
         while (iterator.hasNext()) {
-            Tuple<SymmetricKeyAlgorithm, AEADAlgorithm> tuple = iterator.next();
+            AEADAlgorithmCombination combination = iterator.next();
             combinations.add(new PreferredAEADCiphersuites.Combination(
-                    tuple.getA().getAlgorithmId(), tuple.getB().getAlgorithmId()));
+                    combination.getSymmetricKeyAlgorithm().getAlgorithmId(),
+                    combination.getAeadAlgorithm().getAlgorithmId()));
         }
         PreferredAEADCiphersuites subpacket = new PreferredAEADCiphersuites(
                 isCritical, combinations.toArray(new PreferredAEADCiphersuites.Combination[0]));

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

@@ -21,6 +21,7 @@ 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.PreferredAEADCiphersuites;
 import org.bouncycastle.bcpg.sig.PreferredAlgorithms;
 import org.bouncycastle.bcpg.sig.PrimaryUserID;
 import org.bouncycastle.bcpg.sig.RegularExpression;
@@ -37,6 +38,7 @@ import org.bouncycastle.openpgp.PGPPublicKey;
 import org.bouncycastle.openpgp.PGPSignature;
 import org.bouncycastle.openpgp.PGPSignatureList;
 import org.bouncycastle.openpgp.PGPSignatureSubpacketVector;
+import org.pgpainless.algorithm.AEADAlgorithmCombination;
 import org.pgpainless.algorithm.CompressionAlgorithm;
 import org.pgpainless.algorithm.Feature;
 import org.pgpainless.algorithm.HashAlgorithm;
@@ -334,6 +336,39 @@ public final class SignatureSubpacketsUtil {
         return algorithms;
     }
 
+    public static @Nullable PreferredAEADCiphersuites getPreferredAEADAlgorithms(PGPSignature signature) {
+        org.bouncycastle.bcpg.SignatureSubpacket subpacket = hashed(signature, SignatureSubpacket.preferredAEADAlgorithms);
+        if (subpacket == null) {
+            return null;
+        }
+
+        // Workaround for https://github.com/pgpainless/pgpainless/pull/399
+        // TODO: Remove when BC 1.77 is released
+        if (subpacket instanceof PreferredAlgorithms) {
+            List<PreferredAEADCiphersuites.Combination> combinationList = new ArrayList<>();
+            int[] algorithms = ((PreferredAlgorithms) subpacket).getPreferences();
+            for (int i = 0; i < algorithms.length; i += 2) {
+                combinationList.add(new PreferredAEADCiphersuites.Combination(algorithms[i], algorithms[i + 1]));
+            }
+            PreferredAEADCiphersuites aead = new PreferredAEADCiphersuites(
+                    subpacket.isCritical(), combinationList.toArray(new PreferredAEADCiphersuites.Combination[0]));
+            return aead;
+        }
+
+        return (PreferredAEADCiphersuites) subpacket;
+    }
+
+    public static @Nonnull Set<AEADAlgorithmCombination> parsePreferredAEADAlgorithms(PGPSignature signature) {
+        Set<AEADAlgorithmCombination> algorithms = new LinkedHashSet<>();
+        PreferredAEADCiphersuites preferences = getPreferredAEADAlgorithms(signature);
+        if (preferences != null) {
+            for (PreferredAEADCiphersuites.Combination combination : preferences.getAlgorithms()) {
+                algorithms.add(AEADAlgorithmCombination.from(combination));
+            }
+        }
+        return algorithms;
+    }
+
     /**
      * Return the primary user-id subpacket from the signatures hashed area.
      *