/* * Copyright 2002-2004, Instant802 Networks, Inc. * Copyright 2008, Jouni Malinen <j@w1.fi> * Copyright (C) 2016 Intel Deutschland GmbH * * 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. */ #include <linux/netdevice.h> #include <linux/types.h> #include <linux/skbuff.h> #include <linux/compiler.h> #include <linux/ieee80211.h> #include <linux/gfp.h> #include <asm/unaligned.h> #include <net/mac80211.h> #include <crypto/aes.h> #include <crypto/algapi.h> #include "ieee80211_i.h" #include "michael.h" #include "tkip.h" #include "aes_ccm.h" #include "aes_cmac.h" #include "aes_gmac.h" #include "aes_gcm.h" #include "wpa.h" ieee80211_tx_result ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) { u8 *data, *key, *mic; size_t data_len; unsigned int hdrlen; struct ieee80211_hdr *hdr; struct sk_buff *skb = tx->skb; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); int tail; hdr = (struct ieee80211_hdr *)skb->data; if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control)) return TX_CONTINUE; hdrlen = ieee80211_hdrlen(hdr->frame_control); if (skb->len < hdrlen) return TX_DROP; data = skb->data + hdrlen; data_len = skb->len - hdrlen; if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) { /* Need to use software crypto for the test */ info->control.hw_key = NULL; } if (info->control.hw_key && (info->flags & IEEE80211_TX_CTL_DONTFRAG || ieee80211_hw_check(&tx->local->hw, SUPPORTS_TX_FRAG)) && !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) { /* hwaccel - with no need for SW-generated MMIC */ return TX_CONTINUE; } tail = MICHAEL_MIC_LEN; if (!info->control.hw_key) tail += IEEE80211_TKIP_ICV_LEN; if (WARN(skb_tailroom(skb) < tail || skb_headroom(skb) < IEEE80211_TKIP_IV_LEN, "mmic: not enough head/tail (%d/%d,%d/%d)\n", skb_headroom(skb), IEEE80211_TKIP_IV_LEN, skb_tailroom(skb), tail)) return TX_DROP; key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]; mic = skb_put(skb, MICHAEL_MIC_LEN); michael_mic(key, hdr, data, data_len, mic); if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) mic[0]++; return TX_CONTINUE; } ieee80211_rx_result ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) { u8 *data, *key = NULL; size_t data_len; unsigned int hdrlen; u8 mic[MICHAEL_MIC_LEN]; struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; /* * it makes no sense to check for MIC errors on anything other * than data frames. */ if (!ieee80211_is_data_present(hdr->frame_control)) return RX_CONTINUE; /* * No way to verify the MIC if the hardware stripped it or * the IV with the key index. In this case we have solely rely * on the driver to set RX_FLAG_MMIC_ERROR in the event of a * MIC failure report. */ if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) { if (status->flag & RX_FLAG_MMIC_ERROR) goto mic_fail_no_key; if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP) goto update_iv; return RX_CONTINUE; } /* * Some hardware seems to generate Michael MIC failure reports; even * though, the frame was not encrypted with TKIP and therefore has no * MIC. Ignore the flag them to avoid triggering countermeasures. */ if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || !(status->flag & RX_FLAG_DECRYPTED)) return RX_CONTINUE; if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) { /* * APs with pairwise keys should never receive Michael MIC * errors for non-zero keyidx because these are reserved for * group keys and only the AP is sending real multicast * frames in the BSS. */ return RX_DROP_UNUSABLE; } if (status->flag & RX_FLAG_MMIC_ERROR) goto mic_fail; hdrlen = ieee80211_hdrlen(hdr->frame_control); if (skb->len < hdrlen + MICHAEL_MIC_LEN) return RX_DROP_UNUSABLE; if (skb_linearize(rx->skb)) return RX_DROP_UNUSABLE; hdr = (void *)skb->data; data = skb->data + hdrlen; data_len = skb->len - hdrlen - MICHAEL_MIC_LEN; key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY]; michael_mic(key, hdr, data, data_len, mic); if (crypto_memneq(mic, data + data_len, MICHAEL_MIC_LEN)) goto mic_fail; /* remove Michael MIC from payload */ skb_trim(skb, skb->len - MICHAEL_MIC_LEN); update_iv: /* update IV in key information to be able to detect replays */ rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32; rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16; return RX_CONTINUE; mic_fail: rx->key->u.tkip.mic_failures++; mic_fail_no_key: /* * In some cases the key can be unset - e.g. a multicast packet, in * a driver that supports HW encryption. Send up the key idx only if * the key is set. */ cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2, is_multicast_ether_addr(hdr->addr1) ? NL80211_KEYTYPE_GROUP : NL80211_KEYTYPE_PAIRWISE, rx->key ? rx->key->conf.keyidx : -1, NULL, GFP_ATOMIC); return RX_DROP_UNUSABLE; } static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; struct ieee80211_key *key = tx->key; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); unsigned int hdrlen; int len, tail; u64 pn; u8 *pos; if (info->control.hw_key && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) { /* hwaccel - with no need for software-generated IV */ return 0; } hdrlen = ieee80211_hdrlen(hdr->frame_control); len = skb->len - hdrlen; if (info->control.hw_key) tail = 0; else tail = IEEE80211_TKIP_ICV_LEN; if (WARN_ON(skb_tailroom(skb) < tail || skb_headroom(skb) < IEEE80211_TKIP_IV_LEN)) return -1; pos = skb_push(skb, IEEE80211_TKIP_IV_LEN); memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen); pos += hdrlen; /* the HW only needs room for the IV, but not the actual IV */ if (info->control.hw_key && (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) return 0; /* Increase IV for the frame */ pn = atomic64_inc_return(&key->conf.tx_pn); pos = ieee80211_tkip_add_iv(pos, &key->conf, pn); /* hwaccel - with software IV */ if (info->control.hw_key) return 0; /* Add room for ICV */ skb_put(skb, IEEE80211_TKIP_ICV_LEN); return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, key, skb, pos, len); } ieee80211_tx_result ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) { struct sk_buff *skb; ieee80211_tx_set_protected(tx); skb_queue_walk(&tx->skbs, skb) { if (tkip_encrypt_skb(tx, skb) < 0) return TX_DROP; } return TX_CONTINUE; } ieee80211_rx_result ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; int hdrlen, res, hwaccel = 0; struct ieee80211_key *key = rx->key; struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); hdrlen = ieee80211_hdrlen(hdr->frame_control); if (!ieee80211_is_data(hdr->frame_control)) return RX_CONTINUE; if (!rx->sta || skb->len - hdrlen < 12) return RX_DROP_UNUSABLE; /* it may be possible to optimize this a bit more */ if (skb_linearize(rx->skb)) return RX_DROP_UNUSABLE; hdr = (void *)skb->data; /* * Let TKIP code verify IV, but skip decryption. * In the case where hardware checks the IV as well, * we don't even get here, see ieee80211_rx_h_decrypt() */ if (status->flag & RX_FLAG_DECRYPTED) hwaccel = 1; res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, key, skb->data + hdrlen, skb->len - hdrlen, rx->sta->sta.addr, hdr->addr1, hwaccel, rx->security_idx, &rx->tkip_iv32, &rx->tkip_iv16); if (res != TKIP_DECRYPT_OK) return RX_DROP_UNUSABLE; /* Trim ICV */ if (!(status->flag & RX_FLAG_ICV_STRIPPED)) skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN); /* Remove IV */ memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen); skb_pull(skb, IEEE80211_TKIP_IV_LEN); return RX_CONTINUE; } static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad) { __le16 mask_fc; int a4_included, mgmt; u8 qos_tid; u16 len_a; unsigned int hdrlen; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; /* * Mask FC: zero subtype b4 b5 b6 (if not mgmt) * Retry, PwrMgt, MoreData; set Protected */ mgmt = ieee80211_is_mgmt(hdr->frame_control); mask_fc = hdr->frame_control; mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); if (!mgmt) mask_fc &= ~cpu_to_le16(0x0070); mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); hdrlen = ieee80211_hdrlen(hdr->frame_control); len_a = hdrlen - 2; a4_included = ieee80211_has_a4(hdr->frame_control); if (ieee80211_is_data_qos(hdr->frame_control)) qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; else qos_tid = 0; /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC * mode authentication are not allowed to collide, yet both are derived * from this vector b_0. We only set L := 1 here to indicate that the * data size can be represented in (L+1) bytes. The CCM layer will take * care of storing the data length in the top (L+1) bytes and setting * and clearing the other bits as is required to derive the two IVs. */ b_0[0] = 0x1; /* Nonce: Nonce Flags | A2 | PN * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) */ b_0[1] = qos_tid | (mgmt << 4); memcpy(&b_0[2], hdr->addr2, ETH_ALEN); memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN); /* AAD (extra authenticate-only data) / masked 802.11 header * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ put_unaligned_be16(len_a, &aad[0]); put_unaligned(mask_fc, (__le16 *)&aad[2]); memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); /* Mask Seq#, leave Frag# */ aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; aad[23] = 0; if (a4_included) { memcpy(&aad[24], hdr->addr4, ETH_ALEN); aad[30] = qos_tid; aad[31] = 0; } else { memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); aad[24] = qos_tid; } } static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) { hdr[0] = pn[5]; hdr[1] = pn[4]; hdr[2] = 0; hdr[3] = 0x20 | (key_id << 6); hdr[4] = pn[3]; hdr[5] = pn[2]; hdr[6] = pn[1]; hdr[7] = pn[0]; } static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) { pn[0] = hdr[7]; pn[1] = hdr[6]; pn[2] = hdr[5]; pn[3] = hdr[4]; pn[4] = hdr[1]; pn[5] = hdr[0]; } static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb, unsigned int mic_len) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; struct ieee80211_key *key = tx->key; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); int hdrlen, len, tail; u8 *pos; u8 pn[6]; u64 pn64; u8 aad[CCM_AAD_LEN]; u8 b_0[AES_BLOCK_SIZE]; if (info->control.hw_key && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) && !((info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) && ieee80211_is_mgmt(hdr->frame_control))) { /* * hwaccel has no need for preallocated room for CCMP * header or MIC fields */ return 0; } hdrlen = ieee80211_hdrlen(hdr->frame_control); len = skb->len - hdrlen; if (info->control.hw_key) tail = 0; else tail = mic_len; if (WARN_ON(skb_tailroom(skb) < tail || skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN)) return -1; pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN); memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen); /* the HW only needs room for the IV, but not the actual IV */ if (info->control.hw_key && (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) return 0; hdr = (struct ieee80211_hdr *) pos; pos += hdrlen; pn64 = atomic64_inc_return(&key->conf.tx_pn); pn[5] = pn64; pn[4] = pn64 >> 8; pn[3] = pn64 >> 16; pn[2] = pn64 >> 24; pn[1] = pn64 >> 32; pn[0] = pn64 >> 40; ccmp_pn2hdr(pos, pn, key->conf.keyidx); /* hwaccel - with software CCMP header */ if (info->control.hw_key) return 0; pos += IEEE80211_CCMP_HDR_LEN; ccmp_special_blocks(skb, pn, b_0, aad); return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len, skb_put(skb, mic_len), mic_len); } ieee80211_tx_result ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx, unsigned int mic_len) { struct sk_buff *skb; ieee80211_tx_set_protected(tx); skb_queue_walk(&tx->skbs, skb) { if (ccmp_encrypt_skb(tx, skb, mic_len) < 0) return TX_DROP; } return TX_CONTINUE; } ieee80211_rx_result ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx, unsigned int mic_len) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; int hdrlen; struct ieee80211_key *key = rx->key; struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); u8 pn[IEEE80211_CCMP_PN_LEN]; int data_len; int queue; hdrlen = ieee80211_hdrlen(hdr->frame_control); if (!ieee80211_is_data(hdr->frame_control) && !ieee80211_is_robust_mgmt_frame(skb)) return RX_CONTINUE; if (status->flag & RX_FLAG_DECRYPTED) { if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN)) return RX_DROP_UNUSABLE; if (status->flag & RX_FLAG_MIC_STRIPPED) mic_len = 0; } else { if (skb_linearize(rx->skb)) return RX_DROP_UNUSABLE; } data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len; if (!rx->sta || data_len < 0) return RX_DROP_UNUSABLE; if (!(status->flag & RX_FLAG_PN_VALIDATED)) { int res; ccmp_hdr2pn(pn, skb->data + hdrlen); queue = rx->security_idx; res = memcmp(pn, key->u.ccmp.rx_pn[queue], IEEE80211_CCMP_PN_LEN); if (res < 0 || (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) { key->u.ccmp.replays++; return RX_DROP_UNUSABLE; } if (!(status->flag & RX_FLAG_DECRYPTED)) { u8 aad[2 * AES_BLOCK_SIZE]; u8 b_0[AES_BLOCK_SIZE]; /* hardware didn't decrypt/verify MIC */ ccmp_special_blocks(skb, pn, b_0, aad); if (ieee80211_aes_ccm_decrypt( key->u.ccmp.tfm, b_0, aad, skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN, data_len, skb->data + skb->len - mic_len, mic_len)) return RX_DROP_UNUSABLE; } memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN); } /* Remove CCMP header and MIC */ if (pskb_trim(skb, skb->len - mic_len)) return RX_DROP_UNUSABLE; memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen); skb_pull(skb, IEEE80211_CCMP_HDR_LEN); return RX_CONTINUE; } static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad) { __le16 mask_fc; u8 qos_tid; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; memcpy(j_0, hdr->addr2, ETH_ALEN); memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN); j_0[13] = 0; j_0[14] = 0; j_0[AES_BLOCK_SIZE - 1] = 0x01; /* AAD (extra authenticate-only data) / masked 802.11 header * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]); /* Mask FC: zero subtype b4 b5 b6 (if not mgmt) * Retry, PwrMgt, MoreData; set Protected */ mask_fc = hdr->frame_control; mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); if (!ieee80211_is_mgmt(hdr->frame_control)) mask_fc &= ~cpu_to_le16(0x0070); mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); put_unaligned(mask_fc, (__le16 *)&aad[2]); memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); /* Mask Seq#, leave Frag# */ aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f; aad[23] = 0; if (ieee80211_is_data_qos(hdr->frame_control)) qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; else qos_tid = 0; if (ieee80211_has_a4(hdr->frame_control)) { memcpy(&aad[24], hdr->addr4, ETH_ALEN); aad[30] = qos_tid; aad[31] = 0; } else { memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); aad[24] = qos_tid; } } static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id) { hdr[0] = pn[5]; hdr[1] = pn[4]; hdr[2] = 0; hdr[3] = 0x20 | (key_id << 6); hdr[4] = pn[3]; hdr[5] = pn[2]; hdr[6] = pn[1]; hdr[7] = pn[0]; } static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr) { pn[0] = hdr[7]; pn[1] = hdr[6]; pn[2] = hdr[5]; pn[3] = hdr[4]; pn[4] = hdr[1]; pn[5] = hdr[0]; } static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; struct ieee80211_key *key = tx->key; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); int hdrlen, len, tail; u8 *pos; u8 pn[6]; u64 pn64; u8 aad[GCM_AAD_LEN]; u8 j_0[AES_BLOCK_SIZE]; if (info->control.hw_key && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) && !((info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) && ieee80211_is_mgmt(hdr->frame_control))) { /* hwaccel has no need for preallocated room for GCMP * header or MIC fields */ return 0; } hdrlen = ieee80211_hdrlen(hdr->frame_control); len = skb->len - hdrlen; if (info->control.hw_key) tail = 0; else tail = IEEE80211_GCMP_MIC_LEN; if (WARN_ON(skb_tailroom(skb) < tail || skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN)) return -1; pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN); memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen); skb_set_network_header(skb, skb_network_offset(skb) + IEEE80211_GCMP_HDR_LEN); /* the HW only needs room for the IV, but not the actual IV */ if (info->control.hw_key && (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) return 0; hdr = (struct ieee80211_hdr *)pos; pos += hdrlen; pn64 = atomic64_inc_return(&key->conf.tx_pn); pn[5] = pn64; pn[4] = pn64 >> 8; pn[3] = pn64 >> 16; pn[2] = pn64 >> 24; pn[1] = pn64 >> 32; pn[0] = pn64 >> 40; gcmp_pn2hdr(pos, pn, key->conf.keyidx); /* hwaccel - with software GCMP header */ if (info->control.hw_key) return 0; pos += IEEE80211_GCMP_HDR_LEN; gcmp_special_blocks(skb, pn, j_0, aad); return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len, skb_put(skb, IEEE80211_GCMP_MIC_LEN)); } ieee80211_tx_result ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx) { struct sk_buff *skb; ieee80211_tx_set_protected(tx); skb_queue_walk(&tx->skbs, skb) { if (gcmp_encrypt_skb(tx, skb) < 0) return TX_DROP; } return TX_CONTINUE; } ieee80211_rx_result ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; int hdrlen; struct ieee80211_key *key = rx->key; struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); u8 pn[IEEE80211_GCMP_PN_LEN]; int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN; hdrlen = ieee80211_hdrlen(hdr->frame_control); if (!ieee80211_is_data(hdr->frame_control) && !ieee80211_is_robust_mgmt_frame(skb)) return RX_CONTINUE; if (status->flag & RX_FLAG_DECRYPTED) { if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN)) return RX_DROP_UNUSABLE; if (status->flag & RX_FLAG_MIC_STRIPPED) mic_len = 0; } else { if (skb_linearize(rx->skb)) return RX_DROP_UNUSABLE; } data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len; if (!rx->sta || data_len < 0) return RX_DROP_UNUSABLE; if (!(status->flag & RX_FLAG_PN_VALIDATED)) { int res; gcmp_hdr2pn(pn, skb->data + hdrlen); queue = rx->security_idx; res = memcmp(pn, key->u.gcmp.rx_pn[queue], IEEE80211_GCMP_PN_LEN); if (res < 0 || (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) { key->u.gcmp.replays++; return RX_DROP_UNUSABLE; } if (!(status->flag & RX_FLAG_DECRYPTED)) { u8 aad[2 * AES_BLOCK_SIZE]; u8 j_0[AES_BLOCK_SIZE]; /* hardware didn't decrypt/verify MIC */ gcmp_special_blocks(skb, pn, j_0, aad); if (ieee80211_aes_gcm_decrypt( key->u.gcmp.tfm, j_0, aad, skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN, data_len, skb->data + skb->len - IEEE80211_GCMP_MIC_LEN)) return RX_DROP_UNUSABLE; } memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN); } /* Remove GCMP header and MIC */ if (pskb_trim(skb, skb->len - mic_len)) return RX_DROP_UNUSABLE; memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen); skb_pull(skb, IEEE80211_GCMP_HDR_LEN); return RX_CONTINUE; } static ieee80211_tx_result ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx, struct sk_buff *skb) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; struct ieee80211_key *key = tx->key; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); int hdrlen; u8 *pos, iv_len = key->conf.iv_len; if (info->control.hw_key && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) { /* hwaccel has no need for preallocated head room */ return TX_CONTINUE; } if (unlikely(skb_headroom(skb) < iv_len && pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC))) return TX_DROP; hdrlen = ieee80211_hdrlen(hdr->frame_control); pos = skb_push(skb, iv_len); memmove(pos, pos + iv_len, hdrlen); return TX_CONTINUE; } static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len) { int i; /* pn is little endian */ for (i = len - 1; i >= 0; i--) { if (pn1[i] < pn2[i]) return -1; else if (pn1[i] > pn2[i]) return 1; } return 0; } static ieee80211_rx_result ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx) { struct ieee80211_key *key = rx->key; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; const struct ieee80211_cipher_scheme *cs = NULL; int hdrlen = ieee80211_hdrlen(hdr->frame_control); struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb); int data_len; u8 *rx_pn; u8 *skb_pn; u8 qos_tid; if (!rx->sta || !rx->sta->cipher_scheme || !(status->flag & RX_FLAG_DECRYPTED)) return RX_DROP_UNUSABLE; if (!ieee80211_is_data(hdr->frame_control)) return RX_CONTINUE; cs = rx->sta->cipher_scheme; data_len = rx->skb->len - hdrlen - cs->hdr_len; if (data_len < 0) return RX_DROP_UNUSABLE; if (ieee80211_is_data_qos(hdr->frame_control)) qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; else qos_tid = 0; if (skb_linearize(rx->skb)) return RX_DROP_UNUSABLE; hdr = (struct ieee80211_hdr *)rx->skb->data; rx_pn = key->u.gen.rx_pn[qos_tid]; skb_pn = rx->skb->data + hdrlen + cs->pn_off; if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0) return RX_DROP_UNUSABLE; memcpy(rx_pn, skb_pn, cs->pn_len); /* remove security header and MIC */ if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len)) return RX_DROP_UNUSABLE; memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen); skb_pull(rx->skb, cs->hdr_len); return RX_CONTINUE; } static void bip_aad(struct sk_buff *skb, u8 *aad) { __le16 mask_fc; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; /* BIP AAD: FC(masked) || A1 || A2 || A3 */ /* FC type/subtype */ /* Mask FC Retry, PwrMgt, MoreData flags to zero */ mask_fc = hdr->frame_control; mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); put_unaligned(mask_fc, (__le16 *) &aad[0]); /* A1 || A2 || A3 */ memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN); } static inline void bip_ipn_set64(u8 *d, u64 pn) { *d++ = pn; *d++ = pn >> 8; *d++ = pn >> 16; *d++ = pn >> 24; *d++ = pn >> 32; *d = pn >> 40; } static inline void bip_ipn_swap(u8 *d, const u8 *s) { *d++ = s[5]; *d++ = s[4]; *d++ = s[3]; *d++ = s[2]; *d++ = s[1]; *d = s[0]; } ieee80211_tx_result ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) { struct sk_buff *skb; struct ieee80211_tx_info *info; struct ieee80211_key *key = tx->key; struct ieee80211_mmie *mmie; u8 aad[20]; u64 pn64; if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) return TX_DROP; skb = skb_peek(&tx->skbs); info = IEEE80211_SKB_CB(skb); if (info->control.hw_key) return TX_CONTINUE; if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) return TX_DROP; mmie = skb_put(skb, sizeof(*mmie)); mmie->element_id = WLAN_EID_MMIE; mmie->length = sizeof(*mmie) - 2; mmie->key_id = cpu_to_le16(key->conf.keyidx); /* PN = PN + 1 */ pn64 = atomic64_inc_return(&key->conf.tx_pn); bip_ipn_set64(mmie->sequence_number, pn64); bip_aad(skb, aad); /* * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) */ ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, skb->data + 24, skb->len - 24, mmie->mic); return TX_CONTINUE; } ieee80211_tx_result ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx) { struct sk_buff *skb; struct ieee80211_tx_info *info; struct ieee80211_key *key = tx->key; struct ieee80211_mmie_16 *mmie; u8 aad[20]; u64 pn64; if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) return TX_DROP; skb = skb_peek(&tx->skbs); info = IEEE80211_SKB_CB(skb); if (info->control.hw_key) return TX_CONTINUE; if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) return TX_DROP; mmie = skb_put(skb, sizeof(*mmie)); mmie->element_id = WLAN_EID_MMIE; mmie->length = sizeof(*mmie) - 2; mmie->key_id = cpu_to_le16(key->conf.keyidx); /* PN = PN + 1 */ pn64 = atomic64_inc_return(&key->conf.tx_pn); bip_ipn_set64(mmie->sequence_number, pn64); bip_aad(skb, aad); /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */ ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad, skb->data + 24, skb->len - 24, mmie->mic); return TX_CONTINUE; } ieee80211_rx_result ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) { struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); struct ieee80211_key *key = rx->key; struct ieee80211_mmie *mmie; u8 aad[20], mic[8], ipn[6]; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; if (!ieee80211_is_mgmt(hdr->frame_control)) return RX_CONTINUE; /* management frames are already linear */ if (skb->len < 24 + sizeof(*mmie)) return RX_DROP_UNUSABLE; mmie = (struct ieee80211_mmie *) (skb->data + skb->len - sizeof(*mmie)); if (mmie->element_id != WLAN_EID_MMIE || mmie->length != sizeof(*mmie) - 2) return RX_DROP_UNUSABLE; /* Invalid MMIE */ bip_ipn_swap(ipn, mmie->sequence_number); if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { key->u.aes_cmac.replays++; return RX_DROP_UNUSABLE; } if (!(status->flag & RX_FLAG_DECRYPTED)) { /* hardware didn't decrypt/verify MIC */ bip_aad(skb, aad); ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, skb->data + 24, skb->len - 24, mic); if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) { key->u.aes_cmac.icverrors++; return RX_DROP_UNUSABLE; } } memcpy(key->u.aes_cmac.rx_pn, ipn, 6); /* Remove MMIE */ skb_trim(skb, skb->len - sizeof(*mmie)); return RX_CONTINUE; } ieee80211_rx_result ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx) { struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); struct ieee80211_key *key = rx->key; struct ieee80211_mmie_16 *mmie; u8 aad[20], mic[16], ipn[6]; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; if (!ieee80211_is_mgmt(hdr->frame_control)) return RX_CONTINUE; /* management frames are already linear */ if (skb->len < 24 + sizeof(*mmie)) return RX_DROP_UNUSABLE; mmie = (struct ieee80211_mmie_16 *) (skb->data + skb->len - sizeof(*mmie)); if (mmie->element_id != WLAN_EID_MMIE || mmie->length != sizeof(*mmie) - 2) return RX_DROP_UNUSABLE; /* Invalid MMIE */ bip_ipn_swap(ipn, mmie->sequence_number); if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { key->u.aes_cmac.replays++; return RX_DROP_UNUSABLE; } if (!(status->flag & RX_FLAG_DECRYPTED)) { /* hardware didn't decrypt/verify MIC */ bip_aad(skb, aad); ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad, skb->data + 24, skb->len - 24, mic); if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) { key->u.aes_cmac.icverrors++; return RX_DROP_UNUSABLE; } } memcpy(key->u.aes_cmac.rx_pn, ipn, 6); /* Remove MMIE */ skb_trim(skb, skb->len - sizeof(*mmie)); return RX_CONTINUE; } ieee80211_tx_result ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx) { struct sk_buff *skb; struct ieee80211_tx_info *info; struct ieee80211_key *key = tx->key; struct ieee80211_mmie_16 *mmie; struct ieee80211_hdr *hdr; u8 aad[GMAC_AAD_LEN]; u64 pn64; u8 nonce[GMAC_NONCE_LEN]; if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) return TX_DROP; skb = skb_peek(&tx->skbs); info = IEEE80211_SKB_CB(skb); if (info->control.hw_key) return TX_CONTINUE; if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) return TX_DROP; mmie = skb_put(skb, sizeof(*mmie)); mmie->element_id = WLAN_EID_MMIE; mmie->length = sizeof(*mmie) - 2; mmie->key_id = cpu_to_le16(key->conf.keyidx); /* PN = PN + 1 */ pn64 = atomic64_inc_return(&key->conf.tx_pn); bip_ipn_set64(mmie->sequence_number, pn64); bip_aad(skb, aad); hdr = (struct ieee80211_hdr *)skb->data; memcpy(nonce, hdr->addr2, ETH_ALEN); bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number); /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */ if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce, skb->data + 24, skb->len - 24, mmie->mic) < 0) return TX_DROP; return TX_CONTINUE; } ieee80211_rx_result ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx) { struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); struct ieee80211_key *key = rx->key; struct ieee80211_mmie_16 *mmie; u8 aad[GMAC_AAD_LEN], mic[GMAC_MIC_LEN], ipn[6], nonce[GMAC_NONCE_LEN]; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; if (!ieee80211_is_mgmt(hdr->frame_control)) return RX_CONTINUE; /* management frames are already linear */ if (skb->len < 24 + sizeof(*mmie)) return RX_DROP_UNUSABLE; mmie = (struct ieee80211_mmie_16 *) (skb->data + skb->len - sizeof(*mmie)); if (mmie->element_id != WLAN_EID_MMIE || mmie->length != sizeof(*mmie) - 2) return RX_DROP_UNUSABLE; /* Invalid MMIE */ bip_ipn_swap(ipn, mmie->sequence_number); if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) { key->u.aes_gmac.replays++; return RX_DROP_UNUSABLE; } if (!(status->flag & RX_FLAG_DECRYPTED)) { /* hardware didn't decrypt/verify MIC */ bip_aad(skb, aad); memcpy(nonce, hdr->addr2, ETH_ALEN); memcpy(nonce + ETH_ALEN, ipn, 6); if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce, skb->data + 24, skb->len - 24, mic) < 0 || crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) { key->u.aes_gmac.icverrors++; return RX_DROP_UNUSABLE; } } memcpy(key->u.aes_gmac.rx_pn, ipn, 6); /* Remove MMIE */ skb_trim(skb, skb->len - sizeof(*mmie)); return RX_CONTINUE; } ieee80211_tx_result ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx) { struct sk_buff *skb; struct ieee80211_tx_info *info = NULL; ieee80211_tx_result res; skb_queue_walk(&tx->skbs, skb) { info = IEEE80211_SKB_CB(skb); /* handle hw-only algorithm */ if (!info->control.hw_key) return TX_DROP; if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) { res = ieee80211_crypto_cs_encrypt(tx, skb); if (res != TX_CONTINUE) return res; } } ieee80211_tx_set_protected(tx); return TX_CONTINUE; } ieee80211_rx_result ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx) { if (rx->sta && rx->sta->cipher_scheme) return ieee80211_crypto_cs_decrypt(rx); return RX_DROP_UNUSABLE; }