void
userauth_user_svc_change(Authctxt *authctxt, char *user, char *service)
{
/*
* NOTE:
*
* SSHv2 services should be abstracted and service changes during
* userauth should be supported as per the userauth draft. In the PAM
* case, support for multiple SSHv2 services means that we have to
* format the PAM service name according to the SSHv2 service *and* the
* SSHv2 userauth being attempted ("passwd", "kbdint" and "other").
*
* We'll cross that bridge when we come to it. For now disallow service
* changes during userauth if using PAM, but allow username changes.
*/
/* authctxt->service must == ssh-connection here */
if (service != NULL && strcmp(service, authctxt->service) != 0) {
packet_disconnect("Change of service not "
"allowed: %s and %s",
authctxt->service, service);
}
if (user != NULL && authctxt->user != NULL &&
strcmp(user, authctxt->user) == 0)
return;
/* All good; update authctxt */
xfree(authctxt->user);
authctxt->user = xstrdup(user);
pwfree(&authctxt->pw);
authctxt->pw = getpwnamallow(user);
authctxt->valid = (authctxt->pw != NULL);
/* Forget method state; abandon postponed userauths */
userauth_reset_methods();
}
/*
* To be called from userauth methods, directly (as in keyboard-interactive) or
* indirectly (from auth_pam_password() or from do_pam_non_initial_userauth().
*
* The caller is responsible for calling new_start_pam() first.
*
* PAM state is not cleaned up here on error. This is left to subsequent calls
* to new_start_pam() or to the cleanup function upon authentication error.
*/
int
finish_userauth_do_pam(Authctxt *authctxt)
{
int retval;
char *user, *method;
/* Various checks; fail gracefully */
if (authctxt == NULL || authctxt->pam == NULL)
return PAM_SYSTEM_ERR; /* shouldn't happen */
if (compat20) {
if (authctxt->method == NULL || authctxt->method->name == NULL)
return PAM_SYSTEM_ERR; /* shouldn't happen */
method = authctxt->method->name;
} else if ((method = authctxt->v1_auth_name) == NULL)
return PAM_SYSTEM_ERR; /* shouldn't happen */
if (AUTHPAM_DONE(authctxt))
return PAM_SYSTEM_ERR; /* shouldn't happen */
if (!(authctxt->pam->state & PAM_S_DONE_ACCT_MGMT)) {
retval = pam_acct_mgmt(authctxt->pam->h, 0);
authctxt->pam->last_pam_retval = retval;
if (retval == PAM_NEW_AUTHTOK_REQD) {
userauth_force_kbdint();
return retval;
}
if (retval != PAM_SUCCESS)
return retval;
authctxt->pam->state |= PAM_S_DONE_ACCT_MGMT;
}
/*
* Handle PAM_USER change, if any.
*
* We do this before pam_open_session() because we need the PAM_USER's
* UID for:
*
* a) PermitRootLogin checking
* b) to get at the lastlog entry before pam_open_session() updates it.
*/
retval = pam_get_item(authctxt->pam->h, PAM_USER, (void **) &user);
if (retval != PAM_SUCCESS) {
fatal("PAM failure: pam_get_item(PAM_USER) "
"returned %d: %.200s", retval,
PAM_STRERROR(authctxt->pam->h, retval));
}
if (user == NULL || *user == '\0') {
debug("PAM set NULL PAM_USER");
return PAM_PERM_DENIED;
}
if (strcmp(user, authctxt->user) != 0) {
log("PAM changed the SSH username");
pwfree(&authctxt->pw);
authctxt->pw = PRIVSEP(getpwnamallow(user));
authctxt->valid = (authctxt->pw != NULL);
xfree(authctxt->user);
authctxt->user = xstrdup(user);
}
if (!authctxt->valid) {
debug2("PAM set PAM_USER to unknown user");
/*
* Return success, userauth_finish() will catch
* this and send back a failure message.
*/
return PAM_SUCCESS;
}
/* Check PermitRootLogin semantics */
if (authctxt->pw->pw_uid == 0 && !auth_root_allowed(method))
return PAM_PERM_DENIED;
if (!(authctxt->pam->state & PAM_S_DONE_SETCRED)) {
retval = pam_setcred(authctxt->pam->h,
PAM_ESTABLISH_CRED);
authctxt->pam->last_pam_retval = retval;
if (retval != PAM_SUCCESS)
return retval;
authctxt->pam->state |= PAM_S_DONE_SETCRED;
#ifdef GSSAPI
/*
* Store GSS-API delegated creds after pam_setcred(), which may
* have set the current credential store.
*/
ssh_gssapi_storecreds(NULL, authctxt);
#endif /* GSSAPI */
}
/*
* On Solaris pam_unix_session.so updates the lastlog, but does
* not converse a PAM_TEXT_INFO message about it. So we need to
* fetch the lastlog entry here and save it for use later.
*/
authctxt->last_login_time =
get_last_login_time(authctxt->pw->pw_uid,
authctxt->pw->pw_name,
authctxt->last_login_host,
sizeof(authctxt->last_login_host));
if (!(authctxt->pam->state & PAM_S_DONE_OPEN_SESSION)) {
retval = pam_open_session(authctxt->pam->h, 0);
authctxt->pam->last_pam_retval = retval;
if (retval != PAM_SUCCESS)
return retval;
authctxt->pam->state |= PAM_S_DONE_OPEN_SESSION;
}
/*
* All PAM work done successfully.
*
* PAM handle stays around so we can call pam_close_session() on
* it later.
*/
return PAM_SUCCESS;
}