verify that signing key name matches

core/java/src/net/i2p/crypto/TrustedUpdate.java

@@ -682,6 +682,23 @@ D8usM7Dxp5yrDrCYZ5AIijc=
         return false;
     }
 
+    /**
+     * Verifies the DSA signature of a signed update file.
+     * 
+     * @param signedFile The signed update file to check.
+     * 
+     * @return signer (could be empty string) or null if invalid
+     * @since 0.7.12
+     */
+    public String verifyAndGetSigner(File signedFile) {
+        for (SigningPublicKey signingPublicKey : _trustedKeys.keySet()) {
+            boolean isValidSignature = verify(signedFile, signingPublicKey);
+            if (isValidSignature)
+                return _trustedKeys.get(signingPublicKey);
+        }
+        return null;
+    }
+
     /**
      * Verifies the DSA signature of a signed update file.
      *