+++ /dev/null
-/*
- * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
- *
- * Copyright (c) 2003-2004, 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. See README and COPYING for
- * more details.
- */
-
-#include <linux/version.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/random.h>
-#include <linux/skbuff.h>
-#include <linux/netdevice.h>
-#include <linux/if_ether.h>
-#include <linux/if_arp.h>
-#include <asm/string.h>
-#include <linux/wireless.h>
-
-#include "ieee80211.h"
-
-#include <linux/crypto.h>
-#include <linux/scatterlist.h>
-
-MODULE_AUTHOR("Jouni Malinen");
-MODULE_DESCRIPTION("Host AP crypt: CCMP");
-MODULE_LICENSE("GPL");
-
-#define AES_BLOCK_LEN 16
-#define CCMP_HDR_LEN 8
-#define CCMP_MIC_LEN 8
-#define CCMP_TK_LEN 16
-#define CCMP_PN_LEN 6
-
-struct ieee80211_ccmp_data {
- u8 key[CCMP_TK_LEN];
- int key_set;
-
- u8 tx_pn[CCMP_PN_LEN];
- u8 rx_pn[CCMP_PN_LEN];
-
- u32 dot11RSNAStatsCCMPFormatErrors;
- u32 dot11RSNAStatsCCMPReplays;
- u32 dot11RSNAStatsCCMPDecryptErrors;
-
- int key_idx;
-
- struct crypto_tfm *tfm;
-
- /* scratch buffers for virt_to_page() (crypto API) */
- u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
- tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
- u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
-};
-
-void ieee80211_ccmp_aes_encrypt(struct crypto_tfm *tfm,
- const u8 pt[16], u8 ct[16])
-{
- crypto_cipher_encrypt_one((void*)tfm, ct, pt);
-}
-
-static void * ieee80211_ccmp_init(int key_idx)
-{
- struct ieee80211_ccmp_data *priv;
-
- priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
- if (priv == NULL)
- goto fail;
- priv->key_idx = key_idx;
-
- priv->tfm = (void *)crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(priv->tfm)) {
- printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
- "crypto API aes\n");
- priv->tfm = NULL;
- goto fail;
- }
-
- return priv;
-
-fail:
- if (priv) {
- if (priv->tfm)
- crypto_free_cipher((void*)priv->tfm);
- kfree(priv);
- }
-
- return NULL;
-}
-
-
-static void ieee80211_ccmp_deinit(void *priv)
-{
- struct ieee80211_ccmp_data *_priv = priv;
-
- if (_priv && _priv->tfm)
- crypto_free_cipher((void*)_priv->tfm);
- kfree(priv);
-}
-
-
-static inline void xor_block(u8 *b, u8 *a, size_t len)
-{
- int i;
- for (i = 0; i < len; i++)
- b[i] ^= a[i];
-}
-
-
-
-static void ccmp_init_blocks(struct crypto_tfm *tfm,
- struct ieee80211_hdr_4addr *hdr,
- u8 *pn, size_t dlen, u8 *b0, u8 *auth,
- u8 *s0)
-{
- u8 *pos, qc = 0;
- size_t aad_len;
- u16 fc;
- int a4_included, qc_included;
- u8 aad[2 * AES_BLOCK_LEN];
-
- fc = le16_to_cpu(hdr->frame_ctl);
- a4_included = ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
- (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS));
- /*
- qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
- (WLAN_FC_GET_STYPE(fc) & 0x08));
- */
- qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
- (WLAN_FC_GET_STYPE(fc) & 0x80));
- aad_len = 22;
- if (a4_included)
- aad_len += 6;
- if (qc_included) {
- pos = (u8 *) &hdr->addr4;
- if (a4_included)
- pos += 6;
- qc = *pos & 0x0f;
- aad_len += 2;
- }
- /* CCM Initial Block:
- * Flag (Include authentication header, M=3 (8-octet MIC),
- * L=1 (2-octet Dlen))
- * Nonce: 0x00 | A2 | PN
- * Dlen */
- b0[0] = 0x59;
- b0[1] = qc;
- memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
- memcpy(b0 + 8, pn, CCMP_PN_LEN);
- b0[14] = (dlen >> 8) & 0xff;
- b0[15] = dlen & 0xff;
-
- /* AAD:
- * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
- * A1 | A2 | A3
- * SC with bits 4..15 (seq#) masked to zero
- * A4 (if present)
- * QC (if present)
- */
- pos = (u8 *) hdr;
- aad[0] = 0; /* aad_len >> 8 */
- aad[1] = aad_len & 0xff;
- aad[2] = pos[0] & 0x8f;
- aad[3] = pos[1] & 0xc7;
- memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
- pos = (u8 *) &hdr->seq_ctl;
- aad[22] = pos[0] & 0x0f;
- aad[23] = 0; /* all bits masked */
- memset(aad + 24, 0, 8);
- if (a4_included)
- memcpy(aad + 24, hdr->addr4, ETH_ALEN);
- if (qc_included) {
- aad[a4_included ? 30 : 24] = qc;
- /* rest of QC masked */
- }
-
- /* Start with the first block and AAD */
- ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
- xor_block(auth, aad, AES_BLOCK_LEN);
- ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
- xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
- ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
- b0[0] &= 0x07;
- b0[14] = b0[15] = 0;
- ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
-}
-
-
-
-static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
-{
- struct ieee80211_ccmp_data *key = priv;
- int data_len, i;
- u8 *pos;
- struct ieee80211_hdr_4addr *hdr;
- cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
-
- if (skb_headroom(skb) < CCMP_HDR_LEN ||
- skb_tailroom(skb) < CCMP_MIC_LEN ||
- skb->len < hdr_len)
- return -1;
-
- data_len = skb->len - hdr_len;
- pos = skb_push(skb, CCMP_HDR_LEN);
- memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
- pos += hdr_len;
-
- i = CCMP_PN_LEN - 1;
- while (i >= 0) {
- key->tx_pn[i]++;
- if (key->tx_pn[i] != 0)
- break;
- i--;
- }
-
- *pos++ = key->tx_pn[5];
- *pos++ = key->tx_pn[4];
- *pos++ = 0;
- *pos++ = (key->key_idx << 6) | (1 << 5) /* Ext IV included */;
- *pos++ = key->tx_pn[3];
- *pos++ = key->tx_pn[2];
- *pos++ = key->tx_pn[1];
- *pos++ = key->tx_pn[0];
-
-
- hdr = (struct ieee80211_hdr_4addr *) skb->data;
- if (!tcb_desc->bHwSec)
- {
- int blocks, last, len;
- u8 *mic;
- u8 *b0 = key->tx_b0;
- u8 *b = key->tx_b;
- u8 *e = key->tx_e;
- u8 *s0 = key->tx_s0;
-
- mic = skb_put(skb, CCMP_MIC_LEN);
-
- ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
-
- blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
- last = data_len % AES_BLOCK_LEN;
-
- for (i = 1; i <= blocks; i++) {
- len = (i == blocks && last) ? last : AES_BLOCK_LEN;
- /* Authentication */
- xor_block(b, pos, len);
- ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
- /* Encryption, with counter */
- b0[14] = (i >> 8) & 0xff;
- b0[15] = i & 0xff;
- ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
- xor_block(pos, e, len);
- pos += len;
- }
-
- for (i = 0; i < CCMP_MIC_LEN; i++)
- mic[i] = b[i] ^ s0[i];
- }
- return 0;
-}
-
-
-static int ieee80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
-{
- struct ieee80211_ccmp_data *key = priv;
- u8 keyidx, *pos;
- struct ieee80211_hdr_4addr *hdr;
- cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
- u8 pn[6];
-
- if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
- key->dot11RSNAStatsCCMPFormatErrors++;
- return -1;
- }
-
- hdr = (struct ieee80211_hdr_4addr *) skb->data;
- pos = skb->data + hdr_len;
- keyidx = pos[3];
- if (!(keyidx & (1 << 5))) {
- if (net_ratelimit()) {
- printk(KERN_DEBUG "CCMP: received packet without ExtIV"
- " flag from %pM\n", hdr->addr2);
- }
- key->dot11RSNAStatsCCMPFormatErrors++;
- return -2;
- }
- keyidx >>= 6;
- if (key->key_idx != keyidx) {
- printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
- "keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
- return -6;
- }
- if (!key->key_set) {
- if (net_ratelimit()) {
- printk(KERN_DEBUG "CCMP: received packet from %pM"
- " with keyid=%d that does not have a configured"
- " key\n", hdr->addr2, keyidx);
- }
- return -3;
- }
-
- pn[0] = pos[7];
- pn[1] = pos[6];
- pn[2] = pos[5];
- pn[3] = pos[4];
- pn[4] = pos[1];
- pn[5] = pos[0];
- pos += 8;
-
- if (memcmp(pn, key->rx_pn, CCMP_PN_LEN) <= 0) {
- if (net_ratelimit()) {
- printk(KERN_DEBUG "CCMP: replay detected: STA=%pM"
- " previous PN %pm received PN %pm\n",
- hdr->addr2, key->rx_pn, pn);
- }
- key->dot11RSNAStatsCCMPReplays++;
- return -4;
- }
- if (!tcb_desc->bHwSec)
- {
- size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
- u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
- u8 *b0 = key->rx_b0;
- u8 *b = key->rx_b;
- u8 *a = key->rx_a;
- int i, blocks, last, len;
-
-
- ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
- xor_block(mic, b, CCMP_MIC_LEN);
-
- blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
- last = data_len % AES_BLOCK_LEN;
-
- for (i = 1; i <= blocks; i++) {
- len = (i == blocks && last) ? last : AES_BLOCK_LEN;
- /* Decrypt, with counter */
- b0[14] = (i >> 8) & 0xff;
- b0[15] = i & 0xff;
- ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
- xor_block(pos, b, len);
- /* Authentication */
- xor_block(a, pos, len);
- ieee80211_ccmp_aes_encrypt(key->tfm, a, a);
- pos += len;
- }
-
- if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
- if (net_ratelimit()) {
- printk(KERN_DEBUG "CCMP: decrypt failed: STA="
- "%pM\n", hdr->addr2);
- }
- key->dot11RSNAStatsCCMPDecryptErrors++;
- return -5;
- }
-
- memcpy(key->rx_pn, pn, CCMP_PN_LEN);
- }
- /* Remove hdr and MIC */
- memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
- skb_pull(skb, CCMP_HDR_LEN);
- skb_trim(skb, skb->len - CCMP_MIC_LEN);
-
- return keyidx;
-}
-
-
-static int ieee80211_ccmp_set_key(void *key, int len, u8 *seq, void *priv)
-{
- struct ieee80211_ccmp_data *data = priv;
- int keyidx;
- struct crypto_tfm *tfm = data->tfm;
-
- keyidx = data->key_idx;
- memset(data, 0, sizeof(*data));
- data->key_idx = keyidx;
- data->tfm = tfm;
- if (len == CCMP_TK_LEN) {
- memcpy(data->key, key, CCMP_TK_LEN);
- data->key_set = 1;
- if (seq) {
- data->rx_pn[0] = seq[5];
- data->rx_pn[1] = seq[4];
- data->rx_pn[2] = seq[3];
- data->rx_pn[3] = seq[2];
- data->rx_pn[4] = seq[1];
- data->rx_pn[5] = seq[0];
- }
- crypto_cipher_setkey((void*)data->tfm, data->key, CCMP_TK_LEN);
- } else if (len == 0)
- data->key_set = 0;
- else
- return -1;
-
- return 0;
-}
-
-
-static int ieee80211_ccmp_get_key(void *key, int len, u8 *seq, void *priv)
-{
- struct ieee80211_ccmp_data *data = priv;
-
- if (len < CCMP_TK_LEN)
- return -1;
-
- if (!data->key_set)
- return 0;
- memcpy(key, data->key, CCMP_TK_LEN);
-
- if (seq) {
- seq[0] = data->tx_pn[5];
- seq[1] = data->tx_pn[4];
- seq[2] = data->tx_pn[3];
- seq[3] = data->tx_pn[2];
- seq[4] = data->tx_pn[1];
- seq[5] = data->tx_pn[0];
- }
-
- return CCMP_TK_LEN;
-}
-
-
-static char * ieee80211_ccmp_print_stats(char *p, void *priv)
-{
- struct ieee80211_ccmp_data *ccmp = priv;
- p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
- "tx_pn=%pm rx_pn=%pm "
- "format_errors=%d replays=%d decrypt_errors=%d\n",
- ccmp->key_idx, ccmp->key_set,
- ccmp->tx_pn, ccmp->rx_pn,
- ccmp->dot11RSNAStatsCCMPFormatErrors,
- ccmp->dot11RSNAStatsCCMPReplays,
- ccmp->dot11RSNAStatsCCMPDecryptErrors);
-
- return p;
-}
-
-void ieee80211_ccmp_null(void)
-{
- return;
-}
-
-static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
- .name = "CCMP",
- .init = ieee80211_ccmp_init,
- .deinit = ieee80211_ccmp_deinit,
- .encrypt_mpdu = ieee80211_ccmp_encrypt,
- .decrypt_mpdu = ieee80211_ccmp_decrypt,
- .encrypt_msdu = NULL,
- .decrypt_msdu = NULL,
- .set_key = ieee80211_ccmp_set_key,
- .get_key = ieee80211_ccmp_get_key,
- .print_stats = ieee80211_ccmp_print_stats,
- .extra_prefix_len = CCMP_HDR_LEN,
- .extra_postfix_len = CCMP_MIC_LEN,
- .owner = THIS_MODULE,
-};
-
-int __init ieee80211_crypto_ccmp_init(void)
-{
- return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
-}
-
-void ieee80211_crypto_ccmp_exit(void)
-{
- ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
-}
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