From ea488580c42e8918445a945484de3c8a5addc761 Mon Sep 17 00:00:00 2001
From: "Andrew G. Morgan" <morgan@kernel.org>
Date: Tue, 20 Jun 2000 22:10:38 +0000
Subject: Initial revision

---
 modules/pam_shells/pam_shells.c | 133 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 modules/pam_shells/pam_shells.c

(limited to 'modules/pam_shells/pam_shells.c')

diff --git a/modules/pam_shells/pam_shells.c b/modules/pam_shells/pam_shells.c
new file mode 100644
index 00000000..f460ee5f
--- /dev/null
+++ b/modules/pam_shells/pam_shells.c
@@ -0,0 +1,133 @@
+/* pam_shells module */
+
+#define SHELL_FILE "/etc/shells"
+
+/*
+ * by Erik Troan <ewt@redhat.com>, Red Hat Software.
+ * August 5, 1996.
+ * This code shamelessly ripped from the pam_securetty module.
+ */
+
+#define _BSD_SOURCE
+
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <syslog.h>
+#include <unistd.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
+
+#include <security/pam_modules.h>
+
+/* some syslogging */
+
+static void _pam_log(int err, const char *format, ...)
+{
+    va_list args;
+
+    va_start(args, format);
+    openlog("PAM-shells", LOG_CONS|LOG_PID, LOG_AUTH);
+    vsyslog(err, format, args);
+    va_end(args);
+    closelog();
+}
+
+/* --- authentication management functions (only) --- */
+
+PAM_EXTERN
+int pam_sm_authenticate(pam_handle_t *pamh,int flags,int argc
+			,const char **argv)
+{
+     int retval = PAM_AUTH_ERR;
+     const char *userName;
+     char *userShell;
+     char shellFileLine[256];
+     struct stat sb;
+     struct passwd * pw;
+     FILE * shellFile;
+
+     retval = pam_get_user(pamh,&userName,NULL);
+     if(retval != PAM_SUCCESS) 
+       return PAM_SERVICE_ERR;
+
+     if(!userName || (strlen(userName) <= 0)) {
+       /* Don't let them use a NULL username... */
+       pam_get_user(pamh,&userName,NULL);
+        if (retval != PAM_SUCCESS)
+	  return PAM_SERVICE_ERR;
+     }
+
+     pw = getpwnam(userName);
+     if (!pw)
+	return PAM_AUTH_ERR;		/* user doesn't exist */
+     userShell = pw->pw_shell;
+
+     if(stat(SHELL_FILE,&sb)) {
+	_pam_log(LOG_ERR, SHELL_FILE, " cannot be stat'd (it probably does "
+			"not exist)");
+	return PAM_AUTH_ERR;		/* must have /etc/shells */
+     }
+
+     if((sb.st_mode & S_IWOTH) || !S_ISREG(sb.st_mode)) {
+       _pam_log(LOG_ERR,
+		SHELL_FILE " is either world writable or not a normal file");
+       return PAM_AUTH_ERR;
+     }
+
+     shellFile = fopen(SHELL_FILE,"r");
+     if(shellFile == NULL) { /* Check that we opened it successfully */
+       _pam_log(LOG_ERR,
+		"Error opening " SHELL_FILE);
+       return PAM_SERVICE_ERR;
+     }
+     /* There should be no more errors from here on */
+     retval=PAM_AUTH_ERR;
+     /* This loop assumes that PAM_SUCCESS == 0
+        and PAM_AUTH_ERR != 0 */
+     while((fgets(shellFileLine,255,shellFile) != NULL) 
+	   && retval) {
+       if (shellFileLine[strlen(shellFileLine) - 1] == '\n')
+	   shellFileLine[strlen(shellFileLine) - 1] = '\0';
+       retval = strcmp(shellFileLine, userShell);
+     }
+     fclose(shellFile);
+     if(retval)
+       retval = PAM_AUTH_ERR;
+     return retval;
+}
+
+PAM_EXTERN
+int pam_sm_setcred(pam_handle_t *pamh,int flags,int argc
+		   ,const char **argv)
+{
+     return PAM_SUCCESS;
+}
+
+
+#ifdef PAM_STATIC
+
+/* static module data */
+
+struct pam_module _pam_shells_modstruct = {
+     "pam_shells",
+     pam_sm_authenticate,
+     pam_sm_setcred,
+     NULL,
+     NULL,
+     NULL,
+     NULL,
+};
+
+#endif
+
+/* end of module definition */
-- 
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