CODEWITHSUNDEEP
copensslmd5ntlmhmac
moeCake
moeCake

Reputation: 510

HMAC-MD5 using openSSL

I'm trying to study NTLMv2 response, Eric Glass's work.
but stuck at HMAC-MD5 section. (using function like this)

I got the right NTLM hash, and unicode username & domain.
(he only emphasize the "USERDOMAIN" but no username, so I suppose it's "USER") 

unsigned char v1hash[16];  // "0xcd06ca7c7e10c99b1d33b7485a2ed808"
unsigned short udata[14];
// concated unicode USER+USERDOMAIN "0x550053004500520044004f004d00410049004e00"
unsigned char v2hash[16];
int iLen;

HMAC(EVP_md5(), v1hash, 16, udata, sizeof(udata), v2hash, &iLen);

but the result is: 

v2hash(16): 23 d2 3c a4 dd 1a 20 81 35 cf 3a 42 1c e1 5a 17

which should be "0x04b8e0ba74289cc540826bab1dee63ae"

am I doing something wrong here?

Upvotes: 0

Views: 1172

Answers (1)

shunty
shunty

Reputation: 3758

I'm not a C programmer but...

From my reading of that article USERDOMAIN should be just that - NOT USER+USERDOMAIN ie the uppercase username = "USER" concat with the target = "DOMAIN" to give USERDOMAIN which gives the unicode bytes beginning 55005300...

Then it would appear your udata array is the wrong size. You're only processing 20 bytes of information so don't set the array to 28 otherwise the HMAC/MD5 functions will be processing extra random data at the end of the input array.

Upvotes: 1

Related Questions