1 files changed, 65 insertions, 0 deletions
diff --git a/login-utils/auth.c b/login-utils/auth.c
new file mode 100644
index 0000000..fdeb12b
--- /dev/null
+++ b/login-utils/auth.c
@@ -0,0 +1,65 @@
+/*
+ *   auth.c -- PAM authorization code, common between chsh and chfn
+ *   (c) 2012 by Cody Maloney <cmaloney@theoreticalchaos.com>
+ *
+ *   this program is free software.  you can redistribute it and
+ *   modify it under the terms of the gnu general public license.
+ *   there is no warranty.
+ *
+ */
+
+#include <security/pam_appl.h>
+#ifdef HAVE_SECURITY_PAM_MISC_H
+# include <security/pam_misc.h>
+#elif defined(HAVE_SECURITY_OPENPAM_H)
+# include <security/openpam.h>
+#endif
+
+#include "c.h"
+#include "auth.h"
+
+static int pam_fail_check(pam_handle_t *pamh, int retcode)
+{
+	if (retcode == PAM_SUCCESS)
+		return 0;
+	warnx("%s", pam_strerror(pamh, retcode));
+	pam_end(pamh, retcode);
+	return 1;
+}
+
+int auth_pam(const char *service_name, uid_t uid, const char *username)
+{
+	if (uid != 0) {
+		pam_handle_t *pamh = NULL;
+#ifdef HAVE_SECURITY_PAM_MISC_H
+		struct pam_conv conv = { misc_conv, NULL };
+#elif defined(HAVE_SECURITY_OPENPAM_H)
+		struct pam_conv conv = { openpam_ttyconv, NULL };
+#endif
+		int retcode;
+
+		retcode = pam_start(service_name, username, &conv, &pamh);
+		if (pam_fail_check(pamh, retcode))
+			return FALSE;
+
+		retcode = pam_authenticate(pamh, 0);
+		if (pam_fail_check(pamh, retcode))
+			return FALSE;
+
+		retcode = pam_acct_mgmt(pamh, 0);
+		if (retcode == PAM_NEW_AUTHTOK_REQD)
+			retcode =
+			    pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
+		if (pam_fail_check(pamh, retcode))
+			return FALSE;
+
+		retcode = pam_setcred(pamh, 0);
+		if (pam_fail_check(pamh, retcode))
+			return FALSE;
+
+		pam_end(pamh, 0);
+		/* no need to establish a session; this isn't a
+		 * session-oriented activity...  */
+	}
+	return TRUE;
+}