DGNum/hostapd
6
0
Fork 0
Code Issues Pull requests 1 Projects Releases Packages Wiki Activity Actions

PEAP: Explicitly clear temporary keys from memory when using CMK

Browse source 
The case of PEAPv0 with crypto binding did not clear some of the
temporary keys from stack/heap when those keys were not needed anymore.
Clear those explicitly to avoid unnecessary caching of keying material.

Signed-off-by: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2019-02-02 00:01:29 +02:00
parent 4e1cd3468e
commit d05dda61d8
2 changed files with 18 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
src/eap_peer/eap_peap.c
View file

@ -188,7 +188,7 @@ static void eap_peap_deinit(struct eap_sm *sm, void *priv)
os_free(data->session_id); os_free(data->session_id);
wpabuf_free(data->pending_phase2_req); wpabuf_free(data->pending_phase2_req);
wpabuf_free(data->pending_resp); wpabuf_free(data->pending_resp);
os_free(data); bin_clear_free(data, sizeof(*data));
} }
@ -253,7 +253,7 @@ static int eap_peap_derive_cmk(struct eap_sm *sm, struct eap_peap_data *data)
{ {
u8 *tk; u8 *tk;
u8 isk[32], imck[60]; u8 isk[32], imck[60];
int resumed; int resumed, res;
/* /*
* Tunnel key (TK) is the first 60 octets of the key generated by * Tunnel key (TK) is the first 60 octets of the key generated by
@ -292,9 +292,11 @@ static int eap_peap_derive_cmk(struct eap_sm *sm, struct eap_peap_data *data)
* in the end of the label just before ISK; is that just a typo?) * in the end of the label just before ISK; is that just a typo?)
*/ */
wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: TempKey", tk, 40); wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: TempKey", tk, 40);
if (peap_prfplus(data->peap_version, tk, 40, res = peap_prfplus(data->peap_version, tk, 40,
"Inner Methods Compound Keys", "Inner Methods Compound Keys",
isk, sizeof(isk), imck, sizeof(imck)) < 0) isk, sizeof(isk), imck, sizeof(imck));
os_memset(isk, 0, sizeof(isk));
if (res < 0)
return -1; return -1;
wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: IMCK (IPMKj)", wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: IMCK (IPMKj)",
imck, sizeof(imck)); imck, sizeof(imck));
@ -303,6 +305,7 @@ static int eap_peap_derive_cmk(struct eap_sm *sm, struct eap_peap_data *data)
wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: IPMK (S-IPMKj)", data->ipmk, 40); wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: IPMK (S-IPMKj)", data->ipmk, 40);
os_memcpy(data->cmk, imck + 40, 20); os_memcpy(data->cmk, imck + 40, 20);
wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: CMK (CMKj)", data->cmk, 20); wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: CMK (CMKj)", data->cmk, 20);
os_memset(imck, 0, sizeof(imck));
return 0; return 0;
} }
@ -1263,6 +1266,7 @@ static u8 * eap_peap_getKey(struct eap_sm *sm, void *priv, size_t *len)
os_memcpy(key, csk, EAP_TLS_KEY_LEN); os_memcpy(key, csk, EAP_TLS_KEY_LEN);
wpa_hexdump(MSG_DEBUG, "EAP-PEAP: Derived key", wpa_hexdump(MSG_DEBUG, "EAP-PEAP: Derived key",
key, EAP_TLS_KEY_LEN); key, EAP_TLS_KEY_LEN);
os_memset(csk, 0, sizeof(csk));
} else } else
os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN); os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN);

12
src/eap_server/eap_server_peap.c
View file

@ -324,6 +324,7 @@ static int eap_peap_derive_cmk(struct eap_sm *sm, struct eap_peap_data *data)
{ {
u8 *tk; u8 *tk;
u8 isk[32], imck[60]; u8 isk[32], imck[60];
int res;
/* /*
* Tunnel key (TK) is the first 60 octets of the key generated by * Tunnel key (TK) is the first 60 octets of the key generated by
@ -358,9 +359,11 @@ static int eap_peap_derive_cmk(struct eap_sm *sm, struct eap_peap_data *data)
* in the end of the label just before ISK; is that just a typo?) * in the end of the label just before ISK; is that just a typo?)
*/ */
wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: TempKey", tk, 40); wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: TempKey", tk, 40);
if (peap_prfplus(data->peap_version, tk, 40, res = peap_prfplus(data->peap_version, tk, 40,
"Inner Methods Compound Keys", "Inner Methods Compound Keys",
isk, sizeof(isk), imck, sizeof(imck)) < 0) { isk, sizeof(isk), imck, sizeof(imck));
os_memset(isk, 0, sizeof(isk));
if (res < 0) {
os_free(tk); os_free(tk);
return -1; return -1;
} }
@ -373,6 +376,7 @@ static int eap_peap_derive_cmk(struct eap_sm *sm, struct eap_peap_data *data)
wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: IPMK (S-IPMKj)", data->ipmk, 40); wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: IPMK (S-IPMKj)", data->ipmk, 40);
os_memcpy(data->cmk, imck + 40, 20); os_memcpy(data->cmk, imck + 40, 20);
wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: CMK (CMKj)", data->cmk, 20); wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: CMK (CMKj)", data->cmk, 20);
os_memset(imck, 0, sizeof(imck));
return 0; return 0;
} }
@ -1322,6 +1326,8 @@ static u8 * eap_peap_getKey(struct eap_sm *sm, void *priv, size_t *len)
"key"); "key");
} }
os_memset(csk, 0, sizeof(csk));
return eapKeyData; return eapKeyData;
} }