+#ifdef CYRUS_SASL
+/*
+ * This function implements SASL authentication for SMTP. If this function
+ * completes successfully, then authentication is successful and we've
+ * (optionally) negotiated a security layer.
+ *
+ * Right now we don't support session encryption.
+ */
+static int
+sm_auth_sasl(char *user, char *mechlist, char *host)
+{
+ int result, status, outlen;
+ unsigned int buflen;
+ char *buf, outbuf[BUFSIZ];
+ const char *chosen_mech;
+ sasl_security_properties_t secprops;
+ sasl_external_properties_t extprops;
+ sasl_ssf_t *ssf;
+ int *outbufmax;
+
+ /*
+ * Initialize the callback contexts
+ */
+
+ if (user == NULL)
+ user = getusername();
+
+ callbacks[SM_SASL_N_CB_USER].context = user;
+
+ /*
+ * This is a _bit_ of a hack ... but if the hostname wasn't supplied
+ * to us on the command line, then call getpeername and do a
+ * reverse-address lookup on the IP address to get the name.
+ */
+
+ if (!host) {
+ struct sockaddr_in sin;
+ int len = sizeof(sin);
+ struct hostent *hp;
+
+ if (getpeername(fileno(sm_wfp), (struct sockaddr *) &sin, &len) < 0) {
+ sm_ierror("getpeername on SMTP socket failed: %s",
+ strerror(errno));
+ return NOTOK;
+ }
+
+ if ((hp = gethostbyaddr((void *) &sin.sin_addr, sizeof(sin.sin_addr),
+ sin.sin_family)) == NULL) {
+ sm_ierror("DNS lookup on IP address %s failed",
+ inet_ntoa(sin.sin_addr));
+ return NOTOK;
+ }
+
+ host = strdup(hp->h_name);
+ }
+
+ sasl_pw_context[0] = host;
+ sasl_pw_context[1] = user;
+
+ callbacks[SM_SASL_N_CB_PASS].context = sasl_pw_context;
+
+ result = sasl_client_init(callbacks);
+
+ if (result != SASL_OK) {
+ sm_ierror("SASL library initialization failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ result = sasl_client_new("smtp", host, NULL, SASL_SECURITY_LAYER, &conn);
+
+ if (result != SASL_OK) {
+ sm_ierror("SASL client initialization failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ /*
+ * Initialize the security properties
+ */
+
+ memset(&secprops, 0, sizeof(secprops));
+ secprops.maxbufsize = BUFSIZ;
+ secprops.max_ssf = 0; /* XXX change this when we do encryption */
+ memset(&extprops, 0, sizeof(extprops));
+
+ result = sasl_setprop(conn, SASL_SEC_PROPS, &secprops);
+
+ if (result != SASL_OK) {
+ sm_ierror("SASL security property initialization failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ result = sasl_setprop(conn, SASL_SSF_EXTERNAL, &extprops);
+
+ if (result != SASL_OK) {
+ sm_ierror("SASL external property initialization failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ /*
+ * Start the actual protocol. Feed the mech list into the library
+ * and get out a possible initial challenge
+ */
+
+ result = sasl_client_start(conn, mechlist, NULL, NULL, &buf, &buflen,
+ &chosen_mech);
+
+ if (result != SASL_OK && result != SASL_CONTINUE) {
+ sm_ierror("SASL client start failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ /*
+ * If we got an initial challenge, send it as part of the AUTH
+ * command; otherwise, just send a plain AUTH command.
+ */
+
+ if (buflen) {
+ status = sasl_encode64(buf, buflen, outbuf, sizeof(outbuf), NULL);
+ free(buf);
+ if (status != SASL_OK) {
+ sm_ierror("SASL base64 encode failed: %s",
+ sasl_errstring(status, NULL, NULL));
+ return NOTOK;
+ }
+
+ status = smtalk(SM_AUTH, "AUTH %s %s", chosen_mech, outbuf);
+ } else
+ status = smtalk(SM_AUTH, "AUTH %s", chosen_mech);
+
+ /*
+ * Now we loop until we either fail, get a SASL_OK, or a 235
+ * response code. Receive the challenges and process them until
+ * we're all done.
+ */
+
+ while (result == SASL_CONTINUE) {
+
+ /*
+ * If we get a 235 response, that means authentication has
+ * succeeded and we need to break out of the loop (yes, even if
+ * we still get SASL_CONTINUE from sasl_client_step()).
+ *
+ * Otherwise, if we get a message that doesn't seem to be a
+ * valid response, then abort
+ */
+
+ if (status == 235)
+ break;
+ else if (status < 300 || status > 399)
+ return RP_BHST;
+
+ /*
+ * Special case; a zero-length response from the SMTP server
+ * is returned as a single =. If we get that, then set buflen
+ * to be zero. Otherwise, just decode the response.
+ */
+
+ if (strcmp("=", sm_reply.text) == 0) {
+ outlen = 0;
+ } else {
+ result = sasl_decode64(sm_reply.text, sm_reply.length,
+ outbuf, &outlen);
+
+ if (result != SASL_OK) {
+ smtalk(SM_AUTH, "*");
+ sm_ierror("SASL base64 decode failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+ }
+
+ result = sasl_client_step(conn, outbuf, outlen, NULL, &buf, &buflen);
+
+ if (result != SASL_OK && result != SASL_CONTINUE) {
+ smtalk(SM_AUTH, "*");
+ sm_ierror("SASL client negotiation failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ status = sasl_encode64(buf, buflen, outbuf, sizeof(outbuf), NULL);
+ free(buf);
+
+ if (status != SASL_OK) {
+ smtalk(SM_AUTH, "*");
+ sm_ierror("SASL base64 encode failed: %s",
+ sasl_errstring(status, NULL, NULL));
+ return NOTOK;
+ }
+
+ status = smtalk(SM_AUTH, outbuf);
+ }
+
+ /*
+ * Make sure that we got the correct response
+ */
+
+ if (status < 200 || status > 299)
+ return RP_BHST;
+
+ /*
+ * Depending on the mechanism, we need to do a FINAL call to
+ * sasl_client_step(). Do that now.
+ */
+
+ result = sasl_client_step(conn, NULL, 0, NULL, &buf, &buflen);
+
+ if (result != SASL_OK) {
+ sm_ierror("SASL final client negotiation failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ /*
+ * We _should_ have completed the authentication successfully.
+ * Get a few properties from the authentication exchange.
+ */
+
+ result = sasl_getprop(conn, SASL_MAXOUTBUF, (void **) &outbufmax);
+
+ if (result != SASL_OK) {
+ sm_ierror("Cannot retrieve SASL negotiated output buffer size: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ maxoutbuf = *outbufmax;
+
+ result = sasl_getprop(conn, SASL_SSF, (void **) &ssf);
+
+ sasl_ssf = *ssf;
+
+ if (result != SASL_OK) {
+ sm_ierror("Cannot retrieve SASL negotiated security strength "
+ "factor: %s", sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ if (maxoutbuf == 0 || maxoutbuf > BUFSIZ)
+ maxoutbuf = BUFSIZ;
+
+ sasl_complete = 1;
+
+ return RP_OK;
+}
+
+/*
+ * Our callback functions to feed data to the SASL library
+ */
+
+static int
+sm_get_user(void *context, int id, const char **result, unsigned *len)
+{
+ char *user = (char *) context;
+
+ if (! result || id != SASL_CB_USER)
+ return SASL_BADPARAM;
+
+ *result = user;
+ if (len)
+ *len = strlen(user);
+
+ return SASL_OK;
+}
+
+static int
+sm_get_pass(sasl_conn_t *conn, void *context, int id,
+ sasl_secret_t **psecret)
+{
+ char **pw_context = (char **) context;
+ char *pass = NULL;
+ int len;
+
+ if (! psecret || id != SASL_CB_PASS)
+ return SASL_BADPARAM;
+
+ ruserpass(pw_context[0], &(pw_context[1]), &pass);
+
+ len = strlen(pass);
+
+ *psecret = (sasl_secret_t *) malloc(sizeof(sasl_secret_t) + len);
+
+ if (! *psecret) {
+ free(pass);
+ return SASL_NOMEM;
+ }
+
+ (*psecret)->len = len;
+ strcpy((*psecret)->data, pass);
+/* free(pass); */
+
+ return SASL_OK;
+}
+#endif /* CYRUS_SASL */
+