PEAP client: Update Phase 2 authentication requirements
The previous PEAP client behavior allowed the server to skip Phase 2
authentication with the expectation that the server was authenticated
during Phase 1 through TLS server certificate validation. Various PEAP
specifications are not exactly clear on what the behavior on this front
is supposed to be and as such, this ended up being more flexible than
the TTLS/FAST/TEAP cases. However, this is not really ideal when
unfortunately common misconfiguration of PEAP is used in deployed
devices where the server trust root (ca_cert) is not configured or the
user has an easy option for allowing this validation step to be skipped.
Change the default PEAP client behavior to be to require Phase 2
authentication to be successfully completed for cases where TLS session
resumption is not used and the client certificate has not been
configured. Those two exceptions are the main cases where a deployed
authentication server might skip Phase 2 and as such, where a more
strict default behavior could result in undesired interoperability
issues. Requiring Phase 2 authentication will end up disabling TLS
session resumption automatically to avoid interoperability issues.
Allow Phase 2 authentication behavior to be configured with a new phase1
configuration parameter option:
'phase2_auth' option can be used to control Phase 2 (i.e., within TLS
tunnel) behavior for PEAP:
* 0 = do not require Phase 2 authentication
* 1 = require Phase 2 authentication when client certificate
(private_key/client_cert) is no used and TLS session resumption was
not used (default)
* 2 = require Phase 2 authentication in all cases
Bug: 287119604
Test: Manual - WPA/WPA2 & WPA3 Enterprise connection
Test: Regression test b/289297084
BYPASS_INCLUSIVE_LANGUAGE_REASON=Merged from open source
Change-Id: Ibe441934a28e83b50d38e787f284bd2d16cec169
Signed-off-by: Jouni Malinen <j@w1.fi>
diff --git a/src/eap_peer/eap_config.h b/src/eap_peer/eap_config.h
index 59fac90..1454447 100644
--- a/src/eap_peer/eap_config.h
+++ b/src/eap_peer/eap_config.h
@@ -483,6 +483,14 @@
* 1 = use cryptobinding if server supports it
* 2 = require cryptobinding
*
+ * phase2_auth option can be used to control Phase 2 (i.e., within TLS
+ * tunnel) behavior for PEAP:
+ * 0 = do not require Phase 2 authentication
+ * 1 = require Phase 2 authentication when client certificate
+ * (private_key/client_cert) is not used and TLS session resumption was
+ * not used (default)
+ * 2 = require Phase 2 authentication in all cases
+ *
* EAP-WSC (WPS) uses following options: pin=Device_Password and
* uuid=Device_UUID
*
diff --git a/src/eap_peer/eap_peap.c b/src/eap_peer/eap_peap.c
index 12e30df..6080697 100644
--- a/src/eap_peer/eap_peap.c
+++ b/src/eap_peer/eap_peap.c
@@ -67,6 +67,7 @@
u8 cmk[20];
int soh; /* Whether IF-TNCCS-SOH (Statement of Health; Microsoft NAP)
* is enabled. */
+ enum { NO_AUTH, FOR_INITIAL, ALWAYS } phase2_auth;
};
@@ -114,6 +115,19 @@
wpa_printf(MSG_DEBUG, "EAP-PEAP: Require cryptobinding");
}
+ if (os_strstr(phase1, "phase2_auth=0")) {
+ data->phase2_auth = NO_AUTH;
+ wpa_printf(MSG_DEBUG,
+ "EAP-PEAP: Do not require Phase 2 authentication");
+ } else if (os_strstr(phase1, "phase2_auth=1")) {
+ data->phase2_auth = FOR_INITIAL;
+ wpa_printf(MSG_DEBUG,
+ "EAP-PEAP: Require Phase 2 authentication for initial connection");
+ } else if (os_strstr(phase1, "phase2_auth=2")) {
+ data->phase2_auth = ALWAYS;
+ wpa_printf(MSG_DEBUG,
+ "EAP-PEAP: Require Phase 2 authentication for all cases");
+ }
#ifdef EAP_TNC
if (os_strstr(phase1, "tnc=soh2")) {
data->soh = 2;
@@ -142,6 +156,7 @@
data->force_peap_version = -1;
data->peap_outer_success = 2;
data->crypto_binding = OPTIONAL_BINDING;
+ data->phase2_auth = FOR_INITIAL;
if (config && config->phase1)
eap_peap_parse_phase1(data, config->phase1);
@@ -454,6 +469,20 @@
}
+static bool peap_phase2_sufficient(struct eap_sm *sm,
+ struct eap_peap_data *data)
+{
+ if ((data->phase2_auth == ALWAYS ||
+ (data->phase2_auth == FOR_INITIAL &&
+ !tls_connection_resumed(sm->ssl_ctx, data->ssl.conn) &&
+ !data->ssl.client_cert_conf) ||
+ data->phase2_eap_started) &&
+ !data->phase2_eap_success)
+ return false;
+ return true;
+}
+
+
/**
* eap_tlv_process - Process a received EAP-TLV message and generate a response
* @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
@@ -568,6 +597,11 @@
" - force failed Phase 2");
resp_status = EAP_TLV_RESULT_FAILURE;
ret->decision = DECISION_FAIL;
+ } else if (!peap_phase2_sufficient(sm, data)) {
+ wpa_printf(MSG_INFO,
+ "EAP-PEAP: Server indicated Phase 2 success, but sufficient Phase 2 authentication has not been completed");
+ resp_status = EAP_TLV_RESULT_FAILURE;
+ ret->decision = DECISION_FAIL;
} else {
resp_status = EAP_TLV_RESULT_SUCCESS;
ret->decision = DECISION_UNCOND_SUCC;
@@ -887,8 +921,7 @@
/* EAP-Success within TLS tunnel is used to indicate
* shutdown of the TLS channel. The authentication has
* been completed. */
- if (data->phase2_eap_started &&
- !data->phase2_eap_success) {
+ if (!peap_phase2_sufficient(sm, data)) {
wpa_printf(MSG_DEBUG, "EAP-PEAP: Phase 2 "
"Success used to indicate success, "
"but Phase 2 EAP was not yet "
@@ -1199,8 +1232,9 @@
static bool eap_peap_has_reauth_data(struct eap_sm *sm, void *priv)
{
struct eap_peap_data *data = priv;
+
return tls_connection_established(sm->ssl_ctx, data->ssl.conn) &&
- data->phase2_success;
+ data->phase2_success && data->phase2_auth != ALWAYS;
}
diff --git a/src/eap_peer/eap_tls_common.c b/src/eap_peer/eap_tls_common.c
index 3050456..5594216 100644
--- a/src/eap_peer/eap_tls_common.c
+++ b/src/eap_peer/eap_tls_common.c
@@ -242,6 +242,12 @@
sm->ext_cert_check = !!(params->flags & TLS_CONN_EXT_CERT_CHECK);
+ if (!phase2)
+ data->client_cert_conf = params->client_cert ||
+ params->client_cert_blob ||
+ params->private_key ||
+ params->private_key_blob;
+
return 0;
}
diff --git a/src/eap_peer/eap_tls_common.h b/src/eap_peer/eap_tls_common.h
index 9ac0012..3348634 100644
--- a/src/eap_peer/eap_tls_common.h
+++ b/src/eap_peer/eap_tls_common.h
@@ -79,6 +79,11 @@
* tls_v13 - Whether TLS v1.3 or newer is used
*/
int tls_v13;
+
+ /**
+ * client_cert_conf: Whether client certificate has been configured
+ */
+ bool client_cert_conf;
};
diff --git a/wpa_supplicant/wpa_supplicant.conf b/wpa_supplicant/wpa_supplicant.conf
index 8753fba..a8abf9a 100644
--- a/wpa_supplicant/wpa_supplicant.conf
+++ b/wpa_supplicant/wpa_supplicant.conf
@@ -1378,6 +1378,13 @@
# * 0 = do not use cryptobinding (default)
# * 1 = use cryptobinding if server supports it
# * 2 = require cryptobinding
+# 'phase2_auth' option can be used to control Phase 2 (i.e., within TLS
+# tunnel) behavior for PEAP:
+# * 0 = do not require Phase 2 authentication
+# * 1 = require Phase 2 authentication when client certificate
+# (private_key/client_cert) is not used and TLS session resumption was
+# not used (default)
+# * 2 = require Phase 2 authentication in all cases
# EAP-WSC (WPS) uses following options: pin=<Device Password> or
# pbc=1.
#