From 428bda18d72bb9b344e6a27a26262fe3e684beff Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Wed, 29 Jul 2026 22:35:05 +0200
Subject: [PATCH] Add PGPKeyPairGenerator factory methods for OpenPGP brainpool
 keys

---
 .../openpgp/operator/PGPKeyPairGenerator.java |  97 +++++++
 .../openpgp/test/PGPKeyPairGeneratorTest.java | 236 ++++++++++++++++++
 2 files changed, 333 insertions(+)

diff --git a/pg/src/main/java/org/bouncycastle/openpgp/operator/PGPKeyPairGenerator.java b/pg/src/main/java/org/bouncycastle/openpgp/operator/PGPKeyPairGenerator.java
index 2dc54f5c42..9bcb955c42 100644
--- a/pg/src/main/java/org/bouncycastle/openpgp/operator/PGPKeyPairGenerator.java
+++ b/pg/src/main/java/org/bouncycastle/openpgp/operator/PGPKeyPairGenerator.java
@@ -2,6 +2,7 @@
 
 import org.bouncycastle.asn1.ASN1ObjectIdentifier;
 import org.bouncycastle.asn1.sec.SECObjectIdentifiers;
+import org.bouncycastle.asn1.teletrust.TeleTrusTObjectIdentifiers;
 import org.bouncycastle.bcpg.PublicKeyAlgorithmTags;
 import org.bouncycastle.openpgp.PGPException;
 import org.bouncycastle.openpgp.PGPKeyPair;
@@ -183,6 +184,7 @@ public abstract PGPKeyPair generateLegacyX25519KeyPair()
 
     /**
      * Generate an ECDH elliptic curve encryption key over the NIST p-256 curve.
+     * <pre>NIST P-256</pre> is equivalent to <pre>prime256v1</pre> and <pre>secp256r1</pre>.
      *
      * @return NIST p-256 ECDSA encryption key pair
      * @throws PGPException if the key pair cannot be generated
@@ -198,6 +200,7 @@ public PGPKeyPair generateNistP256ECDHKeyPair()
 
     /**
      * Generate an ECDH elliptic curve encryption key over the NIST p-384 curve.
+     * <pre>NIST P-384</pre> is equivalent to <pre>secp384r1</pre>.
      *
      * @return NIST p-384 ECDSA encryption key pair
      * @throws PGPException if the key pair cannot be generated
@@ -213,6 +216,7 @@ public PGPKeyPair generateNistP384ECDHKeyPair()
 
     /**
      * Generate an ECDH elliptic curve encryption key over the NIST p-521 curve.
+     * <pre>NIST P-521</pre> is equivalent to <pre>secp521r1</pre>.
      *
      * @return NIST p-521 ECDSA encryption key pair
      * @throws PGPException if the key pair cannot be generated
@@ -226,8 +230,54 @@ public PGPKeyPair generateNistP521ECDHKeyPair()
         return generateECDHKeyPair(SECObjectIdentifiers.secp521r1);
     }
 
+    /**
+     * Generate an ECDH elliptic curve encryption key over the brainpoolP256r1 curve.
+     *
+     * @return BrainpoolP256r1 ECDH encryption key pair
+     * @throws PGPException if the key pair cannot be generated
+     *
+     * @see <a href="https://www.rfc-editor.org/rfc/rfc9580.html#name-ecc-curves-for-openpgp">
+     *     RFC9580 - ECC Curves for OpenPGP</a>
+     */
+    public PGPKeyPair generateBrainpoolP256r1ECDHKeyPair()
+            throws PGPException
+    {
+        return generateECDHKeyPair(TeleTrusTObjectIdentifiers.brainpoolP256r1);
+    }
+
+    /**
+     * Generate an ECDH elliptic curve encryption key over the brainpoolP384r1 curve.
+     *
+     * @return BrainpoolP384r1 ECDH encryption key pair
+     * @throws PGPException if the key pair cannot be generated
+     *
+     * @see <a href="https://www.rfc-editor.org/rfc/rfc9580.html#name-ecc-curves-for-openpgp">
+     *     RFC9580 - ECC Curves for OpenPGP</a>
+     */
+    public PGPKeyPair generateBrainpoolP384r1ECDHKeyPair()
+            throws PGPException
+    {
+        return generateECDHKeyPair(TeleTrusTObjectIdentifiers.brainpoolP384r1);
+    }
+
+    /**
+     * Generate an ECDH elliptic curve encryption key over the brainpoolP512r1 curve.
+     *
+     * @return BrainpoolP512r1 ECDH encryption key pair
+     * @throws PGPException if the key pair cannot be generated
+     *
+     * @see <a href="https://www.rfc-editor.org/rfc/rfc9580.html#name-ecc-curves-for-openpgp">
+     *     RFC9580 - ECC Curves for OpenPGP</a>
+     */
+    public PGPKeyPair generateBrainpoolP512r1ECDHKeyPair()
+            throws PGPException
+    {
+        return generateECDHKeyPair(TeleTrusTObjectIdentifiers.brainpoolP512r1);
+    }
+
     /**
      * Generate an ECDSA elliptic curve signing key over the NIST p-256 curve.
+     * <pre>NIST P-256</pre> is equivalent to <pre>prime256v1</pre> and <pre>secp256r1</pre>.
      *
      * @return NIST p-256 ECDSA signing key pair
      * @throws PGPException if the key pair cannot be generated
@@ -243,6 +293,7 @@ public PGPKeyPair generateNistP256ECDSAKeyPair()
 
     /**
      * Generate an ECDSA elliptic curve signing key over the NIST p-384 curve.
+     * <pre>NIST P-384</pre> is equivalent to <pre>secp384r1</pre>.
      *
      * @return NIST p-384 ECDSA signing key pair
      * @throws PGPException if the key pair cannot be generated
@@ -258,6 +309,7 @@ public PGPKeyPair generateNistP384ECDSAKeyPair()
 
     /**
      * Generate an ECDSA elliptic curve signing key over the NIST p-521 curve.
+     * <pre>NIST P-521</pre> is equivalent to <pre>secp521r1</pre>.
      *
      * @return NIST p-521 ECDSA signing key pair
      * @throws PGPException if the key pair cannot be generated
@@ -271,6 +323,51 @@ public PGPKeyPair generateNistP521ECDSAKeyPair()
         return generateECDSAKeyPair(SECObjectIdentifiers.secp521r1);
     }
 
+    /**
+     * Generate an ECDSA elliptic curve signing key over the brainpoolP256r1 curve.
+     *
+     * @return BrainpoolP256r1 ECDSA signing key pair
+     * @throws PGPException if the key pair cannot be generated
+     *
+     * @see <a href="https://www.rfc-editor.org/rfc/rfc9580.html#name-ecc-curves-for-openpgp">
+     *     RFC9580 - ECC Curves for OpenPGP</a>
+     */
+    public PGPKeyPair generateBrainpoolP256r1ECDSAKeyPair()
+            throws PGPException
+    {
+        return generateECDSAKeyPair(TeleTrusTObjectIdentifiers.brainpoolP256r1);
+    }
+
+    /**
+     * Generate an ECDSA elliptic curve signing key over the brainpoolP384r1 curve.
+     *
+     * @return BrainpoolP384r1 ECDSA signing key pair
+     * @throws PGPException if the key pair cannot be generated
+     *
+     * @see <a href="https://www.rfc-editor.org/rfc/rfc9580.html#name-ecc-curves-for-openpgp">
+     *     RFC9580 - ECC Curves for OpenPGP</a>
+     */
+    public PGPKeyPair generateBrainpoolP384r1ECDSAKeyPair()
+            throws PGPException
+    {
+        return generateECDSAKeyPair(TeleTrusTObjectIdentifiers.brainpoolP384r1);
+    }
+
+    /**
+     * Generate an ECDSA elliptic curve signing key over the brainpoolP512r1 curve.
+     *
+     * @return BrainpoolP512r1 ECDSA signing key pair
+     * @throws PGPException if the key pair cannot be generated
+     *
+     * @see <a href="https://www.rfc-editor.org/rfc/rfc9580.html#name-ecc-curves-for-openpgp">
+     *     RFC9580 - ECC Curves for OpenPGP</a>
+     */
+    public PGPKeyPair generateBrainpoolP512r1ECDSAKeyPair()
+            throws PGPException
+    {
+        return generateECDSAKeyPair(TeleTrusTObjectIdentifiers.brainpoolP512r1);
+    }
+
     /**
      * Generate an elliptic curve Diffie-Hellman encryption key pair over the curve identified by the given OID.
      *
diff --git a/pg/src/test/java/org/bouncycastle/openpgp/test/PGPKeyPairGeneratorTest.java b/pg/src/test/java/org/bouncycastle/openpgp/test/PGPKeyPairGeneratorTest.java
index a0f71064f0..1bb6afe249 100644
--- a/pg/src/test/java/org/bouncycastle/openpgp/test/PGPKeyPairGeneratorTest.java
+++ b/pg/src/test/java/org/bouncycastle/openpgp/test/PGPKeyPairGeneratorTest.java
@@ -1,6 +1,7 @@
 package org.bouncycastle.openpgp.test;
 
 import org.bouncycastle.asn1.sec.SECObjectIdentifiers;
+import org.bouncycastle.asn1.teletrust.TeleTrusTObjectIdentifiers;
 import org.bouncycastle.bcpg.ECDHPublicBCPGKey;
 import org.bouncycastle.bcpg.ECDSAPublicBCPGKey;
 import org.bouncycastle.bcpg.PublicKeyAlgorithmTags;
@@ -92,6 +93,25 @@ private void performWith(Factory factory)
 
         testGenerateV4P521ECDSAKey(factory);
         testGenerateV6P521ECDSAKey(factory);
+
+        // Brainpool
+        testGenerateV4BrainpoolP256r1ECDHKey(factory);
+        testGenerateV6BrainpoolP256r1ECDHKey(factory);
+
+        testGenerateV4BrainpoolP256r1ECDSAKey(factory);
+        testGenerateV6BrainpoolP256r1ECDSAKey(factory);
+
+        testGenerateV4BrainpoolP384r1ECDHKey(factory);
+        testGenerateV6BrainpoolP384r1ECDHKey(factory);
+
+        testGenerateV4BrainpoolP384r1ECDSAKey(factory);
+        testGenerateV6BrainpoolP384r1ECDSAKey(factory);
+
+        testGenerateV4BrainpoolP512r1ECDHKey(factory);
+        testGenerateV6BrainpoolP512r1ECDHKey(factory);
+
+        testGenerateV4BrainpoolP512r1ECDSAKey(factory);
+        testGenerateV6BrainpoolP512r1ECDSAKey(factory);
     }
 
     private void testGenerateV4RsaKey(Factory factory)
@@ -556,6 +576,222 @@ private void testGenerateV6P521ECDSAKey(Factory factory)
                 kp.getPublicKey().getCreationTime(), creationTime);
     }
 
+    private void testGenerateV4BrainpoolP256r1ECDHKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_4, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP256r1ECDHKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_4);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDH);
+        ECDHPublicBCPGKey k = (ECDHPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP256r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV6BrainpoolP256r1ECDHKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_6, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP256r1ECDHKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_6);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDH);
+        ECDHPublicBCPGKey k = (ECDHPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP256r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV4BrainpoolP256r1ECDSAKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_4, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP256r1ECDSAKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_4);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDSA);
+        ECDSAPublicBCPGKey k = (ECDSAPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP256r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV6BrainpoolP256r1ECDSAKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_6, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP256r1ECDSAKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_6);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDSA);
+        ECDSAPublicBCPGKey k = (ECDSAPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP256r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV4BrainpoolP384r1ECDHKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_4, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP384r1ECDHKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_4);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDH);
+        ECDHPublicBCPGKey k = (ECDHPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP384r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV6BrainpoolP384r1ECDHKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_6, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP384r1ECDHKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_6);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDH);
+        ECDHPublicBCPGKey k = (ECDHPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP384r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV4BrainpoolP384r1ECDSAKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_4, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP384r1ECDSAKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_4);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDSA);
+        ECDSAPublicBCPGKey k = (ECDSAPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP384r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV6BrainpoolP384r1ECDSAKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_6, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP384r1ECDSAKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_6);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDSA);
+        ECDSAPublicBCPGKey k = (ECDSAPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP384r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV4BrainpoolP512r1ECDHKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_4, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP512r1ECDHKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_4);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDH);
+        ECDHPublicBCPGKey k = (ECDHPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP512r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV6BrainpoolP512r1ECDHKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_6, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP512r1ECDHKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_6);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDH);
+        ECDHPublicBCPGKey k = (ECDHPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP512r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV4BrainpoolP512r1ECDSAKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_4, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP512r1ECDSAKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_4);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDSA);
+        ECDSAPublicBCPGKey k = (ECDSAPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP512r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
+    private void testGenerateV6BrainpoolP512r1ECDSAKey(Factory factory)
+            throws PGPException
+    {
+        Date creationTime = currentTimeRounded();
+        PGPKeyPairGenerator gen = factory.create(PublicKeyPacket.VERSION_6, creationTime);
+
+        PGPKeyPair kp = gen.generateBrainpoolP512r1ECDSAKeyPair();
+
+        isEquals("Key version mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getVersion(), PublicKeyPacket.VERSION_6);
+        isEquals("Key algorithm mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getAlgorithm(), PublicKeyAlgorithmTags.ECDSA);
+        ECDSAPublicBCPGKey k = (ECDSAPublicBCPGKey) kp.getPublicKey().getPublicKeyPacket().getKey();
+        isEquals(TeleTrusTObjectIdentifiers.brainpoolP512r1, k.getCurveOID());
+        isEquals("Key creation time mismatch (" + gen.getClass().getName() + ")",
+                kp.getPublicKey().getCreationTime(), creationTime);
+    }
+
     public static void main(String[] args)
     {
         runTest(new PGPKeyPairGeneratorTest());