diff options
Diffstat (limited to 'modules/pam_filter/pam_filter.c')
| -rw-r--r-- | modules/pam_filter/pam_filter.c | 81 |
1 files changed, 35 insertions, 46 deletions
diff --git a/modules/pam_filter/pam_filter.c b/modules/pam_filter/pam_filter.c index 1c7731b3..41028902 100644 --- a/modules/pam_filter/pam_filter.c +++ b/modules/pam_filter/pam_filter.c @@ -1,5 +1,5 @@ /* - * $Id: pam_filter.c,v 1.12 2005/12/12 14:45:00 ldv Exp $ + * $Id: pam_filter.c,v 1.14 2009/04/03 00:36:25 ldv Exp $ * * written by Andrew Morgan <morgan@transmeta.com> with much help from * Richard Stevens' UNIX Network Programming book. @@ -48,41 +48,18 @@ #include <stdarg.h> -#define TERMINAL_LEN 12 +#define DEV_PTMX "/dev/ptmx" static int -master (const pam_handle_t *pamh, char *terminal) -/* - * try to open all of the terminals in sequence return first free one, - * or -1 - */ +master (void) { - const char ptys[] = "pqrs", *pty = ptys; - const char hexs[] = "0123456789abcdef", *hex; - struct stat tstat; - int fd; - - strcpy(terminal, "/dev/pty??"); - - while (*pty) { /* step through four types */ - terminal[8] = *pty++; - terminal[9] = '0'; - if (stat(terminal,&tstat) < 0) { - pam_syslog(pamh, LOG_WARNING, - "unknown pseudo terminal: %s", terminal); - break; - } - for (hex = hexs; *hex; ) { /* step through 16 of these */ - terminal[9] = *hex++; - if ((fd = open(terminal, O_RDWR)) >= 0) { - return fd; - } - } - } - - /* no terminal found */ - - return -1; + int fd; + + if ((fd = open(DEV_PTMX, O_RDWR)) >= 0) { + return fd; + } + + return -1; } static int process_args(pam_handle_t *pamh @@ -279,7 +256,7 @@ set_filter (pam_handle_t *pamh, int flags UNUSED, int ctrl, const char **evp, const char *filtername) { int status=-1; - char terminal[TERMINAL_LEN]; + char* terminal = NULL; struct termios stored_mode; /* initial terminal mode settings */ int fd[2], child=0, child2=0, aterminal; @@ -299,7 +276,7 @@ set_filter (pam_handle_t *pamh, int flags UNUSED, int ctrl, /* open the master pseudo terminal */ - fd[0] = master(pamh,terminal); + fd[0] = master(); if (fd[0] < 0) { pam_syslog(pamh, LOG_CRIT, "no master terminal"); return PAM_AUTH_ERR; @@ -392,8 +369,27 @@ set_filter (pam_handle_t *pamh, int flags UNUSED, int ctrl, return PAM_ABORT; } + /* grant slave terminal */ + if (grantpt (fd[0]) < 0) { + pam_syslog(pamh, LOG_WARNING, "Cannot grant acccess to slave terminal"); + return PAM_ABORT; + } + + /* unlock slave terminal */ + if (unlockpt (fd[0]) < 0) { + pam_syslog(pamh, LOG_WARNING, "Cannot unlock slave terminal"); + return PAM_ABORT; + } + /* find slave's name */ - terminal[5] = 't'; /* want to open slave terminal */ + terminal = ptsname(fd[0]); /* returned value should not be freed */ + + if (terminal == NULL) { + pam_syslog(pamh, LOG_WARNING, + "Cannot get the name of the slave terminal: %m"); + return PAM_ABORT; + } + fd[1] = open(terminal, O_RDWR); close(fd[0]); /* process is the child -- uses line fd[1] */ @@ -412,7 +408,6 @@ set_filter (pam_handle_t *pamh, int flags UNUSED, int ctrl, close(fd[1]); return PAM_ABORT; } - } else { /* nothing to do for a simple stream socket */ @@ -450,13 +445,6 @@ set_filter (pam_handle_t *pamh, int flags UNUSED, int ctrl, return PAM_SUCCESS; } - /* - * process is the parent here. So we can close the application's - * input/output - */ - - close(fd[1]); - /* Clear out passwords... there is a security problem here in * that this process never executes pam_end. Consequently, any * other sensitive data in this process is *not* explicitly @@ -480,7 +468,7 @@ set_filter (pam_handle_t *pamh, int flags UNUSED, int ctrl, pam_syslog(pamh, LOG_WARNING, "unable to re-assign APPIN/OUT/ERR: %m"); close(fd[0]); - exit(1); + _exit(1); } /* make sure that file descriptors survive 'exec's */ @@ -493,7 +481,7 @@ set_filter (pam_handle_t *pamh, int flags UNUSED, int ctrl, close(APPIN_FILENO); close(APPOUT_FILENO); close(APPERR_FILENO); - exit(1); + _exit(1); } /* now the user input is read from the parent through filter */ @@ -503,6 +491,7 @@ set_filter (pam_handle_t *pamh, int flags UNUSED, int ctrl, /* getting to here is an error */ pam_syslog(pamh, LOG_ALERT, "filter: %s: %m", filtername); + _exit(1); } else { /* wait for either of the two children to exit */ |