wpa_supplicant implementation is divided into number of independent modules. Core code includes functionality for controlling the network selection, association, and configuration. Independent modules include WPA code (key handshake, PMKSA caching, pre-authentication), EAPOL state machine, and EAP state machine and methods. In addition, there are number of separate files for generic helper functions.
Both WPA and EAPOL/EAP state machines can be used separately in other programs than wpa_supplicant. As an example, the included test programs eapol_test and preauth_test are using these modules.
Driver interface API is defined in driver.h and all hardware/driver dependent functionality is implemented in driver_*.c.
main.c main() for UNIX-like operating systems and MinGW (Windows); this uses command line arguments to configure wpa_supplicant
events.c Driver event processing; wpa_supplicant_event() and related functions
wpa_supplicant_i.h Internal definitions for wpa_supplicant core; should not be included into independent modules
wpa_supplicant.h Definitions for driver event data and message logging
eloop.c and eloop.h Event loop (select() loop with registerable timeouts, socket read callbacks, and signal callbacks)
common.c and common.h Common helper functions
defs.h Definitions shared by multiple files
l2_packet.h, l2_packet_linux.c, and l2_packet_pcap.c Layer 2 (link) access wrapper (includes native Linux implementation and wrappers for libdnet/libpcap). A new l2_packet implementation may need to be added when porting to new operating systems that are not supported by libdnet/libpcap. Makefile can be used to select which l2_packet implementation is included. l2_packet_linux.c uses Linux packet sockets and l2_packet_pcap.c has a more portable version using libpcap and libdnet.
pcsc_funcs.c and pcsc_funcs.h Wrapper for PC/SC lite SIM and smart card readers
priv_netlink.h Private version of netlink definitions from Linux kernel header files; this could be replaced with C library header file once suitable version becomes commonly available
version.h Version number definitions
wireless_copy.h Private version of Linux wireless extensions definitions from kernel header files; this could be replaced with C library header file once suitable version becomes commonly available
rc4.c and rc4.h RC4 (broadcast/default key encryption)
sha1.c and sha1.h SHA-1 (replaced with a crypto library if TLS support is included) HMAC-SHA-1 (keyed checksum for message authenticity validation) PRF-SHA-1 (pseudorandom (key/nonce generation) function) PBKDF2-SHA-1 (ASCII passphrase to shared secret) T-PRF (for EAP-FAST) TLS-PRF (RFC 2246)
aes_wrap.c, aes_wrap.h, aes.c AES (replaced with a crypto library if TLS support is included), AES Key Wrap Algorithm with 128-bit KEK, RFC3394 (broadcast/default key encryption), One-Key CBC MAC (OMAC1) hash with AES-128, AES-128 CTR mode encryption, AES-128 EAX mode encryption/decryption, AES-128 CBC
crypto.h Definition of crypto library wrapper
crypto.c Wrapper functions for libcrypto (OpenSSL)
crypto_gnutls.c Wrapper functions for libgcrypt (used by GnuTLS)
ms_funcs.c and ms_funcs.h Helper functions for MSCHAPV2 and LEAP
tls.h Definition of TLS library wrapper
tls_none.c Dummy implementation of TLS library wrapper for cases where TLS functionality is not included.
tls_openssl.c TLS library wrapper for openssl
tls_gnutls.c TLS library wrapper for GnuTLS
config.h Definition of the wpa_supplicant configuration
config.c Configuration parser and common functions
config_file.c Configuration backend for text files (e.g., wpa_supplicant.conf)
ctrl_iface.c and ctrl_iface.h wpa_supplicant-side of the control interface
wpa_ctrl.c and wpa_ctrl.h Library functions for external programs to provide access to the wpa_supplicant control interface
wpa_cli.c Example program for using wpa_supplicant control interface
preauth.c and preauth.h PMKSA caching and pre-authentication (RSN/WPA2)
wpa_i.h Internal definitions for WPA code; not to be included to other modules.
eap.c and eap.h EAP state machine and method interface
eap_defs.h Common EAP definitions
eap_i.h Internal definitions for EAP state machine and EAP methods; not to be included in other modules
eap_sim_common.c and eap_sim_common.h Common code for EAP-SIM and EAP-AKA
eap_tls_common.c and eap_tls_common.h Common code for EAP-PEAP, EAP-TTLS, and EAP-FAST
eap_tlv.c and eap_tlv.h EAP-TLV code for EAP-PEAP and EAP-FAST
eap_ttls.c and eap_ttls.h EAP-TTLS
eap_pax.c, eap_pax_common.h, eap_pax_common.c EAP-PAX
eap_psk.c, eap_psk_common.h, eap_psk_common.c EAP-PSK (note: this is not needed for WPA-PSK)
eap_aka.c, eap_fast.c, eap_gtc.c, eap_leap.c, eap_md5.c, eap_mschapv2.c, eap_otp.c, eap_peap.c, eap_sim.c, eap_tls.c Other EAP method implementations
win_if_list.c External program for listing current network interface
radius.c and radius.h RADIUS message processing for eapol_test
config_types.h and hostapd.h Minimal version of hostapd header files for eapol_test
eapol_test.c Standalone EAP testing tool with integrated RADIUS authentication client
preauth_test.c Standalone RSN pre-authentication tool
wpa_passphrase.c WPA ASCII passphrase to PSK conversion
1.4.2