/* * EAP-FAST common helper functions (RFC 4851) * Copyright (c) 2008, Jouni Malinen * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include "includes.h" #include "common.h" #include "crypto/sha1.h" #include "crypto/tls.h" #include "eap_peer/eap_defs.h" #include "eap_peer/eap_tlv_common.h" #include "eap_peer/eap_fast_common.h" void eap_fast_put_tlv_hdr(struct wpabuf *buf, u16 type, u16 len) { struct pac_tlv_hdr hdr; hdr.type = host_to_be16(type); hdr.len = host_to_be16(len); wpabuf_put_data(buf, &hdr, sizeof(hdr)); } void eap_fast_put_tlv(struct wpabuf *buf, u16 type, const void *data, u16 len) { eap_fast_put_tlv_hdr(buf, type, len); wpabuf_put_data(buf, data, len); } void eap_fast_put_tlv_buf(struct wpabuf *buf, u16 type, const struct wpabuf *data) { eap_fast_put_tlv_hdr(buf, type, wpabuf_len(data)); wpabuf_put_buf(buf, data); } struct wpabuf * eap_fast_tlv_eap_payload(struct wpabuf *buf) { struct wpabuf *e; if (buf == NULL) return NULL; /* Encapsulate EAP packet in EAP-Payload TLV */ wpa_printf(MSG_DEBUG, "EAP-FAST: Add EAP-Payload TLV"); e = wpabuf_alloc(sizeof(struct pac_tlv_hdr) + wpabuf_len(buf)); if (e == NULL) { wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to allocate memory " "for TLV encapsulation"); wpabuf_free(buf); return NULL; } eap_fast_put_tlv_buf(e, EAP_TLV_TYPE_MANDATORY | EAP_TLV_EAP_PAYLOAD_TLV, buf); wpabuf_free(buf); return e; } void eap_fast_derive_master_secret(const u8 *pac_key, const u8 *server_random, const u8 *client_random, u8 *master_secret) { #define TLS_RANDOM_LEN 32 #define TLS_MASTER_SECRET_LEN 48 u8 seed[2 * TLS_RANDOM_LEN]; wpa_hexdump(MSG_DEBUG, "EAP-FAST: client_random", client_random, TLS_RANDOM_LEN); wpa_hexdump(MSG_DEBUG, "EAP-FAST: server_random", server_random, TLS_RANDOM_LEN); /* * RFC 4851, Section 5.1: * master_secret = T-PRF(PAC-Key, "PAC to master secret label hash", * server_random + client_random, 48) */ os_memcpy(seed, server_random, TLS_RANDOM_LEN); os_memcpy(seed + TLS_RANDOM_LEN, client_random, TLS_RANDOM_LEN); sha1_t_prf(pac_key, EAP_FAST_PAC_KEY_LEN, "PAC to master secret label hash", seed, sizeof(seed), master_secret, TLS_MASTER_SECRET_LEN); wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: master_secret", master_secret, TLS_MASTER_SECRET_LEN); } u8 * eap_fast_derive_key(void *ssl_ctx, struct tls_connection *conn, size_t len) { u8 *out; out = os_malloc(len); if (out == NULL) return NULL; if (tls_connection_get_eap_fast_key(ssl_ctx, conn, out, len)) { os_free(out); return NULL; } return out; } int eap_fast_derive_eap_msk(const u8 *simck, u8 *msk) { /* * RFC 4851, Section 5.4: EAP Master Session Key Generation * MSK = T-PRF(S-IMCK[j], "Session Key Generating Function", 64) */ if (sha1_t_prf(simck, EAP_FAST_SIMCK_LEN, "Session Key Generating Function", (u8 *) "", 0, msk, EAP_FAST_KEY_LEN) < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Derived key (MSK)", msk, EAP_FAST_KEY_LEN); return 0; } int eap_fast_derive_eap_emsk(const u8 *simck, u8 *emsk) { /* * RFC 4851, Section 5.4: EAP Master Session Key Genreration * EMSK = T-PRF(S-IMCK[j], * "Extended Session Key Generating Function", 64) */ if (sha1_t_prf(simck, EAP_FAST_SIMCK_LEN, "Extended Session Key Generating Function", (u8 *) "", 0, emsk, EAP_EMSK_LEN) < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Derived key (EMSK)", emsk, EAP_EMSK_LEN); return 0; } int eap_fast_parse_tlv(struct eap_fast_tlv_parse *tlv, int tlv_type, u8 *pos, size_t len) { switch (tlv_type) { case EAP_TLV_EAP_PAYLOAD_TLV: wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: EAP-Payload TLV", pos, len); if (tlv->eap_payload_tlv) { wpa_printf(MSG_DEBUG, "EAP-FAST: More than one " "EAP-Payload TLV in the message"); tlv->iresult = EAP_TLV_RESULT_FAILURE; return -2; } tlv->eap_payload_tlv = pos; tlv->eap_payload_tlv_len = len; break; case EAP_TLV_RESULT_TLV: wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Result TLV", pos, len); if (tlv->result) { wpa_printf(MSG_DEBUG, "EAP-FAST: More than one " "Result TLV in the message"); tlv->result = EAP_TLV_RESULT_FAILURE; return -2; } if (len < 2) { wpa_printf(MSG_DEBUG, "EAP-FAST: Too short " "Result TLV"); tlv->result = EAP_TLV_RESULT_FAILURE; break; } tlv->result = WPA_GET_BE16(pos); if (tlv->result != EAP_TLV_RESULT_SUCCESS && tlv->result != EAP_TLV_RESULT_FAILURE) { wpa_printf(MSG_DEBUG, "EAP-FAST: Unknown Result %d", tlv->result); tlv->result = EAP_TLV_RESULT_FAILURE; } wpa_printf(MSG_DEBUG, "EAP-FAST: Result: %s", tlv->result == EAP_TLV_RESULT_SUCCESS ? "Success" : "Failure"); break; case EAP_TLV_INTERMEDIATE_RESULT_TLV: wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Intermediate Result TLV", pos, len); if (len < 2) { wpa_printf(MSG_DEBUG, "EAP-FAST: Too short " "Intermediate-Result TLV"); tlv->iresult = EAP_TLV_RESULT_FAILURE; break; } if (tlv->iresult) { wpa_printf(MSG_DEBUG, "EAP-FAST: More than one " "Intermediate-Result TLV in the message"); tlv->iresult = EAP_TLV_RESULT_FAILURE; return -2; } tlv->iresult = WPA_GET_BE16(pos); if (tlv->iresult != EAP_TLV_RESULT_SUCCESS && tlv->iresult != EAP_TLV_RESULT_FAILURE) { wpa_printf(MSG_DEBUG, "EAP-FAST: Unknown Intermediate " "Result %d", tlv->iresult); tlv->iresult = EAP_TLV_RESULT_FAILURE; } wpa_printf(MSG_DEBUG, "EAP-FAST: Intermediate Result: %s", tlv->iresult == EAP_TLV_RESULT_SUCCESS ? "Success" : "Failure"); break; case EAP_TLV_CRYPTO_BINDING_TLV: wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Crypto-Binding TLV", pos, len); if (tlv->crypto_binding) { wpa_printf(MSG_DEBUG, "EAP-FAST: More than one " "Crypto-Binding TLV in the message"); tlv->iresult = EAP_TLV_RESULT_FAILURE; return -2; } tlv->crypto_binding_len = sizeof(struct eap_tlv_hdr) + len; if (tlv->crypto_binding_len < sizeof(*tlv->crypto_binding)) { wpa_printf(MSG_DEBUG, "EAP-FAST: Too short " "Crypto-Binding TLV"); tlv->iresult = EAP_TLV_RESULT_FAILURE; return -2; } tlv->crypto_binding = (struct eap_tlv_crypto_binding_tlv *) (pos - sizeof(struct eap_tlv_hdr)); break; case EAP_TLV_REQUEST_ACTION_TLV: wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Request-Action TLV", pos, len); if (tlv->request_action) { wpa_printf(MSG_DEBUG, "EAP-FAST: More than one " "Request-Action TLV in the message"); tlv->iresult = EAP_TLV_RESULT_FAILURE; return -2; } if (len < 2) { wpa_printf(MSG_DEBUG, "EAP-FAST: Too short " "Request-Action TLV"); tlv->iresult = EAP_TLV_RESULT_FAILURE; break; } tlv->request_action = WPA_GET_BE16(pos); wpa_printf(MSG_DEBUG, "EAP-FAST: Request-Action: %d", tlv->request_action); break; case EAP_TLV_PAC_TLV: wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: PAC TLV", pos, len); if (tlv->pac) { wpa_printf(MSG_DEBUG, "EAP-FAST: More than one " "PAC TLV in the message"); tlv->iresult = EAP_TLV_RESULT_FAILURE; return -2; } tlv->pac = pos; tlv->pac_len = len; break; default: /* Unknown TLV */ return -1; } return 0; }