SRP_CLIENT_builtin_param_verify_cb(SRP * srp, const unsigned char * mod, int modlen, const unsigned char * gen, int genlen)
{
struct t_preconf * tpc;
int i;
for(i = 0; i < t_getprecount(); ++i) {
tpc = t_getpreparam(i);
if(tpc->modulus.len == modlen && tpc->generator.len == genlen &&
memcmp(tpc->modulus.data, mod, modlen) == 0 &&
memcmp(tpc->generator.data, gen, genlen) == 0) {
return SRP_SUCCESS; /* Match found, done */
}
}
return SRP_ERROR;
}
int tsrp_client_authenticate(int s, char *user, char *pass, TSRP_SESSION *tsrp)
{
int i, index;
unsigned char username[MAXUSERLEN + 1], sbuf[MAXSALTLEN];
unsigned char msgbuf[MAXPARAMLEN + 1], bbuf[MAXPARAMLEN];
unsigned char passbuf[128], *skey;
struct t_client *tc;
struct t_preconf *tcp; /* @@@ should go away */
struct t_num salt, *A, B;
/* Send the username. */
i = strlen(user);
if (i > MAXUSERLEN) {
i = MAXUSERLEN;
}
msgbuf[0] = i;
memcpy(msgbuf + 1, user, i);
if (send(s, msgbuf, i + 1, 0) < 0) {
return 0;
}
memcpy(username, user, i);
username[i] = '\0';
/* Get the prime index and salt. */
i = recv(s, msgbuf, 2, MSG_WAITALL);
if (i <= 0) {
return 0;
}
index = msgbuf[0];
if (index <= 0 || index > t_getprecount()) {
return 0;
}
tcp = t_getpreparam(index - 1);
salt.len = msgbuf[1];
if (salt.len > MAXSALTLEN) {
return 0;
}
salt.data = sbuf;
i = recv(s, sbuf, salt.len, MSG_WAITALL);
if (i <= 0) {
return 0;
}
/* @@@ t_clientopen() needs a variant that takes the index */
tc = t_clientopen(username, &tcp->modulus, &tcp->generator, &salt);
if (tc == NULL) {
return 0;
}
/* Calculate A and send it to the server. */
A = t_clientgenexp(tc);
msgbuf[0] = A->len - 1; /* len is max 256 */
memcpy(msgbuf + 1, A->data, A->len);
if (send(s, msgbuf, A->len + 1, 0) < 0) {
return 0;
}
/* Ask the user for the passphrase. */
if (pass == NULL) {
t_getpass(passbuf, sizeof(passbuf), "Enter password:");
pass = passbuf;
}
t_clientpasswd(tc, pass);
/* Get B from the server. */
i = recv(s, msgbuf, 1, 0);
if (i <= 0) {
return 0;
}
B.len = msgbuf[0] + 1;
B.data = bbuf;
i = recv(s, bbuf, B.len, MSG_WAITALL);
if (i <= 0) {
return 0;
}
/* Compute the session key. */
skey = t_clientgetkey(tc, &B);
if (skey == NULL) {
return 0;
}
/* Send the response. */
if (send(s, t_clientresponse(tc), RESPONSE_LEN, 0) < 0) {
return 0;
}
/* Get the server's response. */
i = recv(s, msgbuf, RESPONSE_LEN, MSG_WAITALL);
if (i <= 0) {
return 0;
}
if (t_clientverify(tc, msgbuf) != 0) {
return 0;
}
/* All done. Now copy the key and clean up. */
if (tsrp) {
memcpy(tsrp->username, username, strlen(username) + 1);
memcpy(tsrp->key, skey, SESSION_KEY_LEN);
}
t_clientclose(tc);
return 1;
}
