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[sim-auth] Parse auth response according to TS 31.102
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@monich
monich committed May 30, 2021
1 parent d7e7403 commit 97b5fcb
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Showing 4 changed files with 233 additions and 87 deletions.
34 changes: 19 additions & 15 deletions ofono/src/sim-auth.c
View file
Expand Up @@ -208,14 +208,10 @@ static void handle_umts(struct ofono_sim_auth *sa, const uint8_t *resp,
DBusMessage *reply = NULL;
DBusMessageIter iter;
DBusMessageIter dict;
const uint8_t *res = NULL;
const uint8_t *ck = NULL;
const uint8_t *ik = NULL;
const uint8_t *auts = NULL;
const uint8_t *kc = NULL;
struct data_block res, ck, ik, auts, sres, kc;

if (!sim_parse_umts_authenticate(resp, len, &res, &ck, &ik,
&auts, &kc))
&auts, &sres, &kc))
goto umts_end;

reply = dbus_message_new_method_return(sa->pending->msg);
Expand All @@ -225,15 +221,23 @@ static void handle_umts(struct ofono_sim_auth *sa, const uint8_t *resp,
dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY,
"{say}", &dict);

if (auts) {
append_dict_byte_array(&dict, "AUTS", auts, 14);
} else {
append_dict_byte_array(&dict, "RES", res, 8);
append_dict_byte_array(&dict, "CK", ck, 16);
append_dict_byte_array(&dict, "IK", ik, 16);
if (kc)
append_dict_byte_array(&dict, "Kc", kc, 8);
}
if (auts.data)
append_dict_byte_array(&dict, "AUTS", auts.data, auts.len);

if (sres.data)
append_dict_byte_array(&dict, "SRES", sres.data, sres.len);

if (res.data)
append_dict_byte_array(&dict, "RES", res.data, res.len);

if (ck.data)
append_dict_byte_array(&dict, "CK", ck.data, ck.len);

if (ik.data)
append_dict_byte_array(&dict, "IK", ik.data, ik.len);

if (kc.data)
append_dict_byte_array(&dict, "Kc", kc.data, kc.len);

dbus_message_iter_close_container(&iter, &dict);

Expand Down
148 changes: 108 additions & 40 deletions ofono/src/simutil.c
View file
Expand Up @@ -1668,67 +1668,135 @@ int sim_build_gsm_authenticate(unsigned char *buffer, int len,
return build_authenticate(buffer, rand, NULL);
}

gboolean sim_parse_umts_authenticate(const unsigned char *buffer,
int len, const unsigned char **res, const unsigned char **ck,
const unsigned char **ik, const unsigned char **auts,
const unsigned char **kc)
gboolean sim_parse_umts_authenticate(const unsigned char *buffer, int len,
struct data_block *res, struct data_block *ck,
struct data_block *ik, struct data_block *auts,
struct data_block *sres, struct data_block *kc)
{
if (len < 16 || !buffer)
const unsigned char *ptr = buffer;
const unsigned char *end = ptr + len;
unsigned int l;

if (!buffer || len < 2)
return FALSE;

switch (buffer[0]) {
memset(res, 0, sizeof(*res));
memset(ck, 0, sizeof(*ck));
memset(ik, 0, sizeof(*ik));
memset(kc, 0, sizeof(*kc));
memset(auts, 0, sizeof(*auts));
memset(sres, 0, sizeof(*sres));

/*
* TS 31.102
* 7.1.2.1 GSM/3G security context
*/
switch (*ptr++) {
case 0xdb:
/* 'DB' + '08' + RES(16) + '10' + CK(32) + '10' + IK(32) = 43 */
if (len < 43)
goto umts_end;
/*
* Response parameters/data, case 1, 3G security context,
* command successful:
*
* "Successful 3G authentication" tag = 'DB'
* 'DB' + L3 + RES(L3) + L4 + CK(L4) + L5 + IK(L5) + 8 + Kc(8)
*/
l = *ptr++; /* L3 */
if ((ptr + l) > end)
return FALSE;

/* success */
if (buffer[1] != 0x08)
goto umts_end;
res->data = ptr;
res->len = l;
ptr += l;

*res = buffer + 2;
if (ptr == end)
return FALSE;

if (buffer[10] != 0x10)
goto umts_end;
l = *ptr++; /* L4 */
if ((ptr + l) > end)
return FALSE;

*ck = buffer + 11;
ck->data = ptr;
ck->len = l;
ptr += l;

if (buffer[27] != 0x10)
goto umts_end;
if (ptr == end)
return FALSE;

*ik = buffer + 28;
l = *ptr++; /* L5 */
if ((ptr + l) > end)
return FALSE;

if (len >= 53 && kc) {
if (buffer[44] != 0x08)
goto umts_end;
ik->data = ptr;
ik->len = l;
ptr += l;

*kc = buffer + 45;
} else {
*kc = NULL;
if (ptr < end) {
l = *ptr++;
if (l != 8 || (ptr + l) != end)
return FALSE;

kc->data = ptr;
kc->len = l;
ptr += l;
}

*auts = NULL;
return TRUE;

break;
case 0xdc:
/* 'DC' + '0E' + AUTS(14) = 16 */
if (len < 16)
goto umts_end;
/*
* Response parameters/data, case 2, 3G security context,
* synchronisation failure:
*
* "Synchronisation failure" tag = 'DC'
* 'DC' + L1 + AUTS(L1)
*/
l = *ptr++; /* L1 */
if ((ptr + l) > end)
return FALSE;

/* sync error */
if (buffer[1] != 0x0e)
goto umts_end;
auts->data = ptr;
auts->len = l;
ptr += l;

*auts = buffer + 2;
if (ptr != end)
return FALSE;

break;
default:
goto umts_end;
}
return TRUE;

return TRUE;
case 0x04:
/*
* Response parameters/data, case 3, GSM security context,
* command successful:
*
* 4 + SRES(4) + 8 + Kc(8)
*/
l = 4; /* Already skipped this one */
if ((ptr + l) > end)
return FALSE;

sres->data = ptr;
sres->len = l;
ptr += l;

if (ptr == end)
return FALSE;

l = *ptr++; /* 8 */
if (l != 8 || (ptr + l) > end)
return FALSE;

umts_end:
kc->data = ptr;
kc->len = l;
ptr += l;

if (ptr != end)
return FALSE;

return TRUE;

default:
break;
}
return FALSE;
}

Expand Down
13 changes: 9 additions & 4 deletions ofono/src/simutil.h
View file
Expand Up @@ -371,6 +371,11 @@ struct comprehension_tlv_builder {
struct ber_tlv_builder *parent;
};

struct data_block {
const unsigned char *data;
unsigned int len;
};

void simple_tlv_iter_init(struct simple_tlv_iter *iter,
const unsigned char *pdu, unsigned int len);
gboolean simple_tlv_iter_next(struct simple_tlv_iter *iter);
Expand Down Expand Up @@ -526,10 +531,10 @@ int sim_build_umts_authenticate(unsigned char *buffer, int len,
int sim_build_gsm_authenticate(unsigned char *buffer, int len,
const unsigned char *rand);

gboolean sim_parse_umts_authenticate(const unsigned char *buffer,
int len, const unsigned char **res, const unsigned char **ck,
const unsigned char **ik, const unsigned char **auts,
const unsigned char **kc);
gboolean sim_parse_umts_authenticate(const unsigned char *buffer, int len,
struct data_block *res, struct data_block *ck,
struct data_block *ik, struct data_block *auts,
struct data_block *sres, struct data_block *kc);

gboolean sim_parse_gsm_authenticate(const unsigned char *buffer, int len,
const unsigned char **sres, const unsigned char **kc);

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