Add PQC KEM key validation

src/crypto/crypto.js

@@ -569,8 +569,11 @@ export async function validateParams(algo, publicParams, privateParams) {
       return keySize === keyMaterial.length &&
         util.equalsUint8Array(digest, await hash.sha256(hashSeed));
     }
-    case enums.publicKey.pqc_mlkem_x25519:
-      throw new Error('TODO');
+    case enums.publicKey.pqc_mlkem_x25519: {
+      const { eccSecretKey, mlkemSecretKey } = privateParams;
+      const { eccPublicKey, mlkemPublicKey } = publicParams;
+      return publicKey.postQuantum.kem.validateParams(algo, eccPublicKey, eccSecretKey, mlkemPublicKey, mlkemSecretKey);
+    }
     default:
       throw new Error('Unknown public key algorithm.');
   }

src/crypto/public_key/post_quantum/kem/ecc_kem.js

@@ -52,3 +52,12 @@ export async function decaps(algo, eccCipherText, eccSecretKey, eccPublicKey) {
       throw new Error('Unsupported KEM algorithm');
   }
 }
+
+export async function validateParams(algo, eccPublicKey, eccSecretKey) {
+  switch (algo) {
+    case enums.publicKey.pqc_mlkem_x25519:
+      return ecdhX.validateParams(enums.publicKey.x25519, eccPublicKey, eccSecretKey);
+    default:
+      throw new Error('Unsupported KEM algorithm');
+  }
+}

src/crypto/public_key/post_quantum/kem/index.js

@@ -1 +1 @@
-export { generate, encrypt, decrypt } from './kem';
+export { generate, encrypt, decrypt, validateParams } from './kem';

src/crypto/public_key/post_quantum/kem/kem.js

@@ -71,3 +71,10 @@ async function multiKeyCombine(eccKeyShare, eccCipherText, mlkemKeyShare, mlkemC
 
   return mb;
 }
+
+export async function validateParams(algo, eccPublicKey, eccSecretKey, mlkemPublicKey, mlkemSecretKey) {
+  const eccValidationPromise = eccKem.validateParams(algo, eccPublicKey, eccSecretKey);
+  const mlkemValidationPromise = mlKem.validateParams(algo, mlkemPublicKey, mlkemSecretKey);
+  const valid = await eccValidationPromise && await mlkemValidationPromise;
+  return valid;
+}

src/crypto/public_key/post_quantum/kem/ml_kem.js

@@ -1,4 +1,5 @@
 import enums from '../../../../enums';
+import util from '../../../../util';
 
 export async function generate(algo) {
   switch (algo) {
@@ -41,3 +42,16 @@ export async function decaps(algo, mlkemCipherText, mlkemSecretKey) {
       throw new Error('Unsupported KEM algorithm');
   }
 }
+
+export async function validateParams(algo, mlkemPublicKey, mlkemSecretKey) {
+  switch (algo) {
+    case enums.publicKey.pqc_mlkem_x25519: {
+      // TODO confirm this is the best option performance- & security-wise (is key re-generation faster?)
+      const { mlkemCipherText: validationCipherText, mlkemKeyShare: validationKeyShare } = await encaps(algo, mlkemPublicKey);
+      const resultingKeyShare = await decaps(algo, validationCipherText, mlkemSecretKey);
+      return util.equalsUint8Array(resultingKeyShare, validationKeyShare);
+    }
+    default:
+      throw new Error('Unsupported KEM algorithm');
+  }
+}

test/crypto/validate.js

@@ -314,6 +314,38 @@ export default () => {
     });
   });
 
+  describe('PQC parameter validation', function() {
+    let pqcEncryptionSubkey;
+    before(async () => {
+      const key = await generatePrivateKeyObject({ type: 'symmetric', subkeys: [{ type: 'pqc' }] });
+      pqcEncryptionSubkey = key.subkeys[0];
+    });
+
+    async function cloneSubeyPacket(subkey) {
+      const subkeyPacket = new openpgp.SecretSubkeyPacket();
+      await subkeyPacket.read(subkey.keyPacket.write());
+      return subkeyPacket;
+    }
+
+    it('generated params are valid', async function() {
+      await expect(pqcEncryptionSubkey.keyPacket.validate()).to.not.be.rejected;
+    });
+
+    it('detect invalid ML-KEM public key part', async function() {
+      const keyPacket = await cloneSubeyPacket(pqcEncryptionSubkey);
+      const { mlkemPublicKey } = keyPacket.publicParams;
+      mlkemPublicKey[0]++;
+      await expect(keyPacket.validate()).to.be.rejectedWith('Key is invalid');
+    });
+
+    it('detect invalid ECC-KEM key part', async function() {
+      const keyPacket = await cloneSubeyPacket(pqcEncryptionSubkey);
+      const { eccPublicKey } = keyPacket.publicParams;
+      eccPublicKey[0]++;
+      await expect(keyPacket.validate()).to.be.rejectedWith('Key is invalid');
+    });
+  });
+
   describe('DSA parameter validation', function() {
     let dsaKey;
     before(async () => {