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libosmogsm: Allow auth API caller to specify RES length 

There are 3G algorithms which support different lengths of RES values
(4, 8, 16 byte).  For MILENAGE, we never really had to bother, as
the 4-byte RES is simply the first 4 bytes of the 8-byte RES.

However, for TUAK, the expected RES length is an input parameter to
the Keccak crypto functions, so the result of all parameters (including
CK, IK, ...) will be completely different for RES length 4 than RES
length 8.

So let's permit the caller of the osmocom auth API to specify the
requested RES length via the osmo_auth_vector.res_len parameter.

For backwards compatibility of callers of the old osmo_auth_gen_vec/
osmo_auth_gen_vec_auts API: Always force the res_len to 8 in this case,
which was the hard-coded length before this patch.

Change-Id: Ic662843fbe8b5c58e4af39ea630ad5ac13fd6bef
This commit is contained in:
Harald Welte 2023-05-30 15:01:38 +02:00 committed by laforge
parent 0ea9b91e0f
commit d8e5309527
5 changed files with 62 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/osmocom/crypt/auth.h
View File

@ -91,7 +91,7 @@ struct osmo_auth_vector {
uint8_t ck[OSMO_A5_MAX_KEY_LEN_BYTES]; /*!< ciphering key */
uint8_t ik[OSMO_A5_MAX_KEY_LEN_BYTES]; /*!< integrity key */
uint8_t res[16]; /*!< authentication result */
uint8_t res_len; /*!< length (in bytes) of res: 8..16 bytes */
uint8_t res_len; /*!< length (in bytes) of res: 4..16 bytes */
uint8_t kc[8]; /*!< Kc for GSM encryption (A5) */
uint8_t sres[4]; /*!< authentication result for GSM */
uint32_t auth_types; /*!< bitmask of OSMO_AUTH_TYPE_* */

28
src/gsm/auth_core.c
View File

@ -167,7 +167,7 @@ int osmo_auth_3g_from_2g(struct osmo_auth_vector *vec)
}
/*! Generate authentication vector
* \param[out] vec Generated authentication vector
* \param[out] vec Generated authentication vector. See below!
* \param[in] aud Subscriber-specific key material
* \param[in] _rand Random challenge to be used
* \returns 0 on success, negative error on failure
@ -176,7 +176,12 @@ int osmo_auth_3g_from_2g(struct osmo_auth_vector *vec)
* computing authentication triples/quintuples based on the permanent
* subscriber data and a random value. The result is what is forwarded
* by the AUC via HLR and VLR to the MSC which will then be able to
* invoke authentication with the MS
* invoke authentication with the MS.
*
* Contrary to the older osmo_auth_gen_vec(), the caller must specify
* the desired RES length in the vec->res_len field prior to calling
* this function. The requested length must match the capabilities of
* the chosen algorithm (e.g. 4/8 for MILENAGE).
*/
int osmo_auth_gen_vec2(struct osmo_auth_vector *vec,
struct osmo_sub_auth_data2 *aud,
@ -216,6 +221,12 @@ int osmo_auth_gen_vec(struct osmo_auth_vector *vec,
struct osmo_sub_auth_data2 aud2;
int rc;
if (aud->type == OSMO_AUTH_TYPE_UMTS) {
/* old API callers are not expected to initialize this struct field,
* and always expect an 8-byte RES value */
vec->res_len = 8;
}
rc = auth_data2auth_data2(&aud2, aud);
if (rc < 0)
return rc;
@ -228,7 +239,7 @@ int osmo_auth_gen_vec(struct osmo_auth_vector *vec,
}
/*! Generate authentication vector and re-sync sequence
* \param[out] vec Generated authentication vector
* \param[out] vec Generated authentication vector. See below!
* \param[in] aud Subscriber-specific key material
* \param[in] auts AUTS value sent by the SIM/MS
* \param[in] rand_auts RAND value sent by the SIM/MS
@ -241,6 +252,11 @@ int osmo_auth_gen_vec(struct osmo_auth_vector *vec,
* AUTS and RAND values returned by the SIM/MS. This special variant is
* needed if the sequence numbers between MS and AUC have for some
* reason become different.
*
* Contrary to the older osmo_auth_gen_vec_auts(), the caller must specify
* the desired RES length in the vec->res_len field prior to calling
* this function. The requested length must match the capabilities of
* the chosen algorithm (e.g. 4/8 for MILENAGE).
*/
int osmo_auth_gen_vec_auts2(struct osmo_auth_vector *vec,
struct osmo_sub_auth_data2 *aud,
@ -285,6 +301,12 @@ int osmo_auth_gen_vec_auts(struct osmo_auth_vector *vec,
struct osmo_sub_auth_data2 aud2;
int rc;
if (aud->type == OSMO_AUTH_TYPE_UMTS) {
/* old API callers are not expected to initialize this struct field,
* and always expect an 8-byte RES value */
vec->res_len = 8;
}
rc = auth_data2auth_data2(&aud2, aud);
if (rc < 0)
return rc;

4
src/gsm/auth_milenage.c
View File

@ -62,6 +62,8 @@ static int milenage_gen_vec(struct osmo_auth_vector *vec,
return -EINVAL;
if (aud->u.umts.opc_len != 16)
return -EINVAL;
if (vec->res_len != 4 && vec->res_len != 8)
return -EINVAL;
opc = gen_opc_if_needed(aud, gen_opc);
if (!opc)
@ -135,7 +137,7 @@ static int milenage_gen_vec(struct osmo_auth_vector *vec,
milenage_generate(opc, aud->u.umts.amf, aud->u.umts.k,
sqn, _rand,
vec->autn, vec->ik, vec->ck, vec->res, &res_len);
vec->res_len = res_len;
rc = gsm_milenage(opc, aud->u.umts.k, _rand, vec->sres, vec->kc);
if (rc < 0)
return rc;

38
tests/osmo-auc-gen/osmo-auc-gen_test.ok
View File

@ -1,7 +1,7 @@
> osmo-auc-gen -3 -a milenage -r 6a61050765caa32c90371370e5d6dc2d -k 1dc4f974325cce611e54f516dc1fec56 -o 2a48162ff3edca4adf0b7b5e527d6c16 -s 0
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 6a61050765caa32c90371370e5d6dc2d
@ -18,7 +18,7 @@ IND: 0
> osmo-auc-gen -3 -a milenage -r 6a61050765caa32c90371370e5d6dc2d -k 1dc4f974325cce611e54f516dc1fec56 -o 2a48162ff3edca4adf0b7b5e527d6c16 -s 1
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 6a61050765caa32c90371370e5d6dc2d
@ -35,7 +35,7 @@ IND: 1
> osmo-auc-gen -3 -a milenage -r 6a61050765caa32c90371370e5d6dc2d -k 1dc4f974325cce611e54f516dc1fec56 -o 2a48162ff3edca4adf0b7b5e527d6c16 -s 23
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 6a61050765caa32c90371370e5d6dc2d
@ -52,7 +52,7 @@ IND: 23
> osmo-auc-gen -3 -a milenage -r 1dc4f974325cce611e54f516dc1fec56 -k 2a48162ff3edca4adf0b7b5e527d6c16 -o 6a61050765caa32c90371370e5d6dc2d -s 42
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 1dc4f974325cce611e54f516dc1fec56
@ -69,7 +69,7 @@ IND: 10
> osmo-auc-gen -3 -a milenage -r 2a48162ff3edca4adf0b7b5e527d6c16 -k 6a61050765caa32c90371370e5d6dc2d -o 1dc4f974325cce611e54f516dc1fec56 -s 99
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 2a48162ff3edca4adf0b7b5e527d6c16
@ -86,7 +86,7 @@ IND: 3
> osmo-auc-gen -3 -a milenage -r 6a61050765caa32c90371370e5d6dc2d -k 2a48162ff3edca4adf0b7b5e527d6c16 -o 1dc4f974325cce611e54f516dc1fec56 -s 281474976710655
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 6a61050765caa32c90371370e5d6dc2d
@ -103,7 +103,7 @@ IND: 31
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 39fa2f4e3d523d8619a73b4f65c3e14d
@ -121,7 +121,7 @@ SQN.MS: 23
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind 5
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 39fa2f4e3d523d8619a73b4f65c3e14d
@ -139,7 +139,7 @@ SQN.MS: 23
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind 23
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 39fa2f4e3d523d8619a73b4f65c3e14d
@ -157,7 +157,7 @@ SQN.MS: 23
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind 31
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 39fa2f4e3d523d8619a73b4f65c3e14d
@ -175,7 +175,7 @@ SQN.MS: 23
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 0
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 39fa2f4e3d523d8619a73b4f65c3e14d
@ -193,7 +193,7 @@ SQN.MS: 23
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 1
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 39fa2f4e3d523d8619a73b4f65c3e14d
@ -211,7 +211,7 @@ SQN.MS: 23
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 1 --ind 1
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 39fa2f4e3d523d8619a73b4f65c3e14d
@ -229,7 +229,7 @@ SQN.MS: 23
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 8
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 39fa2f4e3d523d8619a73b4f65c3e14d
@ -247,7 +247,7 @@ SQN.MS: 23
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 8 --ind 1
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
RAND: 39fa2f4e3d523d8619a73b4f65c3e14d
@ -266,27 +266,27 @@ SQN.MS: 23
expecting error:
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind -1
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
expecting error:
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind 32
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
expecting error:
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind 42
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
expecting error:
> osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 0 --ind 1
osmo-auc-gen (C) 2011-2012 by Harald Welte
osmo-auc-gen (C) 2011-2023 by Harald Welte
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY

18
utils/osmo-auc-gen.c
View File

@ -98,6 +98,7 @@ static void help(void)
"-s --sqn\tSpecify SQN (only for 3G)\n"
"-i --ind\tSpecify IND slot for new SQN after AUTS (only for 3G)\n"
"-l --ind-len\tSpecify IND bit length (default=5) (only for 3G)\n"
"-L --res-len\tSpecify RES byte length (default=8) (only for 3G)\n"
"-A --auts\tSpecify AUTS (only for 3G)\n"
"-r --rand\tSpecify random value\n"
"-I --ipsec\tOutput in triplets.dat format for strongswan\n");
@ -123,10 +124,12 @@ int main(int argc, char **argv)
int fmt_triplets_dat = 0;
uint64_t ind_mask = 0;
printf("osmo-auc-gen (C) 2011-2012 by Harald Welte\n");
printf("osmo-auc-gen (C) 2011-2023 by Harald Welte\n");
printf("This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY\n\n");
memset(_auts, 0, sizeof(_auts));
memset(vec, 0, sizeof(*vec));
vec->res_len = 8; /* default */
while (1) {
int c;
@ -141,6 +144,7 @@ int main(int argc, char **argv)
{ "sqn", 1, 0, 's' },
{ "ind", 1, 0, 'i' },
{ "ind-len", 1, 0, 'l' },
{ "res-len", 1, 0, 'L' },
{ "rand", 1, 0, 'r' },
{ "auts", 1, 0, 'A' },
{ "help", 0, 0, 'h' },
@ -149,7 +153,7 @@ int main(int argc, char **argv)
rc = 0;
c = getopt_long(argc, argv, "23a:k:o:f:s:i:l:r:hO:A:I", long_options,
c = getopt_long(argc, argv, "23a:k:o:f:s:i:l:L:r:hO:A:I", long_options,
&option_index);
if (c == -1)
@ -265,6 +269,14 @@ int main(int argc, char **argv)
}
test_aud.u.umts.ind_bitlen = atoi(optarg);
break;
case 'L':
rc = atoi(optarg);
if (rc != 4 && rc != 8 && rc != 16) {
fprintf(stderr, "Invalid RES length %u\n", rc);
exit(2);
}
vec->res_len = rc;
break;
case 'r':
rc = osmo_hexparse(optarg, _rand, sizeof(_rand));
if (rc != sizeof(_rand)) {
@ -313,8 +325,6 @@ int main(int argc, char **argv)
exit(2);
}
memset(vec, 0, sizeof(*vec));
if (test_aud.type == OSMO_AUTH_TYPE_UMTS) {
uint64_t seq_1 = 1LL << test_aud.u.umts.ind_bitlen;
ind_mask = seq_1 - 1;