eapol: Handle retransmissions

This commit is contained in:
Denis Kenzior 2017-10-18 20:40:34 -05:00
parent f07164b2ef
commit c93a52c066
1 changed files with 27 additions and 8 deletions

View File

@ -953,12 +953,21 @@ static void eapol_handle_ptk_1_of_4(struct eapol_sm *sm,
}
}
handshake_state_new_snonce(sm->handshake);
/*
* If we're in a state where we have successfully processed Message 3,
* then assume that the new message 1 is a PTK rekey and start a new
* handshake
*/
if (!sm->handshake->have_snonce ||
memcmp(sm->handshake->anonce,
ek->key_nonce, sizeof(ek->key_nonce)) ||
sm->handshake->ptk_complete) {
handshake_state_new_snonce(sm->handshake);
handshake_state_set_anonce(sm->handshake, ek->key_nonce);
handshake_state_set_anonce(sm->handshake, ek->key_nonce);
if (!handshake_state_derive_ptk(sm->handshake))
goto error_unspecified;
if (!handshake_state_derive_ptk(sm->handshake))
goto error_unspecified;
}
if (sm->handshake->akm_suite &
(IE_RSN_AKM_SUITE_FT_OVER_8021X |
@ -1152,6 +1161,15 @@ static void eapol_handle_ptk_3_of_4(struct eapol_sm *sm,
}
}
/*
* If ptk_complete is set, then we are receiving Message 3 again.
* It must be a retransmission, otherwise the anonce wouldn't match
* and we wouldn't get here. Skip processing the rest of the message
* and send our reply. Do not install the keys again.
*/
if (sm->handshake->ptk_complete)
goto retransmit;
/*
* 11.6.6.4: "If a second RSNE is provided in the message, the
* Supplicant uses the pairwise cipher suite specified in the second
@ -1241,6 +1259,7 @@ static void eapol_handle_ptk_3_of_4(struct eapol_sm *sm,
} else
igtk = NULL;
retransmit:
/*
* 802.11-2016, Section 12.7.6.4:
* "b) Verifies the message 3 MIC. If the calculated MIC does not match
@ -1270,6 +1289,9 @@ static void eapol_handle_ptk_3_of_4(struct eapol_sm *sm,
eapol_write(sm, (struct eapol_frame *) step4);
l_free(step4);
if (sm->handshake->ptk_complete)
return;
handshake_state_install_ptk(sm->handshake);
if (gtk)
@ -1506,9 +1528,6 @@ static void eapol_key_handle(struct eapol_sm *sm,
if (!ek->key_mic)
eapol_handle_ptk_1_of_4(sm, ek);
else {
if (sm->handshake->ptk_complete)
goto done;
if (!key_data_len)
goto done;