-/*
- * Copyright (c) 2000 Damien Miller. All rights reserved.
+/*-
+ * Copyright (c) 2002 Networks Associates Technology, Inc.
+ * All rights reserved.
+ *
+ * This software was developed for the FreeBSD Project by ThinkSec AS and
+ * NAI Labs, the Security Research Division of Network Associates, Inc.
+ * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
+ * DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* 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.
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ */
+/*
+ * 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"
+#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 "log.h"
+#include "buffer.h"
+#include "key.h"
+#include "hostfile.h"
#include "auth.h"
-#include "auth-options.h"
#include "auth-pam.h"
-#include "servconf.h"
#include "canohost.h"
-#include "readpass.h"
+#include "log.h"
+#include "msg.h"
+#include "packet.h"
+#include "misc.h"
+#include "servconf.h"
+#include "ssh2.h"
+#include "auth-options.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+#include "monitor_wrap.h"
-extern char *__progname;
+extern ServerOptions options;
+extern Buffer loginmsg;
+extern int compat20;
+extern u_int utmp_len;
-extern int use_privsep;
+/* so we don't silently change behaviour */
+#ifdef USE_POSIX_THREADS
+# error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK"
+#endif
-RCSID("$Id$");
+/*
+ * 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
+ * (e.g. Linux)
+ */
+typedef pthread_t sp_pthread_t;
+#else
+typedef pid_t sp_pthread_t;
+#endif
-#define NEW_AUTHTOK_MSG \
- "Warning: Your password has expired, please change it now."
-#define NEW_AUTHTOK_MSG_PRIVSEP \
- "Your password has expired, the session cannot proceed."
+struct pam_ctxt {
+ sp_pthread_t pam_thread;
+ int pam_psock;
+ int pam_csock;
+ int pam_done;
+};
-static int do_pam_conversation(int num_msg, const struct pam_message **msg,
- struct pam_response **resp, void *appdata_ptr);
+static void sshpam_free_ctx(void *);
+static struct pam_ctxt *cleanup_ctxt;
-/* module-local variables */
-static struct pam_conv conv = {
- (int (*)())do_pam_conversation,
- NULL
-};
-static char *__pam_msg = NULL;
-static pam_handle_t *__pamh = NULL;
-static const char *__pampasswd = NULL;
+#ifndef UNSUPPORTED_POSIX_THREADS_HACK
+/*
+ * Simulate threads with processes.
+ */
+
+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");
+}
-/* states for do_pam_conversation() */
-enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
-/* remember whether pam_acct_mgmt() returned PAM_NEW_AUTHTOK_REQD */
-static int password_change_required = 0;
-/* remember whether the last pam_authenticate() succeeded or not */
-static int was_authenticated = 0;
+/* ARGSUSED */
+static void
+pthread_exit(void *value)
+{
+ _exit(0);
+}
-/* Remember what has been initialised */
-static int session_opened = 0;
-static int creds_set = 0;
+/* ARGSUSED */
+static int
+pthread_create(sp_pthread_t *thread, const void *attr,
+ void *(*thread_start)(void *), void *arg)
+{
+ pid_t pid;
+ struct pam_ctxt *ctx = arg;
-/* accessor which allows us to switch conversation structs according to
- * the authentication method being used */
-void do_pam_set_conv(struct pam_conv *conv)
+ 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)
{
- pam_set_item(__pamh, PAM_CONV, conv);
+ signal(SIGCHLD, sshpam_oldsig);
+ return (kill(thread, SIGTERM));
}
-/* start an authentication run */
-int do_pam_authenticate(int flags)
+/* ARGSUSED */
+static int
+pthread_join(sp_pthread_t thread, void **value)
{
- int retval = pam_authenticate(__pamh, flags);
- was_authenticated = (retval == PAM_SUCCESS);
- return retval;
+ 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 = 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
/*
- * 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 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()
- * and outputs messages to stderr. This mode is used if pam_chauthtok()
- * is called to update expired passwords.
+ * 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.
*/
-static int do_pam_conversation(int num_msg, const struct pam_message **msg,
- struct pam_response **resp, void *appdata_ptr)
+#ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID
+static int
+sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags)
{
- struct pam_response *reply;
- int count;
- char buf[1024];
-
- /* PAM will free this later */
- reply = xmalloc(num_msg * sizeof(*reply));
-
- for (count = 0; count < num_msg; count++) {
- 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:
- xfree(reply);
- return PAM_CONV_ERR;
- case PAM_PROMPT_ECHO_OFF:
- if (__pampasswd == NULL) {
- xfree(reply);
- return PAM_CONV_ERR;
- }
- reply[count].resp = xstrdup(__pampasswd);
- reply[count].resp_retcode = PAM_SUCCESS;
- break;
- case PAM_ERROR_MSG:
- case PAM_TEXT_INFO:
- if (PAM_MSG_MEMBER(msg, count, msg) != NULL) {
- message_cat(&__pam_msg,
- PAM_MSG_MEMBER(msg, count, msg));
- }
- reply[count].resp = xstrdup("");
- reply[count].resp_retcode = PAM_SUCCESS;
- break;
- default:
- xfree(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 =
- read_passphrase(PAM_MSG_MEMBER(msg, count,
- msg), RP_ALLOW_STDIN);
- 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:
- xfree(reply);
- return PAM_CONV_ERR;
- }
- }
+ 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
+
+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;
}
+}
- *resp = reply;
+/* 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);
- return PAM_SUCCESS;
+ 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
}
-/* Called at exit to cleanly shutdown PAM */
-void do_pam_cleanup_proc(void *context)
+/*
+ * Conversation function for authentication thread.
+ */
+static int
+sshpam_thread_conv(int n, sshpam_const struct pam_message **msg,
+ struct pam_response **resp, void *data)
{
- int pam_retval = PAM_SUCCESS;
+ Buffer buffer;
+ struct pam_ctxt *ctxt;
+ struct pam_response *reply;
+ int i;
- if (__pamh && session_opened) {
- pam_retval = pam_close_session(__pamh, 0);
- if (pam_retval != PAM_SUCCESS)
- log("Cannot close PAM session[%d]: %.200s",
- pam_retval, PAM_STRERROR(__pamh, pam_retval));
+ 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);
+
+ if ((reply = calloc(n, sizeof(*reply))) == NULL)
+ return (PAM_CONV_ERR);
- if (__pamh && creds_set) {
- 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));
+ buffer_init(&buffer);
+ for (i = 0; i < n; ++i) {
+ switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
+ case PAM_PROMPT_ECHO_OFF:
+ 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;
+ reply[i].resp = buffer_get_string(&buffer, NULL);
+ break;
+ case PAM_PROMPT_ECHO_ON:
+ 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;
+ reply[i].resp = buffer_get_string(&buffer, NULL);
+ break;
+ case PAM_ERROR_MSG:
+ 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));
+ 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);
- if (__pamh) {
- pam_retval = pam_end(__pamh, pam_retval);
- if (pam_retval != PAM_SUCCESS)
- log("Cannot release PAM authentication[%d]: %.200s",
- pam_retval, PAM_STRERROR(__pamh, pam_retval));
+ fail:
+ for(i = 0; i < n; i++) {
+ if (reply[i].resp != NULL)
+ xfree(reply[i].resp);
}
+ xfree(reply);
+ buffer_free(&buffer);
+ return (PAM_CONV_ERR);
}
-/* Attempt password authentation using PAM */
-int auth_pam_password(Authctxt *authctxt, const char *password)
+/*
+ * Authentication thread.
+ */
+static void *
+sshpam_thread(void *ctxtp)
{
- extern ServerOptions options;
- int pam_retval;
- struct passwd *pw = authctxt->pw;
+ struct pam_ctxt *ctxt = ctxtp;
+ Buffer buffer;
+ struct pam_conv sshpam_conv;
+ 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");
- do_pam_set_conv(&conv);
+ pam_get_item(sshpam_handle, PAM_USER,
+ (sshpam_const void **)ptr_pam_user);
- /* deny if no user. */
- if (pw == NULL)
- return 0;
- if (pw->pw_uid == 0 && options.permit_root_login == PERMIT_NO_PASSWD)
- return 0;
- if (*password == '\0' && options.permit_empty_passwd == 0)
- return 0;
+ environ[0] = NULL;
+ if (tz != NULL)
+ if (setenv("TZ", tz, 1) == -1)
+ error("PAM: could not set TZ environment: %s",
+ strerror(errno));
- __pampasswd = password;
+ if (sshpam_authctxt != NULL) {
+ setproctitle("%s [pam]",
+ sshpam_authctxt->valid ? pam_user : "unknown");
+ }
+#endif
- pamstate = INITIAL_LOGIN;
- pam_retval = do_pam_authenticate(
- options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0);
- if (pam_retval == PAM_SUCCESS) {
- 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));
- return 0;
+ 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, 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));
+ /* 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 */
}
-/* Do account management using PAM */
-int do_pam_account(char *username, char *remote_user)
+void
+sshpam_thread_cleanup(void)
{
- int pam_retval;
-
- do_pam_set_conv(&conv);
+ struct pam_ctxt *ctxt = cleanup_ctxt;
- 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));
+ 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;
}
+}
- pam_retval = pam_acct_mgmt(__pamh, 0);
- debug2("pam_acct_mgmt() = %d", pam_retval);
- switch (pam_retval) {
- case PAM_SUCCESS:
- /* This is what we want */
- break;
-#if 0
- case PAM_NEW_AUTHTOK_REQD:
- message_cat(&__pam_msg, use_privsep ?
- NEW_AUTHTOK_MSG_PRIVSEP : NEW_AUTHTOK_MSG);
- /* flag that password change is necessary */
- password_change_required = 1;
- /* disallow other functionality for now */
- no_port_forwarding_flag |= 2;
- no_agent_forwarding_flag |= 2;
- no_x11_forwarding_flag |= 2;
+static int
+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 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;
-#endif
default:
- log("PAM rejected by account configuration[%d]: "
- "%.200s", pam_retval, PAM_STRERROR(__pamh,
- pam_retval));
- return(0);
+ 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)
+{
+ 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_session_open) {
+ debug("PAM: closing session");
+ pam_close_session(sshpam_handle, PAM_SILENT);
+ sshpam_session_open = 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(Authctxt *authctxt)
+{
+ extern char *__progname;
+ const char *pam_rhost, *pam_user, *user = authctxt->user;
+ const char **ptr_pam_user = &pam_user;
- return(1);
+ if (sshpam_handle != NULL) {
+ /* We already have a PAM context; check if the user matches */
+ sshpam_err = pam_get_item(sshpam_handle,
+ PAM_USER, (sshpam_const void **)ptr_pam_user);
+ if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0)
+ return (0);
+ pam_end(sshpam_handle, sshpam_err);
+ sshpam_handle = NULL;
+ }
+ debug("PAM: initializing for \"%s\"", user);
+ sshpam_err =
+ 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);
+ }
+ pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns);
+ debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
+ sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
+ 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
+ * 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) {
+ pam_end(sshpam_handle, sshpam_err);
+ sshpam_handle = NULL;
+ return (-1);
+ }
+#endif
+ return (0);
}
-/* Do PAM-specific session initialisation */
-void do_pam_session(char *username, const char *ttyname)
+static void *
+sshpam_init_ctx(Authctxt *authctxt)
{
- int pam_retval;
+ struct pam_ctxt *ctxt;
+ int socks[2];
- do_pam_set_conv(&conv);
+ 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;
- if (ttyname != NULL) {
- debug("PAM setting tty to \"%.200s\"", ttyname);
- 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));
+ /* Initialize PAM */
+ if (sshpam_init(authctxt) == -1) {
+ error("PAM: initialization failed");
+ return (NULL);
}
- 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));
+ ctxt = xcalloc(1, sizeof *ctxt);
- session_opened = 1;
+ /* Start the authentication thread */
+ if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
+ error("PAM: failed create sockets: %s", strerror(errno));
+ xfree(ctxt);
+ return (NULL);
+ }
+ ctxt->pam_psock = socks[0];
+ ctxt->pam_csock = socks[1];
+ if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) {
+ error("PAM: failed to start authentication thread: %s",
+ strerror(errno));
+ close(socks[0]);
+ close(socks[1]);
+ xfree(ctxt);
+ return (NULL);
+ }
+ cleanup_ctxt = ctxt;
+ return (ctxt);
}
-/* Set PAM credentials */
-void do_pam_setcred(int init)
+static int
+sshpam_query(void *ctx, char **name, char **info,
+ u_int *num, char ***prompts, u_int **echo_on)
{
- int pam_retval;
+ Buffer buffer;
+ struct pam_ctxt *ctxt = ctx;
+ size_t plen;
+ u_char type;
+ char *msg;
+ size_t len, mlen;
- if (__pamh == NULL)
- return;
+ debug3("PAM: %s entering", __func__);
+ buffer_init(&buffer);
+ *name = xstrdup("");
+ *info = xstrdup("");
+ *prompts = xmalloc(sizeof(char *));
+ **prompts = NULL;
+ plen = 0;
+ *echo_on = xmalloc(sizeof(u_int));
+ 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 + 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 + 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_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 */
+ 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 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;
+ xfree(msg);
+ ctxt->pam_done = -1;
+ return (-1);
+ }
+ }
+ return (-1);
+}
- do_pam_set_conv(&conv);
+/* XXX - see also comment in auth-chall.c:verify_response */
+static int
+sshpam_respond(void *ctx, u_int num, char **resp)
+{
+ Buffer buffer;
+ struct pam_ctxt *ctxt = ctx;
- debug("PAM establishing creds");
- pam_retval = pam_setcred(__pamh,
- init ? PAM_ESTABLISH_CRED : PAM_REINITIALIZE_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));
- } else
- creds_set = 1;
+ debug2("PAM: %s entering, %u responses", __func__, num);
+ switch (ctxt->pam_done) {
+ case 1:
+ sshpam_authenticated = 1;
+ return (0);
+ case 0:
+ break;
+ default:
+ return (-1);
+ }
+ if (num != 1) {
+ error("PAM: expected one response, got %u", num);
+ return (-1);
+ }
+ buffer_init(&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);
}
-/* accessor function for file scope static variable */
-int is_pam_password_change_required(void)
+static void
+sshpam_free_ctx(void *ctxtp)
{
- return password_change_required;
+ struct pam_ctxt *ctxt = ctxtp;
+
+ debug3("PAM: %s entering", __func__);
+ sshpam_thread_cleanup();
+ xfree(ctxt);
+ /*
+ * We don't call sshpam_cleanup() here because we may need the PAM
+ * handle at a later stage, e.g. when setting up a session. It's
+ * still on the cleanup list, so pam_end() *will* be called before
+ * the server process terminates.
+ */
}
+KbdintDevice sshpam_device = {
+ "pam",
+ sshpam_init_ctx,
+ sshpam_query,
+ sshpam_respond,
+ sshpam_free_ctx
+};
+
+KbdintDevice mm_sshpam_device = {
+ "pam",
+ mm_sshpam_init_ctx,
+ mm_sshpam_query,
+ mm_sshpam_respond,
+ mm_sshpam_free_ctx
+};
+
/*
- * 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/stdout/stderr.
+ * This replaces auth-pam.c
*/
-void do_pam_chauthtok(void)
-{
- int pam_retval;
-
- do_pam_set_conv(&conv);
-
- if (password_change_required) {
- if (use_privsep)
- fatal("Password changing is currently unsupported"
- " with privilege separation");
- pamstate = OTHER;
- pam_retval = pam_chauthtok(__pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
- if (pam_retval != PAM_SUCCESS)
- fatal("PAM pam_chauthtok failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(__pamh, pam_retval));
-#if 0
- /* XXX: This would need to be done in the parent process,
- * but there's currently no way to pass such request. */
- no_port_forwarding_flag &= ~2;
- no_agent_forwarding_flag &= ~2;
- no_x11_forwarding_flag &= ~2;
- if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
- channel_permit_all_opens();
-#endif
- }
+void
+start_pam(Authctxt *authctxt)
+{
+ if (!options.use_pam)
+ fatal("PAM: initialisation requested when UsePAM=no");
+
+ if (sshpam_init(authctxt) == -1)
+ fatal("PAM: initialisation failed");
}
-/* Cleanly shutdown PAM */
-void finish_pam(void)
+void
+finish_pam(void)
{
- do_pam_cleanup_proc(NULL);
- fatal_remove_cleanup(&do_pam_cleanup_proc, NULL);
+ sshpam_cleanup();
}
-/* Start PAM authentication for specified account */
-void start_pam(const char *user)
+u_int
+do_pam_account(void)
{
- int pam_retval;
- extern ServerOptions options;
- extern u_int utmp_len;
- const char *rhost;
+ debug("%s: called", __func__);
+ if (sshpam_account_status != -1)
+ return (sshpam_account_status);
- debug("Starting up PAM with username \"%.200s\"", user);
+ 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));
- pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &__pamh);
-
- if (pam_retval != PAM_SUCCESS)
- fatal("PAM initialisation failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(__pamh, pam_retval));
+ if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) {
+ sshpam_account_status = 0;
+ return (sshpam_account_status);
+ }
- rhost = get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping);
- debug("PAM setting rhost to \"%.200s\"", rhost);
+ if (sshpam_err == PAM_NEW_AUTHTOK_REQD)
+ sshpam_password_change_required(1);
- pam_retval = pam_set_item(__pamh, PAM_RHOST, rhost);
- if (pam_retval != PAM_SUCCESS)
- fatal("PAM set rhost 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, "NODEVssh");
- if (pam_retval != PAM_SUCCESS)
- fatal("PAM set tty failed[%d]: %.200s",
- pam_retval, PAM_STRERROR(__pamh, pam_retval));
-#endif /* PAM_TTY_KLUDGE */
+ sshpam_account_status = 1;
+ return (sshpam_account_status);
+}
- fatal_add_cleanup(&do_pam_cleanup_proc, NULL);
+void
+do_pam_set_tty(const char *tty)
+{
+ if (tty != NULL) {
+ debug("PAM: setting PAM_TTY to \"%s\"", tty);
+ sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty);
+ if (sshpam_err != PAM_SUCCESS)
+ fatal("PAM: failed to set PAM_TTY: %s",
+ pam_strerror(sshpam_handle, sshpam_err));
+ }
}
-/* Return list of PAM environment strings */
-char **fetch_pam_environment(void)
+void
+do_pam_setcred(int init)
{
-#ifdef HAVE_PAM_GETENVLIST
- return(pam_getenvlist(__pamh));
-#else /* HAVE_PAM_GETENVLIST */
- return(NULL);
-#endif /* HAVE_PAM_GETENVLIST */
+ 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));
+ if (init) {
+ debug("PAM: establishing credentials");
+ sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED);
+ } else {
+ debug("PAM: reinitializing credentials");
+ sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED);
+ }
+ if (sshpam_err == PAM_SUCCESS) {
+ sshpam_cred_established = 1;
+ return;
+ }
+ if (sshpam_authenticated)
+ fatal("PAM: pam_setcred(): %s",
+ pam_strerror(sshpam_handle, sshpam_err));
+ else
+ debug("PAM: pam_setcred(): %s",
+ pam_strerror(sshpam_handle, sshpam_err));
}
-void free_pam_environment(char **env)
+static int
+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 (env != NULL) {
- for (i = 0; env[i] != NULL; i++)
- xfree(env[i]);
+ 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);
+
+ for (i = 0; i < n; ++i) {
+ switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
+ case PAM_PROMPT_ECHO_OFF:
+ reply[i].resp =
+ read_passphrase(PAM_MSG_MEMBER(msg, i, msg),
+ RP_ALLOW_STDIN);
+ reply[i].resp_retcode = PAM_SUCCESS;
+ break;
+ case PAM_PROMPT_ECHO_ON:
+ 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:
+ 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:
+ 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)
+{
+ if (use_privsep)
+ fatal("Password expired (unable to change with privsep)");
+ sshpam_err = pam_set_item(sshpam_handle, 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));
+ debug("PAM: changing password");
+ sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK);
+ if (sshpam_err != PAM_SUCCESS)
+ fatal("PAM: pam_chauthtok(): %s",
+ 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)
+{
+ int ret = 1;
+#ifdef HAVE_PAM_PUTENV
+ char *compound;
+ size_t len;
+
+ 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);
+}
+
+char **
+fetch_pam_child_environment(void)
+{
+ return sshpam_env;
+}
+
+char **
+fetch_pam_environment(void)
+{
+ return (pam_getenvlist(sshpam_handle));
}
-/* Print any messages that have been generated during authentication */
-/* or account checking to stderr */
-void print_pam_messages(void)
+void
+free_pam_environment(char **env)
{
- if (__pam_msg != NULL)
- fputs(__pam_msg, stderr);
+ char **envp;
+
+ if (env == NULL)
+ return;
+
+ for (envp = env; *envp; envp++)
+ xfree(*envp);
+ xfree(env);
}
-/* Append a message to buffer */
-void message_cat(char **p, const char *a)
+/*
+ * "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)
{
- char *cp;
- size_t new_len;
+ struct pam_response *reply;
+ int i;
+ size_t len;
+
+ debug3("PAM: %s called with %d messages", __func__, n);
- new_len = strlen(a);
+ *resp = NULL;
- if (*p) {
- size_t len = strlen(*p);
+ if (n <= 0 || n > PAM_MAX_NUM_MSG)
+ return (PAM_CONV_ERR);
- *p = xrealloc(*p, new_len + len + 2);
- cp = *p + len;
- } else
- *p = cp = xmalloc(new_len + 2);
+ 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);
- memcpy(cp, a, new_len);
- cp[new_len] = '\n';
- cp[new_len + 1] = '\0';
+ 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