eap-aka: Memzero secrets after use

This commit is contained in:
Andrew Zaborowski 2019-03-19 01:25:25 +01:00 committed by Denis Kenzior
parent 28840b29a8
commit b1317d3984
1 changed files with 31 additions and 13 deletions

View File

@ -107,6 +107,16 @@ struct eap_aka_handle {
unsigned int auth_watch;
};
static void eap_aka_clear_secrets(struct eap_aka_handle *aka)
{
explicit_bzero(aka->mk, sizeof(aka->mk));
explicit_bzero(aka->k_encr, sizeof(aka->k_encr));
explicit_bzero(aka->k_aut, sizeof(aka->k_aut));
explicit_bzero(aka->k_re, sizeof(aka->k_re));
explicit_bzero(aka->msk, sizeof(aka->msk));
explicit_bzero(aka->emsk, sizeof(aka->emsk));
}
static void eap_aka_free(struct eap_state *eap)
{
struct eap_aka_handle *aka = eap_get_data(eap);
@ -114,6 +124,8 @@ static void eap_aka_free(struct eap_state *eap)
if (aka->auth)
sim_auth_unregistered_watch_remove(aka->auth, aka->auth_watch);
eap_aka_clear_secrets(aka);
l_free(aka->identity);
l_free(aka->kdf_in);
l_free(aka);
@ -160,12 +172,9 @@ static void check_milenage_cb(const uint8_t *res, const uint8_t *ck,
struct eap_state *eap = data;
struct eap_aka_handle *aka = eap_get_data(eap);
uint8_t prng_buf[160];
size_t resp_len = aka->protected ? 44 : 40;
uint8_t response[resp_len + 4];
uint8_t *pos = response;
uint8_t ik_p[EAP_AKA_IK_LEN];
uint8_t ck_p[EAP_AKA_CK_LEN];
if (auts) {
/*
@ -190,6 +199,10 @@ static void check_milenage_cb(const uint8_t *res, const uint8_t *ck,
goto chal_error;
if (aka->type == EAP_TYPE_AKA_PRIME) {
bool r;
uint8_t ik_p[EAP_AKA_IK_LEN];
uint8_t ck_p[EAP_AKA_CK_LEN];
if (!eap_aka_derive_primes(ck, ik, aka->autn,
(uint8_t *)aka->kdf_in, strlen(aka->kdf_in),
ck_p, ik_p)) {
@ -197,12 +210,19 @@ static void check_milenage_cb(const uint8_t *res, const uint8_t *ck,
goto chal_fatal;
}
if (!eap_aka_prf_prime(ik_p, ck_p, aka->identity, aka->k_encr,
aka->k_aut, aka->k_re, aka->msk, aka->emsk)) {
r = eap_aka_prf_prime(ik_p, ck_p, aka->identity, aka->k_encr,
aka->k_aut, aka->k_re, aka->msk, aka->emsk);
explicit_bzero(ik_p, sizeof(ik_p));
explicit_bzero(ck_p, sizeof(ck_p));
if (!r) {
l_error("could not derive encryption keys");
goto chal_fatal;
}
} else {
uint8_t prng_buf[160];
bool r;
if (!derive_aka_mk(aka->identity, ik, ck, aka->mk)) {
l_error("error deriving MK");
goto chal_fatal;
@ -210,8 +230,11 @@ static void check_milenage_cb(const uint8_t *res, const uint8_t *ck,
eap_sim_fips_prf(aka->mk, 20, prng_buf, 160);
if (!eap_sim_get_encryption_keys(prng_buf, aka->k_encr,
aka->k_aut, aka->msk, aka->emsk)) {
r = eap_sim_get_encryption_keys(prng_buf, aka->k_encr,
aka->k_aut, aka->msk, aka->emsk);
explicit_bzero(prng_buf, sizeof(prng_buf));
if (!r) {
l_error("could not derive encryption keys");
goto chal_fatal;
}
@ -695,12 +718,7 @@ static bool eap_aka_reset_state(struct eap_state *eap)
l_free(aka->chal_pkt);
aka->chal_pkt = NULL;
memset(aka->mk, 0, sizeof(aka->mk));
memset(aka->k_encr, 0, sizeof(aka->k_encr));
memset(aka->k_aut, 0, sizeof(aka->k_aut));
memset(aka->msk, 0, sizeof(aka->msk));
memset(aka->emsk, 0, sizeof(aka->emsk));
memset(aka->k_re, 0, sizeof(aka->k_re));
eap_aka_clear_secrets(aka);
memset(aka->autn, 0, sizeof(aka->autn));
return true;