hostapd/src/eap_peer/eap_tls_common.h
Jouni Malinen 8e6485a1bc 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

Signed-off-by: Jouni Malinen <j@w1.fi>
2023-07-17 21:09:26 +03:00

145 lines
4.1 KiB
C

/*
* EAP peer: EAP-TLS/PEAP/TTLS/FAST common functions
* Copyright (c) 2004-2009, 2012, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#ifndef EAP_TLS_COMMON_H
#define EAP_TLS_COMMON_H
/**
* struct eap_ssl_data - TLS data for EAP methods
*/
struct eap_ssl_data {
/**
* conn - TLS connection context data from tls_connection_init()
*/
struct tls_connection *conn;
/**
* tls_out - TLS message to be sent out in fragments
*/
struct wpabuf *tls_out;
/**
* tls_out_pos - The current position in the outgoing TLS message
*/
size_t tls_out_pos;
/**
* tls_out_limit - Maximum fragment size for outgoing TLS messages
*/
size_t tls_out_limit;
/**
* tls_in - Received TLS message buffer for re-assembly
*/
struct wpabuf *tls_in;
/**
* tls_in_left - Number of remaining bytes in the incoming TLS message
*/
size_t tls_in_left;
/**
* tls_in_total - Total number of bytes in the incoming TLS message
*/
size_t tls_in_total;
/**
* phase2 - Whether this TLS connection is used in EAP phase 2 (tunnel)
*/
int phase2;
/**
* include_tls_length - Whether the TLS length field is included even
* if the TLS data is not fragmented
*/
int include_tls_length;
/**
* eap - EAP state machine allocated with eap_peer_sm_init()
*/
struct eap_sm *eap;
/**
* ssl_ctx - TLS library context to use for the connection
*/
void *ssl_ctx;
/**
* eap_type - EAP method used in Phase 1
* (EAP_TYPE_TLS/PEAP/TTLS/FAST/TEAP)
*/
u8 eap_type;
/**
* 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;
};
/* EAP TLS Flags */
#define EAP_TLS_FLAGS_LENGTH_INCLUDED 0x80
#define EAP_TLS_FLAGS_MORE_FRAGMENTS 0x40
#define EAP_TLS_FLAGS_START 0x20
#define EAP_TEAP_FLAGS_OUTER_TLV_LEN 0x10
#define EAP_TLS_VERSION_MASK 0x07
/* could be up to 128 bytes, but only the first 64 bytes are used */
#define EAP_TLS_KEY_LEN 64
/* stub type used as a flag for UNAUTH-TLS */
#define EAP_UNAUTH_TLS_TYPE 255
#define EAP_WFA_UNAUTH_TLS_TYPE 254
int eap_peer_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
struct eap_peer_config *config, u8 eap_type);
void eap_peer_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data);
u8 * eap_peer_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
const char *label, const u8 *context,
size_t context_len, size_t len);
u8 * eap_peer_tls_derive_session_id(struct eap_sm *sm,
struct eap_ssl_data *data, u8 eap_type,
size_t *len);
int eap_peer_tls_process_helper(struct eap_sm *sm, struct eap_ssl_data *data,
enum eap_type eap_type, int peap_version,
u8 id, const struct wpabuf *in_data,
struct wpabuf **out_data);
struct wpabuf * eap_peer_tls_build_ack(u8 id, enum eap_type eap_type,
int peap_version);
int eap_peer_tls_reauth_init(struct eap_sm *sm, struct eap_ssl_data *data);
int eap_peer_tls_status(struct eap_sm *sm, struct eap_ssl_data *data,
char *buf, size_t buflen, int verbose);
const u8 * eap_peer_tls_process_init(struct eap_sm *sm,
struct eap_ssl_data *data,
enum eap_type eap_type,
struct eap_method_ret *ret,
const struct wpabuf *reqData,
size_t *len, u8 *flags);
void eap_peer_tls_reset_input(struct eap_ssl_data *data);
void eap_peer_tls_reset_output(struct eap_ssl_data *data);
int eap_peer_tls_decrypt(struct eap_sm *sm, struct eap_ssl_data *data,
const struct wpabuf *in_data,
struct wpabuf **in_decrypted);
int eap_peer_tls_encrypt(struct eap_sm *sm, struct eap_ssl_data *data,
enum eap_type eap_type, int peap_version, u8 id,
const struct wpabuf *in_data,
struct wpabuf **out_data);
int eap_peer_select_phase2_methods(struct eap_peer_config *config,
const char *prefix,
struct eap_method_type **types,
size_t *num_types, int use_machine_cred);
int eap_peer_tls_phase2_nak(struct eap_method_type *types, size_t num_types,
struct eap_hdr *hdr, struct wpabuf **resp);
#endif /* EAP_TLS_COMMON_H */