Analysis to Man-in-the-Middle Attack for IKEv1 on the Aggressive Mode

In the paper a method of man-in-the middle attack to IKEv1 is discussed and analyzed is based on the aggressive mode of IKEv1 key exchange with pre-share-key authentication.The conditions and implementing methods of the attack are obtained by analyzing the principle of the attack to IKEv1 on the mode.For implementing man-in-the middle attack,the pre-share-key is first achieved by exhaustion method with offline password of IKEv1. The theory of Diffie-Hellman (DH) man-in-the middle attack to applied to the aggressive mode of IKEv1.Because there are some offline password leaks in the mode for obtaining pre-share-key,the conclusion is that the attack would jeopardize IPsec VPN in practice.