diff options
Diffstat (limited to 'auth-pam.c')
-rw-r--r-- | auth-pam.c | 143 |
1 files changed, 95 insertions, 48 deletions
@@ -9,11 +9,6 @@ * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by Markus Friedl. - * 4. The name of the author may not be used to endorse or promote products - * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES @@ -34,10 +29,10 @@ #include "xmalloc.h" #include "servconf.h" -RCSID("$Id: auth-pam.c,v 1.12 2000/08/29 22:57:50 djm Exp $"); +RCSID("$Id: auth-pam.c,v 1.13 2000/09/16 05:09:27 djm Exp $"); #define NEW_AUTHTOK_MSG \ - "Warning: You password has expired, please change it now" + "Warning: Your password has expired, please change it now" /* Callbacks */ static int pamconv(int num_msg, const struct pam_message **msg, @@ -50,40 +45,72 @@ static struct pam_conv conv = { pamconv, NULL }; -static struct pam_handle_t *pamh = NULL; +static pam_handle_t *pamh = NULL; static const char *pampasswd = NULL; static char *pam_msg = NULL; -/* PAM conversation function. This is really a kludge to get the password */ -/* into PAM and to pick up any messages generated by PAM into pamconv_msg */ +/* states for pamconv() */ +typedef enum { INITIAL_LOGIN, OTHER } pamstates; +static pamstates pamstate = INITIAL_LOGIN; +/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */ +static int password_change_required = 0; + +/* + * PAM conversation function. + * There are two states this can run in. + * + * INITIAL_LOGIN mode simply feeds the password from the client into + * PAM in response to PAM_PROMPT_ECHO_OFF, and collects output + * messages with pam_msg_cat(). This is used during initial + * authentication to bypass the normal PAM password prompt. + * + * OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase(prompt, 1) + * and outputs messages to stderr. This mode is used if pam_chauthtok() + * is called to update expired passwords. + */ static int pamconv(int num_msg, const struct pam_message **msg, struct pam_response **resp, void *appdata_ptr) { struct pam_response *reply; int count; + char buf[1024]; /* PAM will free this later */ reply = malloc(num_msg * sizeof(*reply)); if (reply == NULL) return PAM_CONV_ERR; - for(count = 0; count < num_msg; count++) { - switch (msg[count]->msg_style) { + for (count = 0; count < num_msg; count++) { + switch ((*msg)[count].msg_style) { + case PAM_PROMPT_ECHO_ON: + fputs((*msg)[count].msg, stderr); + fgets(buf, sizeof(buf), stdin); + reply[count].resp = xstrdup(buf); + reply[count].resp_retcode = PAM_SUCCESS; + break; case PAM_PROMPT_ECHO_OFF: - if (pampasswd == NULL) { - free(reply); - return PAM_CONV_ERR; - } + if (pamstate == INITIAL_LOGIN) { + if (pampasswd == NULL) { + free(reply); + return PAM_CONV_ERR; + } + reply[count].resp = xstrdup(pampasswd); + } else + reply[count].resp = xstrdup(read_passphrase((*msg)[count].msg, 1)); reply[count].resp_retcode = PAM_SUCCESS; - reply[count].resp = xstrdup(pampasswd); break; + case PAM_ERROR_MSG: case PAM_TEXT_INFO: - reply[count].resp_retcode = PAM_SUCCESS; + if ((*msg)[count].msg != NULL) { + if (pamstate == INITIAL_LOGIN) + pam_msg_cat((*msg)[count].msg); + else { + fputs((*msg)[count].msg, stderr); + fputs("\n", stderr); + } + } reply[count].resp = xstrdup(""); - - if (msg[count]->msg != NULL) - pam_msg_cat(msg[count]->msg); - + reply[count].resp_retcode = PAM_SUCCESS; break; default: free(reply); @@ -103,22 +130,22 @@ void pam_cleanup_proc(void *context) if (pamh != NULL) { - pam_retval = pam_close_session((pam_handle_t *)pamh, 0); + pam_retval = pam_close_session(pamh, 0); if (pam_retval != PAM_SUCCESS) { log("Cannot close PAM session: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); } - pam_retval = pam_setcred((pam_handle_t *)pamh, PAM_DELETE_CRED); + pam_retval = pam_setcred(pamh, PAM_DELETE_CRED); if (pam_retval != PAM_SUCCESS) { debug("Cannot delete credentials: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); } - pam_retval = pam_end((pam_handle_t *)pamh, pam_retval); + pam_retval = pam_end(pamh, pam_retval); if (pam_retval != PAM_SUCCESS) { log("Cannot release PAM authentication: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); } } } @@ -139,14 +166,15 @@ int auth_pam_password(struct passwd *pw, const char *password) pampasswd = password; - pam_retval = pam_authenticate((pam_handle_t *)pamh, 0); + pamstate = INITIAL_LOGIN; + pam_retval = pam_authenticate(pamh, 0); if (pam_retval == PAM_SUCCESS) { debug("PAM Password authentication accepted for user \"%.100s\"", pw->pw_name); return 1; } else { debug("PAM Password authentication for \"%.100s\" failed: %s", - pw->pw_name, PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + pw->pw_name, PAM_STRERROR(pamh, pam_retval)); return 0; } } @@ -157,33 +185,35 @@ int do_pam_account(char *username, char *remote_user) int pam_retval; debug("PAM setting rhost to \"%.200s\"", get_canonical_hostname()); - pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RHOST, + pam_retval = pam_set_item(pamh, PAM_RHOST, get_canonical_hostname()); if (pam_retval != PAM_SUCCESS) { fatal("PAM set rhost failed: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); } if (remote_user != NULL) { debug("PAM setting ruser to \"%.200s\"", remote_user); - pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RUSER, remote_user); + pam_retval = pam_set_item(pamh, PAM_RUSER, remote_user); if (pam_retval != PAM_SUCCESS) { fatal("PAM set ruser failed: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); } } - pam_retval = pam_acct_mgmt((pam_handle_t *)pamh, 0); + pam_retval = pam_acct_mgmt(pamh, 0); switch (pam_retval) { case PAM_SUCCESS: /* This is what we want */ break; case PAM_NEW_AUTHTOK_REQD: pam_msg_cat(NEW_AUTHTOK_MSG); + /* flag that password change is necessary */ + password_change_required = 1; break; default: log("PAM rejected by account configuration: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); return(0); } @@ -197,17 +227,17 @@ void do_pam_session(char *username, const char *ttyname) if (ttyname != NULL) { debug("PAM setting tty to \"%.200s\"", ttyname); - pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_TTY, ttyname); + pam_retval = pam_set_item(pamh, PAM_TTY, ttyname); if (pam_retval != PAM_SUCCESS) { fatal("PAM set tty failed: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); } } - pam_retval = pam_open_session((pam_handle_t *)pamh, 0); + pam_retval = pam_open_session(pamh, 0); if (pam_retval != PAM_SUCCESS) { fatal("PAM session setup failed: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); } } @@ -217,10 +247,28 @@ void do_pam_setcred() int pam_retval; debug("PAM establishing creds"); - pam_retval = pam_setcred((pam_handle_t *)pamh, PAM_ESTABLISH_CRED); + pam_retval = pam_setcred(pamh, PAM_ESTABLISH_CRED); if (pam_retval != PAM_SUCCESS) { fatal("PAM setcred failed: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); + } +} + +/* + * Have user change authentication token if pam_acct_mgmt() indicated + * it was expired. This needs to be called after an interactive + * session is established and the user's pty is connected to + * stdin/stout/stderr. + */ +void do_pam_chauthtok() +{ + int pam_retval; + + if (password_change_required) { + pamstate = OTHER; + do { + pam_retval = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK); + } while (pam_retval != PAM_SUCCESS); } } @@ -238,12 +286,11 @@ void start_pam(struct passwd *pw) debug("Starting up PAM with username \"%.200s\"", pw->pw_name); - pam_retval = pam_start(SSHD_PAM_SERVICE, pw->pw_name, &conv, - (pam_handle_t**)&pamh); + pam_retval = pam_start(SSHD_PAM_SERVICE, pw->pw_name, &conv, &pamh); if (pam_retval != PAM_SUCCESS) { fatal("PAM initialisation failed: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); } #ifdef PAM_TTY_KLUDGE @@ -254,10 +301,10 @@ void start_pam(struct passwd *pw) * not even need one (for tty-less connections) * Kludge: Set a fake PAM_TTY */ - pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_TTY, "ssh"); + pam_retval = pam_set_item(pamh, PAM_TTY, "ssh"); if (pam_retval != PAM_SUCCESS) { fatal("PAM set tty failed: %.200s", - PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); + PAM_STRERROR(pamh, pam_retval)); } #endif /* PAM_TTY_KLUDGE */ @@ -268,7 +315,7 @@ void start_pam(struct passwd *pw) char **fetch_pam_environment(void) { #ifdef HAVE_PAM_GETENVLIST - return(pam_getenvlist((pam_handle_t *)pamh)); + return(pam_getenvlist(pamh)); #else /* HAVE_PAM_GETENVLIST */ return(NULL); #endif /* HAVE_PAM_GETENVLIST */ |