Reworked MSC1915. Add request validation.

src/main/java/io/kamax/mxisd/crypto/CryptoFactory.java

@@ -58,5 +58,4 @@ public class CryptoFactory {
     public static SignatureManager getSignatureManager(MxisdConfig cfg, Ed25519KeyManager keyMgr) {
         return new Ed25519SignatureManager(cfg, keyMgr);
     }
-
 }

src/main/java/io/kamax/mxisd/crypto/SignatureManager.java

@@ -26,6 +26,7 @@ import io.kamax.matrix.event.EventKey;
 import io.kamax.matrix.json.MatrixJson;
 
 import java.nio.charset.StandardCharsets;
+import java.security.PublicKey;
 import java.util.Objects;
 
 public interface SignatureManager {
@@ -106,4 +107,13 @@ public interface SignatureManager {
      */
     Signature sign(byte[] data);
 
+    /**
+     * Verify the data.
+     *
+     * @param publicKey public key to verify
+     * @param signature signature to verify
+     * @param data      the data to verify
+     * @return {@code true} if signature is valid, else {@code false}
+     */
+    boolean verify(PublicKey publicKey, String signature, byte[] data);
 }

src/main/java/io/kamax/mxisd/crypto/ed25519/Ed25519SignatureManager.java

@@ -33,7 +33,9 @@ import net.i2p.crypto.eddsa.EdDSAEngine;
 import java.security.InvalidKeyException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.security.PublicKey;
 import java.security.SignatureException;
+import java.util.Base64;
 
 public class Ed25519SignatureManager implements SignatureManager {
 
@@ -92,4 +94,15 @@ public class Ed25519SignatureManager implements SignatureManager {
         }
     }
 
+    @Override
+    public boolean verify(PublicKey publicKey, String signature, byte[] data) {
+        try {
+            EdDSAEngine signEngine = new EdDSAEngine(MessageDigest.getInstance(keyMgr.getKeySpecs().getHashAlgorithm()));
+            signEngine.initVerify(publicKey);
+            signEngine.update(data);
+            return signEngine.verify(Base64.getDecoder().decode(signature));
+        } catch (NoSuchAlgorithmException | InvalidKeyException | SignatureException e) {
+            throw new RuntimeException(e);
+        }
+    }
 }