merge upstream version 1.0.1

1 files changed, 219 insertions, 0 deletions

diff --git a/modules/pam_securetty/pam_securetty.c b/modules/pam_securetty/pam_securetty.c
new file mode 100644
index 00000000..9dbe9bc4
--- /dev/null
+++ b/modules/pam_securetty/pam_securetty.c
@@ -0,0 +1,219 @@
+/* pam_securetty module */
+
+#define SECURETTY_FILE "/etc/securetty"
+#define TTY_PREFIX     "/dev/"
+
+/*
+ * by Elliot Lee <sopwith@redhat.com>, Red Hat Software.
+ * July 25, 1996.
+ * This code shamelessly ripped from the pam_rootok module.
+ * Slight modifications AGM. 1996/12/3
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <stdarg.h>
+#include <pwd.h>
+#include <string.h>
+#include <ctype.h>
+
+/*
+ * here, we make a definition for the externally accessible function
+ * in this file (this definition is required for static a module
+ * but strongly encouraged generally) it is used to instruct the
+ * modules include file to define the function prototypes.
+ */
+
+#define PAM_SM_AUTH
+#define PAM_SM_ACCOUNT
+
+#include <security/pam_modules.h>
+#include <security/pam_modutil.h>
+#include <security/pam_ext.h>
+
+#define PAM_DEBUG_ARG       0x0001
+
+static int
+_pam_parse (const pam_handle_t *pamh, int argc, const char **argv)
+{
+    int ctrl=0;
+
+    /* step through arguments */
+    for (ctrl=0; argc-- > 0; ++argv) {
+
+	/* generic options */
+
+	if (!strcmp(*argv,"debug"))
+	    ctrl |= PAM_DEBUG_ARG;
+	else {
+	    pam_syslog(pamh, LOG_ERR, "unknown option: %s", *argv);
+	}
+    }
+
+    return ctrl;
+}
+
+static int
+securetty_perform_check (pam_handle_t *pamh, int ctrl,
+			 const char *function_name)
+{
+    int retval = PAM_AUTH_ERR;
+    const char *username;
+    const char *uttyname;
+    const void *void_uttyname;
+    char ttyfileline[256];
+    char ptname[256];
+    struct stat ttyfileinfo;
+    struct passwd *user_pwd;
+    FILE *ttyfile;
+
+    /* log a trail for debugging */
+    if (ctrl & PAM_DEBUG_ARG) {
+        pam_syslog(pamh, LOG_DEBUG, "pam_securetty called via %s function",
+		   function_name);
+    }
+
+    retval = pam_get_user(pamh, &username, NULL);
+    if (retval != PAM_SUCCESS || username == NULL) {
+        pam_syslog(pamh, LOG_WARNING, "cannot determine username");
+	return (retval == PAM_CONV_AGAIN ? PAM_INCOMPLETE:PAM_SERVICE_ERR);
+    }
+
+    user_pwd = pam_modutil_getpwnam(pamh, username);
+    if (user_pwd == NULL) {
+	return PAM_USER_UNKNOWN;
+    } else if (user_pwd->pw_uid != 0) { /* If the user is not root,
+					   securetty's does not apply
+					   to them */
+	return PAM_SUCCESS;
+    }
+
+    retval = pam_get_item(pamh, PAM_TTY, &void_uttyname);
+    uttyname = void_uttyname;
+    if (retval != PAM_SUCCESS || uttyname == NULL) {
+        pam_syslog (pamh, LOG_WARNING, "cannot determine user's tty");
+	return PAM_SERVICE_ERR;
+    }
+
+    /* The PAM_TTY item may be prefixed with "/dev/" - skip that */
+    if (strncmp(TTY_PREFIX, uttyname, sizeof(TTY_PREFIX)-1) == 0) {
+	uttyname += sizeof(TTY_PREFIX)-1;
+    }
+
+    if (stat(SECURETTY_FILE, &ttyfileinfo)) {
+	pam_syslog(pamh, LOG_NOTICE, "Couldn't open %s: %m", SECURETTY_FILE);
+	return PAM_SUCCESS; /* for compatibility with old securetty handling,
+			       this needs to succeed.  But we still log the
+			       error. */
+    }
+
+    if ((ttyfileinfo.st_mode & S_IWOTH) || !S_ISREG(ttyfileinfo.st_mode)) {
+	/* If the file is world writable or is not a
+	   normal file, return error */
+	pam_syslog(pamh, LOG_ERR,
+		   "%s is either world writable or not a normal file",
+		   SECURETTY_FILE);
+	return PAM_AUTH_ERR;
+    }
+
+    ttyfile = fopen(SECURETTY_FILE,"r");
+    if (ttyfile == NULL) { /* Check that we opened it successfully */
+	pam_syslog(pamh, LOG_ERR, "Error opening %s: %m", SECURETTY_FILE);
+	return PAM_SERVICE_ERR;
+    }
+
+    if (isdigit(uttyname[0])) {
+	snprintf(ptname, sizeof(ptname), "pts/%s", uttyname);
+    } else {
+	ptname[0] = '\0';
+    }
+
+    retval = 1;
+
+    while ((fgets(ttyfileline, sizeof(ttyfileline)-1, ttyfile) != NULL)
+	   && retval) {
+	if (ttyfileline[strlen(ttyfileline) - 1] == '\n')
+	    ttyfileline[strlen(ttyfileline) - 1] = '\0';
+
+	retval = ( strcmp(ttyfileline, uttyname)
+		   && (!ptname[0] || strcmp(ptname, uttyname)) );
+    }
+    fclose(ttyfile);
+
+    if (retval) {
+	    pam_syslog(pamh, LOG_WARNING, "access denied: tty '%s' is not secure !",
+		     uttyname);
+
+	    retval = PAM_AUTH_ERR;
+    } else {
+	if ((retval == PAM_SUCCESS) && (ctrl & PAM_DEBUG_ARG)) {
+	    pam_syslog(pamh, LOG_DEBUG, "access allowed for '%s' on '%s'",
+		     username, uttyname);
+	}
+	retval = PAM_SUCCESS;
+
+    }
+
+    return retval;
+}
+
+/* --- authentication management functions --- */
+
+PAM_EXTERN
+int pam_sm_authenticate(pam_handle_t *pamh, int flags UNUSED, int argc,
+			const char **argv)
+{
+    int ctrl;
+
+    /* parse the arguments */
+    ctrl = _pam_parse (pamh, argc, argv);
+
+    return securetty_perform_check(pamh, ctrl, __FUNCTION__);
+}
+
+PAM_EXTERN int
+pam_sm_setcred (pam_handle_t *pamh UNUSED, int flags UNUSED,
+		int argc UNUSED, const char **argv UNUSED)
+{
+    return PAM_SUCCESS;
+}
+
+/* --- account management functions --- */
+
+PAM_EXTERN int
+pam_sm_acct_mgmt (pam_handle_t *pamh, int flags UNUSED,
+		  int argc, const char **argv)
+{
+    int ctrl;
+
+    /* parse the arguments */
+    ctrl = _pam_parse (pamh, argc, argv);
+
+    /* take the easy route */
+    return securetty_perform_check(pamh, ctrl, __FUNCTION__);
+}
+
+
+#ifdef PAM_STATIC
+
+/* static module data */
+
+struct pam_module _pam_securetty_modstruct = {
+     "pam_securetty",
+     pam_sm_authenticate,
+     pam_sm_setcred,
+     pam_sm_acct_mgmt,
+     NULL,
+     NULL,
+     NULL,
+};
+
+#endif /* PAM_STATIC */
+
+/* end of module definition */