static struct wpabuf * eap_psk_build_1(struct eap_sm *sm,
struct eap_psk_data *data, u8 id)
{
struct wpabuf *req;
struct eap_psk_hdr_1 *psk;
wpa_printf(MSG_DEBUG, "EAP-PSK: PSK-1 (sending)");
if (random_get_bytes(data->rand_s, EAP_PSK_RAND_LEN)) {
wpa_printf(MSG_ERROR, "EAP-PSK: Failed to get random data");
data->state = FAILURE;
return NULL;
}
wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: RAND_S (server rand)",
data->rand_s, EAP_PSK_RAND_LEN);
req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK,
sizeof(*psk) + data->id_s_len,
EAP_CODE_REQUEST, id);
if (req == NULL) {
wpa_printf(MSG_ERROR, "EAP-PSK: Failed to allocate memory "
"request");
data->state = FAILURE;
return NULL;
}
psk = wpabuf_put(req, sizeof(*psk));
psk->flags = EAP_PSK_FLAGS_SET_T(0); /* T=0 */
os_memcpy(psk->rand_s, data->rand_s, EAP_PSK_RAND_LEN);
wpabuf_put_data(req, data->id_s, data->id_s_len);
return req;
}
static struct wpabuf * eap_psk_process_1(struct eap_psk_data *data,
struct eap_method_ret *ret,
const struct wpabuf *reqData)
{
const struct eap_psk_hdr_1 *hdr1;
struct eap_psk_hdr_2 *hdr2;
struct wpabuf *resp;
u8 *buf, *pos;
size_t buflen, len;
const u8 *cpos;
wpa_printf(MSG_DEBUG, "EAP-PSK: in INIT state");
cpos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, reqData, &len);
hdr1 = (const struct eap_psk_hdr_1 *) cpos;
if (cpos == NULL || len < sizeof(*hdr1)) {
wpa_printf(MSG_INFO, "EAP-PSK: Invalid first message "
"length (%lu; expected %lu or more)",
(unsigned long) len,
(unsigned long) sizeof(*hdr1));
ret->ignore = TRUE;
return NULL;
}
wpa_printf(MSG_DEBUG, "EAP-PSK: Flags=0x%x", hdr1->flags);
if (EAP_PSK_FLAGS_GET_T(hdr1->flags) != 0) {
wpa_printf(MSG_INFO, "EAP-PSK: Unexpected T=%d (expected 0)",
EAP_PSK_FLAGS_GET_T(hdr1->flags));
ret->methodState = METHOD_DONE;
ret->decision = DECISION_FAIL;
return NULL;
}
wpa_hexdump(MSG_DEBUG, "EAP-PSK: RAND_S", hdr1->rand_s,
EAP_PSK_RAND_LEN);
os_free(data->id_s);
data->id_s_len = len - sizeof(*hdr1);
data->id_s = os_malloc(data->id_s_len);
if (data->id_s == NULL) {
wpa_printf(MSG_ERROR, "EAP-PSK: Failed to allocate memory for "
"ID_S (len=%lu)", (unsigned long) data->id_s_len);
ret->ignore = TRUE;
return NULL;
}
os_memcpy(data->id_s, (u8 *) (hdr1 + 1), data->id_s_len);
wpa_hexdump_ascii(MSG_DEBUG, "EAP-PSK: ID_S",
data->id_s, data->id_s_len);
if (os_get_random(data->rand_p, EAP_PSK_RAND_LEN)) {
wpa_printf(MSG_ERROR, "EAP-PSK: Failed to get random data");
ret->ignore = TRUE;
return NULL;
}
resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK,
sizeof(*hdr2) + data->id_p_len, EAP_CODE_RESPONSE,
eap_get_id(reqData));
if (resp == NULL)
return NULL;
hdr2 = wpabuf_put(resp, sizeof(*hdr2));
hdr2->flags = EAP_PSK_FLAGS_SET_T(1); /* T=1 */
os_memcpy(hdr2->rand_s, hdr1->rand_s, EAP_PSK_RAND_LEN);
os_memcpy(hdr2->rand_p, data->rand_p, EAP_PSK_RAND_LEN);
wpabuf_put_data(resp, data->id_p, data->id_p_len);
/* MAC_P = OMAC1-AES-128(AK, ID_P||ID_S||RAND_S||RAND_P) */
buflen = data->id_p_len + data->id_s_len + 2 * EAP_PSK_RAND_LEN;
buf = os_malloc(buflen);
if (buf == NULL) {
wpabuf_free(resp);
return NULL;
}
os_memcpy(buf, data->id_p, data->id_p_len);
pos = buf + data->id_p_len;
os_memcpy(pos, data->id_s, data->id_s_len);
pos += data->id_s_len;
os_memcpy(pos, hdr1->rand_s, EAP_PSK_RAND_LEN);
pos += EAP_PSK_RAND_LEN;
os_memcpy(pos, data->rand_p, EAP_PSK_RAND_LEN);
if (omac1_aes_128(data->ak, buf, buflen, hdr2->mac_p)) {
os_free(buf);
wpabuf_free(resp);
return NULL;
}
os_free(buf);
wpa_hexdump(MSG_DEBUG, "EAP-PSK: RAND_P", hdr2->rand_p,
EAP_PSK_RAND_LEN);
wpa_hexdump(MSG_DEBUG, "EAP-PSK: MAC_P", hdr2->mac_p, EAP_PSK_MAC_LEN);
wpa_hexdump_ascii(MSG_DEBUG, "EAP-PSK: ID_P",
data->id_p, data->id_p_len);
data->state = PSK_MAC_SENT;
return resp;
}
static struct wpabuf * eap_psk_process_3(struct eap_psk_data *data,
struct eap_method_ret *ret,
const struct wpabuf *reqData)
{
const struct eap_psk_hdr_3 *hdr3;
struct eap_psk_hdr_4 *hdr4;
struct wpabuf *resp;
u8 *buf, *rpchannel, nonce[16], *decrypted;
const u8 *pchannel, *tag, *msg;
u8 mac[EAP_PSK_MAC_LEN];
size_t buflen, left, data_len, len, plen;
int failed = 0;
const u8 *pos;
wpa_printf(MSG_DEBUG, "EAP-PSK: in MAC_SENT state");
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK,
reqData, &len);
hdr3 = (const struct eap_psk_hdr_3 *) pos;
if (pos == NULL || len < sizeof(*hdr3)) {
wpa_printf(MSG_INFO, "EAP-PSK: Invalid third message "
"length (%lu; expected %lu or more)",
(unsigned long) len,
(unsigned long) sizeof(*hdr3));
ret->ignore = TRUE;
return NULL;
}
left = len - sizeof(*hdr3);
pchannel = (const u8 *) (hdr3 + 1);
wpa_printf(MSG_DEBUG, "EAP-PSK: Flags=0x%x", hdr3->flags);
if (EAP_PSK_FLAGS_GET_T(hdr3->flags) != 2) {
wpa_printf(MSG_INFO, "EAP-PSK: Unexpected T=%d (expected 2)",
EAP_PSK_FLAGS_GET_T(hdr3->flags));
ret->methodState = METHOD_DONE;
ret->decision = DECISION_FAIL;
return NULL;
}
wpa_hexdump(MSG_DEBUG, "EAP-PSK: RAND_S", hdr3->rand_s,
EAP_PSK_RAND_LEN);
wpa_hexdump(MSG_DEBUG, "EAP-PSK: MAC_S", hdr3->mac_s, EAP_PSK_MAC_LEN);
wpa_hexdump(MSG_DEBUG, "EAP-PSK: PCHANNEL", pchannel, left);
if (left < 4 + 16 + 1) {
wpa_printf(MSG_INFO, "EAP-PSK: Too short PCHANNEL data in "
"third message (len=%lu, expected 21)",
(unsigned long) left);
ret->ignore = TRUE;
return NULL;
}
/* MAC_S = OMAC1-AES-128(AK, ID_S||RAND_P) */
buflen = data->id_s_len + EAP_PSK_RAND_LEN;
buf = os_malloc(buflen);
if (buf == NULL)
return NULL;
os_memcpy(buf, data->id_s, data->id_s_len);
os_memcpy(buf + data->id_s_len, data->rand_p, EAP_PSK_RAND_LEN);
if (omac1_aes_128(data->ak, buf, buflen, mac)) {
os_free(buf);
return NULL;
}
os_free(buf);
if (os_memcmp(mac, hdr3->mac_s, EAP_PSK_MAC_LEN) != 0) {
wpa_printf(MSG_WARNING, "EAP-PSK: Invalid MAC_S in third "
"message");
ret->methodState = METHOD_DONE;
ret->decision = DECISION_FAIL;
return NULL;
}
wpa_printf(MSG_DEBUG, "EAP-PSK: MAC_S verified successfully");
if (eap_psk_derive_keys(data->kdk, data->rand_p, data->tek,
data->msk, data->emsk)) {
ret->methodState = METHOD_DONE;
ret->decision = DECISION_FAIL;
return NULL;
}
wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: TEK", data->tek, EAP_PSK_TEK_LEN);
wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: MSK", data->msk, EAP_MSK_LEN);
wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: EMSK", data->emsk, EAP_EMSK_LEN);
os_memset(nonce, 0, 12);
os_memcpy(nonce + 12, pchannel, 4);
pchannel += 4;
left -= 4;
tag = pchannel;
pchannel += 16;
left -= 16;
msg = pchannel;
wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: PCHANNEL - nonce",
nonce, sizeof(nonce));
wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: PCHANNEL - hdr",
wpabuf_head(reqData), 5);
wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: PCHANNEL - cipher msg", msg, left);
decrypted = os_malloc(left);
if (decrypted == NULL) {
ret->methodState = METHOD_DONE;
ret->decision = DECISION_FAIL;
return NULL;
}
os_memcpy(decrypted, msg, left);
if (aes_128_eax_decrypt(data->tek, nonce, sizeof(nonce),
wpabuf_head(reqData),
sizeof(struct eap_hdr) + 1 +
sizeof(*hdr3) - EAP_PSK_MAC_LEN, decrypted,
left, tag)) {
wpa_printf(MSG_WARNING, "EAP-PSK: PCHANNEL decryption failed");
os_free(decrypted);
return NULL;
}
wpa_hexdump(MSG_DEBUG, "EAP-PSK: Decrypted PCHANNEL message",
decrypted, left);
/* Verify R flag */
switch (decrypted[0] >> 6) {
case EAP_PSK_R_FLAG_CONT:
wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - CONT - unsupported");
failed = 1;
break;
case EAP_PSK_R_FLAG_DONE_SUCCESS:
wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - DONE_SUCCESS");
break;
case EAP_PSK_R_FLAG_DONE_FAILURE:
wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - DONE_FAILURE");
wpa_printf(MSG_INFO, "EAP-PSK: Authentication server rejected "
"authentication");
failed = 1;
break;
}
data_len = 1;
if ((decrypted[0] & EAP_PSK_E_FLAG) && left > 1)
data_len++;
plen = sizeof(*hdr4) + 4 + 16 + data_len;
resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK, plen,
EAP_CODE_RESPONSE, eap_get_id(reqData));
if (resp == NULL) {
os_free(decrypted);
return NULL;
}
hdr4 = wpabuf_put(resp, sizeof(*hdr4));
hdr4->flags = EAP_PSK_FLAGS_SET_T(3); /* T=3 */
os_memcpy(hdr4->rand_s, hdr3->rand_s, EAP_PSK_RAND_LEN);
rpchannel = wpabuf_put(resp, 4 + 16 + data_len);
/* nonce++ */
inc_byte_array(nonce, sizeof(nonce));
os_memcpy(rpchannel, nonce + 12, 4);
if (decrypted[0] & EAP_PSK_E_FLAG) {
wpa_printf(MSG_DEBUG, "EAP-PSK: Unsupported E (Ext) flag");
failed = 1;
rpchannel[4 + 16] = (EAP_PSK_R_FLAG_DONE_FAILURE << 6) |
EAP_PSK_E_FLAG;
if (left > 1) {
/* Add empty EXT_Payload with same EXT_Type */
rpchannel[4 + 16 + 1] = decrypted[1];
}
} else if (failed)
rpchannel[4 + 16] = EAP_PSK_R_FLAG_DONE_FAILURE << 6;
else
rpchannel[4 + 16] = EAP_PSK_R_FLAG_DONE_SUCCESS << 6;
wpa_hexdump(MSG_DEBUG, "EAP-PSK: reply message (plaintext)",
rpchannel + 4 + 16, data_len);
if (aes_128_eax_encrypt(data->tek, nonce, sizeof(nonce),
wpabuf_head(resp),
sizeof(struct eap_hdr) + 1 + sizeof(*hdr4),
rpchannel + 4 + 16, data_len, rpchannel + 4)) {
os_free(decrypted);
wpabuf_free(resp);
return NULL;
}
wpa_hexdump(MSG_DEBUG, "EAP-PSK: reply message (PCHANNEL)",
rpchannel, 4 + 16 + data_len);
wpa_printf(MSG_DEBUG, "EAP-PSK: Completed %ssuccessfully",
failed ? "un" : "");
data->state = PSK_DONE;
ret->methodState = METHOD_DONE;
ret->decision = failed ? DECISION_FAIL : DECISION_UNCOND_SUCC;
os_free(decrypted);
return resp;
}
static struct wpabuf * eap_psk_build_3(struct eap_sm *sm,
struct eap_psk_data *data, u8 id)
{
struct wpabuf *req;
struct eap_psk_hdr_3 *psk;
u8 *buf, *pchannel, nonce[16];
size_t buflen;
wpa_printf(MSG_DEBUG, "EAP-PSK: PSK-3 (sending)");
req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK,
sizeof(*psk) + 4 + 16 + 1, EAP_CODE_REQUEST, id);
if (req == NULL) {
wpa_printf(MSG_ERROR, "EAP-PSK: Failed to allocate memory "
"request");
data->state = FAILURE;
return NULL;
}
psk = wpabuf_put(req, sizeof(*psk));
psk->flags = EAP_PSK_FLAGS_SET_T(2); /* T=2 */
os_memcpy(psk->rand_s, data->rand_s, EAP_PSK_RAND_LEN);
/* MAC_S = OMAC1-AES-128(AK, ID_S||RAND_P) */
buflen = data->id_s_len + EAP_PSK_RAND_LEN;
buf = os_malloc(buflen);
if (buf == NULL)
goto fail;
os_memcpy(buf, data->id_s, data->id_s_len);
os_memcpy(buf + data->id_s_len, data->rand_p, EAP_PSK_RAND_LEN);
if (omac1_aes_128(data->ak, buf, buflen, psk->mac_s))
goto fail;
os_free(buf);
if (eap_psk_derive_keys(data->kdk, data->rand_p, data->tek, data->msk,
data->emsk))
goto fail;
wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: TEK", data->tek, EAP_PSK_TEK_LEN);
wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: MSK", data->msk, EAP_MSK_LEN);
wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: EMSK", data->emsk, EAP_EMSK_LEN);
os_memset(nonce, 0, sizeof(nonce));
pchannel = wpabuf_put(req, 4 + 16 + 1);
os_memcpy(pchannel, nonce + 12, 4);
os_memset(pchannel + 4, 0, 16); /* Tag */
pchannel[4 + 16] = EAP_PSK_R_FLAG_DONE_SUCCESS << 6;
wpa_hexdump(MSG_DEBUG, "EAP-PSK: PCHANNEL (plaintext)",
pchannel, 4 + 16 + 1);
if (aes_128_eax_encrypt(data->tek, nonce, sizeof(nonce),
wpabuf_head(req), 22,
pchannel + 4 + 16, 1, pchannel + 4))
goto fail;
wpa_hexdump(MSG_DEBUG, "EAP-PSK: PCHANNEL (encrypted)",
pchannel, 4 + 16 + 1);
return req;
fail:
wpabuf_free(req);
data->state = FAILURE;
return NULL;
}
