<s>
Mbed	B-Language
TLS	I-Language
(	O
previously	O
PolarSSL	B-Language
)	O
is	O
an	O
implementation	O
of	O
the	O
TLS	B-Protocol
and	I-Protocol
SSL	I-Protocol
protocols	O
and	O
the	O
respective	O
cryptographic	O
algorithms	O
and	O
support	O
code	O
required	O
.	O
</s>
<s>
It	O
is	O
distributed	O
under	O
the	O
Apache	B-Application
License	I-Application
version	O
2.0	O
.	O
</s>
<s>
Stated	O
on	O
the	O
website	O
is	O
that	O
Mbed	B-Language
TLS	I-Language
aims	O
to	O
be	O
"	O
easy	O
to	O
understand	O
,	O
use	O
,	O
integrate	O
and	O
expand	O
"	O
.	O
</s>
<s>
The	O
PolarSSL	B-Language
SSL	O
library	B-Library
is	O
the	O
official	O
continuation	O
fork	O
of	O
the	O
XySSL	B-Language
SSL	O
library	B-Library
.	O
</s>
<s>
XySSL	B-Language
was	O
created	O
by	O
the	O
French	O
"	O
white	O
hat	O
hacker	O
"	O
Christophe	O
Devine	O
and	O
was	O
first	O
released	O
on	O
November	O
1	O
,	O
2006	O
,	O
under	O
GNU	O
GPL	O
v2	O
and	O
BSD	O
licenses	O
.	O
</s>
<s>
In	O
2008	O
,	O
Christophe	O
Devine	O
was	O
no	O
longer	O
able	O
to	O
support	O
XySSL	B-Language
and	O
allowed	O
Paul	O
Bakker	O
to	O
create	O
the	O
official	O
fork	O
,	O
named	O
PolarSSL	B-Language
.	O
</s>
<s>
In	O
November	O
2014	O
,	O
PolarSSL	B-Language
was	O
acquired	O
by	O
ARM	O
Holdings	O
.	O
</s>
<s>
In	O
2011	O
,	O
the	O
Dutch	O
government	O
approved	O
an	O
integration	O
between	O
OpenVPN	B-Language
and	O
PolarSSL	B-Language
,	O
which	O
is	O
named	O
OpenVPN-NL	O
.	O
</s>
<s>
This	O
version	O
of	O
OpenVPN	B-Language
has	O
been	O
approved	O
for	O
use	O
in	O
protecting	O
government	O
communications	O
up	O
to	O
the	O
level	O
of	O
Restricted	O
.	O
</s>
<s>
As	O
of	O
the	O
release	O
of	O
version	O
1.3.10	O
,	O
PolarSSL	B-Language
has	O
been	O
rebranded	O
to	O
Mbed	B-Language
TLS	I-Language
to	O
better	O
show	O
its	O
fit	O
inside	O
the	O
Mbed	B-Operating_System
ecosystem	O
.	O
</s>
<s>
Starting	O
from	O
version	O
2.1.0	O
,	O
the	O
library	B-Library
was	O
made	O
available	O
under	O
both	O
the	O
GPL	O
v2	O
and	O
Apache	B-Application
License	I-Application
v2.0	O
.	O
</s>
<s>
Since	O
version	O
2.17	O
,	O
Mbed	B-Language
TLS	I-Language
is	O
solely	O
licensed	O
under	O
the	O
Apache	B-Application
License	I-Application
version	O
2.0	O
.	O
</s>
<s>
In	O
2020	O
,	O
Mbed	B-Language
TLS	I-Language
joined	O
the	O
TrustedFirmware	O
project	O
.	O
</s>
<s>
The	O
core	O
SSL	O
library	B-Library
is	O
written	O
in	O
the	O
C	B-Language
programming	I-Language
language	I-Language
and	O
implements	O
the	O
SSL	O
module	O
,	O
the	O
basic	O
cryptographic	O
functions	O
and	O
provides	O
various	O
utility	O
functions	O
.	O
</s>
<s>
Unlike	O
OpenSSL	B-Language
and	O
other	O
implementations	O
of	O
TLS	O
,	O
Mbed	B-Language
TLS	I-Language
is	O
like	O
wolfSSL	B-Protocol
in	O
that	O
it	O
is	O
designed	O
to	O
fit	O
on	O
small	O
embedded	O
devices	O
,	O
with	O
the	O
minimum	O
complete	O
TLS	O
stack	O
requiring	O
under	O
60KB	O
of	O
program	O
space	O
and	O
under	O
64KB	O
of	O
RAM	O
.	O
</s>
<s>
Versions	O
are	O
also	O
available	O
for	O
Microsoft	B-Application
Windows	I-Application
and	O
Linux	B-Application
.	O
</s>
<s>
Because	O
Mbed	B-Language
TLS	I-Language
is	O
written	O
in	O
the	O
C	B-Language
programming	I-Language
language	I-Language
,	O
without	O
external	O
dependencies	O
,	O
it	O
works	O
on	O
most	O
operating	O
systems	O
and	O
architectures	O
.	O
</s>
<s>
The	O
Mbed	B-Language
TLS	I-Language
library	B-Library
expresses	O
a	O
focus	O
on	O
readability	O
of	O
the	O
code	O
,	O
documentation	O
,	O
automated	O
regression	O
tests	O
,	O
a	O
loosely	O
coupled	O
design	O
and	O
portable	O
code	O
.	O
</s>
<s>
High	O
Level	O
Design	O
:	O
a	O
high	O
level	O
description	O
of	O
the	O
different	O
modules	O
inside	O
the	O
library	B-Library
,	O
with	O
UML	O
diagrams	O
,	O
use	O
cases	O
and	O
interactions	O
in	O
common	O
scenarios	O
.	O
</s>
<s>
API	O
documentation	O
:	O
Doxygen-generated	O
documentation	O
from	O
the	O
header	O
files	O
of	O
the	O
library	B-Library
.	O
</s>
<s>
Source	O
code	O
documentation	O
:	O
The	O
source	O
code	O
of	O
the	O
library	B-Library
is	O
documented	O
to	O
clarify	O
structures	O
,	O
decisions	O
and	O
code	O
constructs	O
.	O
</s>
<s>
The	O
automated	O
testing	O
of	O
Mbed	B-Language
TLS	I-Language
includes	O
:	O
</s>
<s>
A	O
test	O
framework	O
is	O
included	O
with	O
the	O
source	O
code	O
that	O
contains	O
over	O
5000	O
automated	O
tests	O
(	O
based	O
on	O
the	O
number	O
of	O
tests	O
in	O
version	O
1.3.2	O
of	O
the	O
library	B-Library
)	O
to	O
test	O
for	O
regressions	O
and	O
compatibility	O
on	O
different	O
platforms	O
.	O
</s>
<s>
A	O
compatibility	O
script	O
(	O
compat.sh	O
)	O
that	O
tests	O
compatibility	O
of	O
SSL	O
communication	O
with	O
OpenSSL	B-Language
and	O
GnuTLS	B-Application
.	O
</s>
<s>
A	O
continuous	O
integration	O
system	O
based	O
on	O
Travis	B-Application
CI	I-Application
and	O
Jenkins	B-Language
.	O
</s>
<s>
Mbed	B-Language
TLS	I-Language
is	O
used	O
as	O
the	O
SSL	O
component	O
in	O
large	O
open	O
source	O
projects	O
:	O
</s>
<s>
Mbed	B-Language
TLS	I-Language
is	O
currently	O
available	O
for	O
most	O
Operating	O
Systems	O
including	O
Linux	B-Application
,	O
Microsoft	B-Application
Windows	I-Application
,	O
OS	B-Operating_System
X	I-Operating_System
,	O
OpenWrt	B-Application
,	O
Android	B-Application
,	O
iOS	B-Application
,	O
RISC	B-Operating_System
OS	I-Operating_System
and	O
FreeRTOS	B-Operating_System
.	O
</s>
<s>
Mbed	B-Language
TLS	I-Language
supports	O
a	O
number	O
of	O
different	O
cryptographic	O
algorithms	O
:	O
</s>
<s>
CCM	O
,	O
GCM	O
,	O
NIST	B-Algorithm
Key	I-Algorithm
Wrap	I-Algorithm
,	O
</s>
<s>
RSA	B-Architecture
,	O
Diffie	B-Protocol
–	I-Protocol
Hellman	I-Protocol
key	I-Protocol
exchange	I-Protocol
,	O
</s>
