]> andersk Git - openssh.git/blobdiff - auth-pam.c
- (stevesk) [auth-pam.c] cast to avoid initialization type mismatch
[openssh.git] / auth-pam.c
index fc7c91b50734e5df3f24ed5987d6760c93e34780..708d0ae9a903d89329ce8eca15479daafc9a9134 100644 (file)
 #include "ssh.h"
 #include "xmalloc.h"
 #include "log.h"
+#include "auth.h"
+#include "auth-options.h"
 #include "auth-pam.h"
 #include "servconf.h"
 #include "canohost.h"
 #include "readpass.h"
 
+extern char *__progname;
+
+extern int use_privsep;
+
 RCSID("$Id$");
 
 #define NEW_AUTHTOK_MSG \
-       "Warning: Your password has expired, please change it now"
+       "Warning: Your password has expired, please change it now."
+#define NEW_AUTHTOK_MSG_PRIVSEP \
+       "Your password has expired, the session cannot proceed."
 
 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 = {
-       do_pam_conversation,
+       (int (*)())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;
+static pam_handle_t *__pamh = NULL;
+static const char *__pampasswd = NULL;
 
 /* states for do_pam_conversation() */
 enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
-/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
+/* 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;
 
+/* Remember what has been initialised */
+static int session_opened = 0;
+static int creds_set = 0;
+
 /* accessor which allows us to switch conversation structs according to
  * the authentication method being used */
-void pam_set_conv(struct pam_conv *conv)
+void do_pam_set_conv(struct pam_conv *conv)
 {
-       pam_set_item(pamh, PAM_CONV, conv);
+       pam_set_item(__pamh, PAM_CONV, conv);
 }
 
 /* start an authentication run */
 int do_pam_authenticate(int flags)
 {
-       int retval = pam_authenticate(pamh, flags);
+       int retval = pam_authenticate(__pamh, flags);
        was_authenticated = (retval == PAM_SUCCESS);
        return retval;
 }
@@ -78,10 +90,10 @@ 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 into pam_msg.  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)
+ * 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.
  */
@@ -93,9 +105,7 @@ static int do_pam_conversation(int num_msg, const struct pam_message **msg,
        char buf[1024];
 
        /* PAM will free this later */
-       reply = malloc(num_msg * sizeof(*reply));
-       if (reply == NULL)
-               return PAM_CONV_ERR;
+       reply = xmalloc(num_msg * sizeof(*reply));
 
        for (count = 0; count < num_msg; count++) {
                if (pamstate == INITIAL_LOGIN) {
@@ -105,27 +115,27 @@ static int do_pam_conversation(int num_msg, const struct pam_message **msg,
                         */
                        switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
                        case PAM_PROMPT_ECHO_ON:
-                               free(reply);
+                               xfree(reply);
                                return PAM_CONV_ERR;
                        case PAM_PROMPT_ECHO_OFF:
-                               if (pampasswd == NULL) {
-                                       free(reply);
+                               if (__pampasswd == NULL) {
+                                       xfree(reply);
                                        return PAM_CONV_ERR;
                                }
-                               reply[count].resp = xstrdup(pampasswd);
+                               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) {
-                                       message_cat(&pam_msg, 
+                               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:
-                               free(reply);
+                               xfree(reply);
                                return PAM_CONV_ERR;
                        }
                } else {
@@ -140,9 +150,9 @@ static int do_pam_conversation(int num_msg, const struct pam_message **msg,
                                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 = 
+                                   read_passphrase(PAM_MSG_MEMBER(msg, count,
+                                       msg), RP_ALLOW_STDIN);
                                reply[count].resp_retcode = PAM_SUCCESS;
                                break;
                        case PAM_ERROR_MSG:
@@ -154,7 +164,7 @@ static int do_pam_conversation(int num_msg, const struct pam_message **msg,
                                reply[count].resp_retcode = PAM_SUCCESS;
                                break;
                        default:
-                               free(reply);
+                               xfree(reply);
                                return PAM_CONV_ERR;
                        }
                }
@@ -166,48 +176,54 @@ static int do_pam_conversation(int num_msg, const struct pam_message **msg,
 }
 
 /* Called at exit to cleanly shutdown PAM */
-void pam_cleanup_proc(void *context)
+void do_pam_cleanup_proc(void *context)
 {
-       int pam_retval;
+       int pam_retval = PAM_SUCCESS;
 
-       if (pamh) {
-               pam_retval = pam_close_session(pamh, 0);
+       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));
+                           pam_retval, PAM_STRERROR(__pamh, pam_retval));
+       }
 
-               pam_retval = pam_setcred(pamh, PAM_DELETE_CRED);
+       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));
+                           pam_retval, PAM_STRERROR(__pamh, pam_retval));
+       }
 
-               pam_retval = pam_end(pamh, pam_retval);
+       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));
+                           pam_retval, PAM_STRERROR(__pamh, pam_retval));
        }
 }
 
 /* Attempt password authentation using PAM */
-int auth_pam_password(struct passwd *pw, const char *password)
+int auth_pam_password(Authctxt *authctxt, const char *password)
 {
        extern ServerOptions options;
        int pam_retval;
+       struct passwd *pw = authctxt->pw;
 
-       pam_set_conv(&conv);
+       do_pam_set_conv(&conv);
 
        /* deny if no user. */
        if (pw == NULL)
                return 0;
-       if (pw->pw_uid == 0 && options.permit_root_login == 2)
+       if (pw->pw_uid == 0 && options.permit_root_login == PERMIT_NO_PASSWD)
                return 0;
        if (*password == '\0' && options.permit_empty_passwd == 0)
                return 0;
 
-       pampasswd = password;
+       __pampasswd = password;
 
        pamstate = INITIAL_LOGIN;
-       pam_retval = do_pam_authenticate(0);
+       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);
@@ -215,7 +231,7 @@ int auth_pam_password(struct passwd *pw, const char *password)
        } else {
                debug("PAM Password authentication for \"%.100s\" "
                    "failed[%d]: %s", pw->pw_name, pam_retval, 
-                   PAM_STRERROR(pamh, pam_retval));
+                   PAM_STRERROR(__pamh, pam_retval));
                return 0;
        }
 }
@@ -225,29 +241,37 @@ int do_pam_account(char *username, char *remote_user)
 {
        int pam_retval;
 
-       pam_set_conv(&conv);
+       do_pam_set_conv(&conv);
 
        if (remote_user) {
                debug("PAM setting ruser to \"%.200s\"", remote_user);
-               pam_retval = pam_set_item(pamh, PAM_RUSER, remote_user);
+               pam_retval = pam_set_item(__pamh, PAM_RUSER, remote_user);
                if (pam_retval != PAM_SUCCESS)
                        fatal("PAM set ruser failed[%d]: %.200s", pam_retval, 
-                           PAM_STRERROR(pamh, pam_retval));
+                           PAM_STRERROR(__pamh, pam_retval));
        }
 
-       pam_retval = pam_acct_mgmt(pamh, 0);
+       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, NEW_AUTHTOK_MSG);
+                       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;
                        break;
+#endif
                default:
                        log("PAM rejected by account configuration[%d]: "
-                           "%.200s", pam_retval, PAM_STRERROR(pamh, 
+                           "%.200s", pam_retval, PAM_STRERROR(__pamh, 
                            pam_retval));
                        return(0);
        }
@@ -260,39 +284,50 @@ void do_pam_session(char *username, const char *ttyname)
 {
        int pam_retval;
 
+       do_pam_set_conv(&conv);
+
        if (ttyname != NULL) {
                debug("PAM setting tty to \"%.200s\"", ttyname);
-               pam_retval = pam_set_item(pamh, PAM_TTY, 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));
+                           pam_retval, PAM_STRERROR(__pamh, pam_retval));
        }
 
-       pam_retval = pam_open_session(pamh, 0);
+       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));
+                   pam_retval, PAM_STRERROR(__pamh, pam_retval));
+
+       session_opened = 1;
 }
 
 /* Set PAM credentials */
-void do_pam_setcred(void)
+void do_pam_setcred(int init)
 {
        int pam_retval;
 
+       if (__pamh == NULL)
+               return;
+
+       do_pam_set_conv(&conv);
+
        debug("PAM establishing creds");
-       pam_retval = pam_setcred(pamh, PAM_ESTABLISH_CRED);
+       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));
+                           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));
+       } else
+               creds_set = 1;
 }
 
 /* accessor function for file scope static variable */
-int pam_password_change_required(void)
+int is_pam_password_change_required(void)
 {
        return password_change_required;
 }
@@ -301,30 +336,40 @@ int pam_password_change_required(void)
  * Have user change authentication token if pam_acct_mgmt() indicated
  * it was expired.  This needs to be called after an interactive
  * session is established and the user's pty is connected to
- * stdin/stout/stderr.
+ * stdin/stdout/stderr.
  */
 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;
-               /* XXX: should we really loop forever? */
-               do {
-                       pam_retval = pam_chauthtok(pamh, 
-                           PAM_CHANGE_EXPIRED_AUTHTOK);
-                       if (pam_retval != PAM_SUCCESS)
-                               log("PAM pam_chauthtok failed[%d]: %.200s",
-                                   pam_retval, PAM_STRERROR(pamh, pam_retval));
-               } while (pam_retval != PAM_SUCCESS);
+               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
        }
 }
 
 /* Cleanly shutdown PAM */
 void finish_pam(void)
 {
-       pam_cleanup_proc(NULL);
-       fatal_remove_cleanup(&pam_cleanup_proc, NULL);
+       do_pam_cleanup_proc(NULL);
+       fatal_remove_cleanup(&do_pam_cleanup_proc, NULL);
 }
 
 /* Start PAM authentication for specified account */
@@ -332,22 +377,24 @@ void start_pam(const char *user)
 {
        int pam_retval;
        extern ServerOptions options;
+       extern u_int utmp_len;
+       const char *rhost;
 
        debug("Starting up PAM with username \"%.200s\"", user);
 
-       pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &pamh);
+       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));
+                   pam_retval, PAM_STRERROR(__pamh, pam_retval));
+
+       rhost = get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping);
+       debug("PAM setting rhost to \"%.200s\"", rhost);
 
-       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));
+       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));
+                   PAM_STRERROR(__pamh, pam_retval));
 #ifdef PAM_TTY_KLUDGE
        /*
         * Some PAM modules (e.g. pam_time) require a TTY to operate,
@@ -356,20 +403,20 @@ void start_pam(const char *user)
         * not even need one (for tty-less connections)
         * Kludge: Set a fake PAM_TTY
         */
-       pam_retval = pam_set_item(pamh, PAM_TTY, "ssh");
+       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));
+                   pam_retval, PAM_STRERROR(__pamh, pam_retval));
 #endif /* PAM_TTY_KLUDGE */
 
-       fatal_add_cleanup(&pam_cleanup_proc, NULL);
+       fatal_add_cleanup(&do_pam_cleanup_proc, NULL);
 }
 
 /* Return list of PAM enviornment strings */
 char **fetch_pam_environment(void)
 {
 #ifdef HAVE_PAM_GETENVLIST
-       return(pam_getenvlist(pamh));
+       return(pam_getenvlist(__pamh));
 #else /* HAVE_PAM_GETENVLIST */
        return(NULL);
 #endif /* HAVE_PAM_GETENVLIST */
@@ -379,8 +426,8 @@ char **fetch_pam_environment(void)
 /* or account checking to stderr */
 void print_pam_messages(void)
 {
-       if (pam_msg != NULL)
-               fputs(pam_msg, stderr);
+       if (__pam_msg != NULL)
+               fputs(__pam_msg, stderr);
 }
 
 /* Append a message to buffer */
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