/** * Creates signature for data. * * @param alg Algorithm. * @param prv Provider. * @param key Private key. * @param data Data. * @return Signature. * @throws GeneralSecurityException If any exception occurs while signature creation. */ public static byte[] createSignature(String alg, String prv, PrivateKey key, byte[] data) throws GeneralSecurityException { assert !F.isEmpty(alg); assert !F.isEmpty(prv); assert key != null; assert data != null; Signature sign = Signature.getInstance(alg, prv); sign.initSign(key); sign.update(data); return sign.sign(); }
/** * Verifies signature for data. * * @param alg Algorithm. * @param prv Provider. * @param key Public key. * @param data Data. * @param sign Signature. * @return {@code true} if signature was verified, {@code false} - otherwise. * @throws GeneralSecurityException If any exception occurs while verifying. */ public static boolean verifySignature( String alg, String prv, PublicKey key, byte[] data, byte[] sign) throws GeneralSecurityException { assert !F.isEmpty(alg); assert !F.isEmpty(prv); assert key != null; assert data != null; assert sign != null; Signature sign0 = Signature.getInstance(alg, prv); sign0.initVerify(key); sign0.update(data); return sign0.verify(sign); }