/* * * Wireless daemon for Linux * * Copyright (C) 2013-2014 Intel Corporation. All rights reserved. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include "sha1.h" #include "md5.h" #include "eapol.h" #define VERIFY_IS_ZERO(field) \ do { \ unsigned int i; \ for (i = 0; i < sizeof(field); i++) \ if ((field)[i] != 0) \ return false; \ } while (false) \ /* * MIC calculation depends on the selected hash function. The has function * is given in the EAPoL Key Descriptor Version field. * * The MIC length is always 16 bytes for currently known Key Descriptor * Versions. * * The input struct eapol_key *frame should have a zero-d MIC field */ bool eapol_calculate_mic(const uint8_t *kck, const struct eapol_key *frame, uint8_t *mic) { size_t frame_len = sizeof(struct eapol_key); frame_len += L_BE16_TO_CPU(frame->key_data_len); switch (frame->key_descriptor_version) { case EAPOL_KEY_DESCRIPTOR_VERSION_HMAC_MD5_ARC4: return hmac_md5(kck, 16, frame, frame_len, mic, 16); case EAPOL_KEY_DESCRIPTOR_VERSION_HMAC_SHA1_AES: return hmac_sha1(kck, 16, frame, frame_len, mic, 16); case EAPOL_KEY_DESCRIPTOR_VERSION_AES_128_CMAC_AES: return false; default: return false; } } const struct eapol_key *eapol_key_validate(const uint8_t *frame, size_t len) { const struct eapol_key *ek; uint16_t key_data_len; if (len < sizeof(struct eapol_key)) return NULL; ek = (const struct eapol_key *) frame; if (ek->protocol_version != EAPOL_PROTOCOL_VERSION_2001 && ek->protocol_version != EAPOL_PROTOCOL_VERSION_2004) return NULL; if (ek->packet_type != 3) return NULL; switch (ek->descriptor_type) { case EAPOL_DESCRIPTOR_TYPE_RC4: case EAPOL_DESCRIPTOR_TYPE_80211: case EAPOL_DESCRIPTOR_TYPE_WPA: break; default: return NULL; } switch (ek->key_descriptor_version) { case EAPOL_KEY_DESCRIPTOR_VERSION_HMAC_MD5_ARC4: case EAPOL_KEY_DESCRIPTOR_VERSION_HMAC_SHA1_AES: case EAPOL_KEY_DESCRIPTOR_VERSION_AES_128_CMAC_AES: break; default: return NULL; } key_data_len = L_BE16_TO_CPU(ek->key_data_len); if (len < sizeof(struct eapol_key) + key_data_len) return NULL; return ek; } bool eapol_process_ptk_1_of_4(const uint8_t *frame, size_t len, uint8_t out_anonce[]) { const struct eapol_key *ek; ek = eapol_key_validate(frame, len); if (!ek) return false; /* Verify according to 802.11, Section 11.6.6.2 */ if (!ek->key_type) return false; if (ek->smk_message) return false; if (ek->install) return false; if (!ek->key_ack) return false; if (ek->key_mic) return false; if (ek->secure) return false; if (ek->error) return false; if (ek->request) return false; if (ek->encrypted_key_data) return false; VERIFY_IS_ZERO(ek->eapol_key_iv); VERIFY_IS_ZERO(ek->key_rsc); VERIFY_IS_ZERO(ek->reserved); VERIFY_IS_ZERO(ek->key_mic_data); memcpy(out_anonce, ek->key_nonce, sizeof(ek->key_nonce)); return true; } bool eapol_process_ptk_2_of_4(const uint8_t *frame, size_t len, uint8_t out_snonce[]) { const struct eapol_key *ek; uint16_t key_len; ek = eapol_key_validate(frame, len); if (!ek) return false; /* Verify according to 802.11, Section 11.6.6.2 */ if (!ek->key_type) return false; if (ek->smk_message) return false; if (ek->install) return false; if (ek->key_ack) return false; if (!ek->key_mic) return false; if (ek->secure) return false; if (ek->error) return false; if (ek->request) return false; if (ek->encrypted_key_data) return false; key_len = L_BE16_TO_CPU(ek->key_length); if (key_len != 0) return false; memcpy(out_snonce, ek->key_nonce, sizeof(ek->key_nonce)); return true; } static struct eapol_key *eapol_create_common( enum eapol_protocol_version protocol, enum eapol_key_descriptor_version version, bool secure, uint64_t key_replay_counter, const uint8_t snonce[], size_t extra_len, const uint8_t *extra_data) { size_t to_alloc = sizeof(struct eapol_key); struct eapol_key *out_frame = l_malloc(to_alloc + extra_len); memset(out_frame, 0, to_alloc + extra_len); out_frame->protocol_version = protocol; out_frame->packet_type = 0x3; out_frame->packet_len = L_CPU_TO_BE16(to_alloc + extra_len - 4); out_frame->descriptor_type = EAPOL_DESCRIPTOR_TYPE_80211; out_frame->key_descriptor_version = version; out_frame->key_type = true; out_frame->install = false; out_frame->key_ack = false; out_frame->key_mic = true; out_frame->secure = secure; out_frame->error = false; out_frame->request = false; out_frame->encrypted_key_data = false; out_frame->smk_message = false; out_frame->key_length = 0; out_frame->key_replay_counter = L_CPU_TO_BE64(key_replay_counter); memcpy(out_frame->key_nonce, snonce, sizeof(out_frame->key_nonce)); out_frame->key_data_len = L_CPU_TO_BE16(extra_len); memcpy(out_frame->key_data, extra_data, extra_len); return out_frame; } struct eapol_key *eapol_create_ptk_2_of_4( enum eapol_protocol_version protocol, enum eapol_key_descriptor_version version, uint64_t key_replay_counter, const uint8_t snonce[], size_t extra_len, const uint8_t *extra_data) { return eapol_create_common(protocol, version, false, key_replay_counter, snonce, extra_len, extra_data); } struct eapol_key *eapol_create_ptk_4_of_4( enum eapol_protocol_version protocol, enum eapol_key_descriptor_version version, uint64_t key_replay_counter, const uint8_t snonce[]) { return eapol_create_common(protocol, version, true, key_replay_counter, snonce, 0, NULL); }