- (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
This commit is contained in:
Damien Miller 2001-02-07 12:58:33 +11:00
parent 582d3983d2
commit 63dc3e90e5
4 changed files with 170 additions and 166 deletions

View File

@ -1,6 +1,12 @@
20010107
- (bal) Save the whole path to AR in configure. Some Solaris 2.7 installs
seem lose track of it while in openbsd-compat/ (two confirmed reports)
- (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
20010105
- (bal) Disable groupaccess by setting NGROUPS_MAX to 0 for platforms

View File

@ -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 @@ int do_pam_authenticate(int flags)
*
* 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 @@ static int pamconv(int num_msg, const struct pam_message **msg,
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 @@ static int pamconv(int num_msg, const struct pam_message **msg,
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 @@ void pam_cleanup_proc(void *context)
{
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 @@ int auth_pam_password(struct passwd *pw, const char *password)
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 do_pam_account(char *username, char *remote_user)
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 @@ int do_pam_account(char *username, char *remote_user)
/* 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 @@ void do_pam_session(char *username, const char *ttyname)
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 @@ void do_pam_setcred(void)
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 @@ void do_pam_chauthtok(void)
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 @@ void start_pam(const char *user)
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 @@ void start_pam(const char *user)
* 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 @@ void print_pam_messages(void)
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 */

View File

@ -15,5 +15,6 @@ void print_pam_messages(void);
int pam_password_change_required(void);
void do_pam_chauthtok(void);
void pam_set_conv(struct pam_conv *);
void message_cat(char **p, const char *a);
#endif /* USE_PAM */

View File

@ -1,5 +1,5 @@
#include "includes.h"
RCSID("$Id: auth2-pam.c,v 1.7 2001/01/30 23:50:49 djm Exp $");
RCSID("$Id: auth2-pam.c,v 1.8 2001/02/07 01:58:33 djm Exp $");
#ifdef USE_PAM
#include <security/pam_appl.h>
@ -7,28 +7,28 @@ RCSID("$Id: auth2-pam.c,v 1.7 2001/01/30 23:50:49 djm Exp $");
#include "ssh.h"
#include "ssh2.h"
#include "auth.h"
#include "auth-pam.h"
#include "packet.h"
#include "xmalloc.h"
#include "dispatch.h"
#include "log.h"
static int do_pam_conversation_kbd_int(int num_msg,
const struct pam_message **msg, struct pam_response **resp,
void *appdata_ptr);
void input_userauth_info_response_pam(int type, int plen, void *ctxt);
struct {
int finished, num_received, num_expected;
int *prompts;
struct pam_response *responses;
} context_pam2 = {0, 0, 0, NULL};
static int do_conversation2(int num_msg, const struct pam_message **msg,
struct pam_response **resp, void *appdata_ptr);
static struct pam_conv
conv2 = {
do_conversation2,
static struct pam_conv conv2 = {
do_pam_conversation_kbd_int,
NULL,
};
void input_userauth_info_response_pam(int type, int plen, void *ctxt);
int
auth2_pam(Authctxt *authctxt)
{
@ -41,7 +41,7 @@ auth2_pam(Authctxt *authctxt)
pam_set_conv(&conv2);
dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE,
&input_userauth_info_response_pam);
&input_userauth_info_response_pam);
retval = (do_pam_authenticate(0) == PAM_SUCCESS);
dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL);
@ -49,11 +49,11 @@ auth2_pam(Authctxt *authctxt)
}
static int
do_conversation2(int num_msg, const struct pam_message **msg,
struct pam_response **resp, void *appdata_ptr)
do_pam_conversation_kbd_int(int num_msg, const struct pam_message **msg,
struct pam_response **resp, void *appdata_ptr)
{
int echo = 0, i = 0, j = 0, done = 0;
char *tmp = NULL, *text = NULL;
int i, j, done;
char *text;
context_pam2.finished = 0;
context_pam2.num_received = 0;
@ -62,53 +62,47 @@ do_conversation2(int num_msg, const struct pam_message **msg,
context_pam2.responses = xmalloc(sizeof(struct pam_response) * num_msg);
memset(context_pam2.responses, 0, sizeof(struct pam_response) * num_msg);
packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
packet_put_cstring(""); /* Name */
packet_put_cstring(""); /* Instructions */
packet_put_cstring(""); /* Language */
for (i = 0, j = 0; i < num_msg; i++) {
if((PAM_MSG_MEMBER(msg, i, msg_style) == PAM_PROMPT_ECHO_ON) ||
(PAM_MSG_MEMBER(msg, i, msg_style) == PAM_PROMPT_ECHO_OFF) ||
(i == num_msg - 1)) {
j++;
text = NULL;
for (i = 0, context_pam2.num_expected = 0; i < num_msg; i++) {
int style = PAM_MSG_MEMBER(msg, i, msg_style);
switch (style) {
case PAM_PROMPT_ECHO_ON:
case PAM_PROMPT_ECHO_OFF:
context_pam2.num_expected++;
break;
case PAM_TEXT_INFO:
case PAM_ERROR_MSG:
default:
/* Capture all these messages to be sent at once */
message_cat(&text, PAM_MSG_MEMBER(msg, i, msg));
break;
}
}
packet_put_int(j); /* Number of prompts. */
context_pam2.num_expected = j;
if (context_pam2.num_expected == 0)
return PAM_SUCCESS;
packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
packet_put_cstring(""); /* Name */
packet_put_cstring(""); /* Instructions */
packet_put_cstring(""); /* Language */
packet_put_int(context_pam2.num_expected);
for (i = 0, j = 0; i < num_msg; i++) {
switch(PAM_MSG_MEMBER(msg, i, msg_style)) {
case PAM_PROMPT_ECHO_ON:
echo = 1;
break;
case PAM_PROMPT_ECHO_OFF:
echo = 0;
break;
default:
echo = 0;
break;
}
if(text) {
tmp = xmalloc(strlen(text) + strlen(PAM_MSG_MEMBER(msg, i, msg)) + 2);
strcpy(tmp, text);
strcat(tmp, "\n");
strcat(tmp, PAM_MSG_MEMBER(msg, i, msg));
xfree(text);
text = tmp;
tmp = NULL;
} else {
text = xstrdup(PAM_MSG_MEMBER(msg, i, msg));
}
if((PAM_MSG_MEMBER(msg, i, msg_style) == PAM_PROMPT_ECHO_ON) ||
(PAM_MSG_MEMBER(msg, i, msg_style) == PAM_PROMPT_ECHO_OFF) ||
(i == num_msg - 1)) {
debug("sending prompt ssh-%d(pam-%d) = \"%s\"",
j, i, text);
context_pam2.prompts[j++] = i;
int style = PAM_MSG_MEMBER(msg, i, msg_style);
/* Skip messages which don't need a reply */
if (style != PAM_PROMPT_ECHO_ON && style != PAM_PROMPT_ECHO_OFF)
continue;
context_pam2.prompts[j++] = i;
if (text) {
message_cat(&text, PAM_MSG_MEMBER(msg, i, msg));
packet_put_cstring(text);
packet_put_char(echo);
xfree(text);
text = NULL;
}
} else
packet_put_cstring(PAM_MSG_MEMBER(msg, i, msg));
packet_put_char(style == PAM_PROMPT_ECHO_ON);
}
packet_send();
packet_write_wait();
@ -120,17 +114,15 @@ do_conversation2(int num_msg, const struct pam_message **msg,
while(context_pam2.finished == 0) {
done = 1;
dispatch_run(DISPATCH_BLOCK, &done, appdata_ptr);
if(context_pam2.finished == 0) {
if(context_pam2.finished == 0)
debug("extra packet during conversation");
}
}
if(context_pam2.num_received == context_pam2.num_expected) {
*resp = context_pam2.responses;
return PAM_SUCCESS;
} else {
} else
return PAM_CONV_ERR;
}
}
void
@ -151,6 +143,7 @@ input_userauth_info_response_pam(int type, int plen, void *ctxt)
for (i = 0; i < nresp; i++) {
int j = context_pam2.prompts[i];
resp = packet_get_string(&rlen);
context_pam2.responses[j].resp_retcode = PAM_SUCCESS;
context_pam2.responses[j].resp = xstrdup(resp);