/*
- * Author: Damien Miller
- * Copyright (c) 1999 Damien Miller <djm@mindrot.org>
- * All rights reserved
- * Created: Thursday December 30 1999
- * PAM authentication and session management code.
+ * Copyright (c) 2000 Damien Miller. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
RCSID("$Id$");
+#define NEW_AUTHTOK_MSG \
+ "Warning: Your password has expired, please change it now"
+
/* Callbacks */
static int pamconv(int num_msg, const struct pam_message **msg,
struct pam_response **resp, void *appdata_ptr);
void pam_cleanup_proc(void *context);
+void pam_msg_cat(const char *msg);
/* module-local variables */
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 *pamconv_msg = NULL;
+static char *pam_msg = NULL;
+
+/* states for pamconv() */
+enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
+/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
+static int password_change_required = 0;
+/* remember whether the last pam_authenticate() succeeded or not */
+static int was_authenticated = 0;
+
+/* accessor which allows us to switch conversation structs according to
+ * the authentication method being used */
+void pam_set_conv(struct pam_conv *conv)
+{
+ pam_set_item(pamh, PAM_CONV, conv);
+}
-/* 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 */
+/* start an authentication run */
+int do_pam_authenticate(int flags)
+{
+ int retval = pam_authenticate(pamh, flags);
+ was_authenticated = (retval == PAM_SUCCESS);
+ return retval;
+}
+
+/*
+ * 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;
- size_t msg_len;
- char *p;
+ 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) {
- case PAM_PROMPT_ECHO_OFF:
- if (pampasswd == NULL) {
+ for (count = 0; count < num_msg; count++) {
+ switch ((*msg)[count].msg_style) {
+ case PAM_PROMPT_ECHO_ON:
+ if (pamstate == INITIAL_LOGIN) {
free(reply);
return PAM_CONV_ERR;
+ } else {
+ 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 (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;
- reply[count].resp = xstrdup("");
-
- if (msg[count]->msg == NULL)
- break;
-
- debug("Adding PAM message: %s", msg[count]->msg);
-
- msg_len = strlen(msg[count]->msg);
- if (pamconv_msg) {
- size_t n = strlen(pamconv_msg);
- pamconv_msg = xrealloc(pamconv_msg, n + msg_len + 2);
- p = pamconv_msg + n;
- } else {
- pamconv_msg = p = xmalloc(msg_len + 2);
+ if ((*msg)[count].msg != NULL) {
+ if (pamstate == INITIAL_LOGIN)
+ pam_msg_cat((*msg)[count].msg);
+ else {
+ fputs((*msg)[count].msg, stderr);
+ fputs("\n", stderr);
+ }
}
- memcpy(p, msg[count]->msg, msg_len);
- p[msg_len] = '\n';
- p[msg_len + 1] = '\0';
+ reply[count].resp = xstrdup("");
+ reply[count].resp_retcode = PAM_SUCCESS;
break;
-
- case PAM_PROMPT_ECHO_ON:
- case PAM_ERROR_MSG:
default:
free(reply);
return PAM_CONV_ERR;
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));
+ log("Cannot close PAM session[%d]: %.200s",
+ 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) {
- log("Cannot delete credentials: %.200s",
- PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+ debug("Cannot delete credentials[%d]: %.200s",
+ 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));
+ log("Cannot release PAM authentication[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
}
}
}
extern ServerOptions options;
int pam_retval;
+ pam_set_conv(&conv);
+
/* deny if no user. */
if (pw == NULL)
return 0;
pampasswd = password;
- pam_retval = pam_authenticate((pam_handle_t *)pamh, 0);
+ pamstate = INITIAL_LOGIN;
+ pam_retval = do_pam_authenticate(0);
if (pam_retval == PAM_SUCCESS) {
- debug("PAM Password authentication accepted for user \"%.100s\"", pw->pw_name);
+ 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));
+ debug("PAM Password authentication for \"%.100s\" failed[%d]: %s",
+ pw->pw_name, pam_retval, PAM_STRERROR(pamh, pam_retval));
return 0;
}
}
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));
+ fatal("PAM set rhost failed[%d]: %.200s",
+ 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));
+ fatal("PAM set ruser failed[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
}
}
- pam_retval = pam_acct_mgmt((pam_handle_t *)pamh, 0);
- if (pam_retval != PAM_SUCCESS) {
- log("PAM rejected by account configuration: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
- return(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[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
+ return(0);
}
return(1);
if (ttyname != NULL) {
debug("PAM setting tty to \"%.200s\"", ttyname);
- pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_TTY, ttyname);
- if (pam_retval != PAM_SUCCESS)
- fatal("PAM set tty failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+ pam_retval = pam_set_item(pamh, PAM_TTY, ttyname);
+ if (pam_retval != PAM_SUCCESS) {
+ fatal("PAM set tty failed[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
+ }
}
- pam_retval = pam_open_session((pam_handle_t *)pamh, 0);
- if (pam_retval != PAM_SUCCESS)
- fatal("PAM session setup failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+ pam_retval = pam_open_session(pamh, 0);
+ if (pam_retval != PAM_SUCCESS) {
+ fatal("PAM session setup failed[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
+ }
}
/* Set PAM credentials */
-void do_pam_setcred()
+void do_pam_setcred(void)
{
int pam_retval;
debug("PAM establishing creds");
- pam_retval = pam_setcred((pam_handle_t *)pamh, PAM_ESTABLISH_CRED);
- if (pam_retval != PAM_SUCCESS)
- fatal("PAM setcred failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+ pam_retval = pam_setcred(pamh, PAM_ESTABLISH_CRED);
+ if (pam_retval != PAM_SUCCESS) {
+ if(was_authenticated) {
+ fatal("PAM setcred failed[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
+ } else {
+ debug("PAM setcred failed[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
+ }
+ }
+}
+
+/* accessor function for file scope static variable */
+int pam_password_change_required(void)
+{
+ return password_change_required;
+}
+
+/*
+ * 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(void)
+{
+ int pam_retval;
+
+ if (password_change_required) {
+ pamstate = OTHER;
+ /*
+ * XXX: should we really loop forever?
+ */
+ do {
+ pam_retval = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
+ if (pam_retval != PAM_SUCCESS) {
+ log("PAM pam_chauthtok failed[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
+ }
+ } while (pam_retval != PAM_SUCCESS);
+ }
}
/* Cleanly shutdown PAM */
debug("Starting up PAM with username \"%.200s\"", pw->pw_name);
- pam_retval = pam_start("sshd", pw->pw_name, &conv, (pam_handle_t**)&pamh);
- if (pam_retval != PAM_SUCCESS)
- fatal("PAM initialisation failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+ pam_retval = pam_start(SSHD_PAM_SERVICE, pw->pw_name, &conv, &pamh);
+
+ if (pam_retval != PAM_SUCCESS) {
+ fatal("PAM initialisation failed[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
+ }
+
+#ifdef PAM_TTY_KLUDGE
+ /*
+ * Some PAM modules (e.g. pam_time) require a TTY to operate,
+ * and will fail in various stupid ways if they don't get one.
+ * sshd doesn't set the tty until too late in the auth process and may
+ * not even need one (for tty-less connections)
+ * Kludge: Set a fake PAM_TTY
+ */
+ pam_retval = pam_set_item(pamh, PAM_TTY, "ssh");
+ if (pam_retval != PAM_SUCCESS) {
+ fatal("PAM set tty failed[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
+ }
+#endif /* PAM_TTY_KLUDGE */
fatal_add_cleanup(&pam_cleanup_proc, NULL);
}
/* Return list of PAM enviornment strings */
char **fetch_pam_environment(void)
{
- return(pam_getenvlist((pam_handle_t *)pamh));
+#ifdef HAVE_PAM_GETENVLIST
+ return(pam_getenvlist(pamh));
+#else /* HAVE_PAM_GETENVLIST */
+ return(NULL);
+#endif /* HAVE_PAM_GETENVLIST */
}
/* Print any messages that have been generated during authentication */
/* or account checking to stderr */
void print_pam_messages(void)
{
- if (pamconv_msg != NULL)
- fprintf(stderr, pamconv_msg);
+ if (pam_msg != NULL)
+ fputs(pam_msg, stderr);
+}
+
+/* Append a message to the PAM message buffer */
+void pam_msg_cat(const char *msg)
+{
+ char *p;
+ size_t new_msg_len;
+ size_t pam_msg_len;
+
+ new_msg_len = strlen(msg);
+
+ if (pam_msg) {
+ pam_msg_len = strlen(pam_msg);
+ pam_msg = xrealloc(pam_msg, new_msg_len + pam_msg_len + 2);
+ p = pam_msg + pam_msg_len;
+ } else {
+ pam_msg = p = xmalloc(new_msg_len + 2);
+ }
+
+ memcpy(p, msg, new_msg_len);
+ p[new_msg_len] = '\n';
+ p[new_msg_len + 1] = '\0';
}
#endif /* USE_PAM */
andersk / openssh.git / blobdiff