Implementations of comp128v1, comp128v2, comp128v3 algorithms. More...

#include <string.h>
#include <stdint.h>
#include <stdbool.h>

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Functions
void	comp128v1 (uint8_t sres[static 4], uint8_t kc[static 8], uint8_t const ki[static 16], uint8_t const rand[static 16])
	Calculate comp128v1 sres and kc from ki and rand. More...

void	comp128v23 (uint8_t sres[static 4], uint8_t kc[static 8], uint8_t const ki[static 16], uint8_t const rand[static 16], bool v2)
	Calculate comp128v2 or comp128v3 sres and kc from ki and rand. More...

Detailed Description

Implementations of comp128v1, comp128v2, comp128v3 algorithms.

Id: 72c18b820b806aa608f9628de94195f5fc081ba4

Note: The above GPL license only applies to comp128v1, the license for comp128v2 and comp128v3 is unknown.

Copyright: 2013 The FreeRADIUS server project; 2013 Hacking projects [http://www.hackingprojects.net/]; 2009 Sylvain Munaut (tnt@2.nosp@m.46tN.nosp@m.t.com)

Definition in file comp128.h.

Function Documentation

◆ comp128v1()

void comp128v1	(	uint8_t	sres[static 4],
		uint8_t	kc[static 8],
		uint8_t const	ki[static 16],
		uint8_t const	rand[static 16]
	)

Calculate comp128v1 sres and kc from ki and rand.

This code derived from a leaked document from the GSM standards. Some missing pieces were filled in by reverse-engineering a working SIM. We have verified that this is the correct COMP128 algorithm.

The first page of the document identifies it as Technical Information: GSM System Security Study. 10-1617-01, 10th June 1988. The bottom of the title page is marked Racal Research Ltd. Worton Drive, Worton Grange Industrial Estate, Reading, Berks. RG2 0SB, England. Telephone: Reading (0734) 868601 Telex: 847152 The relevant bits are in Part I, Section 20 (pages 66–67). Enjoy!

Note: There are three typos in the spec (discovered by reverse-engineering). First, "z = (2 * x[n] + x[n]) mod 2^(9-j)" should clearly read "z = (2 * x[m] + x[n]) mod 2^(9-j)". Second, the "k" loop in the "Form bits from bytes" section is severely botched: the k index should run only from 0 to 3, and clearly the range on "the (8-k)th bit of byte j" is also off (should be 0..7, not 1..8, to be consistent with the subsequent section). Third, SRES is taken from the first 8 nibbles of x[], not the last 8 as claimed in the document. (And the document doesn't specify how Kc is derived, but that was also easily discovered with reverse engineering.) All of these typos have been corrected in the following code.

Parameters

[out]	sres	4 byte value derived from ki and rand.
[out]	kc	8 byte value derived from ki and rand.
[in]	ki	known only by the SIM and AuC (us in this case).
[in]	rand	16 bytes of randomness.

Definition at line 241 of file comp128.c.

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◆ comp128v23()

void comp128v23	(	uint8_t	sres[static 4],
		uint8_t	kc[static 8],
		uint8_t const	ki[static 16],
		uint8_t const	rand[static 16],
		bool	v2
	)

Calculate comp128v2 or comp128v3 sres and kc from ki and rand.