<s>
FreeLAN	B-Application
is	O
computer	O
software	O
that	O
implements	O
peer-to-peer	O
,	O
full	O
mesh	O
,	O
virtual	B-Application
private	I-Application
network	I-Application
(	O
VPN	B-Application
)	O
techniques	O
for	O
creating	O
secure	O
point-to-point	O
or	O
site-to-site	O
connections	O
in	O
routed	B-Protocol
or	O
bridged	B-Protocol
configurations	O
and	O
remote	O
access	O
facilities	O
.	O
</s>
<s>
It	O
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
licensed	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
Version	O
3	O
(	O
GNU	B-License
GPLv3	I-License
)	O
.	O
</s>
<s>
FreeLAN	B-Application
uses	O
the	O
OpenSSL	B-Language
library	O
to	O
provide	O
encryption	O
of	O
both	O
the	O
data	O
and	O
control	O
channels	O
.	O
</s>
<s>
It	O
lets	O
OpenSSL	B-Language
do	O
all	O
the	O
encryption	O
and	O
authentication	O
work	O
,	O
allowing	O
FreeLAN	B-Application
to	O
use	O
all	O
the	O
ciphers	O
available	O
in	O
the	O
OpenSSL	B-Language
package	O
.	O
</s>
<s>
FreeLAN	B-Application
has	O
several	O
ways	O
to	O
authenticate	O
peers	O
with	O
each	O
other	O
.	O
</s>
<s>
From	O
version	O
2.0	O
FreeLAN	B-Application
offers	O
pre-shared	O
keys	O
,	O
certificate-based	O
,	O
and	O
username-password	O
based	O
authentication	O
.	O
</s>
