eap-tls: Migrate to eap-tls-common framework
The conversion transitions EAP-TLS implementation to use a common Phase 1 implementation shared among all TLS based EAP methods.
This commit is contained in:
Tim Kourt
Denis Kenzior
parent
645b72be06
commit
aafa4d50bb
526
src/eap-tls.c
526
src/eap-tls.c
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@ -2,7 +2,7 @@
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*
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* Wireless daemon for Linux
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*
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* Copyright (C) 2013-2014 Intel Corporation. All rights reserved.
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* Copyright (C) 2013-2018 Intel Corporation. All rights reserved.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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@ -29,503 +29,63 @@
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#include <errno.h>
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#include <ell/ell.h>
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#include "eap.h"
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#include "eap-private.h"
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#include "src/eap.h"
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#include "src/eap-private.h"
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#include "src/eap-tls-common.h"
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struct eap_tls_state {
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char *ca_cert;
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char *client_cert;
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char *client_key;
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char *passphrase;
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struct l_tls *tls;
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uint8_t *rx_pkt_buf;
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size_t rx_pkt_received, rx_pkt_len;
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uint8_t *tx_pkt_buf;
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size_t tx_pkt_len, tx_pkt_capacity, tx_pkt_offset;
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bool completed;
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};
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static void __eap_tls_reset_state(struct eap_tls_state *tls)
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static bool eap_tls_tunnel_ready(struct eap_state *eap,
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const char *peer_identity)
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{
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tls->completed = false;
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l_free(tls->rx_pkt_buf);
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tls->rx_pkt_buf = NULL;
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tls->rx_pkt_received = 0;
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tls->rx_pkt_len = 0;
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l_free(tls->tx_pkt_buf);
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tls->tx_pkt_buf = NULL;
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tls->tx_pkt_capacity = 0;
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tls->tx_pkt_len = 0;
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tls->tx_pkt_offset = 0;
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if (tls->tls) {
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l_tls_free(tls->tls);
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tls->tls = NULL;
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}
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}
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static bool eap_tls_reset_state(struct eap_state *eap)
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{
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struct eap_tls_state *tls = eap_get_data(eap);
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__eap_tls_reset_state(tls);
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return true;
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}
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static void eap_tls_free(struct eap_state *eap)
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{
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struct eap_tls_state *tls = eap_get_data(eap);
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__eap_tls_reset_state(tls);
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eap_set_data(eap, NULL);
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l_free(tls->ca_cert);
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l_free(tls->client_cert);
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l_free(tls->client_key);
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if (tls->passphrase) {
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memset(tls->passphrase, 0, strlen(tls->passphrase));
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l_free(tls->passphrase);
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}
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l_free(tls);
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}
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#define EAP_TLS_RESPONSE_HEADER_LEN 10
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#define EAP_TLS_FLAG_L (1 << 7)
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#define EAP_TLS_FLAG_M (1 << 6)
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#define EAP_TLS_FLAG_S (1 << 5)
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#define EAP_TLS_FLAG_LM_MASK \
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(EAP_TLS_FLAG_L | EAP_TLS_FLAG_M)
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static uint8_t *eap_tls_tx_buf_reserve(struct eap_tls_state *tls, size_t size)
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{
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int offset = tls->tx_pkt_offset + tls->tx_pkt_len;
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size_t end_offset = offset + size;
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tls->tx_pkt_len += size;
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if (end_offset > tls->tx_pkt_capacity) {
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tls->tx_pkt_capacity = end_offset + 1024;
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tls->tx_pkt_buf =
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l_realloc(tls->tx_pkt_buf, tls->tx_pkt_capacity);
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}
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return tls->tx_pkt_buf + offset;
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}
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static void eap_tls_tx_cb(const uint8_t *data, size_t len, void *user_data)
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{
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struct eap_state *eap = user_data;
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struct eap_tls_state *tls = eap_get_data(eap);
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memcpy(eap_tls_tx_buf_reserve(tls, len), data, len);
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}
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static void eap_tls_data_cb(const uint8_t *data, size_t len, void *user_data)
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{
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/* This should never be called */
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}
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static void eap_tls_ready_cb(const char *peer_identity, void *user_data)
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{
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struct eap_state *eap = user_data;
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struct eap_tls_state *tls = eap_get_data(eap);
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uint8_t msk_emsk[128];
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uint8_t iv[64];
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/* TODO: if we have a CA certificate require non-NULL peer_identity */
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eap_method_success(eap);
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tls->completed = true;
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eap_start_complete_timeout(eap);
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eap_tls_common_set_completed(eap);
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/* MSK, EMSK and IV derivation */
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l_tls_prf_get_bytes(tls->tls, true,
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"client EAP encryption", msk_emsk, 128);
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l_tls_prf_get_bytes(tls->tls, false,
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"client EAP encryption", iv, 64);
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eap_tls_common_tunnel_prf_get_bytes(eap, true, "client EAP encryption",
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msk_emsk, 128);
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eap_tls_common_tunnel_prf_get_bytes(eap, false, "client EAP encryption",
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iv, 64);
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eap_set_key_material(eap, msk_emsk + 0, 64, msk_emsk + 64, 64, iv, 64);
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eap_tls_common_send_empty_response(eap);
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return true;
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}
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static void eap_tls_disconnect_cb(enum l_tls_alert_desc reason,
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bool remote, void *user_data)
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static int eap_tls_settings_check(struct l_settings *settings,
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struct l_queue *secrets,
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const char *prefix,
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struct l_queue **out_missing)
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{
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struct eap_state *eap = user_data;
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struct eap_tls_state *tls = eap_get_data(eap);
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char tls_prefix[72];
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tls->completed = true;
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snprintf(tls_prefix, sizeof(tls_prefix), "%sTLS-", prefix);
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return eap_tls_common_settings_check(settings, secrets, tls_prefix,
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out_missing);
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}
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static void eap_tls_debug_cb(const char *str, void *user_data)
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static const struct eap_tls_variant_ops eap_tls_ops = {
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.tunnel_ready = eap_tls_tunnel_ready,
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};
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static bool eap_tls_settings_load(struct eap_state *eap,
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struct l_settings *settings,
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const char *prefix)
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{
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l_info("EAP-TLS %s", str);
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}
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char setting_key_prefix[72];
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static void eap_tls_handle_request(struct eap_state *eap,
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const uint8_t *pkt, size_t len)
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{
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uint8_t flags;
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uint32_t total_len;
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struct eap_tls_state *tls = eap_get_data(eap);
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size_t fragment_len;
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uint8_t *tx_buf;
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snprintf(setting_key_prefix, sizeof(setting_key_prefix), "%sTLS-",
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prefix);
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if (len < 1) {
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l_error("EAP-TLS request too short");
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goto err;
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}
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flags = pkt[0];
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pkt += 1;
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len -= 1;
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/* Check if we're expecting a fragment ACK */
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if (tls->tx_pkt_len) {
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if (flags || len) {
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l_error("EAP-TLS request is not an ACK");
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goto err;
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}
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/* Send next response fragment, prepend the 6-byte header */
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tx_buf = &tls->tx_pkt_buf[tls->tx_pkt_offset - 6];
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fragment_len = eap_get_mtu(eap) - 6;
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tx_buf[5] = EAP_TLS_FLAG_M; /* Flags */
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if (tls->tx_pkt_len <= fragment_len) {
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fragment_len = tls->tx_pkt_len;
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tx_buf[5] = 0; /* Flags */
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}
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eap_send_response(eap, EAP_TYPE_TLS_EAP,
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tx_buf, fragment_len + 6);
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tls->tx_pkt_len -= fragment_len;
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tls->tx_pkt_offset += fragment_len;
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return;
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}
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/* Complain if S bit is not correct */
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if (!(flags & EAP_TLS_FLAG_S) == !tls->tls) {
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l_error("EAP-TLS request S flag invalid");
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goto err;
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}
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/* Method can't be restarted */
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if ((flags & EAP_TLS_FLAG_S) && tls->completed) {
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l_error("EAP-TLS start after completed");
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goto err;
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}
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/* Sanity check that first fragmented request has L flag set */
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if ((flags & EAP_TLS_FLAG_LM_MASK) == EAP_TLS_FLAG_M &&
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!tls->rx_pkt_buf) {
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l_error("EAP-TLS request 1st fragment with no length");
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goto err;
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}
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if (flags & EAP_TLS_FLAG_L) {
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if (len < 7) {
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l_error("EAP-TLS request with L flag too short");
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goto err;
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}
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total_len = l_get_be32(pkt);
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pkt += 4;
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len -= 4;
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if ((flags & EAP_TLS_FLAG_M) && !tls->rx_pkt_buf) {
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if (total_len > 512 * 1024) {
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l_error("EAP-TLS Message too long");
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goto err;
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}
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tls->rx_pkt_buf = l_malloc(total_len);
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tls->rx_pkt_len = total_len;
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tls->rx_pkt_received = 0;
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}
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if ((tls->rx_pkt_buf && total_len != tls->rx_pkt_len) ||
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(!tls->rx_pkt_buf && total_len != len)) {
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l_error("EAP-TLS request length mismatch");
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l_free(tls->rx_pkt_buf);
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tls->rx_pkt_buf = NULL;
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goto err;
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}
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}
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if (tls->rx_pkt_buf) {
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if (
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((flags & EAP_TLS_FLAG_M) &&
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tls->rx_pkt_received + len >=
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tls->rx_pkt_len) ||
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(!(flags & EAP_TLS_FLAG_M) &&
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tls->rx_pkt_received + len !=
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tls->rx_pkt_len)) {
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l_error("EAP-TLS request fragment length mismatch");
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l_free(tls->rx_pkt_buf);
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tls->rx_pkt_buf = NULL;
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goto err;
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}
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memcpy(tls->rx_pkt_buf + tls->rx_pkt_received, pkt, len);
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tls->rx_pkt_received += len;
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}
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if (flags & EAP_TLS_FLAG_M) {
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uint8_t buf[6];
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/* Send an empty response as ACK */
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buf[5] = 0;
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eap_send_response(eap, EAP_TYPE_TLS_EAP, buf, 6);
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return;
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}
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if (tls->rx_pkt_buf) {
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pkt = tls->rx_pkt_buf;
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len = tls->rx_pkt_len;
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}
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eap_tls_tx_buf_reserve(tls, EAP_TLS_RESPONSE_HEADER_LEN);
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tls->tx_pkt_offset = tls->tx_pkt_len;
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tls->tx_pkt_len = 0;
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if (flags & EAP_TLS_FLAG_S) {
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tls->tls = l_tls_new(false, eap_tls_data_cb,
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eap_tls_tx_cb, eap_tls_ready_cb,
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eap_tls_disconnect_cb, eap);
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if (!tls->tls) {
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l_error("Creating a TLS instance failed");
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goto err;
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}
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if (getenv("IWD_TLS_DEBUG"))
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l_tls_set_debug(tls->tls, eap_tls_debug_cb, NULL, NULL);
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if (!l_tls_set_auth_data(tls->tls, tls->client_cert,
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tls->client_key, tls->passphrase) ||
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(tls->ca_cert &&
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!l_tls_set_cacert(tls->tls, tls->ca_cert))) {
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l_error("Error loading EAP-TLS keys or certificates");
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goto err;
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}
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}
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/*
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* Here we take advantage of knowing that ell will send all the
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* records corresponding to the current handshake step from within
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* the l_tls_handle_rx call because it doesn't use any other context
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* such as timers - basic TLS specifies no timeouts. Otherwise we
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* would need to analyze the record types in eap_tls_tx_cb to decide
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* when we're ready to send out a response.
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*/
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if (len)
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l_tls_handle_rx(tls->tls, pkt, len);
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if (tls->rx_pkt_buf) {
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l_free(tls->rx_pkt_buf);
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tls->rx_pkt_buf = NULL;
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}
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/*
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* Note if tls->completed && !eap->method_success we can send an empty
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* response instead of passing the TLS alert.
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*/
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if (tls->tx_pkt_len + 6 <= eap_get_mtu(eap)) {
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/*
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* Response fits in a single response packet, prepend the
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* 6-byte header (no length) before the data.
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*/
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tx_buf = &tls->tx_pkt_buf[tls->tx_pkt_offset - 6];
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tx_buf[5] = 0; /* Flags */
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eap_send_response(eap, EAP_TYPE_TLS_EAP,
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tx_buf, tls->tx_pkt_len + 6);
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tls->tx_pkt_len = 0;
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} else {
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/*
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* Fragmentation needed, prepend the 10-byte header
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* (4 EAP header + 2 response + 4 length) to build the
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* initial fragment packet.
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*/
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tx_buf = &tls->tx_pkt_buf[tls->tx_pkt_offset - 10];
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tx_buf[5] = EAP_TLS_FLAG_L | EAP_TLS_FLAG_M; /* Flags */
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l_put_be32(tls->tx_pkt_len, &tx_buf[6]);
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fragment_len = eap_get_mtu(eap) - 10;
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eap_send_response(eap, EAP_TYPE_TLS_EAP,
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tx_buf, fragment_len + 10);
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tls->tx_pkt_len -= fragment_len;
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tls->tx_pkt_offset += fragment_len;
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}
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if (tls->completed) {
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l_tls_free(tls->tls);
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tls->tls = NULL;
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}
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return;
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err:
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tls->completed = true;
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l_tls_free(tls->tls);
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tls->tls = NULL;
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eap_method_error(eap);
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}
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static int eap_tls_check_settings(struct l_settings *settings,
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struct l_queue *secrets,
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const char *prefix,
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struct l_queue **out_missing)
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{
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char setting[64], client_cert_setting[64], passphrase_setting[64];
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L_AUTO_FREE_VAR(char *, path) = NULL;
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L_AUTO_FREE_VAR(char *, client_cert) = NULL;
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L_AUTO_FREE_VAR(char *, passphrase) = NULL;
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uint8_t *cert;
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size_t size;
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snprintf(setting, sizeof(setting), "%sTLS-CACert", prefix);
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path = l_settings_get_string(settings, "Security", setting);
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if (path) {
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cert = l_pem_load_certificate(path, &size);
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if (!cert) {
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l_error("Failed to load %s", path);
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return -EIO;
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}
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l_free(cert);
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}
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snprintf(client_cert_setting, sizeof(client_cert_setting),
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"%sTLS-ClientCert", prefix);
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client_cert = l_settings_get_string(settings, "Security",
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client_cert_setting);
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if (client_cert) {
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cert = l_pem_load_certificate(client_cert, &size);
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if (!cert) {
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l_error("Failed to load %s", client_cert);
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return -EIO;
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}
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l_free(cert);
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}
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l_free(path);
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snprintf(setting, sizeof(setting), "%sTLS-ClientKey", prefix);
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path = l_settings_get_string(settings, "Security", setting);
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if (path && !client_cert) {
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l_error("%s present but no client certificate (%s)",
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setting, client_cert_setting);
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return -ENOENT;
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}
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snprintf(passphrase_setting, sizeof(passphrase_setting),
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"%sTLS-ClientKeyPassphrase", prefix);
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passphrase = l_settings_get_string(settings, "Security",
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passphrase_setting);
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if (!passphrase) {
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const struct eap_secret_info *secret;
|
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secret = l_queue_find(secrets, eap_secret_info_match,
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passphrase_setting);
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if (secret)
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passphrase = l_strdup(secret->value);
|
||||
}
|
||||
|
||||
if (path) {
|
||||
struct l_key *priv_key;
|
||||
bool encrypted;
|
||||
|
||||
priv_key = l_pem_load_private_key(path, passphrase, &encrypted);
|
||||
if (!priv_key) {
|
||||
if (!encrypted) {
|
||||
l_error("Error loading client private key %s",
|
||||
path);
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
if (passphrase) {
|
||||
l_error("Error loading encrypted client "
|
||||
"private key %s", path);
|
||||
return -EACCES;
|
||||
}
|
||||
|
||||
/*
|
||||
* We've got an encrypted key and passphrase was not
|
||||
* saved in the network settings, need to request
|
||||
* the passphrase.
|
||||
*/
|
||||
eap_append_secret(out_missing,
|
||||
EAP_SECRET_LOCAL_PKEY_PASSPHRASE,
|
||||
passphrase_setting, NULL, path,
|
||||
EAP_CACHE_TEMPORARY);
|
||||
} else {
|
||||
l_key_free(priv_key);
|
||||
|
||||
if (passphrase && !encrypted) {
|
||||
l_error("%s present but client private "
|
||||
"key %s is not encrypted",
|
||||
passphrase_setting, path);
|
||||
return -ENOENT;
|
||||
}
|
||||
}
|
||||
} else if (passphrase) {
|
||||
l_error("%s present but no client private key path set (%s)",
|
||||
passphrase_setting, setting);
|
||||
return -ENOENT;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static bool eap_tls_load_settings(struct eap_state *eap,
|
||||
struct l_settings *settings,
|
||||
const char *prefix)
|
||||
{
|
||||
struct eap_tls_state *tls;
|
||||
char setting[64];
|
||||
|
||||
tls = l_new(struct eap_tls_state, 1);
|
||||
|
||||
snprintf(setting, sizeof(setting), "%sTLS-CACert", prefix);
|
||||
tls->ca_cert = l_settings_get_string(settings, "Security", setting);
|
||||
|
||||
snprintf(setting, sizeof(setting), "%sTLS-ClientCert", prefix);
|
||||
tls->client_cert = l_settings_get_string(settings, "Security", setting);
|
||||
|
||||
snprintf(setting, sizeof(setting), "%sTLS-ClientKey", prefix);
|
||||
tls->client_key = l_settings_get_string(settings, "Security", setting);
|
||||
|
||||
snprintf(setting, sizeof(setting), "%sTLS-ClientKeyPassphrase", prefix);
|
||||
tls->passphrase = l_settings_get_string(settings, "Security", setting);
|
||||
|
||||
eap_set_data(eap, tls);
|
||||
if (!eap_tls_common_settings_load(eap, settings, setting_key_prefix,
|
||||
&eap_tls_ops, NULL))
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
|
@ -535,11 +95,13 @@ static struct eap_method eap_tls = {
|
|||
.exports_msk = true,
|
||||
.name = "TLS",
|
||||
|
||||
.free = eap_tls_free,
|
||||
.handle_request = eap_tls_handle_request,
|
||||
.check_settings = eap_tls_check_settings,
|
||||
.load_settings = eap_tls_load_settings,
|
||||
.reset_state = eap_tls_reset_state,
|
||||
.handle_request = eap_tls_common_handle_request,
|
||||
.handle_retransmit = eap_tls_common_handle_retransmit,
|
||||
.reset_state = eap_tls_common_state_reset,
|
||||
.free = eap_tls_common_state_free,
|
||||
|
||||
.check_settings = eap_tls_settings_check,
|
||||
.load_settings = eap_tls_settings_load,
|
||||
};
|
||||
|
||||
static int eap_tls_init(void)
|
||||
|
|
|
|||
Loading…
Reference in New Issue