/**
* Perform an NTLMv2 check
*
* @param md4hash String
* @param challenge byte[]
* @param type3Msg Type3NTLMMessage
* @return boolean
*/
protected final boolean checkNTLMv2(String md4hash, byte[] challenge, Type3NTLMMessage type3Msg) {
if (getLogger().isDebugEnabled()) getLogger().debug(("Perform an NTLMv2 check."));
boolean ntlmv2OK = false;
boolean lmv2OK = false;
try {
// Generate the v2 hash using the challenge that was sent to the client
byte[] v2hash =
m_encryptor.doNTLM2Encryption(
m_md4Encoder.decodeHash(md4hash), type3Msg.getUserName(), type3Msg.getDomain());
// Get the NTLMv2 blob sent by the client and the challenge that was sent by the server
NTLMv2Blob v2blob = new NTLMv2Blob(type3Msg.getNTLMHash());
// Calculate the HMAC of the received blob and compare
byte[] srvHmac = v2blob.calculateHMAC(challenge, v2hash);
byte[] clientHmac = v2blob.getHMAC();
if (clientHmac != null && srvHmac != null && clientHmac.length == srvHmac.length) {
int i = 0;
while (i < clientHmac.length && clientHmac[i] == srvHmac[i]) {
i++;
}
if (i == clientHmac.length) {
if (getLogger().isDebugEnabled())
getLogger().debug(("HMAC matches the client, user authenticated."));
ntlmv2OK = true;
}
}
// NTLMv2 check failed, try the LMv2 value
if (ntlmv2OK == false) {
byte[] lmv2 = type3Msg.getLMHash();
byte[] clChallenge = v2blob.getClientChallenge();
if (lmv2 != null && lmv2.length == 24 && clChallenge != null && clChallenge.length == 8) {
// Check that the LM hash contains the client challenge as the last 8 bytes
int i = 0;
while (i < clChallenge.length && lmv2[i + 16] == clChallenge[i]) i++;
if (i == clChallenge.length) {
// Calculate the LMv2 value
byte[] lmv2Hmac = v2blob.calculateLMv2HMAC(v2hash, challenge, clChallenge);
// Check if the LMv2 HMAC matches
i = 0;
while (i < lmv2Hmac.length && lmv2[i] == lmv2Hmac[i]) i++;
if (i == lmv2Hmac.length) {
if (getLogger().isDebugEnabled())
getLogger().debug(("LMv2 HMAC matches the client, user authenticated."));
// return true;
lmv2OK = true;
}
}
}
}
} catch (Exception ex) {
if (getLogger().isDebugEnabled()) getLogger().debug(ex);
}
// Check if either of the NTLMv2 checks passed
if (ntlmv2OK || lmv2OK) return true;
return false;
}
