[patch] login_yubikey: delete keys

[fritjof]

Wipe out the key from "user.key".

--f.

Index: login_yubikey.c
===================================================================
RCS file: /cvs/src/libexec/login_yubikey/login_yubikey.c,v
retrieving revision 1.10
diff -u -p -u -r1.10 login_yubikey.c
--- login_yubikey.c     16 Jan 2015 06:39:50 -0000      1.10
+++ login_yubikey.c     31 Mar 2016 09:38:01 -0000
@@ -224,6 +224,8 @@ yubikey_login(const char *username, cons
        yubikey_hex_decode(uid, hexuid, YUBIKEY_UID_SIZE);
        yubikey_hex_decode(key, hexkey, YUBIKEY_KEY_SIZE);
 
+       explicit_bzero(hexkey, sizeof(hexkey));
+
        /* 
         * Cycle through the key mapping table.
          * XXX brute force, unoptimized; a lookup table for valid mappings may
@@ -268,6 +270,8 @@ yubikey_login(const char *username, cons
                }
                break; /* only reached through the bottom of case 0 */
        }
+
+       explicit_bzero(key, sizeof(key));
 
        syslog(LOG_INFO, "user %s uid %s: %d matching keymaps (%d checked), "
            "%d crc ok", username, hexuid, mapok, i, crcok);