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Diffstat (limited to 'src/wpa.c')
| -rw-r--r-- | src/wpa.c | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/src/wpa.c b/src/wpa.c new file mode 100644 index 00000000..5f4fd024 --- /dev/null +++ b/src/wpa.c @@ -0,0 +1,455 @@ +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */ +/* + * WPA Supplicant - WPA state machine and EAPOL-Key processing + * Copyright (c) 2003-2005, Jouni Malinen <jkmaline@cc.hut.fi> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Alternatively, this file may be distributed under the terms of BSD + * license. + * + * See README and COPYING for more details. + */ + +#include "wireless-helper.h" + +#include <stdint.h> +#include <string.h> +#include <glib.h> + +#include "wpa.h" +#include "nm-logging.h" + +typedef guint16 u16; +typedef guint8 u8; + +#define WPA_GET_LE16(a) ((u16) (((a)[1] << 8) | (a)[0])) + +#define BIT(n) (1 << (n)) +#define WPA_CAPABILITY_PREAUTH BIT(0) + +#define WPA_REPLAY_COUNTER_LEN 8 +#define WPA_NONCE_LEN 32 + +#define PMKID_LEN 16 + +static const int WPA_SELECTOR_LEN = 4; +static const u8 WPA_OUI_TYPE[] = { 0x00, 0x50, 0xf2, 1 }; +static const u16 WPA_VERSION = 1; +static const u8 WPA_AUTH_KEY_MGMT_NONE[] = { 0x00, 0x50, 0xf2, 0 }; +static const u8 WPA_AUTH_KEY_MGMT_UNSPEC_802_1X[] = { 0x00, 0x50, 0xf2, 1 }; +static const u8 WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X[] = { 0x00, 0x50, 0xf2, 2 }; +static const u8 WPA_CIPHER_SUITE_NONE[] = { 0x00, 0x50, 0xf2, 0 }; +static const u8 WPA_CIPHER_SUITE_WEP40[] = { 0x00, 0x50, 0xf2, 1 }; +static const u8 WPA_CIPHER_SUITE_TKIP[] = { 0x00, 0x50, 0xf2, 2 }; +static const u8 WPA_CIPHER_SUITE_WRAP[] = { 0x00, 0x50, 0xf2, 3 }; +static const u8 WPA_CIPHER_SUITE_CCMP[] = { 0x00, 0x50, 0xf2, 4 }; +static const u8 WPA_CIPHER_SUITE_WEP104[] = { 0x00, 0x50, 0xf2, 5 }; + +/* WPA IE version 1 + * 00-50-f2:1 (OUI:OUI type) + * 0x01 0x00 (version; little endian) + * (all following fields are optional:) + * Group Suite Selector (4 octets) (default: TKIP) + * Pairwise Suite Count (2 octets, little endian) (default: 1) + * Pairwise Suite List (4 * n octets) (default: TKIP) + * Authenticated Key Management Suite Count (2 octets, little endian) + * (default: 1) + * Authenticated Key Management Suite List (4 * n octets) + * (default: unspec 802.1X) + * WPA Capabilities (2 octets, little endian) (default: 0) + */ + +struct wpa_ie_hdr { + u8 elem_id; + u8 len; + u8 oui[3]; + u8 oui_type; + u8 version[2]; +} __attribute__ ((packed)); + + +static const int RSN_SELECTOR_LEN = 4; +static const u16 RSN_VERSION = 1; +static const u8 RSN_AUTH_KEY_MGMT_UNSPEC_802_1X[] = { 0x00, 0x0f, 0xac, 1 }; +static const u8 RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X[] = { 0x00, 0x0f, 0xac, 2 }; +static const u8 RSN_CIPHER_SUITE_NONE[] = { 0x00, 0x0f, 0xac, 0 }; +static const u8 RSN_CIPHER_SUITE_WEP40[] = { 0x00, 0x0f, 0xac, 1 }; +static const u8 RSN_CIPHER_SUITE_TKIP[] = { 0x00, 0x0f, 0xac, 2 }; +static const u8 RSN_CIPHER_SUITE_WRAP[] = { 0x00, 0x0f, 0xac, 3 }; +static const u8 RSN_CIPHER_SUITE_CCMP[] = { 0x00, 0x0f, 0xac, 4 }; +static const u8 RSN_CIPHER_SUITE_WEP104[] = { 0x00, 0x0f, 0xac, 5 }; + +/* EAPOL-Key Key Data Encapsulation + * GroupKey and STAKey require encryption, otherwise, encryption is optional. + */ +static const u8 RSN_KEY_DATA_GROUPKEY[] = { 0x00, 0x0f, 0xac, 1 }; +static const u8 RSN_KEY_DATA_STAKEY[] = { 0x00, 0x0f, 0xac, 2 }; +static const u8 RSN_KEY_DATA_MAC_ADDR[] = { 0x00, 0x0f, 0xac, 3 }; +static const u8 RSN_KEY_DATA_PMKID[] = { 0x00, 0x0f, 0xac, 4 }; + +/* RSN IE version 1 + * 0x01 0x00 (version; little endian) + * (all following fields are optional:) + * Group Suite Selector (4 octets) (default: CCMP) + * Pairwise Suite Count (2 octets, little endian) (default: 1) + * Pairwise Suite List (4 * n octets) (default: CCMP) + * Authenticated Key Management Suite Count (2 octets, little endian) + * (default: 1) + * Authenticated Key Management Suite List (4 * n octets) + * (default: unspec 802.1X) + * RSN Capabilities (2 octets, little endian) (default: 0) + * PMKID Count (2 octets) (default: 0) + * PMKID List (16 * n octets) + */ + +struct rsn_ie_hdr { + u8 elem_id; /* WLAN_EID_RSN */ + u8 len; + u8 version[2]; +} __attribute__ ((packed)); + + +#define WPA_KEY_INFO_TYPE_MASK (BIT(0) | BIT(1) | BIT(2)) +#define WPA_KEY_INFO_TYPE_HMAC_MD5_RC4 BIT(0) +#define WPA_KEY_INFO_TYPE_HMAC_SHA1_AES BIT(1) +#define WPA_KEY_INFO_KEY_TYPE BIT(3) /* 1 = Pairwise, 0 = Group key */ +/* bit4..5 is used in WPA, but is reserved in IEEE 802.11i/RSN */ +#define WPA_KEY_INFO_KEY_INDEX_MASK (BIT(4) | BIT(5)) +#define WPA_KEY_INFO_KEY_INDEX_SHIFT 4 +#define WPA_KEY_INFO_INSTALL BIT(6) /* pairwise */ +#define WPA_KEY_INFO_TXRX BIT(6) /* group */ +#define WPA_KEY_INFO_ACK BIT(7) +#define WPA_KEY_INFO_MIC BIT(8) +#define WPA_KEY_INFO_SECURE BIT(9) +#define WPA_KEY_INFO_ERROR BIT(10) +#define WPA_KEY_INFO_REQUEST BIT(11) +#define WPA_KEY_INFO_ENCR_KEY_DATA BIT(12) /* IEEE 802.11i/RSN only */ + + + +static int wpa_selector_to_bitfield(const u8 *s) +{ + if (memcmp(s, WPA_CIPHER_SUITE_NONE, WPA_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_NONE; + if (memcmp(s, WPA_CIPHER_SUITE_WEP40, WPA_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_WEP40; + if (memcmp(s, WPA_CIPHER_SUITE_TKIP, WPA_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_TKIP; + if (memcmp(s, WPA_CIPHER_SUITE_CCMP, WPA_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_CCMP; + if (memcmp(s, WPA_CIPHER_SUITE_WEP104, WPA_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_WEP104; + return 0; +} + + +static int wpa_key_mgmt_to_bitfield(const u8 *s) +{ + if (memcmp(s, WPA_AUTH_KEY_MGMT_UNSPEC_802_1X, WPA_SELECTOR_LEN) == 0) + return IW_AUTH_KEY_MGMT_802_1X; + if (memcmp(s, WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X, WPA_SELECTOR_LEN) == + 0) + return IW_AUTH_KEY_MGMT_PSK; + if (memcmp(s, WPA_AUTH_KEY_MGMT_NONE, WPA_SELECTOR_LEN) == 0) + return 0; + return 0; +} + + +static int rsn_selector_to_bitfield(const u8 *s) +{ + if (memcmp(s, RSN_CIPHER_SUITE_NONE, RSN_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_NONE; + if (memcmp(s, RSN_CIPHER_SUITE_WEP40, RSN_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_WEP40; + if (memcmp(s, RSN_CIPHER_SUITE_TKIP, RSN_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_TKIP; + if (memcmp(s, RSN_CIPHER_SUITE_CCMP, RSN_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_CCMP; + if (memcmp(s, RSN_CIPHER_SUITE_WEP104, RSN_SELECTOR_LEN) == 0) + return IW_AUTH_CIPHER_WEP104; + return 0; +} + + +static int rsn_key_mgmt_to_bitfield(const u8 *s) +{ + if (memcmp(s, RSN_AUTH_KEY_MGMT_UNSPEC_802_1X, RSN_SELECTOR_LEN) == 0) + return IW_AUTH_KEY_MGMT_802_1X; + if (memcmp(s, RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X, RSN_SELECTOR_LEN) == + 0) + return IW_AUTH_KEY_MGMT_PSK; + return 0; +} + + +static int wpa_parse_wpa_ie_wpa(const u8 *wpa_ie, size_t wpa_ie_len, + struct wpa_ie_data *data) +{ + const struct wpa_ie_hdr *hdr; + const u8 *pos; + int left; + int i, count; + + data->proto = IW_AUTH_WPA_VERSION_WPA; + data->pairwise_cipher = IW_AUTH_CIPHER_TKIP; + data->group_cipher = IW_AUTH_CIPHER_TKIP; + data->key_mgmt = IW_AUTH_KEY_MGMT_802_1X; + data->capabilities = 0; + data->pmkid = NULL; + data->num_pmkid = 0; + + if (wpa_ie_len == 0) { + /* No WPA IE - fail silently */ + return -1; + } + + if (wpa_ie_len < sizeof(struct wpa_ie_hdr)) { + nm_log_dbg (LOGD_WIFI, "IE len too short %lu", + (unsigned long) wpa_ie_len); + return -1; + } + + hdr = (const struct wpa_ie_hdr *) wpa_ie; + + if (hdr->elem_id != WPA_GENERIC_INFO_ELEM || + hdr->len != wpa_ie_len - 2 || + memcmp(hdr->oui, WPA_OUI_TYPE, WPA_SELECTOR_LEN) != 0 || + WPA_GET_LE16(hdr->version) != WPA_VERSION) { + nm_log_dbg (LOGD_WIFI, "malformed IE or unknown version"); + return -1; + } + + pos = (const u8 *) (hdr + 1); + left = wpa_ie_len - sizeof(*hdr); + + if (left >= WPA_SELECTOR_LEN) { + data->group_cipher = wpa_selector_to_bitfield(pos); + pos += WPA_SELECTOR_LEN; + left -= WPA_SELECTOR_LEN; + } else if (left > 0) { + nm_log_dbg (LOGD_WIFI, "IE length mismatch, %u too much", left); + return -1; + } + + if (left >= 2) { + data->pairwise_cipher = 0; + count = WPA_GET_LE16(pos); + pos += 2; + left -= 2; + if (count == 0 || left < count * WPA_SELECTOR_LEN) { + nm_log_dbg (LOGD_WIFI, "IE count botch (pairwise), " + "count %u left %u", count, left); + return -1; + } + for (i = 0; i < count; i++) { + data->pairwise_cipher |= wpa_selector_to_bitfield(pos); + pos += WPA_SELECTOR_LEN; + left -= WPA_SELECTOR_LEN; + } + } else if (left == 1) { + nm_log_dbg (LOGD_WIFI, "IE too short (for key mgmt)"); + return -1; + } + + if (left >= 2) { + data->key_mgmt = 0; + count = WPA_GET_LE16(pos); + pos += 2; + left -= 2; + if (count == 0 || left < count * WPA_SELECTOR_LEN) { + nm_log_dbg (LOGD_WIFI, "IE count botch (key mgmt), " + "count %u left %u", count, left); + return -1; + } + for (i = 0; i < count; i++) { + data->key_mgmt |= wpa_key_mgmt_to_bitfield(pos); + pos += WPA_SELECTOR_LEN; + left -= WPA_SELECTOR_LEN; + } + } else if (left == 1) { + nm_log_dbg (LOGD_WIFI, "IE too short (for capabilities)"); + return -1; + } + + if (left >= 2) { + if (WPA_GET_LE16 (pos) & WPA_CAPABILITY_PREAUTH) + data->capabilities |= IW_PMKID_CAND_PREAUTH; + pos += 2; + left -= 2; + } + + if (left > 0) { + nm_log_dbg (LOGD_WIFI, "IE has %u trailing bytes", left); + return -1; + } + + return 0; +} + + +static int wpa_parse_wpa_ie_rsn(const u8 *rsn_ie, size_t rsn_ie_len, + struct wpa_ie_data *data) +{ + const struct rsn_ie_hdr *hdr; + const u8 *pos; + int left; + int i, count; + + data->proto = IW_AUTH_WPA_VERSION_WPA2; + data->pairwise_cipher = IW_AUTH_CIPHER_CCMP; + data->group_cipher = IW_AUTH_CIPHER_CCMP; + data->key_mgmt = IW_AUTH_KEY_MGMT_802_1X; + data->capabilities = 0; + data->pmkid = NULL; + data->num_pmkid = 0; + + if (rsn_ie_len == 0) { + /* No RSN IE - fail silently */ + return -1; + } + + if (rsn_ie_len < sizeof(struct rsn_ie_hdr)) { + nm_log_dbg (LOGD_WIFI, "IE len too short %lu", + (unsigned long) rsn_ie_len); + return -1; + } + + hdr = (const struct rsn_ie_hdr *) rsn_ie; + + if (hdr->elem_id != WPA_RSN_INFO_ELEM || + hdr->len != rsn_ie_len - 2 || + WPA_GET_LE16(hdr->version) != RSN_VERSION) { + nm_log_dbg (LOGD_WIFI, "malformed IE or unknown version"); + return -1; + } + + pos = (const u8 *) (hdr + 1); + left = rsn_ie_len - sizeof(*hdr); + + if (left >= RSN_SELECTOR_LEN) { + data->group_cipher = rsn_selector_to_bitfield(pos); + pos += RSN_SELECTOR_LEN; + left -= RSN_SELECTOR_LEN; + } else if (left > 0) { + nm_log_dbg (LOGD_WIFI, "IE length mismatch, %u too much", left); + return -1; + } + + if (left >= 2) { + data->pairwise_cipher = 0; + count = WPA_GET_LE16(pos); + pos += 2; + left -= 2; + if (count == 0 || left < count * RSN_SELECTOR_LEN) { + nm_log_dbg (LOGD_WIFI, "IE count botch (pairwise), " + "count %u left %u", count, left); + return -1; + } + for (i = 0; i < count; i++) { + data->pairwise_cipher |= rsn_selector_to_bitfield(pos); + pos += RSN_SELECTOR_LEN; + left -= RSN_SELECTOR_LEN; + } + } else if (left == 1) { + nm_log_dbg (LOGD_WIFI, "IE too short (for key mgmt)"); + return -1; + } + + if (left >= 2) { + data->key_mgmt = 0; + count = WPA_GET_LE16(pos); + pos += 2; + left -= 2; + if (count == 0 || left < count * RSN_SELECTOR_LEN) { + nm_log_dbg (LOGD_WIFI, "IE count botch (key mgmt), " + "count %u left %u", count, left); + return -1; + } + for (i = 0; i < count; i++) { + data->key_mgmt |= rsn_key_mgmt_to_bitfield(pos); + pos += RSN_SELECTOR_LEN; + left -= RSN_SELECTOR_LEN; + } + } else if (left == 1) { + nm_log_dbg (LOGD_WIFI, "IE too short (for capabilities)"); + return -1; + } + + if (left >= 2) { + if (WPA_GET_LE16 (pos) & WPA_CAPABILITY_PREAUTH) + data->capabilities |= IW_PMKID_CAND_PREAUTH; + pos += 2; + left -= 2; + } + + if (left >= 2) { + data->num_pmkid = WPA_GET_LE16(pos); + pos += 2; + left -= 2; + if (left < data->num_pmkid * PMKID_LEN) { + nm_log_dbg (LOGD_WIFI, "PMKID underflow " + "(num_pmkid=%d left=%d)", + data->num_pmkid, left); + data->num_pmkid = 0; + } else { + data->pmkid = pos; + pos += data->num_pmkid * PMKID_LEN; + left -= data->num_pmkid * PMKID_LEN; + } + } + + if (left > 0) { + nm_log_dbg (LOGD_WIFI, "IE has %u trailing bytes - ignored", left); + } + + return 0; +} + + +/** + * wpa_parse_wpa_ie - Parse WPA/RSN IE + * @wpa_ie: Pointer to WPA or RSN IE + * @wpa_ie_len: Length of the WPA/RSN IE + * @data: Pointer to data area for parsing results + * Returns: parsed results on success, NULL on failure + * + * Parse the contents of WPA or RSN IE and write the parsed data into data. + */ +wpa_ie_data * wpa_parse_wpa_ie(const u8 *wpa_ie, size_t wpa_ie_len) +{ + wpa_ie_data *data = NULL; + int err = -1; + + if (!wpa_ie || wpa_ie_len <= 0) + return NULL; + + data = g_slice_new0 (wpa_ie_data); + + if (wpa_ie_len >= 1 && wpa_ie[0] == WPA_RSN_INFO_ELEM) + err = wpa_parse_wpa_ie_rsn(wpa_ie, wpa_ie_len, data); + else + err = wpa_parse_wpa_ie_wpa(wpa_ie, wpa_ie_len, data); + + if (err != 0) { + g_slice_free (wpa_ie_data, data); + data = NULL; + } + + if (data) { + nm_log_dbg (LOGD_WIFI, "WPA IE: -------------------"); + nm_log_dbg (LOGD_WIFI, " proto 0x%X", data->proto); + nm_log_dbg (LOGD_WIFI, " pw cipher 0x%X", data->pairwise_cipher); + nm_log_dbg (LOGD_WIFI, " gr cipher 0x%X", data->group_cipher); + nm_log_dbg (LOGD_WIFI, " key mgmt 0x%X", data->key_mgmt); + nm_log_dbg (LOGD_WIFI, " capabilities 0x%X", data->capabilities); + nm_log_dbg (LOGD_WIFI, " # pmkid 0x%X", data->num_pmkid); + nm_log_dbg (LOGD_WIFI, ""); + } + + return data; +} + |