- (djm) Much KNF on PAM code
- (djm) Revise auth-pam.c conversation function to be a little more readable.
- (djm) Revise kbd-int PAM conversation function to fold all text messages
to before first prompt. Fixes hangs if last pam_message did not require
a reply.
- (djm) Fix password changing when using PAM kbd-int authentication
diff --git a/auth-pam.c b/auth-pam.c
index ab985d1..e6fddec 100644
--- a/auth-pam.c
+++ b/auth-pam.c
@@ -28,31 +28,29 @@
#include "ssh.h"
#include "xmalloc.h"
#include "log.h"
+#include "auth-pam.h"
#include "servconf.h"
#include "canohost.h"
#include "readpass.h"
-RCSID("$Id: auth-pam.c,v 1.24 2001/02/05 12:42:17 stevesk Exp $");
+RCSID("$Id: auth-pam.c,v 1.25 2001/02/07 01:58:34 djm Exp $");
#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);
+static int do_pam_conversation(int num_msg, const struct pam_message **msg,
+ struct pam_response **resp, void *appdata_ptr);
/* module-local variables */
static struct pam_conv conv = {
- pamconv,
+ do_pam_conversation,
NULL
};
+static char *pam_msg = NULL;
static pam_handle_t *pamh = NULL;
static const char *pampasswd = NULL;
-static char *pam_msg = NULL;
-/* states for pamconv() */
+/* states for do_pam_conversation() */
enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
static int password_change_required = 0;
@@ -80,14 +78,14 @@
*
* 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
+ * messages with into pam_msg. 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,
+static int do_pam_conversation(int num_msg, const struct pam_message **msg,
struct pam_response **resp, void *appdata_ptr)
{
struct pam_response *reply;
@@ -100,40 +98,28 @@
return PAM_CONV_ERR;
for (count = 0; count < num_msg; count++) {
- switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
+ if (pamstate == INITIAL_LOGIN) {
+ /*
+ * We can't use stdio yet, queue messages for
+ * printing later
+ */
+ switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
case PAM_PROMPT_ECHO_ON:
- if (pamstate == INITIAL_LOGIN) {
+ free(reply);
+ return PAM_CONV_ERR;
+ case PAM_PROMPT_ECHO_OFF:
+ if (pampasswd == NULL) {
free(reply);
return PAM_CONV_ERR;
- } else {
- fputs(PAM_MSG_MEMBER(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(PAM_MSG_MEMBER(msg, count, msg), 1));
- }
+ reply[count].resp = xstrdup(pampasswd);
reply[count].resp_retcode = PAM_SUCCESS;
break;
case PAM_ERROR_MSG:
case PAM_TEXT_INFO:
if ((*msg)[count].msg != NULL) {
- if (pamstate == INITIAL_LOGIN)
- pam_msg_cat(PAM_MSG_MEMBER(msg, count, msg));
- else {
- fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
- fputs("\n", stderr);
- }
+ message_cat(&pam_msg,
+ PAM_MSG_MEMBER(msg, count, msg));
}
reply[count].resp = xstrdup("");
reply[count].resp_retcode = PAM_SUCCESS;
@@ -141,6 +127,36 @@
default:
free(reply);
return PAM_CONV_ERR;
+ }
+ } else {
+ /*
+ * stdio is connected, so interact directly
+ */
+ switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
+ case PAM_PROMPT_ECHO_ON:
+ fputs(PAM_MSG_MEMBER(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:
+ reply[count].resp = xstrdup(
+ read_passphrase(PAM_MSG_MEMBER(msg, count,
+ msg), 1));
+ reply[count].resp_retcode = PAM_SUCCESS;
+ break;
+ case PAM_ERROR_MSG:
+ case PAM_TEXT_INFO:
+ if ((*msg)[count].msg != NULL)
+ fprintf(stderr, "%s\n",
+ PAM_MSG_MEMBER(msg, count, msg));
+ reply[count].resp = xstrdup("");
+ reply[count].resp_retcode = PAM_SUCCESS;
+ break;
+ default:
+ free(reply);
+ return PAM_CONV_ERR;
+ }
}
}
@@ -154,25 +170,21 @@
{
int pam_retval;
- if (pamh != NULL)
- {
+ if (pamh) {
pam_retval = pam_close_session(pamh, 0);
- if (pam_retval != PAM_SUCCESS) {
+ if (pam_retval != PAM_SUCCESS)
log("Cannot close PAM session[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
pam_retval = pam_setcred(pamh, PAM_DELETE_CRED);
- if (pam_retval != PAM_SUCCESS) {
- debug("Cannot delete credentials[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
+ if (pam_retval != PAM_SUCCESS)
+ debug("Cannot delete credentials[%d]: %.200s",
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
pam_retval = pam_end(pamh, pam_retval);
- if (pam_retval != PAM_SUCCESS) {
+ if (pam_retval != PAM_SUCCESS)
log("Cannot release PAM authentication[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
}
}
@@ -197,12 +209,13 @@
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[%d]: %s",
- pw->pw_name, pam_retval, PAM_STRERROR(pamh, pam_retval));
+ debug("PAM Password authentication for \"%.100s\" "
+ "failed[%d]: %s", pw->pw_name, pam_retval,
+ PAM_STRERROR(pamh, pam_retval));
return 0;
}
}
@@ -213,22 +226,21 @@
int pam_retval;
extern ServerOptions options;
+ pam_set_conv(&conv);
+
debug("PAM setting rhost to \"%.200s\"",
get_canonical_hostname(options.reverse_mapping_check));
pam_retval = pam_set_item(pamh, PAM_RHOST,
get_canonical_hostname(options.reverse_mapping_check));
- if (pam_retval != PAM_SUCCESS) {
- fatal("PAM set rhost failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
-
- if (remote_user != NULL) {
+ if (pam_retval != PAM_SUCCESS)
+ fatal("PAM set rhost failed[%d]: %.200s", pam_retval,
+ PAM_STRERROR(pamh, pam_retval));
+ if (remote_user) {
debug("PAM setting ruser to \"%.200s\"", remote_user);
pam_retval = pam_set_item(pamh, PAM_RUSER, remote_user);
- if (pam_retval != PAM_SUCCESS) {
- fatal("PAM set ruser failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
+ if (pam_retval != PAM_SUCCESS)
+ fatal("PAM set ruser failed[%d]: %.200s", pam_retval,
+ PAM_STRERROR(pamh, pam_retval));
}
pam_retval = pam_acct_mgmt(pamh, 0);
@@ -237,13 +249,14 @@
/* This is what we want */
break;
case PAM_NEW_AUTHTOK_REQD:
- pam_msg_cat(NEW_AUTHTOK_MSG);
+ message_cat(&pam_msg, 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));
+ log("PAM rejected by account configuration[%d]: "
+ "%.200s", pam_retval, PAM_STRERROR(pamh,
+ pam_retval));
return(0);
}
@@ -258,17 +271,15 @@
if (ttyname != NULL) {
debug("PAM setting tty to \"%.200s\"", ttyname);
pam_retval = pam_set_item(pamh, PAM_TTY, ttyname);
- if (pam_retval != PAM_SUCCESS) {
+ if (pam_retval != PAM_SUCCESS)
fatal("PAM set tty failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
}
pam_retval = pam_open_session(pamh, 0);
- if (pam_retval != PAM_SUCCESS) {
+ if (pam_retval != PAM_SUCCESS)
fatal("PAM session setup failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
}
/* Set PAM credentials */
@@ -279,13 +290,12 @@
debug("PAM establishing creds");
pam_retval = pam_setcred(pamh, PAM_ESTABLISH_CRED);
if (pam_retval != PAM_SUCCESS) {
- if(was_authenticated) {
+ if (was_authenticated)
fatal("PAM setcred failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- } else {
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
+ else
debug("PAM setcred failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
}
}
@@ -307,15 +317,13 @@
if (password_change_required) {
pamstate = OTHER;
- /*
- * XXX: should we really loop forever?
- */
+ /* XXX: should we really loop forever? */
do {
- pam_retval = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
- if (pam_retval != PAM_SUCCESS) {
+ 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));
- }
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
} while (pam_retval != PAM_SUCCESS);
}
}
@@ -336,11 +344,9 @@
pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &pamh);
- if (pam_retval != PAM_SUCCESS) {
+ if (pam_retval != PAM_SUCCESS)
fatal("PAM initialisation failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
-
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
#ifdef PAM_TTY_KLUDGE
/*
* Some PAM modules (e.g. pam_time) require a TTY to operate,
@@ -350,10 +356,9 @@
* Kludge: Set a fake PAM_TTY
*/
pam_retval = pam_set_item(pamh, PAM_TTY, "ssh");
- if (pam_retval != PAM_SUCCESS) {
+ if (pam_retval != PAM_SUCCESS)
fatal("PAM set tty failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(pamh, pam_retval));
- }
+ pam_retval, PAM_STRERROR(pamh, pam_retval));
#endif /* PAM_TTY_KLUDGE */
fatal_add_cleanup(&pam_cleanup_proc, NULL);
@@ -377,26 +382,25 @@
fputs(pam_msg, stderr);
}
-/* Append a message to the PAM message buffer */
-void pam_msg_cat(const char *msg)
+/* Append a message to buffer */
+void message_cat(char **p, const char *a)
{
- char *p;
- size_t new_msg_len;
- size_t pam_msg_len;
+ char *cp;
+ size_t new_len;
- new_msg_len = strlen(msg);
+ new_len = strlen(a);
- 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);
- }
+ if (*p) {
+ size_t len = strlen(*p);
- memcpy(p, msg, new_msg_len);
- p[new_msg_len] = '\n';
- p[new_msg_len + 1] = '\0';
+ *p = xrealloc(*p, new_len + len + 2);
+ cp = *p + len;
+ } else
+ *p = cp = xmalloc(new_len + 2);
+
+ memcpy(cp, a, new_len);
+ cp[new_len] = '\n';
+ cp[new_len + 1] = '\0';
}
#endif /* USE_PAM */