* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
+/*
+ * Copyright (c) 2003,2004 Damien Miller <djm@mindrot.org>
+ * Copyright (c) 2003,2004 Darren Tucker <dtucker@zip.com.au>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
/* Based on $FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */
#include "includes.h"
-RCSID("$Id$");
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+#include <errno.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
#ifdef USE_PAM
+#if defined(HAVE_SECURITY_PAM_APPL_H)
#include <security/pam_appl.h>
+#elif defined (HAVE_PAM_PAM_APPL_H)
+#include <pam/pam_appl.h>
+#endif
+
+/* OpenGroup RFC86.0 and XSSO specify no "const" on arguments */
+#ifdef PAM_SUN_CODEBASE
+# define sshpam_const /* Solaris, HP-UX, AIX */
+#else
+# define sshpam_const const /* LinuxPAM, OpenPAM */
+#endif
+/* Ambiguity in spec: is it an array of pointers or a pointer to an array? */
+#ifdef PAM_SUN_CODEBASE
+# define PAM_MSG_MEMBER(msg, n, member) ((*(msg))[(n)].member)
+#else
+# define PAM_MSG_MEMBER(msg, n, member) ((msg)[(n)]->member)
+#endif
+
+#include "xmalloc.h"
+#include "buffer.h"
+#include "key.h"
+#include "hostfile.h"
#include "auth.h"
#include "auth-pam.h"
-#include "buffer.h"
-#include "bufaux.h"
#include "canohost.h"
#include "log.h"
-#include "monitor_wrap.h"
#include "msg.h"
#include "packet.h"
-#include "readpass.h"
+#include "misc.h"
#include "servconf.h"
#include "ssh2.h"
-#include "xmalloc.h"
#include "auth-options.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+#include "monitor_wrap.h"
extern ServerOptions options;
+extern Buffer loginmsg;
+extern int compat20;
+extern u_int utmp_len;
-#define __unused
-
+/* so we don't silently change behaviour */
#ifdef USE_POSIX_THREADS
+# error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK"
+#endif
+
+/*
+ * Formerly known as USE_POSIX_THREADS, using this is completely unsupported
+ * and generally a bad idea. Use at own risk and do not expect support if
+ * this breaks.
+ */
+#ifdef UNSUPPORTED_POSIX_THREADS_HACK
#include <pthread.h>
/*
- * Avoid namespace clash when *not* using pthreads for systems *with*
- * pthreads, which unconditionally define pthread_t via sys/types.h
+ * Avoid namespace clash when *not* using pthreads for systems *with*
+ * pthreads, which unconditionally define pthread_t via sys/types.h
* (e.g. Linux)
*/
-typedef pthread_t sp_pthread_t;
+typedef pthread_t sp_pthread_t;
#else
+typedef pid_t sp_pthread_t;
+#endif
+
+struct pam_ctxt {
+ sp_pthread_t pam_thread;
+ int pam_psock;
+ int pam_csock;
+ int pam_done;
+};
+
+static void sshpam_free_ctx(void *);
+static struct pam_ctxt *cleanup_ctxt;
+
+#ifndef UNSUPPORTED_POSIX_THREADS_HACK
/*
* Simulate threads with processes.
*/
-typedef pid_t sp_pthread_t;
+static int sshpam_thread_status = -1;
+static mysig_t sshpam_oldsig;
+
+static void
+sshpam_sigchld_handler(int sig)
+{
+ signal(SIGCHLD, SIG_DFL);
+ if (cleanup_ctxt == NULL)
+ return; /* handler called after PAM cleanup, shouldn't happen */
+ if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, WNOHANG)
+ <= 0) {
+ /* PAM thread has not exitted, privsep slave must have */
+ kill(cleanup_ctxt->pam_thread, SIGTERM);
+ if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0)
+ <= 0)
+ return; /* could not wait */
+ }
+ if (WIFSIGNALED(sshpam_thread_status) &&
+ WTERMSIG(sshpam_thread_status) == SIGTERM)
+ return; /* terminated by pthread_cancel */
+ if (!WIFEXITED(sshpam_thread_status))
+ sigdie("PAM: authentication thread exited unexpectedly");
+ if (WEXITSTATUS(sshpam_thread_status) != 0)
+ sigdie("PAM: authentication thread exited uncleanly");
+}
+
+/* ARGSUSED */
static void
-pthread_exit(void *value __unused)
+pthread_exit(void *value)
{
_exit(0);
}
+/* ARGSUSED */
static int
-pthread_create(sp_pthread_t *thread, const void *attr __unused,
+pthread_create(sp_pthread_t *thread, const void *attr,
void *(*thread_start)(void *), void *arg)
{
pid_t pid;
+ struct pam_ctxt *ctx = arg;
+ sshpam_thread_status = -1;
switch ((pid = fork())) {
case -1:
error("fork(): %s", strerror(errno));
return (-1);
case 0:
+ close(ctx->pam_psock);
+ ctx->pam_psock = -1;
thread_start(arg);
_exit(1);
default:
*thread = pid;
+ close(ctx->pam_csock);
+ ctx->pam_csock = -1;
+ sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler);
return (0);
}
}
static int
pthread_cancel(sp_pthread_t thread)
{
+ signal(SIGCHLD, sshpam_oldsig);
return (kill(thread, SIGTERM));
}
+/* ARGSUSED */
static int
-pthread_join(sp_pthread_t thread, void **value __unused)
+pthread_join(sp_pthread_t thread, void **value)
{
int status;
+ if (sshpam_thread_status != -1)
+ return (sshpam_thread_status);
+ signal(SIGCHLD, sshpam_oldsig);
waitpid(thread, &status, 0);
return (status);
}
#endif
-static pam_handle_t *sshpam_handle;
-static int sshpam_err;
-static int sshpam_authenticated;
-static int sshpam_new_authtok_reqd;
-static int sshpam_session_open;
-static int sshpam_cred_established;
+static pam_handle_t *sshpam_handle = NULL;
+static int sshpam_err = 0;
+static int sshpam_authenticated = 0;
+static int sshpam_session_open = 0;
+static int sshpam_cred_established = 0;
+static int sshpam_account_status = -1;
+static char **sshpam_env = NULL;
+static Authctxt *sshpam_authctxt = NULL;
+static const char *sshpam_password = NULL;
+static char badpw[] = "\b\n\r\177INCORRECT";
+
+/* Some PAM implementations don't implement this */
+#ifndef HAVE_PAM_GETENVLIST
+static char **
+pam_getenvlist(pam_handle_t *pamh)
+{
+ /*
+ * XXX - If necessary, we can still support envrionment passing
+ * for platforms without pam_getenvlist by searching for known
+ * env vars (e.g. KRB5CCNAME) from the PAM environment.
+ */
+ return NULL;
+}
+#endif
-struct pam_ctxt {
- sp_pthread_t pam_thread;
- int pam_psock;
- int pam_csock;
- int pam_done;
-};
+/*
+ * Some platforms, notably Solaris, do not enforce password complexity
+ * rules during pam_chauthtok() if the real uid of the calling process
+ * is 0, on the assumption that it's being called by "passwd" run by root.
+ * This wraps pam_chauthtok and sets/restore the real uid so PAM will do
+ * the right thing.
+ */
+#ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID
+static int
+sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags)
+{
+ int result;
+
+ if (sshpam_authctxt == NULL)
+ fatal("PAM: sshpam_authctxt not initialized");
+ if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1)
+ fatal("%s: setreuid failed: %s", __func__, strerror(errno));
+ result = pam_chauthtok(pamh, flags);
+ if (setreuid(0, -1) == -1)
+ fatal("%s: setreuid failed: %s", __func__, strerror(errno));
+ return result;
+}
+# define pam_chauthtok(a,b) (sshpam_chauthtok_ruid((a), (b)))
+#endif
-static void sshpam_free_ctx(void *);
+void
+sshpam_password_change_required(int reqd)
+{
+ debug3("%s %d", __func__, reqd);
+ if (sshpam_authctxt == NULL)
+ fatal("%s: PAM authctxt not initialized", __func__);
+ sshpam_authctxt->force_pwchange = reqd;
+ if (reqd) {
+ no_port_forwarding_flag |= 2;
+ no_agent_forwarding_flag |= 2;
+ no_x11_forwarding_flag |= 2;
+ } else {
+ no_port_forwarding_flag &= ~2;
+ no_agent_forwarding_flag &= ~2;
+ no_x11_forwarding_flag &= ~2;
+ }
+}
+
+/* Import regular and PAM environment from subprocess */
+static void
+import_environments(Buffer *b)
+{
+ char *env;
+ u_int i, num_env;
+ int err;
+
+ debug3("PAM: %s entering", __func__);
+
+#ifndef UNSUPPORTED_POSIX_THREADS_HACK
+ /* Import variables set by do_pam_account */
+ sshpam_account_status = buffer_get_int(b);
+ sshpam_password_change_required(buffer_get_int(b));
+
+ /* Import environment from subprocess */
+ num_env = buffer_get_int(b);
+ if (num_env > 1024)
+ fatal("%s: received %u environment variables, expected <= 1024",
+ __func__, num_env);
+ sshpam_env = xcalloc(num_env + 1, sizeof(*sshpam_env));
+ debug3("PAM: num env strings %d", num_env);
+ for(i = 0; i < num_env; i++)
+ sshpam_env[i] = buffer_get_string(b, NULL);
+
+ sshpam_env[num_env] = NULL;
+
+ /* Import PAM environment from subprocess */
+ num_env = buffer_get_int(b);
+ debug("PAM: num PAM env strings %d", num_env);
+ for(i = 0; i < num_env; i++) {
+ env = buffer_get_string(b, NULL);
+
+#ifdef HAVE_PAM_PUTENV
+ /* Errors are not fatal here */
+ if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) {
+ error("PAM: pam_putenv: %s",
+ pam_strerror(sshpam_handle, sshpam_err));
+ }
+#endif
+ }
+#endif
+}
/*
* Conversation function for authentication thread.
*/
static int
-sshpam_thread_conv(int n, const struct pam_message **msg,
+sshpam_thread_conv(int n, sshpam_const struct pam_message **msg,
struct pam_response **resp, void *data)
{
Buffer buffer;
struct pam_ctxt *ctxt;
+ struct pam_response *reply;
int i;
+ debug3("PAM: %s entering, %d messages", __func__, n);
+ *resp = NULL;
+
+ if (data == NULL) {
+ error("PAM: conversation function passed a null context");
+ return (PAM_CONV_ERR);
+ }
ctxt = data;
if (n <= 0 || n > PAM_MAX_NUM_MSG)
return (PAM_CONV_ERR);
- *resp = xmalloc(n * sizeof **resp);
+
+ if ((reply = calloc(n, sizeof(*reply))) == NULL)
+ return (PAM_CONV_ERR);
+
buffer_init(&buffer);
for (i = 0; i < n; ++i) {
- resp[i]->resp_retcode = 0;
- resp[i]->resp = NULL;
switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
case PAM_PROMPT_ECHO_OFF:
- buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
- ssh_msg_send(ctxt->pam_csock,
- PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
- ssh_msg_recv(ctxt->pam_csock, &buffer);
+ buffer_put_cstring(&buffer,
+ PAM_MSG_MEMBER(msg, i, msg));
+ if (ssh_msg_send(ctxt->pam_csock,
+ PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
+ goto fail;
+ if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
+ goto fail;
if (buffer_get_char(&buffer) != PAM_AUTHTOK)
goto fail;
- resp[i]->resp = buffer_get_string(&buffer, NULL);
+ reply[i].resp = buffer_get_string(&buffer, NULL);
break;
case PAM_PROMPT_ECHO_ON:
- buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
- ssh_msg_send(ctxt->pam_csock,
- PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
- ssh_msg_recv(ctxt->pam_csock, &buffer);
+ buffer_put_cstring(&buffer,
+ PAM_MSG_MEMBER(msg, i, msg));
+ if (ssh_msg_send(ctxt->pam_csock,
+ PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
+ goto fail;
+ if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1)
+ goto fail;
if (buffer_get_char(&buffer) != PAM_AUTHTOK)
goto fail;
- resp[i]->resp = buffer_get_string(&buffer, NULL);
+ reply[i].resp = buffer_get_string(&buffer, NULL);
break;
case PAM_ERROR_MSG:
- buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
- ssh_msg_send(ctxt->pam_csock,
- PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
+ buffer_put_cstring(&buffer,
+ PAM_MSG_MEMBER(msg, i, msg));
+ if (ssh_msg_send(ctxt->pam_csock,
+ PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
+ goto fail;
break;
case PAM_TEXT_INFO:
- buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg));
- ssh_msg_send(ctxt->pam_csock,
- PAM_MSG_MEMBER(msg, i, msg_style), &buffer);
+ buffer_put_cstring(&buffer,
+ PAM_MSG_MEMBER(msg, i, msg));
+ if (ssh_msg_send(ctxt->pam_csock,
+ PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1)
+ goto fail;
break;
default:
goto fail;
buffer_clear(&buffer);
}
buffer_free(&buffer);
+ *resp = reply;
return (PAM_SUCCESS);
+
fail:
- while (i)
- xfree(resp[--i]);
- xfree(*resp);
- *resp = NULL;
+ for(i = 0; i < n; i++) {
+ if (reply[i].resp != NULL)
+ xfree(reply[i].resp);
+ }
+ xfree(reply);
buffer_free(&buffer);
return (PAM_CONV_ERR);
}
struct pam_ctxt *ctxt = ctxtp;
Buffer buffer;
struct pam_conv sshpam_conv;
-#ifndef USE_POSIX_THREADS
+ int flags = (options.permit_empty_passwd == 0 ?
+ PAM_DISALLOW_NULL_AUTHTOK : 0);
+#ifndef UNSUPPORTED_POSIX_THREADS_HACK
+ extern char **environ;
+ char **env_from_pam;
+ u_int i;
const char *pam_user;
+ const char **ptr_pam_user = &pam_user;
+ char *tz = getenv("TZ");
+
+ pam_get_item(sshpam_handle, PAM_USER,
+ (sshpam_const void **)ptr_pam_user);
- pam_get_item(sshpam_handle, PAM_USER, (const void **)&pam_user);
- setproctitle("%s [pam]", pam_user);
+ environ[0] = NULL;
+ if (tz != NULL)
+ if (setenv("TZ", tz, 1) == -1)
+ error("PAM: could not set TZ environment: %s",
+ strerror(errno));
+
+ if (sshpam_authctxt != NULL) {
+ setproctitle("%s [pam]",
+ sshpam_authctxt->valid ? pam_user : "unknown");
+ }
#endif
sshpam_conv.conv = sshpam_thread_conv;
sshpam_conv.appdata_ptr = ctxt;
+ if (sshpam_authctxt == NULL)
+ fatal("%s: PAM authctxt not initialized", __func__);
+
buffer_init(&buffer);
sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
(const void *)&sshpam_conv);
if (sshpam_err != PAM_SUCCESS)
goto auth_fail;
- sshpam_err = pam_authenticate(sshpam_handle, 0);
+ sshpam_err = pam_authenticate(sshpam_handle, flags);
if (sshpam_err != PAM_SUCCESS)
goto auth_fail;
+
+ if (compat20) {
+ if (!do_pam_account()) {
+ sshpam_err = PAM_ACCT_EXPIRED;
+ goto auth_fail;
+ }
+ if (sshpam_authctxt->force_pwchange) {
+ sshpam_err = pam_chauthtok(sshpam_handle,
+ PAM_CHANGE_EXPIRED_AUTHTOK);
+ if (sshpam_err != PAM_SUCCESS)
+ goto auth_fail;
+ sshpam_password_change_required(0);
+ }
+ }
+
buffer_put_cstring(&buffer, "OK");
+
+#ifndef UNSUPPORTED_POSIX_THREADS_HACK
+ /* Export variables set by do_pam_account */
+ buffer_put_int(&buffer, sshpam_account_status);
+ buffer_put_int(&buffer, sshpam_authctxt->force_pwchange);
+
+ /* Export any environment strings set in child */
+ for(i = 0; environ[i] != NULL; i++)
+ ; /* Count */
+ buffer_put_int(&buffer, i);
+ for(i = 0; environ[i] != NULL; i++)
+ buffer_put_cstring(&buffer, environ[i]);
+
+ /* Export any environment strings set by PAM in child */
+ env_from_pam = pam_getenvlist(sshpam_handle);
+ for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
+ ; /* Count */
+ buffer_put_int(&buffer, i);
+ for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++)
+ buffer_put_cstring(&buffer, env_from_pam[i]);
+#endif /* UNSUPPORTED_POSIX_THREADS_HACK */
+
+ /* XXX - can't do much about an error here */
ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
buffer_free(&buffer);
pthread_exit(NULL);
auth_fail:
buffer_put_cstring(&buffer,
pam_strerror(sshpam_handle, sshpam_err));
- ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
+ /* XXX - can't do much about an error here */
+ if (sshpam_err == PAM_ACCT_EXPIRED)
+ ssh_msg_send(ctxt->pam_csock, PAM_ACCT_EXPIRED, &buffer);
+ else
+ ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer);
buffer_free(&buffer);
pthread_exit(NULL);
-
+
return (NULL); /* Avoid warning for non-pthread case */
}
-static void
-sshpam_thread_cleanup(void *ctxtp)
+void
+sshpam_thread_cleanup(void)
{
- struct pam_ctxt *ctxt = ctxtp;
-
- pthread_cancel(ctxt->pam_thread);
- pthread_join(ctxt->pam_thread, NULL);
- close(ctxt->pam_psock);
- close(ctxt->pam_csock);
+ struct pam_ctxt *ctxt = cleanup_ctxt;
+
+ debug3("PAM: %s entering", __func__);
+ if (ctxt != NULL && ctxt->pam_thread != 0) {
+ pthread_cancel(ctxt->pam_thread);
+ pthread_join(ctxt->pam_thread, NULL);
+ close(ctxt->pam_psock);
+ close(ctxt->pam_csock);
+ memset(ctxt, 0, sizeof(*ctxt));
+ cleanup_ctxt = NULL;
+ }
}
static int
-sshpam_null_conv(int n, const struct pam_message **msg,
+sshpam_null_conv(int n, sshpam_const struct pam_message **msg,
struct pam_response **resp, void *data)
{
+ debug3("PAM: %s entering, %d messages", __func__, n);
return (PAM_CONV_ERR);
}
static struct pam_conv null_conv = { sshpam_null_conv, NULL };
-static void
-sshpam_cleanup(void *arg)
+static int
+sshpam_store_conv(int n, sshpam_const struct pam_message **msg,
+ struct pam_response **resp, void *data)
+{
+ struct pam_response *reply;
+ int i;
+ size_t len;
+
+ debug3("PAM: %s called with %d messages", __func__, n);
+ *resp = NULL;
+
+ if (n <= 0 || n > PAM_MAX_NUM_MSG)
+ return (PAM_CONV_ERR);
+
+ if ((reply = calloc(n, sizeof(*reply))) == NULL)
+ return (PAM_CONV_ERR);
+
+ for (i = 0; i < n; ++i) {
+ switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
+ case PAM_ERROR_MSG:
+ case PAM_TEXT_INFO:
+ len = strlen(PAM_MSG_MEMBER(msg, i, msg));
+ buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len);
+ buffer_append(&loginmsg, "\n", 1 );
+ reply[i].resp_retcode = PAM_SUCCESS;
+ break;
+ default:
+ goto fail;
+ }
+ }
+ *resp = reply;
+ return (PAM_SUCCESS);
+
+ fail:
+ for(i = 0; i < n; i++) {
+ if (reply[i].resp != NULL)
+ xfree(reply[i].resp);
+ }
+ xfree(reply);
+ return (PAM_CONV_ERR);
+}
+
+static struct pam_conv store_conv = { sshpam_store_conv, NULL };
+
+void
+sshpam_cleanup(void)
{
- (void)arg;
+ if (sshpam_handle == NULL || (use_privsep && !mm_is_monitor()))
+ return;
debug("PAM: cleanup");
pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv);
- if (sshpam_cred_established) {
- pam_setcred(sshpam_handle, PAM_DELETE_CRED);
- sshpam_cred_established = 0;
- }
if (sshpam_session_open) {
+ debug("PAM: closing session");
pam_close_session(sshpam_handle, PAM_SILENT);
sshpam_session_open = 0;
}
- sshpam_authenticated = sshpam_new_authtok_reqd = 0;
+ if (sshpam_cred_established) {
+ debug("PAM: deleting credentials");
+ pam_setcred(sshpam_handle, PAM_DELETE_CRED);
+ sshpam_cred_established = 0;
+ }
+ sshpam_authenticated = 0;
pam_end(sshpam_handle, sshpam_err);
sshpam_handle = NULL;
}
static int
-sshpam_init(const char *user)
+sshpam_init(Authctxt *authctxt)
{
- extern u_int utmp_len;
- const char *pam_rhost, *pam_user;
+ extern char *__progname;
+ const char *pam_rhost, *pam_user, *user = authctxt->user;
+ const char **ptr_pam_user = &pam_user;
if (sshpam_handle != NULL) {
/* We already have a PAM context; check if the user matches */
sshpam_err = pam_get_item(sshpam_handle,
- PAM_USER, (const void **)&pam_user);
+ PAM_USER, (sshpam_const void **)ptr_pam_user);
if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
return (0);
- fatal_remove_cleanup(sshpam_cleanup, NULL);
pam_end(sshpam_handle, sshpam_err);
sshpam_handle = NULL;
}
debug("PAM: initializing for \"%s\"", user);
sshpam_err =
- pam_start(SSHD_PAM_SERVICE, user, &null_conv, &sshpam_handle);
+ pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle);
+ sshpam_authctxt = authctxt;
+
if (sshpam_err != PAM_SUCCESS) {
pam_end(sshpam_handle, sshpam_err);
sshpam_handle = NULL;
return (-1);
}
#ifdef PAM_TTY_KLUDGE
- /*
- * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
- * sshd doesn't set the tty until too late in the auth process and
+ /*
+ * Some silly PAM modules (e.g. pam_time) require a TTY to operate.
+ * sshd doesn't set the tty until too late in the auth process and
* may not even set one (for tty-less connections)
- */
+ */
debug("PAM: setting PAM_TTY to \"ssh\"");
sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh");
if (sshpam_err != PAM_SUCCESS) {
return (-1);
}
#endif
- fatal_add_cleanup(sshpam_cleanup, NULL);
return (0);
}
struct pam_ctxt *ctxt;
int socks[2];
- /* Refuse to start if we don't have PAM enabled */
- if (!options.use_pam)
+ debug3("PAM: %s entering", __func__);
+ /*
+ * Refuse to start if we don't have PAM enabled or do_pam_account
+ * has previously failed.
+ */
+ if (!options.use_pam || sshpam_account_status == 0)
return NULL;
/* Initialize PAM */
- if (sshpam_init(authctxt->user) == -1) {
+ if (sshpam_init(authctxt) == -1) {
error("PAM: initialization failed");
return (NULL);
}
- ctxt = xmalloc(sizeof *ctxt);
- ctxt->pam_done = 0;
+ ctxt = xcalloc(1, sizeof *ctxt);
/* Start the authentication thread */
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
xfree(ctxt);
return (NULL);
}
- fatal_add_cleanup(sshpam_thread_cleanup, ctxt);
+ cleanup_ctxt = ctxt;
return (ctxt);
}
size_t plen;
u_char type;
char *msg;
- size_t len;
+ size_t len, mlen;
+ debug3("PAM: %s entering", __func__);
buffer_init(&buffer);
*name = xstrdup("");
*info = xstrdup("");
while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) {
type = buffer_get_char(&buffer);
msg = buffer_get_string(&buffer, NULL);
+ mlen = strlen(msg);
switch (type) {
case PAM_PROMPT_ECHO_ON:
case PAM_PROMPT_ECHO_OFF:
*num = 1;
- len = plen + strlen(msg) + 1;
- **prompts = xrealloc(**prompts, len);
- plen += snprintf(**prompts + plen, len, "%s", msg);
+ len = plen + mlen + 1;
+ **prompts = xrealloc(**prompts, 1, len);
+ strlcpy(**prompts + plen, msg, len - plen);
+ plen += mlen;
**echo_on = (type == PAM_PROMPT_ECHO_ON);
xfree(msg);
return (0);
case PAM_ERROR_MSG:
case PAM_TEXT_INFO:
/* accumulate messages */
- len = plen + strlen(msg) + 1;
- **prompts = xrealloc(**prompts, len);
- plen += snprintf(**prompts + plen, len, "%s", msg);
+ len = plen + mlen + 2;
+ **prompts = xrealloc(**prompts, 1, len);
+ strlcpy(**prompts + plen, msg, len - plen);
+ plen += mlen;
+ strlcat(**prompts + plen, "\n", len - plen);
+ plen++;
xfree(msg);
break;
- case PAM_SUCCESS:
+ case PAM_ACCT_EXPIRED:
+ sshpam_account_status = 0;
+ /* FALLTHROUGH */
case PAM_AUTH_ERR:
+ debug3("PAM: %s", pam_strerror(sshpam_handle, type));
+ if (**prompts != NULL && strlen(**prompts) != 0) {
+ *info = **prompts;
+ **prompts = NULL;
+ *num = 0;
+ **echo_on = 0;
+ ctxt->pam_done = -1;
+ xfree(msg);
+ return 0;
+ }
+ /* FALLTHROUGH */
+ case PAM_SUCCESS:
if (**prompts != NULL) {
/* drain any accumulated messages */
-#if 0 /* XXX - not compatible with privsep */
- packet_start(SSH2_MSG_USERAUTH_BANNER);
- packet_put_cstring(**prompts);
- packet_put_cstring("");
- packet_send();
- packet_write_wait();
-#endif
+ debug("PAM: %s", **prompts);
+ buffer_append(&loginmsg, **prompts,
+ strlen(**prompts));
xfree(**prompts);
**prompts = NULL;
}
if (type == PAM_SUCCESS) {
+ if (!sshpam_authctxt->valid ||
+ (sshpam_authctxt->pw->pw_uid == 0 &&
+ options.permit_root_login != PERMIT_YES))
+ fatal("Internal error: PAM auth "
+ "succeeded when it should have "
+ "failed");
+ import_environments(&buffer);
*num = 0;
**echo_on = 0;
ctxt->pam_done = 1;
xfree(msg);
return (0);
}
- error("PAM: %s", msg);
+ error("PAM: %s for %s%.100s from %.100s", msg,
+ sshpam_authctxt->valid ? "" : "illegal user ",
+ sshpam_authctxt->user,
+ get_remote_name_or_ip(utmp_len, options.use_dns));
+ /* FALLTHROUGH */
default:
*num = 0;
**echo_on = 0;
Buffer buffer;
struct pam_ctxt *ctxt = ctx;
- debug2("PAM: %s", __func__);
+ debug2("PAM: %s entering, %u responses", __func__, num);
switch (ctxt->pam_done) {
case 1:
sshpam_authenticated = 1;
return (-1);
}
buffer_init(&buffer);
- buffer_put_cstring(&buffer, *resp);
- ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer);
+ if (sshpam_authctxt->valid &&
+ (sshpam_authctxt->pw->pw_uid != 0 ||
+ options.permit_root_login == PERMIT_YES))
+ buffer_put_cstring(&buffer, *resp);
+ else
+ buffer_put_cstring(&buffer, badpw);
+ if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) {
+ buffer_free(&buffer);
+ return (-1);
+ }
buffer_free(&buffer);
return (1);
}
{
struct pam_ctxt *ctxt = ctxtp;
- fatal_remove_cleanup(sshpam_thread_cleanup, ctxt);
- sshpam_thread_cleanup(ctxtp);
+ debug3("PAM: %s entering", __func__);
+ sshpam_thread_cleanup();
xfree(ctxt);
/*
* We don't call sshpam_cleanup() here because we may need the PAM
* This replaces auth-pam.c
*/
void
-start_pam(const char *user)
+start_pam(Authctxt *authctxt)
{
if (!options.use_pam)
fatal("PAM: initialisation requested when UsePAM=no");
- if (sshpam_init(user) == -1)
+ if (sshpam_init(authctxt) == -1)
fatal("PAM: initialisation failed");
}
void
finish_pam(void)
{
- fatal_remove_cleanup(sshpam_cleanup, NULL);
- sshpam_cleanup(NULL);
+ sshpam_cleanup();
}
u_int
do_pam_account(void)
{
- sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
- debug3("%s: pam_acct_mgmt = %d", __func__, sshpam_err);
-
- if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD)
- return (0);
+ debug("%s: called", __func__);
+ if (sshpam_account_status != -1)
+ return (sshpam_account_status);
- if (sshpam_err == PAM_NEW_AUTHTOK_REQD) {
- sshpam_new_authtok_reqd = 1;
+ sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
+ debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err,
+ pam_strerror(sshpam_handle, sshpam_err));
- /* Prevent forwardings until password changed */
- no_port_forwarding_flag |= 2;
- no_agent_forwarding_flag |= 2;
- no_x11_forwarding_flag |= 2;
+ if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) {
+ sshpam_account_status = 0;
+ return (sshpam_account_status);
}
- return (1);
-}
+ if (sshpam_err == PAM_NEW_AUTHTOK_REQD)
+ sshpam_password_change_required(1);
-void
-do_pam_session(void)
-{
- sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
- (const void *)&null_conv);
- if (sshpam_err != PAM_SUCCESS)
- fatal("PAM: failed to set PAM_CONV: %s",
- pam_strerror(sshpam_handle, sshpam_err));
- sshpam_err = pam_open_session(sshpam_handle, 0);
- if (sshpam_err != PAM_SUCCESS)
- fatal("PAM: pam_open_session(): %s",
- pam_strerror(sshpam_handle, sshpam_err));
- sshpam_session_open = 1;
+ sshpam_account_status = 1;
+ return (sshpam_account_status);
}
void
do_pam_setcred(int init)
{
sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
- (const void *)&null_conv);
+ (const void *)&store_conv);
if (sshpam_err != PAM_SUCCESS)
fatal("PAM: failed to set PAM_CONV: %s",
pam_strerror(sshpam_handle, sshpam_err));
pam_strerror(sshpam_handle, sshpam_err));
}
-int
-is_pam_password_change_required(void)
-{
- return (sshpam_new_authtok_reqd);
-}
-
static int
-pam_chauthtok_conv(int n, const struct pam_message **msg,
+sshpam_tty_conv(int n, sshpam_const struct pam_message **msg,
struct pam_response **resp, void *data)
{
char input[PAM_MAX_MSG_SIZE];
+ struct pam_response *reply;
int i;
- if (n <= 0 || n > PAM_MAX_NUM_MSG)
+ debug3("PAM: %s called with %d messages", __func__, n);
+
+ *resp = NULL;
+
+ if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO))
+ return (PAM_CONV_ERR);
+
+ if ((reply = calloc(n, sizeof(*reply))) == NULL)
return (PAM_CONV_ERR);
- *resp = xmalloc(n * sizeof **resp);
+
for (i = 0; i < n; ++i) {
switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
case PAM_PROMPT_ECHO_OFF:
- resp[i]->resp =
- read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
+ reply[i].resp =
+ read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
RP_ALLOW_STDIN);
- resp[i]->resp_retcode = PAM_SUCCESS;
+ reply[i].resp_retcode = PAM_SUCCESS;
break;
case PAM_PROMPT_ECHO_ON:
- fputs(PAM_MSG_MEMBER(msg, i, msg), stderr);
- fgets(input, sizeof input, stdin);
- resp[i]->resp = xstrdup(input);
- resp[i]->resp_retcode = PAM_SUCCESS;
+ fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
+ if (fgets(input, sizeof input, stdin) == NULL)
+ input[0] = '\0';
+ if ((reply[i].resp = strdup(input)) == NULL)
+ goto fail;
+ reply[i].resp_retcode = PAM_SUCCESS;
break;
case PAM_ERROR_MSG:
case PAM_TEXT_INFO:
- fputs(PAM_MSG_MEMBER(msg, i, msg), stderr);
- resp[i]->resp_retcode = PAM_SUCCESS;
+ fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg));
+ reply[i].resp_retcode = PAM_SUCCESS;
break;
default:
goto fail;
}
}
+ *resp = reply;
return (PAM_SUCCESS);
+
fail:
- while (i)
- xfree(resp[--i]);
- xfree(*resp);
- *resp = NULL;
+ for(i = 0; i < n; i++) {
+ if (reply[i].resp != NULL)
+ xfree(reply[i].resp);
+ }
+ xfree(reply);
return (PAM_CONV_ERR);
}
+static struct pam_conv tty_conv = { sshpam_tty_conv, NULL };
+
/*
* XXX this should be done in the authentication phase, but ssh1 doesn't
* support that
void
do_pam_chauthtok(void)
{
- struct pam_conv pam_conv;
-
- pam_conv.conv = pam_chauthtok_conv;
- pam_conv.appdata_ptr = NULL;
-
if (use_privsep)
fatal("Password expired (unable to change with privsep)");
sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
- (const void *)&pam_conv);
+ (const void *)&tty_conv);
if (sshpam_err != PAM_SUCCESS)
fatal("PAM: failed to set PAM_CONV: %s",
pam_strerror(sshpam_handle, sshpam_err));
pam_strerror(sshpam_handle, sshpam_err));
}
-/*
+void
+do_pam_session(void)
+{
+ debug3("PAM: opening session");
+ sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
+ (const void *)&store_conv);
+ if (sshpam_err != PAM_SUCCESS)
+ fatal("PAM: failed to set PAM_CONV: %s",
+ pam_strerror(sshpam_handle, sshpam_err));
+ sshpam_err = pam_open_session(sshpam_handle, 0);
+ if (sshpam_err == PAM_SUCCESS)
+ sshpam_session_open = 1;
+ else {
+ sshpam_session_open = 0;
+ disable_forwarding();
+ error("PAM: pam_open_session(): %s",
+ pam_strerror(sshpam_handle, sshpam_err));
+ }
+
+}
+
+int
+is_pam_session_open(void)
+{
+ return sshpam_session_open;
+}
+
+/*
* Set a PAM environment string. We need to do this so that the session
* modules can handle things like Kerberos/GSI credentials that appear
* during the ssh authentication process.
*/
-
int
-do_pam_putenv(char *name, char *value)
+do_pam_putenv(char *name, char *value)
{
- char *compound;
int ret = 1;
+#ifdef HAVE_PAM_PUTENV
+ char *compound;
+ size_t len;
-#ifdef HAVE_PAM_PUTENV
- compound = xmalloc(strlen(name)+strlen(value)+2);
- if (compound) {
- sprintf(compound,"%s=%s",name,value);
- ret = pam_putenv(sshpam_handle,compound);
- xfree(compound);
- }
+ len = strlen(name) + strlen(value) + 2;
+ compound = xmalloc(len);
+
+ snprintf(compound, len, "%s=%s", name, value);
+ ret = pam_putenv(sshpam_handle, compound);
+ xfree(compound);
#endif
+
return (ret);
}
-void
-print_pam_messages(void)
+char **
+fetch_pam_child_environment(void)
{
- /* XXX */
+ return sshpam_env;
}
char **
fetch_pam_environment(void)
{
-#ifdef HAVE_PAM_GETENVLIST
- debug("PAM: retrieving environment");
return (pam_getenvlist(sshpam_handle));
-#else
- return (NULL);
-#endif
}
void
xfree(env);
}
+/*
+ * "Blind" conversation function for password authentication. Assumes that
+ * echo-off prompts are for the password and stores messages for later
+ * display.
+ */
+static int
+sshpam_passwd_conv(int n, sshpam_const struct pam_message **msg,
+ struct pam_response **resp, void *data)
+{
+ struct pam_response *reply;
+ int i;
+ size_t len;
+
+ debug3("PAM: %s called with %d messages", __func__, n);
+
+ *resp = NULL;
+
+ if (n <= 0 || n > PAM_MAX_NUM_MSG)
+ return (PAM_CONV_ERR);
+
+ if ((reply = calloc(n, sizeof(*reply))) == NULL)
+ return (PAM_CONV_ERR);
+
+ for (i = 0; i < n; ++i) {
+ switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
+ case PAM_PROMPT_ECHO_OFF:
+ if (sshpam_password == NULL)
+ goto fail;
+ if ((reply[i].resp = strdup(sshpam_password)) == NULL)
+ goto fail;
+ reply[i].resp_retcode = PAM_SUCCESS;
+ break;
+ case PAM_ERROR_MSG:
+ case PAM_TEXT_INFO:
+ len = strlen(PAM_MSG_MEMBER(msg, i, msg));
+ if (len > 0) {
+ buffer_append(&loginmsg,
+ PAM_MSG_MEMBER(msg, i, msg), len);
+ buffer_append(&loginmsg, "\n", 1);
+ }
+ if ((reply[i].resp = strdup("")) == NULL)
+ goto fail;
+ reply[i].resp_retcode = PAM_SUCCESS;
+ break;
+ default:
+ goto fail;
+ }
+ }
+ *resp = reply;
+ return (PAM_SUCCESS);
+
+ fail:
+ for(i = 0; i < n; i++) {
+ if (reply[i].resp != NULL)
+ xfree(reply[i].resp);
+ }
+ xfree(reply);
+ return (PAM_CONV_ERR);
+}
+
+static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL };
+
+/*
+ * Attempt password authentication via PAM
+ */
+int
+sshpam_auth_passwd(Authctxt *authctxt, const char *password)
+{
+ int flags = (options.permit_empty_passwd == 0 ?
+ PAM_DISALLOW_NULL_AUTHTOK : 0);
+
+ if (!options.use_pam || sshpam_handle == NULL)
+ fatal("PAM: %s called when PAM disabled or failed to "
+ "initialise.", __func__);
+
+ sshpam_password = password;
+ sshpam_authctxt = authctxt;
+
+ /*
+ * If the user logging in is invalid, or is root but is not permitted
+ * by PermitRootLogin, use an invalid password to prevent leaking
+ * information via timing (eg if the PAM config has a delay on fail).
+ */
+ if (!authctxt->valid || (authctxt->pw->pw_uid == 0 &&
+ options.permit_root_login != PERMIT_YES))
+ sshpam_password = badpw;
+
+ sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
+ (const void *)&passwd_conv);
+ if (sshpam_err != PAM_SUCCESS)
+ fatal("PAM: %s: failed to set PAM_CONV: %s", __func__,
+ pam_strerror(sshpam_handle, sshpam_err));
+
+ sshpam_err = pam_authenticate(sshpam_handle, flags);
+ sshpam_password = NULL;
+ if (sshpam_err == PAM_SUCCESS && authctxt->valid) {
+ debug("PAM: password authentication accepted for %.100s",
+ authctxt->user);
+ return 1;
+ } else {
+ debug("PAM: password authentication failed for %.100s: %s",
+ authctxt->valid ? authctxt->user : "an illegal user",
+ pam_strerror(sshpam_handle, sshpam_err));
+ return 0;
+ }
+}
#endif /* USE_PAM */
andersk / openssh.git / blobdiff