function verifySig(bytes32 tosignh, bytes dersig, bytes pubkey) internal returns (bool){
        bool sigok;
        address signer;
        
        bytes32 sigr;
        bytes32 sigs;
        
        bytes memory sigr_ = new bytes(32);
        uint offset = 4+(uint(dersig[3]) - 0x20);
        sigr_ = copyBytes(dersig, offset, 32, sigr_, 0);
        bytes memory sigs_ = new bytes(32);
        offset += 32 + 2;
        sigs_ = copyBytes(dersig, offset+(uint(dersig[offset-1]) - 0x20), 32, sigs_, 0);

        assembly {
            sigr := mload(add(sigr_, 32))
            sigs := mload(add(sigs_, 32))
        }
        
        
        (sigok, signer) = safer_ecrecover(tosignh, 27, sigr, sigs);
        if (address(sha3(pubkey)) == signer) return true;
        else {
            (sigok, signer) = safer_ecrecover(tosignh, 28, sigr, sigs);
            return (address(sha3(pubkey)) == signer);
        }
    }