- int rchallenge_len;
- u_char *rchallenge;
- int secret_len;
- char secret[MAXSECRETLEN];
- char rhostname[256];
- MD5_CTX mdContext;
- u_char hash[MD5_SIGNATURE_SIZE];
-
- if (cstate->clientstate == CHAPCS_CLOSED ||
- cstate->clientstate == CHAPCS_PENDING) {
- CHAPDEBUG(("ChapReceiveChallenge: in state %d", cstate->clientstate));
- return;
- }
-
- if (len < 2) {
- CHAPDEBUG(("ChapReceiveChallenge: rcvd short packet."));
- return;
- }
-
- GETCHAR(rchallenge_len, inp);
- len -= sizeof (u_char) + rchallenge_len; /* now name field length */
- if (len < 0) {
- CHAPDEBUG(("ChapReceiveChallenge: rcvd short packet."));
- return;
- }
- rchallenge = inp;
- INCPTR(rchallenge_len, inp);
-
- if (len >= sizeof(rhostname))
- len = sizeof(rhostname) - 1;
- BCOPY(inp, rhostname, len);
- rhostname[len] = '\000';
-
- /* Microsoft doesn't send their name back in the PPP packet */
- if (explicit_remote || (remote_name[0] != 0 && rhostname[0] == 0)) {
- strlcpy(rhostname, remote_name, sizeof(rhostname));
- CHAPDEBUG(("ChapReceiveChallenge: using '%q' as remote name",
- rhostname));
- }
-
- /* get secret for authenticating ourselves with the specified host */
- if (!get_secret(cstate->unit, cstate->resp_name, rhostname,
- secret, &secret_len, 0)) {
- secret_len = 0; /* assume null secret if can't find one */
- warn("No CHAP secret found for authenticating us to %q", rhostname);
- }
-
- /* cancel response send timeout if necessary */
- if (cstate->clientstate == CHAPCS_RESPONSE)
- UNTIMEOUT(ChapResponseTimeout, cstate);
-
- cstate->resp_id = id;
- cstate->resp_transmits = 0;
-
- /* generate MD based on negotiated type */
- switch (cstate->resp_type) {
-
- case CHAP_DIGEST_MD5:
- MD5Init(&mdContext);
- MD5Update(&mdContext, &cstate->resp_id, 1);
- MD5Update(&mdContext, secret, secret_len);
- MD5Update(&mdContext, rchallenge, rchallenge_len);
- MD5Final(hash, &mdContext);
- BCOPY(hash, cstate->response, MD5_SIGNATURE_SIZE);
- cstate->resp_length = MD5_SIGNATURE_SIZE;
- break;
-
-#ifdef CHAPMS
- case CHAP_MICROSOFT:
- ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len);
- break;
-#endif
-
- default:
- CHAPDEBUG(("unknown digest type %d", cstate->resp_type));
- return;
- }
-
- BZERO(secret, sizeof(secret));
- ChapSendResponse(cstate);
+ int clen = 1, nlen, len;
+ unsigned char *p;
+
+ p = ss->challenge;
+ MAKEHEADER(p, PPP_CHAP);
+ p += CHAP_HDRLEN;
+ ss->digest->generate_challenge(p);
+ clen = *p;
+ nlen = strlen(ss->name);
+ memcpy(p + 1 + clen, ss->name, nlen);
+
+ len = CHAP_HDRLEN + 1 + clen + nlen;
+ ss->challenge_pktlen = PPP_HDRLEN + len;
+
+ p = ss->challenge + PPP_HDRLEN;
+ p[0] = CHAP_CHALLENGE;
+ p[1] = ++ss->id;
+ p[2] = len >> 8;
+ p[3] = len;