1 files changed, 448 insertions, 0 deletions
diff --git a/net/wireless/lib80211_crypt_ccmp.c b/net/wireless/lib80211_crypt_ccmp.c
new file mode 100644
index 0000000000..cca5e1cf08
--- /dev/null
+++ b/net/wireless/lib80211_crypt_ccmp.c
@@ -0,0 +1,448 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * lib80211 crypt: host-based CCMP encryption implementation for lib80211
+ *
+ * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/err.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 <linux/ieee80211.h>
+
+#include <linux/crypto.h>
+#include <crypto/aead.h>
+
+#include <net/lib80211.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 lib80211_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_aead *tfm;
+
+	/* scratch buffers for virt_to_page() (crypto API) */
+	u8 tx_aad[2 * AES_BLOCK_LEN];
+	u8 rx_aad[2 * AES_BLOCK_LEN];
+};
+
+static void *lib80211_ccmp_init(int key_idx)
+{
+	struct lib80211_ccmp_data *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
+	if (priv == NULL)
+		goto fail;
+	priv->key_idx = key_idx;
+
+	priv->tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(priv->tfm)) {
+		priv->tfm = NULL;
+		goto fail;
+	}
+
+	return priv;
+
+      fail:
+	if (priv) {
+		if (priv->tfm)
+			crypto_free_aead(priv->tfm);
+		kfree(priv);
+	}
+
+	return NULL;
+}
+
+static void lib80211_ccmp_deinit(void *priv)
+{
+	struct lib80211_ccmp_data *_priv = priv;
+	if (_priv && _priv->tfm)
+		crypto_free_aead(_priv->tfm);
+	kfree(priv);
+}
+
+static int ccmp_init_iv_and_aad(const struct ieee80211_hdr *hdr,
+				const u8 *pn, u8 *iv, u8 *aad)
+{
+	u8 *pos, qc = 0;
+	size_t aad_len;
+	int a4_included, qc_included;
+
+	a4_included = ieee80211_has_a4(hdr->frame_control);
+	qc_included = ieee80211_is_data_qos(hdr->frame_control);
+
+	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;
+	}
+
+	/* 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 the same vector. 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.
+	 */
+	iv[0] = 0x1;
+
+	/* Nonce: QC | A2 | PN */
+	iv[1] = qc;
+	memcpy(iv + 2, hdr->addr2, ETH_ALEN);
+	memcpy(iv + 8, pn, CCMP_PN_LEN);
+
+	/* 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] = pos[0] & 0x8f;
+	aad[1] = pos[1] & 0xc7;
+	memcpy(aad + 2, &hdr->addrs, 3 * ETH_ALEN);
+	pos = (u8 *) & hdr->seq_ctrl;
+	aad[20] = pos[0] & 0x0f;
+	aad[21] = 0;		/* all bits masked */
+	memset(aad + 22, 0, 8);
+	if (a4_included)
+		memcpy(aad + 22, hdr->addr4, ETH_ALEN);
+	if (qc_included) {
+		aad[a4_included ? 28 : 22] = qc;
+		/* rest of QC masked */
+	}
+	return aad_len;
+}
+
+static int lib80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
+			      u8 *aeskey, int keylen, void *priv)
+{
+	struct lib80211_ccmp_data *key = priv;
+	int i;
+	u8 *pos;
+
+	if (skb_headroom(skb) < CCMP_HDR_LEN || skb->len < hdr_len)
+		return -1;
+
+	if (aeskey != NULL && keylen >= CCMP_TK_LEN)
+		memcpy(aeskey, key->key, CCMP_TK_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];
+
+	return CCMP_HDR_LEN;
+}
+
+static int lib80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
+{
+	struct lib80211_ccmp_data *key = priv;
+	struct ieee80211_hdr *hdr;
+	struct aead_request *req;
+	struct scatterlist sg[2];
+	u8 *aad = key->tx_aad;
+	u8 iv[AES_BLOCK_LEN];
+	int len, data_len, aad_len;
+	int ret;
+
+	if (skb_tailroom(skb) < CCMP_MIC_LEN || skb->len < hdr_len)
+		return -1;
+
+	data_len = skb->len - hdr_len;
+	len = lib80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
+	if (len < 0)
+		return -1;
+
+	req = aead_request_alloc(key->tfm, GFP_ATOMIC);
+	if (!req)
+		return -ENOMEM;
+
+	hdr = (struct ieee80211_hdr *)skb->data;
+	aad_len = ccmp_init_iv_and_aad(hdr, key->tx_pn, iv, aad);
+
+	skb_put(skb, CCMP_MIC_LEN);
+
+	sg_init_table(sg, 2);
+	sg_set_buf(&sg[0], aad, aad_len);
+	sg_set_buf(&sg[1], skb->data + hdr_len + CCMP_HDR_LEN,
+		   data_len + CCMP_MIC_LEN);
+
+	aead_request_set_callback(req, 0, NULL, NULL);
+	aead_request_set_ad(req, aad_len);
+	aead_request_set_crypt(req, sg, sg, data_len, iv);
+
+	ret = crypto_aead_encrypt(req);
+	aead_request_free(req);
+
+	return ret;
+}
+
+/*
+ * deal with seq counter wrapping correctly.
+ * refer to timer_after() for jiffies wrapping handling
+ */
+static inline int ccmp_replay_check(u8 *pn_n, u8 *pn_o)
+{
+	u32 iv32_n, iv16_n;
+	u32 iv32_o, iv16_o;
+
+	iv32_n = (pn_n[0] << 24) | (pn_n[1] << 16) | (pn_n[2] << 8) | pn_n[3];
+	iv16_n = (pn_n[4] << 8) | pn_n[5];
+
+	iv32_o = (pn_o[0] << 24) | (pn_o[1] << 16) | (pn_o[2] << 8) | pn_o[3];
+	iv16_o = (pn_o[4] << 8) | pn_o[5];
+
+	if ((s32)iv32_n - (s32)iv32_o < 0 ||
+	    (iv32_n == iv32_o && iv16_n <= iv16_o))
+		return 1;
+	return 0;
+}
+
+static int lib80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
+{
+	struct lib80211_ccmp_data *key = priv;
+	u8 keyidx, *pos;
+	struct ieee80211_hdr *hdr;
+	struct aead_request *req;
+	struct scatterlist sg[2];
+	u8 *aad = key->rx_aad;
+	u8 iv[AES_BLOCK_LEN];
+	u8 pn[6];
+	int aad_len, ret;
+	size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN;
+
+	if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
+		key->dot11RSNAStatsCCMPFormatErrors++;
+		return -1;
+	}
+
+	hdr = (struct ieee80211_hdr *)skb->data;
+	pos = skb->data + hdr_len;
+	keyidx = pos[3];
+	if (!(keyidx & (1 << 5))) {
+		net_dbg_ratelimited("CCMP: received packet without ExtIV flag from %pM\n",
+				    hdr->addr2);
+		key->dot11RSNAStatsCCMPFormatErrors++;
+		return -2;
+	}
+	keyidx >>= 6;
+	if (key->key_idx != keyidx) {
+		net_dbg_ratelimited("CCMP: RX tkey->key_idx=%d frame keyidx=%d\n",
+				    key->key_idx, keyidx);
+		return -6;
+	}
+	if (!key->key_set) {
+		net_dbg_ratelimited("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 (ccmp_replay_check(pn, key->rx_pn)) {
+#ifdef CONFIG_LIB80211_DEBUG
+		net_dbg_ratelimited("CCMP: replay detected: STA=%pM previous PN %02x%02x%02x%02x%02x%02x received PN %02x%02x%02x%02x%02x%02x\n",
+				    hdr->addr2,
+				    key->rx_pn[0], key->rx_pn[1], key->rx_pn[2],
+				    key->rx_pn[3], key->rx_pn[4], key->rx_pn[5],
+				    pn[0], pn[1], pn[2], pn[3], pn[4], pn[5]);
+#endif
+		key->dot11RSNAStatsCCMPReplays++;
+		return -4;
+	}
+
+	req = aead_request_alloc(key->tfm, GFP_ATOMIC);
+	if (!req)
+		return -ENOMEM;
+
+	aad_len = ccmp_init_iv_and_aad(hdr, pn, iv, aad);
+
+	sg_init_table(sg, 2);
+	sg_set_buf(&sg[0], aad, aad_len);
+	sg_set_buf(&sg[1], pos, data_len);
+
+	aead_request_set_callback(req, 0, NULL, NULL);
+	aead_request_set_ad(req, aad_len);
+	aead_request_set_crypt(req, sg, sg, data_len, iv);
+
+	ret = crypto_aead_decrypt(req);
+	aead_request_free(req);
+
+	if (ret) {
+		net_dbg_ratelimited("CCMP: decrypt failed: STA=%pM (%d)\n",
+				    hdr->addr2, ret);
+		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 lib80211_ccmp_set_key(void *key, int len, u8 * seq, void *priv)
+{
+	struct lib80211_ccmp_data *data = priv;
+	int keyidx;
+	struct crypto_aead *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];
+		}
+		if (crypto_aead_setauthsize(data->tfm, CCMP_MIC_LEN) ||
+		    crypto_aead_setkey(data->tfm, data->key, CCMP_TK_LEN))
+			return -1;
+	} else if (len == 0)
+		data->key_set = 0;
+	else
+		return -1;
+
+	return 0;
+}
+
+static int lib80211_ccmp_get_key(void *key, int len, u8 * seq, void *priv)
+{
+	struct lib80211_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 lib80211_ccmp_print_stats(struct seq_file *m, void *priv)
+{
+	struct lib80211_ccmp_data *ccmp = priv;
+
+	seq_printf(m,
+		   "key[%d] alg=CCMP key_set=%d "
+		   "tx_pn=%02x%02x%02x%02x%02x%02x "
+		   "rx_pn=%02x%02x%02x%02x%02x%02x "
+		   "format_errors=%d replays=%d decrypt_errors=%d\n",
+		   ccmp->key_idx, ccmp->key_set,
+		   ccmp->tx_pn[0], ccmp->tx_pn[1], ccmp->tx_pn[2],
+		   ccmp->tx_pn[3], ccmp->tx_pn[4], ccmp->tx_pn[5],
+		   ccmp->rx_pn[0], ccmp->rx_pn[1], ccmp->rx_pn[2],
+		   ccmp->rx_pn[3], ccmp->rx_pn[4], ccmp->rx_pn[5],
+		   ccmp->dot11RSNAStatsCCMPFormatErrors,
+		   ccmp->dot11RSNAStatsCCMPReplays,
+		   ccmp->dot11RSNAStatsCCMPDecryptErrors);
+}
+
+static struct lib80211_crypto_ops lib80211_crypt_ccmp = {
+	.name = "CCMP",
+	.init = lib80211_ccmp_init,
+	.deinit = lib80211_ccmp_deinit,
+	.encrypt_mpdu = lib80211_ccmp_encrypt,
+	.decrypt_mpdu = lib80211_ccmp_decrypt,
+	.encrypt_msdu = NULL,
+	.decrypt_msdu = NULL,
+	.set_key = lib80211_ccmp_set_key,
+	.get_key = lib80211_ccmp_get_key,
+	.print_stats = lib80211_ccmp_print_stats,
+	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
+	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
+	.owner = THIS_MODULE,
+};
+
+static int __init lib80211_crypto_ccmp_init(void)
+{
+	return lib80211_register_crypto_ops(&lib80211_crypt_ccmp);
+}
+
+static void __exit lib80211_crypto_ccmp_exit(void)
+{
+	lib80211_unregister_crypto_ops(&lib80211_crypt_ccmp);
+}
+
+module_init(lib80211_crypto_ccmp_init);
+module_exit(lib80211_crypto_ccmp_exit);