--- /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/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 <linux/string.h>
+#include <linux/wireless.h>
+#include "rtllib.h"
+
+#include <linux/crypto.h>
+
+#include <linux/scatterlist.h>
+
+#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 rtllib_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];
+};
+
+static void rtllib_ccmp_aes_encrypt(struct crypto_tfm *tfm,
+ const u8 pt[16], u8 ct[16])
+{
+ crypto_cipher_encrypt_one((void *)tfm, ct, pt);
+}
+
+static void *rtllib_ccmp_init(int key_idx)
+{
+ struct rtllib_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)) {
+ pr_debug("rtllib_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 rtllib_ccmp_deinit(void *priv)
+{
+ struct rtllib_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 rtllib_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 & (RTLLIB_FCTL_TODS | RTLLIB_FCTL_FROMDS)) ==
+ (RTLLIB_FCTL_TODS | RTLLIB_FCTL_FROMDS));
+
+ qc_included = ((WLAN_FC_GET_TYPE(fc) == RTLLIB_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 */
+ rtllib_ccmp_aes_encrypt(tfm, b0, auth);
+ xor_block(auth, aad, AES_BLOCK_LEN);
+ rtllib_ccmp_aes_encrypt(tfm, auth, auth);
+ xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
+ rtllib_ccmp_aes_encrypt(tfm, auth, auth);
+ b0[0] &= 0x07;
+ b0[14] = b0[15] = 0;
+ rtllib_ccmp_aes_encrypt(tfm, b0, s0);
+}
+
+
+
+static int rtllib_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
+{
+ struct rtllib_ccmp_data *key = priv;
+ int data_len, i;
+ u8 *pos;
+ struct rtllib_hdr_4addr *hdr;
+ struct cb_desc *tcb_desc = (struct 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 rtllib_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);
+ rtllib_ccmp_aes_encrypt(key->tfm, b, b);
+ /* Encryption, with counter */
+ b0[14] = (i >> 8) & 0xff;
+ b0[15] = i & 0xff;
+ rtllib_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 rtllib_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
+{
+ struct rtllib_ccmp_data *key = priv;
+ u8 keyidx, *pos;
+ struct rtllib_hdr_4addr *hdr;
+ struct cb_desc *tcb_desc = (struct 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 rtllib_hdr_4addr *) skb->data;
+ pos = skb->data + hdr_len;
+ keyidx = pos[3];
+ if (!(keyidx & (1 << 5))) {
+ if (net_ratelimit()) {
+ pr_debug("CCMP: received packet without ExtIV flag from %pM\n",
+ hdr->addr2);
+ }
+ key->dot11RSNAStatsCCMPFormatErrors++;
+ return -2;
+ }
+ keyidx >>= 6;
+ if (key->key_idx != keyidx) {
+ pr_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()) {
+ pr_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) {
+ 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;
+ rtllib_ccmp_aes_encrypt(key->tfm, b0, b);
+ xor_block(pos, b, len);
+ /* Authentication */
+ xor_block(a, pos, len);
+ rtllib_ccmp_aes_encrypt(key->tfm, a, a);
+ pos += len;
+ }
+
+ if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
+ if (net_ratelimit()) {
+ pr_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 rtllib_ccmp_set_key(void *key, int len, u8 *seq, void *priv)
+{
+ struct rtllib_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 rtllib_ccmp_get_key(void *key, int len, u8 *seq, void *priv)
+{
+ struct rtllib_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 void rtllib_ccmp_print_stats(struct seq_file *m, void *priv)
+{
+ struct rtllib_ccmp_data *ccmp = priv;
+
+ seq_printf(m,
+ "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);
+}
+
+static struct lib80211_crypto_ops rtllib_crypt_ccmp = {
+ .name = "R-CCMP",
+ .init = rtllib_ccmp_init,
+ .deinit = rtllib_ccmp_deinit,
+ .encrypt_mpdu = rtllib_ccmp_encrypt,
+ .decrypt_mpdu = rtllib_ccmp_decrypt,
+ .encrypt_msdu = NULL,
+ .decrypt_msdu = NULL,
+ .set_key = rtllib_ccmp_set_key,
+ .get_key = rtllib_ccmp_get_key,
+ .print_stats = rtllib_ccmp_print_stats,
+ .extra_mpdu_prefix_len = CCMP_HDR_LEN,
+ .extra_mpdu_postfix_len = CCMP_MIC_LEN,
+ .owner = THIS_MODULE,
+};
+
+
+static int __init rtllib_crypto_ccmp_init(void)
+{
+ return lib80211_register_crypto_ops(&rtllib_crypt_ccmp);
+}
+
+
+static void __exit rtllib_crypto_ccmp_exit(void)
+{
+ lib80211_unregister_crypto_ops(&rtllib_crypt_ccmp);
+}
+
+module_init(rtllib_crypto_ccmp_init);
+module_exit(rtllib_crypto_ccmp_exit);
+
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff