/***********************************************************
single function to calculate an HMAC MD5 digest from data
using optimised hmacmd5 init method because the key is 16 bytes.
************************************************************/
void hmac_md5(const unsigned char *key, const unsigned char *data,
int data_len, unsigned char *digest)
{
HMACMD5Context ctx;
hmac_md5_init_K16(key, &ctx);
if (data_len != 0)
hmac_md5_update(data, data_len, &ctx);
hmac_md5_final(digest, &ctx);
}
/* Calculate the LMv2 response for the given challenge, using the
specified authentication identity (username and domain), password
and client nonce.
*/
static int crypt_all(int *pcount, struct db_salt *salt)
{
int count = *pcount;
int i = 0;
#ifdef _OPENMP
#pragma omp parallel for
for(i = 0; i < count; i++)
#endif
{
unsigned char ntlm_v2_hash[16];
HMACMD5Context ctx; // can't be moved above the OMP pragma
if (!keys_prepared) {
int len;
unsigned char ntlm[16];
/* Generate 16-byte NTLM hash */
len = E_md4hash(saved_plain[i], saved_len[i], ntlm);
// We do key setup of the next HMAC_MD5 here (once per salt)
hmac_md5_init_K16(ntlm, &saved_ctx[i]);
if (len <= 0)
saved_plain[i][-len] = 0; // match truncation
}
/* HMAC-MD5(Username + Domain, NTLM Hash) */
memcpy(&ctx, &saved_ctx[i], sizeof(ctx));
hmac_md5_update(&challenge[17], (int)challenge[16], &ctx);
hmac_md5_final(ntlm_v2_hash, &ctx);
/* Generate 16-byte non-client nonce portion of LMv2 Response */
/* HMAC-MD5(Challenge + Nonce, NTLMv2 Hash) + Nonce */
hmac_md5(ntlm_v2_hash, challenge, 16, (unsigned char*)output[i]);
}
keys_prepared = 1;
return count;
}
/* Calculate the NTLMv2 response for the given challenge, using the
specified authentication identity (username and domain), password
and client nonce.
challenge: Identity length, Identity\0, Challenge Size, Server Challenge + Client Challenge
*/
static int crypt_all(int *pcount, struct db_salt *salt)
{
int count = *pcount;
int identity_length, challenge_size;
int i = 0;
/* --- HMAC #1 Calculations --- */
identity_length = challenge[0];
challenge_size = (*(challenge + 1 + identity_length + 1) << 8) | *(challenge + 1 + identity_length + 2);
#ifdef _OPENMP
#pragma omp parallel for
for(i=0; i<count; i++)
#endif
{
unsigned char ntlm_v2_hash[16];
HMACMD5Context ctx;
if (!keys_prepared) {
unsigned char ntlm[16];
int len;
/* Generate 16-byte NTLM hash */
len = E_md4hash(saved_plain[i], saved_len[i], ntlm);
// We do key setup of the next HMAC_MD5 here (once per salt)
hmac_md5_init_K16(ntlm, &saved_ctx[i]);
if (len <= 0)
saved_plain[i][-len] = 0; // match truncation
}
/* HMAC-MD5(Username + Domain, NTLM Hash) */
memcpy(&ctx, &saved_ctx[i], sizeof(ctx));
hmac_md5_update((unsigned char *)&challenge[1], identity_length, &ctx);
hmac_md5_final(ntlm_v2_hash, &ctx);
/* --- Blob Construction --- */
/*
The blob consists of the target (from Type 2 message), client nonce and timestamp.
This data was provided by the client during authentication and we can use it as is.
*/
/* --- HMAC #2 Caculations --- */
/*
The (server) challenge from the Type 2 message is concatenated with the blob. The
HMAC-MD5 message authentication code algorithm is applied to this value using the
16-byte NTLMv2 hash (calculated above) as the key. This results in a 16-byte output
value.
*/
/*
Generate 16-byte non-client nonce portion of NTLMv2 Response
HMAC-MD5(Challenge + Nonce, NTLMv2 Hash)
The length of the challenge was set in get_salt(). We find the server
challenge and blob following the identity and challenge size value.
challenge -> Identity length, Identity\0, Size (2 bytes), Server Challenge + Client Challenge (Blob)
*/
hmac_md5(ntlm_v2_hash, challenge + 1 + identity_length + 1 + 2, challenge_size, (unsigned char*)output[i]);
}
keys_prepared = 1;
return count;
}
