/* authenticates user on remote TACACS+ server
* returns PAM_SUCCESS if the supplied username and password
* pair is valid
*/
PAM_EXTERN
int pam_sm_authenticate (pam_handle_t * pamh, int flags,
int argc, const char **argv) {
int ctrl, retval;
char *user;
char *pass;
char *tty;
char *r_addr;
int srv_i;
int tac_fd, status, msg, communicating;
user = pass = tty = r_addr = NULL;
ctrl = _pam_parse(argc, argv);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: called (pam_tacplus v%u.%u.%u)",
__FUNCTION__, PAM_TAC_VMAJ, PAM_TAC_VMIN, PAM_TAC_VPAT);
if ((user = _pam_get_user(pamh)) == NULL)
return PAM_USER_UNKNOWN;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: user [%s] obtained", __FUNCTION__, user);
// read config file
_read_config(ctrl);
retval = tacacs_get_password (pamh, flags, ctrl, &pass);
if (retval != PAM_SUCCESS || pass == NULL || *pass == '\0') {
_pam_log(LOG_ERR, "unable to obtain password");
xfree(pass);
return PAM_CRED_INSUFFICIENT;
}
retval = pam_set_item (pamh, PAM_AUTHTOK, pass);
if (retval != PAM_SUCCESS) {
_pam_log(LOG_ERR, "unable to set password");
xfree(pass);
return PAM_CRED_INSUFFICIENT;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: password obtained", __FUNCTION__);
tty = _pam_get_terminal(pamh);
if (!strncmp(tty, "/dev/", 5))
tty += 5;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tty [%s] obtained", __FUNCTION__, tty);
r_addr = _pam_get_rhost(pamh);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: rhost [%s] obtained", __FUNCTION__, r_addr);
status = PAM_AUTHINFO_UNAVAIL;
for (srv_i = 0; srv_i < tac_srv_no; srv_i++) {
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: trying srv %d", __FUNCTION__, srv_i );
tac_fd = tac_connect_single(tac_srv[srv_i].addr, tac_srv[srv_i].key, NULL, tac_timeout);
if (tac_fd < 0) {
_pam_log(LOG_ERR, "connection failed srv %d: %m", srv_i);
continue;
}
if (tac_authen_send(tac_fd, user, pass, tty, r_addr, TAC_PLUS_AUTHEN_LOGIN) < 0) {
close(tac_fd);
_pam_log(LOG_ERR, "error sending auth req to TACACS+ server");
continue;
}
communicating = 1;
while (communicating) {
struct areply re = { .attr = NULL, .msg = NULL, status = 0, flags = 0 };
struct pam_message conv_msg = { .msg_style = 0, .msg = NULL };
struct pam_response *resp = NULL;
msg = tac_authen_read(tac_fd, &re);
if (NULL != re.msg) {
conv_msg.msg = re.msg;
}
/* talk the protocol */
switch (msg) {
case TAC_PLUS_AUTHEN_STATUS_PASS:
/* success */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_PASS");
if (NULL != conv_msg.msg) {
int retval = -1;
conv_msg.msg_style = PAM_TEXT_INFO;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
}
else {
_pam_log(LOG_WARNING, "%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
}
}
status = PAM_SUCCESS;
communicating = 0;
if (active_server.addr != NULL)
{
xfree(active_server.addr);
}
active_server.addr = (struct addrinfo*)xcalloc(1, sizeof(struct addrinfo));
bcopy(tac_srv[srv_i].addr, active_server.addr, sizeof(struct addrinfo));
if (active_server.key != NULL)
{
xfree(active_server.key);
}
active_server.key = xstrdup(tac_srv[srv_i].key);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: active srv %d", __FUNCTION__, srv_i);
break;
case TAC_PLUS_AUTHEN_STATUS_FAIL:
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_FAIL");
if (NULL != conv_msg.msg) {
int retval = -1;
conv_msg.msg_style = PAM_ERROR_MSG;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
}
else {
_pam_log(LOG_WARNING, "%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
}
}
status = PAM_AUTH_ERR;
communicating = 0;
_pam_log(LOG_ERR, "auth failed: %d", msg);
break;
case TAC_PLUS_AUTHEN_STATUS_GETDATA:
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_GETDATA");
if (NULL != conv_msg.msg) {
int retval = -1;
int echo_off = (0x1 == (re.flags & 0x1));
conv_msg.msg_style = echo_off ? PAM_PROMPT_ECHO_OFF : PAM_PROMPT_ECHO_ON;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "sent msg=\"%s\", resp=\"%s\"",
conv_msg.msg, resp->resp);
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "%s: calling tac_cont_send", __FUNCTION__);
if (0 > tac_cont_send_seq(tac_fd, resp->resp, re.seq_no + 1)) {
_pam_log(LOG_ERR, "error sending continue req to TACACS+ server");
status = PAM_AUTH_ERR;
communicating = 0;
}
}
else {
_pam_log(LOG_WARNING, "%s: error sending msg=\"%s\", retval=%d (%s)",
__FUNCTION__, conv_msg.msg, retval, pam_strerror(pamh, retval));
status = PAM_AUTH_ERR;
communicating = 0;
}
}
else {
syslog(LOG_ERR, "GETDATA response with no message, returning PAM_AUTH_ERR");
status = PAM_AUTH_ERR;
communicating = 0;
}
break;
case TAC_PLUS_AUTHEN_STATUS_GETUSER:
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_GETUSER");
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_GETPASS:
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_GETPASS");
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tac_cont_send called", __FUNCTION__);
if (tac_cont_send(tac_fd, pass) < 0) {
_pam_log (LOG_ERR, "error sending continue req to TACACS+ server");
communicating = 0;
}
/* continue the while loop; go read tac response */
break;
case TAC_PLUS_AUTHEN_STATUS_RESTART:
/* try it again */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_RESTART");
/*
* not implemented
* WdJ: I *think* you can just do tac_authen_send(user, pass) again
* but I'm not sure
*/
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_ERROR:
/* server has problems */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_ERROR");
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_FOLLOW:
/* server tells to try a different server address */
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_FOLLOW");
communicating = 0;
break;
default:
if (msg < 0) {
/* connection error */
communicating = 0;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "error communicating with tacacs server");
break;
}
/* unknown response code */
communicating = 0;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: unknown response 0x%02x", msg);
}
if (NULL != resp)
{
if (resp->resp != NULL)
{
xfree(resp->resp);
}
xfree(resp);
}
if (re.msg != NULL)
{
xfree(re.msg);
}
} /* end while(communicating) */
close(tac_fd);
if (status == PAM_SUCCESS || status == PAM_AUTH_ERR)
break;
}
if (status != PAM_SUCCESS && status != PAM_AUTH_ERR)
_pam_log(LOG_ERR, "no more servers to connect");
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: exit with pam status: %d", __FUNCTION__, status);
if (NULL != pass) {
bzero(pass, strlen (pass));
xfree(pass);
pass = NULL;
}
return status;
} /* pam_sm_authenticate */
/* no-op function to satisfy PAM authentication module */
PAM_EXTERN
int pam_sm_setcred (pam_handle_t * pamh, int flags,
int argc, const char **argv) {
int ctrl = _pam_parse (argc, argv);
if (ctrl & PAM_TAC_DEBUG)
syslog (LOG_DEBUG, "%s: called (pam_tacplus v%u.%u.%u)"
, __FUNCTION__, PAM_TAC_VMAJ, PAM_TAC_VMIN, PAM_TAC_VPAT);
return PAM_SUCCESS;
} /* pam_sm_setcred */
/* authorizes user on remote TACACS+ server, i.e. checks
* his permission to access requested service
* returns PAM_SUCCESS if the service is allowed
*/
PAM_EXTERN
int pam_sm_acct_mgmt (pam_handle_t * pamh, int flags,
int argc, const char **argv) {
int retval, ctrl, status=PAM_AUTH_ERR;
char *user;
char *tty;
char *r_addr;
struct areply arep;
struct tac_attrib *attr = NULL;
int tac_fd;
user = tty = r_addr = NULL;
memset(&arep, 0, sizeof(arep));
/* this also obtains service name for authorization
this should be normally performed by pam_get_item(PAM_SERVICE)
but since PAM service names are incompatible TACACS+
we have to pass it via command line argument until a better
solution is found ;) */
ctrl = _pam_parse (argc, argv);
if (ctrl & PAM_TAC_DEBUG)
syslog (LOG_DEBUG, "%s: called (pam_tacplus v%u.%u.%u)"
, __FUNCTION__, PAM_TAC_VMAJ, PAM_TAC_VMIN, PAM_TAC_VPAT);
if ((user = _pam_get_user(pamh)) == NULL)
return PAM_USER_UNKNOWN;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: username obtained [%s]", __FUNCTION__, user);
// read config file
_read_config(ctrl);
tty = _pam_get_terminal(pamh);
if(!strncmp(tty, "/dev/", 5))
tty += 5;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tty obtained [%s]", __FUNCTION__, tty);
r_addr = _pam_get_rhost(pamh);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: rhost obtained [%s]", __FUNCTION__, r_addr);
/* checks if user has been successfully authenticated
by TACACS+; we cannot solely authorize user if it hasn't
been authenticated or has been authenticated by method other
than TACACS+ */
if(active_server.addr == NULL) {
_pam_log (LOG_ERR, "user not authenticated by TACACS+");
return PAM_AUTH_ERR;
}
if (ctrl & PAM_TAC_DEBUG)
syslog (LOG_DEBUG, "%s: active server is [%s]", __FUNCTION__,
tac_ntop(active_server.addr->ai_addr));
/* checks for specific data required by TACACS+, which should
be supplied in command line */
if(!*tac_service) {
_pam_log (LOG_ERR, "SM: TACACS+ service type not configured");
return PAM_AUTH_ERR;
}
if(!*tac_protocol) {
_pam_log (LOG_ERR, "SM: TACACS+ protocol type not configured (IGNORED)");
}
tac_add_attrib(&attr, "service", tac_service);
if(tac_protocol[0] != '\0')
tac_add_attrib(&attr, "protocol", tac_protocol);
tac_fd = tac_connect_single(active_server.addr, active_server.key, NULL, tac_timeout);
if(tac_fd < 0) {
_pam_log (LOG_ERR, "TACACS+ server unavailable");
if(arep.msg != NULL)
xfree (arep.msg);
return PAM_AUTH_ERR;
}
retval = tac_author_send(tac_fd, user, tty, r_addr, attr);
tac_free_attrib(&attr);
if(retval < 0) {
_pam_log (LOG_ERR, "error getting authorization");
if(arep.msg != NULL)
xfree (arep.msg);
close(tac_fd);
return PAM_AUTH_ERR;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: sent authorization request", __FUNCTION__);
tac_author_read(tac_fd, &arep);
if(arep.status != AUTHOR_STATUS_PASS_ADD &&
arep.status != AUTHOR_STATUS_PASS_REPL) {
_pam_log (LOG_ERR, "TACACS+ authorisation failed for [%s]", user);
if(arep.msg != NULL)
xfree (arep.msg);
close(tac_fd);
return PAM_PERM_DENIED;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: user [%s] successfully authorized", __FUNCTION__, user);
status = PAM_SUCCESS;
attr = arep.attr;
while (attr != NULL) {
char attribute[attr->attr_len];
char value[attr->attr_len];
char *sep;
sep = index(attr->attr, '=');
if(sep == NULL)
sep = index(attr->attr, '*');
if(sep != NULL) {
bcopy(attr->attr, attribute, attr->attr_len-strlen(sep));
attribute[attr->attr_len-strlen(sep)] = '\0';
bcopy(sep, value, strlen(sep));
value[strlen(sep)] = '\0';
size_t i;
for (i = 0; attribute[i] != '\0'; i++) {
attribute[i] = toupper(attribute[i]);
if (attribute[i] == '-')
attribute[i] = '_';
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: returned attribute `%s%s' from server", __FUNCTION__, attribute, value);
/* make returned attributes available for other PAM modules via PAM environment */
if (pam_putenv(pamh, strncat(attribute, value, strlen(value))) != PAM_SUCCESS)
syslog(LOG_WARNING, "%s: unable to set PAM environment", __FUNCTION__);
} else {
syslog(LOG_WARNING, "%s: invalid attribute `%s', no separator", __FUNCTION__, attr->attr);
}
attr = attr->next;
}
/* free returned attributes */
if(arep.attr != NULL)
tac_free_attrib(&arep.attr);
if(arep.msg != NULL)
xfree (arep.msg);
close(tac_fd);
return status;
} /* pam_sm_acct_mgmt */
/* no-op function for future use */
PAM_EXTERN
int pam_sm_chauthtok(pam_handle_t * pamh, int flags,
int argc, const char **argv) {
int ctrl, retval;
char *user;
char *pass;
char *tty;
char *r_addr;
const void *pam_pass = NULL;
int srv_i;
int tac_fd, status, msg, communicating;
user = pass = tty = r_addr = NULL;
ctrl = _pam_parse(argc, argv);
if (ctrl & PAM_TAC_DEBUG)
syslog (LOG_DEBUG, "%s: called (pam_tacplus v%u.%u.%u)"
, __FUNCTION__, PAM_TAC_VMAJ, PAM_TAC_VMIN, PAM_TAC_VPAT);
syslog(LOG_DEBUG, "%s(flags=%d, argc=%d)", __func__, flags, argc);
// read config file
_read_config(ctrl);
if ( (pam_get_item(pamh, PAM_OLDAUTHTOK, &pam_pass) == PAM_SUCCESS)
&& (pam_pass != NULL) ) {
if ((pass = strdup(pam_pass)) == NULL)
return PAM_BUF_ERR;
} else {
pass = strdup("");
}
if ((user = _pam_get_user(pamh)) == NULL) {
if(pass) {
xfree(pass);
}
return PAM_USER_UNKNOWN;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: user [%s] obtained", __FUNCTION__, user);
tty = _pam_get_terminal(pamh);
if (!strncmp(tty, "/dev/", 5))
tty += 5;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tty [%s] obtained", __FUNCTION__, tty);
r_addr = _pam_get_rhost(pamh);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: rhost [%s] obtained", __FUNCTION__, r_addr);
if (PAM_SILENT == (flags & PAM_SILENT)) {
status = PAM_AUTHTOK_ERR;
goto finish;
}
status = PAM_TRY_AGAIN;
for (srv_i = 0; srv_i < tac_srv_no; srv_i++) {
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: trying srv %d", __FUNCTION__, srv_i );
tac_fd = tac_connect_single(tac_srv[srv_i].addr, tac_srv[srv_i].key, NULL, tac_timeout);
if (tac_fd < 0) {
_pam_log(LOG_ERR, "connection failed srv %d: %m", srv_i);
continue;
}
if (PAM_PRELIM_CHECK == (flags & PAM_PRELIM_CHECK)) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "%s: finishing PAM_PRELIM_CHECK with srv %d",
__FUNCTION__, srv_i);
close(tac_fd);
status = PAM_SUCCESS;
goto finish;
}
if (tac_authen_send(tac_fd, user, "", tty, r_addr, TAC_PLUS_AUTHEN_CHPASS) < 0) {
close(tac_fd);
_pam_log(LOG_ERR, "error sending auth req to TACACS+ server");
continue;
}
communicating = 1;
while (communicating) {
struct areply re = { .attr = NULL, .msg = NULL, status = 0, flags = 0 };
struct pam_message conv_msg = { .msg_style = 0, .msg = NULL };
struct pam_response *resp = NULL;
msg = tac_authen_read(tac_fd, &re);
if (NULL != re.msg) {
conv_msg.msg = re.msg;
}
/* talk the protocol */
switch (msg) {
case TAC_PLUS_AUTHEN_STATUS_PASS:
/* success */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_PASS");
if (NULL != conv_msg.msg) {
int retval = -1;
conv_msg.msg_style = PAM_TEXT_INFO;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
}
else {
_pam_log(LOG_WARNING, "%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
}
}
status = PAM_SUCCESS;
communicating = 0;
if (active_server.addr != NULL)
{
xfree(active_server.addr);
}
active_server.addr = (struct addrinfo*)xcalloc(1, sizeof(struct addrinfo));
bcopy(tac_srv[srv_i].addr, active_server.addr, sizeof(struct addrinfo));
if (active_server.key != NULL)
{
xfree(active_server.key);
}
active_server.key = xstrdup(tac_srv[srv_i].key);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: active srv %d", __FUNCTION__, srv_i);
break;
case TAC_PLUS_AUTHEN_STATUS_FAIL:
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_FAIL");
if (NULL != conv_msg.msg) {
int retval = -1;
conv_msg.msg_style = PAM_ERROR_MSG;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
}
else {
_pam_log(LOG_WARNING, "%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
}
}
status = PAM_AUTHTOK_ERR;
communicating = 0;
_pam_log(LOG_ERR, "chauthtok failed: %d", msg);
break;
case TAC_PLUS_AUTHEN_STATUS_GETDATA:
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_GETDATA");
if (NULL != conv_msg.msg) {
int retval = -1;
int echo_off = (0x1 == (re.flags & 0x1));
conv_msg.msg_style = echo_off ? PAM_PROMPT_ECHO_OFF : PAM_PROMPT_ECHO_ON;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "sent msg=\"%s\", resp=\"%s\"",
conv_msg.msg, resp->resp);
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "%s: calling tac_cont_send", __FUNCTION__);
if (0 > tac_cont_send_seq(tac_fd, resp->resp, re.seq_no + 1)) {
_pam_log(LOG_ERR, "error sending continue req to TACACS+ server");
communicating = 0;
}
}
else {
_pam_log(LOG_WARNING, "%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
communicating = 0;
}
}
else {
syslog(LOG_ERR, "GETDATA response with no message, returning PAM_TRY_AGAIN");
communicating = 0;
}
break;
case TAC_PLUS_AUTHEN_STATUS_GETUSER:
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_GETUSER");
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_GETPASS:
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_GETPASS");
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: calling tac_cont_send", __FUNCTION__);
if (tac_cont_send(tac_fd, pass) < 0) {
_pam_log (LOG_ERR, "error sending continue req to TACACS+ server");
communicating = 0;
break;
}
/* continue the while loop; go read tac response */
break;
case TAC_PLUS_AUTHEN_STATUS_RESTART:
/* try it again */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_RESTART");
/*
* not implemented
* WdJ: I *think* you can just do tac_authen_send(user, pass) again
* but I'm not sure
*/
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_ERROR:
/* server has problems */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_ERROR");
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_FOLLOW:
/* server tells to try a different server address */
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_FOLLOW");
communicating = 0;
break;
default:
if (msg < 0) {
/* connection error */
communicating = 0;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "error communicating with tacacs server");
break;
}
/* unknown response code */
communicating = 0;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: unknown response 0x%02x", msg);
}
if (NULL != resp) {
xfree(resp->resp);
xfree(resp);
}
xfree(re.msg);
} /* end while(communicating) */
close(tac_fd);
if (status == PAM_SUCCESS || status == PAM_AUTHTOK_ERR)
break;
}
finish:
if (status != PAM_SUCCESS && status != PAM_AUTHTOK_ERR)
_pam_log(LOG_ERR, "no more servers to connect");
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: exit with pam status: %d", __FUNCTION__, status);
if (NULL != pass) {
bzero(pass, strlen(pass));
xfree(pass);
pass = NULL;
}
return status;
} /* pam_sm_chauthtok */
#endif
#ifdef PAM_STATIC
struct pam_module _pam_tacplus_modstruct {
"pam_tacplus",
pam_sm_authenticate,
pam_sm_setcred,
pam_sm_acct_mgmt,
pam_sm_open_session,
pam_sm_close_session,
#ifdef PAM_SM_PASSWORD
pam_sm_chauthtok
#else
NULL
#endif
};
/*
* Talk to the server for authentication
*/
static int tac_auth_converse(int ctrl, int fd, int *sptr,
char *pass, pam_handle_t * pamh) {
int msg, status, flags;
int ret = 1;
struct areply re = { .attr = NULL, .msg = NULL, .status = 0, .flags = 0 };
struct pam_message conv_msg = { .msg_style = 0, .msg = NULL };
struct pam_response *resp = NULL;
msg = tac_authen_read(fd, &re);
if (NULL != re.msg) {
conv_msg.msg = re.msg;
}
/* talk the protocol */
switch (msg) {
case TAC_PLUS_AUTHEN_STATUS_PASS:
/* success */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_PASS");
if (NULL != conv_msg.msg) {
int retval = -1;
conv_msg.msg_style = PAM_TEXT_INFO;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
}
else {
_pam_log(LOG_WARNING, "%s: error sending msg=\"%s\", retval=%d",
__func__, conv_msg.msg, retval);
}
}
*sptr = PAM_SUCCESS;
ret = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_FAIL:
/*
* This can be a user unknown case, so we don't want to stop
* trying other servers when we hit this case during authentication
*/
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_FAIL");
if (NULL != conv_msg.msg) {
int retval = -1;
conv_msg.msg_style = PAM_ERROR_MSG;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
}
else {
_pam_log(LOG_WARNING, "%s: error sending msg=\"%s\", retval=%d",
__func__, conv_msg.msg, retval);
}
}
*sptr = PAM_AUTH_ERR;
ret = 0;
_pam_log(LOG_NOTICE, "auth failed %d", msg);
break;
case TAC_PLUS_AUTHEN_STATUS_GETDATA:
/* not implemented */
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_GETDATA");
if (NULL != conv_msg.msg) {
int retval = -1;
int echo_off = (0x1 == (re.flags & 0x1));
conv_msg.msg_style = echo_off ? PAM_PROMPT_ECHO_OFF : PAM_PROMPT_ECHO_ON;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "sent msg=\"%s\", resp=\"%s\"",
conv_msg.msg, resp->resp);
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "%s: calling tac_cont_send", __func__);
if (0 > tac_cont_send_seq(fd, resp->resp, re.seq_no + 1)) {
_pam_log(LOG_ERR, "error sending continue req to TACACS+ server");
status = PAM_AUTH_ERR;
}
}
else {
_pam_log(LOG_WARNING, "%s: error sending msg=\"%s\", retval=%d (%s)",
__func__, conv_msg.msg, retval, pam_strerror(pamh, retval));
status = PAM_AUTH_ERR;
}
}
else {
syslog(LOG_ERR, "GETDATA response with no message, returning PAM_AUTH_ERR");
status = PAM_AUTH_ERR;
}
ret = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_GETUSER:
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_GETUSER");
ret = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_GETPASS:
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_GETPASS");
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tac_cont_send called", __func__);
if (tac_cont_send(fd, pass) < 0) {
_pam_log (LOG_ERR, "error sending continue req to TACACS+ server");
ret = 0;
break;
}
/* continue the while loop; go read tac response */
break;
case TAC_PLUS_AUTHEN_STATUS_RESTART:
/* try it again */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_RESTART (not impl)");
/*
* not implemented
* WdJ: I *think* you can just do tac_authen_send(user, pass) again
* but I'm not sure
*/
ret = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_ERROR:
/* server has problems */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_ERROR");
ret = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_FOLLOW:
/* server tells to try a different server address */
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: TAC_PLUS_AUTHEN_STATUS_FOLLOW");
ret = 0;
break;
default:
if (msg < 0) {
/* connection error */
ret = 0;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "error communicating with tacacs server");
break;
}
/* unknown response code */
ret = 0;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: unknown response 0x%02x", msg);
}
if (NULL != resp) {
free(resp->resp);
free(resp);
}
if (NULL != re.msg);
free(re.msg);
return ret;
}
/*
* Only acct and auth now; should handle all the cases here
* Talk to the tacacs server for each type of transaction conversation
*/
static void talk_tac_server(int ctrl, int fd, char *user, char *pass,
char *tty, char *r_addr, struct tac_attrib **attr,
int *sptr, struct areply *reply,
pam_handle_t * pamh) {
if(!pass && attr) { /* acct, much simpler */
int retval;
struct areply arep;
retval = tac_author_send(fd, user, tty, r_addr, *attr);
if(retval < 0) {
_pam_log (LOG_ERR, "error getting authorization");
*sptr = PAM_AUTH_ERR;
return;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: sent authorization request for [%s]",
__func__, user);
arep.msg = NULL;
tac_author_read(fd, &arep);
if (reply)
*reply = arep;
if(arep.status != AUTHOR_STATUS_PASS_ADD &&
arep.status != AUTHOR_STATUS_PASS_REPL) {
/*
* this is debug because we can get called for any user for
* commands like sudo, not just tacacs users
*/
*sptr = PAM_PERM_DENIED;
_pam_log (LOG_ERR, "TACACS+ authorization failed for [%s] (status=%d)",
user, arep.status);
if(arep.msg != NULL && !reply)
free (arep.msg); /* if reply is set, caller will free */
}
else {
*sptr = PAM_SUCCESS;
}
}
else if (pass) { /* auth */
if (tac_authen_send(fd, user, pass, tty, r_addr, TAC_PLUS_AUTHEN_LOGIN) < 0) {
_pam_log(LOG_ERR, "error sending auth req to TACACS+ server");
}
else {
while ( tac_auth_converse(ctrl, fd, sptr, pass, pamh))
;
}
}
}
/*
* find a responding tacacs server, and converse with it.
* See comments at do_tac_connect() below
*/
static void find_tac_server(int ctrl, int *tacfd, char *user, char *pass,
char *tty, char *r_addr, struct tac_attrib **attr,
int *sptr, struct areply *reply, pam_handle_t * pamh) {
int fd = -1, srv_i;
for (srv_i = 0; srv_i < tac_srv_no; srv_i++) {
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: trying srv[%d] %s", __func__, srv_i,
tac_srv[srv_i].addr ?
tac_ntop(tac_srv[srv_i].addr->ai_addr) : "not set");
fd = tac_connect_single(tac_srv[srv_i].addr, tac_srv[srv_i].key, NULL,
__vrfname);
if (fd < 0) {
_pam_log(LOG_ERR, "connection to srv[%d] %s failed: %m", srv_i,
tac_srv[srv_i].addr ?
tac_ntop(tac_srv[srv_i].addr->ai_addr) : "not set");
active_server.addr = NULL; /* in case last in list */
continue;
}
talk_tac_server(ctrl, fd, user, pass, tty, r_addr, attr, sptr,
reply, pamh);
if (*sptr == PAM_SUCCESS || *sptr == PAM_AUTH_ERR ||
*sptr == PAM_PERM_DENIED) {
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: srv[%d] %s, pam_status=%d", __func__,
srv_i, tac_ntop(tac_srv[srv_i].addr->ai_addr), *sptr);
if (*sptr == PAM_SUCCESS) {
if (active_server.addr == NULL) {
active_server.addr = tac_srv[srv_i].addr;
active_server.key = tac_srv[srv_i].key;
}
break;
}
/* else try other servers, if any. On errs, won't need fd */
}
else /* in case end of list */
active_server.addr = NULL;
close(fd);
fd = -1;
}
*tacfd = fd;
}
/*
* We have to make a new connection each time, because libtac is single
* threaded (doesn't support multiple connects at the same time due to
* use of globals), and doesn't have support for persistent connections.
* That's fixable, but not worth the effort at this point.
*
* Trying to make this common code is ugly, but worth it to simplify
* maintenance and debugging.
*
* The problem is that the definition allows for multiple tacacs
* servers to be consulted, but a lot of the code was written such
* that once a server is found that responds, it keeps using it.
* That means when we are finding a server we need to do the full sequence.
* The related issue is that the lower level code can't communicate
* with multiple servers at the same time, and can't keep a connection
* open.
*
* TODO: Really should have a structure to pass user, pass, tty, and r_addr
* around everywhere.
*/
static int do_tac_connect(int ctrl, int *tacfd, char *user, char *pass,
char *tty, char *r_addr, struct tac_attrib **attr,
struct areply *reply, pam_handle_t * pamh) {
int status = PAM_AUTHINFO_UNAVAIL, fd;
if (active_server.addr == NULL) { /* find a server with the info we want */
find_tac_server(ctrl, &fd, user, pass, tty, r_addr, attr, &status,
reply, pamh);
}
else { /* connect to the already chosen server, so we get
* consistent results. */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: use previous server %s", __func__,
tac_ntop(active_server.addr->ai_addr));
fd = tac_connect_single(active_server.addr, active_server.key, NULL,
__vrfname);
if (fd < 0)
_pam_log(LOG_ERR, "reconnect failed: %m");
else
talk_tac_server(ctrl, fd, user, pass, tty, r_addr, attr, &status,
reply, pamh);
}
/*
* this is debug because we can get called for any user for
* commands like sudo, not just tacacs users, so it's not an
* error to fail here. The caller can handle the logging.
*/
if ((ctrl & PAM_TAC_DEBUG) && status != PAM_SUCCESS &&
status != PAM_AUTH_ERR)
_pam_log(LOG_ERR, "no more servers to connect");
if (tacfd)
*tacfd = fd; /* auth caller needs fd */
else if (fd != -1)
close(fd); /* acct caller doesn't need connection */
return status;
}
