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Added support for A5/2, A5/3, A5/4. Issue #85

This commit is contained in:
Roman Khassraf 2015-07-17 18:32:22 +02:00
parent c51f12bb4e
commit 4dec540b6e
4 changed files with 66 additions and 27 deletions
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16
grc/decryption/gsm_decryption.xml
View File

@ -3,15 +3,25 @@
<name>Decryption</name>
<key>gsm_decryption</key>
<import>import grgsm</import>
<make>grgsm.decryption($k_c)</make>
<make>grgsm.decryption($k_c, $a5_version)</make>
<param>
<name>Kc session key</name>
<key>k_c</key>
<value>[0,0,0,0,0,0,0,0]</value>
<value>[0,0,0,0,0,0,0,0]</value>
<type>int_vector</type>
</param>
<param>
<name>A5 version</name>
<key>a5_version</key>
<value>1</value>
<type>int</type>
</param>
<check>$a5_version &gt; 0</check>
<check>$a5_version &lt; 5</check>
<sink>
<name>bursts</name>
<type>message</type>
@ -20,5 +30,5 @@
<name>bursts</name>
<type>message</type>
</source>
</block>

11
include/grgsm/decryption/decryption.h
View File

@ -1,14 +1,14 @@
/* -*- c++ -*- */
/*
/*
* @file
* @author Piotr Krysik <ptrkrysik@gmail.com>
* @section LICENSE
*
*
* Gr-gsm is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
*
* Gr-gsm is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
@ -18,7 +18,7 @@
* along with gr-gsm; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*
*
*/
@ -50,8 +50,9 @@ namespace gr {
* class. gsm::decryption::make is the public interface for
* creating new instances.
*/
static sptr make(const std::vector<uint8_t> & k_c);
static sptr make(const std::vector<uint8_t> & k_c, unsigned int a5_version);
virtual void set_k_c(const std::vector<uint8_t> & k_c) = 0;
virtual void set_a5_version(unsigned int a5_version) = 0;
};
} // namespace gsm

57
lib/decryption/decryption_impl.cc
View File

@ -25,6 +25,7 @@
#include <gnuradio/io_signature.h>
#include <grgsm/gsmtap.h>
#include <grgsm/endian.h>
#include <numeric>
#include "decryption_impl.h"
extern "C" {
@ -37,21 +38,24 @@ namespace gr {
namespace gsm {
decryption::sptr
decryption::make(const std::vector<uint8_t> & k_c)
decryption::make(const std::vector<uint8_t> & k_c, unsigned int a5_version)
{
return gnuradio::get_initial_sptr
(new decryption_impl(k_c));
(new decryption_impl(k_c, a5_version));
}
/*
* The private constructor
*/
decryption_impl::decryption_impl(const std::vector<uint8_t> & k_c)
decryption_impl::decryption_impl(const std::vector<uint8_t> & k_c, unsigned int a5_version)
: gr::block("decryption",
gr::io_signature::make(0, 0, 0),
gr::io_signature::make(0, 0, 0))
gr::io_signature::make(0, 0, 0)),
d_k_c_valid(false)
{
set_k_c(k_c);
set_a5_version(a5_version);
validate_k_c();
// std::cout << "Be careful with decryption block - it wasn't tested yet!" << std::endl;
message_port_register_in(pmt::mp("bursts"));
@ -68,29 +72,50 @@ namespace gr {
void decryption_impl::set_k_c(const std::vector<uint8_t> & k_c)
{
if (k_c.size() == 8)
d_k_c = k_c;
}
void decryption_impl::set_a5_version(unsigned int a5_version)
{
d_a5_version = 1;
if (a5_version >= 1 && a5_version <= 4)
{
for (int i=0; i<8; i++)
{
d_k_c[i] = k_c[i];
}
d_a5_version = a5_version;
}
}
void decryption_impl::validate_k_c()
{
if (d_k_c.size() == 0)
{
d_k_c_valid = false;
return;
}
else if ((d_a5_version < 4 && d_k_c.size() != 8) || (d_a5_version == 4 && d_k_c.size() != 16))
{
d_k_c_valid = false;
return;
}
else
{
for (int i=0; i<8; i++)
for (int i=0; i<d_k_c.size(); i++)
{
d_k_c[i] = 0;
if (d_k_c[i] != 0)
{
d_k_c_valid = true;
return;
}
}
}
}
void decryption_impl::decrypt(pmt::pmt_t msg)
{
if(d_k_c[0] == 0 && d_k_c[1] == 0 && d_k_c[2] == 0 && d_k_c[3] == 0 &
d_k_c[4] == 0 && d_k_c[5] == 0 && d_k_c[6] == 0 && d_k_c[7] == 0)
if (!d_k_c_valid)
{
message_port_pub(pmt::mp("bursts"), msg);
} else
}
else
{
uint8_t decrypted_data[BURST_SIZE];
uint8_t keystream[114];
@ -104,10 +129,10 @@ namespace gr {
if(uplink_burst){
//process uplink burst
osmo_a5(1, d_k_c, frame_number, NULL, keystream);
osmo_a5(d_a5_version, &d_k_c[0], frame_number, NULL, keystream);
} else {
//process downlink burst
osmo_a5(1, d_k_c, frame_number, keystream, NULL);
osmo_a5(d_a5_version, &d_k_c[0], frame_number, keystream, NULL);
}
/* guard bits */
for (int i = 0; i < 3; i++) {

9
lib/decryption/decryption_impl.h
View File

@ -30,13 +30,16 @@ namespace gr {
class decryption_impl : public decryption
{
private:
// std::vector<uint8_t> d_k_c;
uint8_t d_k_c[8];
std::vector<uint8_t> d_k_c;
bool d_k_c_valid;
uint8_t d_a5_version;
void decrypt(pmt::pmt_t msg);
void validate_k_c();
public:
decryption_impl(const std::vector<uint8_t> & k_c);
decryption_impl(const std::vector<uint8_t> & k_c, unsigned int a5_version);
~decryption_impl();
virtual void set_k_c(const std::vector<uint8_t> & k_c);
virtual void set_a5_version(unsigned int a5_version);
};
} // namespace gsm
} // namespace gr