<s>
blackra1n	B-Operating_System
is	O
a	O
program	O
that	O
jailbreaks	B-Application
versions	O
3.1	O
,	O
3.1.1	O
and	O
3.1.2	O
of	O
Apple	O
's	O
operating	B-General_Concept
system	I-General_Concept
for	O
the	O
iPhone	B-Operating_System
and	O
the	O
iPod	B-Device
Touch	I-Device
,	O
known	O
as	O
iOS	B-Operating_System
.	O
</s>
<s>
The	O
program	O
uses	O
a	O
bug	B-Error_Name
in	O
the	O
USB	B-Protocol
code	O
of	O
the	O
firmware	B-Application
for	O
the	O
iPhone	B-Operating_System
and	O
the	O
iPod	B-Device
Touch	I-Device
,	O
allowing	O
unsigned	O
code	O
to	O
be	O
executed	O
.	O
</s>
<s>
blackra1n	B-Operating_System
uses	O
this	O
exploit	O
to	O
patch	O
the	O
firmware	B-Application
of	O
the	O
iPhone	B-Operating_System
or	O
iPod	B-Device
Touch	I-Device
while	O
in	O
DFU	O
(	O
Device	O
Firmware	B-Application
Upgrade	O
)	O
mode	O
.	O
</s>
<s>
This	O
mode	O
is	O
used	O
when	O
upgrading	O
firmware	B-Application
through	O
iTunes	O
,	O
but	O
also	O
can	O
be	O
activated	O
by	O
the	O
user	O
.	O
</s>
<s>
The	O
program	O
allows	O
users	O
to	O
install	O
the	O
Cydia	B-Device
,	O
Icy	B-Operating_System
(	O
removed	O
in	O
blackra1n	B-Operating_System
RC3	O
)	O
,	O
and	O
Rock	O
package	B-Application
managers	I-Application
.	O
</s>
<s>
These	O
applications	O
allow	O
the	O
user	O
to	O
access	O
tweaks	B-Device
,	O
homebrew	B-Application
applications	O
,	O
the	O
root	B-Application
directory	I-Application
and	O
the	O
file	B-Application
system	I-Application
of	O
the	O
iOS	B-Operating_System
device	O
.	O
</s>
<s>
blackra1n	B-Operating_System
can	O
also	O
perform	O
tethered	B-Application
jailbreaks	I-Application
on	O
the	O
iPod	B-Device
Touch	I-Device
3G	O
and	O
the	O
iPhone	B-Operating_System
3GS	I-Operating_System
,	O
if	O
the	O
devices	O
are	O
running	O
OS	O
3.1.2	O
.	O
</s>
<s>
When	O
iOS	B-Operating_System
3.1.3	O
was	O
released	O
,	O
SpiritJB	O
was	O
released	O
,	O
and	O
provided	O
untethered	O
jailbreaks	B-Application
for	O
both	O
3.1.2	O
and	O
3.1.3	O
.	O
</s>
<s>
blackra1n	B-Operating_System
has	O
been	O
superseded	O
by	O
Spirit	O
by	O
comex	O
.	O
</s>
<s>
Supports	O
iPhone	B-Operating_System
OS	I-Operating_System
version	O
3.1.2	O
on	O
all	O
models	O
of	O
iPhone	B-Operating_System
and	O
iPod	B-Device
Touch	I-Device
.	O
</s>
<s>
RC2	O
October	O
25	O
,	O
2009	O
Fixed	O
iPhone	B-Operating_System
3G	I-Operating_System
issues.Tethered	O
3.1	O
jailbreak	B-Application
for	O
iPod	B-Device
Touch	I-Device
2G	O
and	O
iPhone	B-Operating_System
3GS	I-Operating_System
with	O
updated	O
boot	O
ROM	O
.	O
</s>
<s>
Fixed	O
Icy	B-Operating_System
issues	O
.	O
</s>
<s>
Icy	B-Operating_System
no	O
longer	O
included	O
.	O
</s>
