https://bugs.gentoo.org/708372
--- a/auth.c
+++ b/auth.c
@@ -70,7 +70,7 @@ void gen_chal(char *buf)
 void encrypt_chal(char *chal, char *pwd)
 { 
    register int i;
-   BF_KEY key;
+   extern BF_KEY key;
 
    BF_set_key(&key, 16, MD5(pwd,strlen(pwd),NULL));
 
--- a/lfd_encrypt.c
+++ b/lfd_encrypt.c
@@ -64,8 +64,8 @@
 #define ENC_BUF_SIZE VTUN_FRAME_SIZE + 128 
 #define ENC_KEY_SIZE 16
 
-BF_KEY key;
-char * enc_buf;
+extern BF_KEY key;
+extern char * enc_buf;
 char * dec_buf;
 
 #define CIPHER_INIT		0