1 files changed, 303 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/net/80211/wep.c b/contrib/syslinux-4.02/gpxe/src/net/80211/wep.c
new file mode 100644
index 0000000..1c37e0c
--- /dev/null
+++ b/contrib/syslinux-4.02/gpxe/src/net/80211/wep.c
@@ -0,0 +1,303 @@
+/*
+ * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <gpxe/net80211.h>
+#include <gpxe/sec80211.h>
+#include <gpxe/crypto.h>
+#include <gpxe/arc4.h>
+#include <gpxe/crc32.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+/** @file
+ *
+ * The WEP wireless encryption method (insecure!)
+ *
+ * The data field in a WEP-encrypted packet contains a 3-byte
+ * initialisation vector, one-byte Key ID field (only the bottom two
+ * bits are ever used), encrypted data, and a 4-byte encrypted CRC of
+ * the plaintext data, called the ICV. To decrypt it, the IV is
+ * prepended to the shared key and the data stream (including ICV) is
+ * run through the ARC4 stream cipher; if the ICV matches a CRC32
+ * calculated on the plaintext, the packet is valid.
+ *
+ * For efficiency and code-size reasons, this file assumes it is
+ * running on a little-endian machine.
+ */
+
+/** Length of WEP initialisation vector */
+#define WEP_IV_LEN	3
+
+/** Length of WEP key ID byte */
+#define WEP_KID_LEN	1
+
+/** Length of WEP ICV checksum */
+#define WEP_ICV_LEN	4
+
+/** Maximum length of WEP key */
+#define WEP_MAX_KEY	16
+
+/** Amount of data placed before the encrypted bytes */
+#define WEP_HEADER_LEN	4
+
+/** Amount of data placed after the encrypted bytes */
+#define WEP_TRAILER_LEN	4
+
+/** Total WEP overhead bytes */
+#define WEP_OVERHEAD	8
+
+/** Context for WEP encryption and decryption */
+struct wep_ctx
+{
+	/** Encoded WEP key
+	 *
+	 * The actual key bytes are stored beginning at offset 3, to
+	 * leave room for easily inserting the IV before a particular
+	 * operation.
+	 */
+	u8 key[WEP_IV_LEN + WEP_MAX_KEY];
+
+	/** Length of WEP key (not including IV bytes) */
+	int keylen;
+
+	/** ARC4 context */
+	struct arc4_ctx arc4;
+};
+
+/**
+ * Initialize WEP algorithm
+ *
+ * @v crypto	802.11 cryptographic algorithm
+ * @v key	WEP key to use
+ * @v keylen	Length of WEP key
+ * @v rsc	Initial receive sequence counter (unused)
+ * @ret rc	Return status code
+ *
+ * Standard key lengths are 5 and 13 bytes; 16-byte keys are
+ * occasionally supported as an extension to the standard.
+ */
+static int wep_init ( struct net80211_crypto *crypto, const void *key,
+		      int keylen, const void *rsc __unused )
+{
+	struct wep_ctx *ctx = crypto->priv;
+
+	ctx->keylen = ( keylen > WEP_MAX_KEY ? WEP_MAX_KEY : keylen );
+	memcpy ( ctx->key + WEP_IV_LEN, key, ctx->keylen );
+
+	return 0;
+}
+
+/**
+ * Encrypt packet using WEP
+ *
+ * @v crypto	802.11 cryptographic algorithm
+ * @v iob	I/O buffer of plaintext packet
+ * @ret eiob	Newly allocated I/O buffer for encrypted packet, or NULL
+ *
+ * If memory allocation fails, @c NULL is returned.
+ */
+static struct io_buffer * wep_encrypt ( struct net80211_crypto *crypto,
+					struct io_buffer *iob )
+{
+	struct wep_ctx *ctx = crypto->priv;
+	struct io_buffer *eiob;
+	struct ieee80211_frame *hdr;
+	const int hdrlen = IEEE80211_TYP_FRAME_HEADER_LEN;
+	int datalen = iob_len ( iob ) - hdrlen;
+	int newlen = hdrlen + datalen + WEP_OVERHEAD;
+	u32 iv, icv;
+
+	eiob = alloc_iob ( newlen );
+	if ( ! eiob )
+		return NULL;
+
+	memcpy ( iob_put ( eiob, hdrlen ), iob->data, hdrlen );
+	hdr = eiob->data;
+	hdr->fc |= IEEE80211_FC_PROTECTED;
+
+	/* Calculate IV, put it in the header (with key ID byte = 0), and
+	   set it up at the start of the encryption key. */
+	iv = random() & 0xffffff; /* IV in bottom 3 bytes, top byte = KID = 0 */
+	memcpy ( iob_put ( eiob, WEP_HEADER_LEN ), &iv, WEP_HEADER_LEN );
+	memcpy ( ctx->key, &iv, WEP_IV_LEN );
+
+	/* Encrypt the data using RC4 */
+	cipher_setkey ( &arc4_algorithm, &ctx->arc4, ctx->key,
+			ctx->keylen + WEP_IV_LEN );
+	cipher_encrypt ( &arc4_algorithm, &ctx->arc4, iob->data + hdrlen,
+			 iob_put ( eiob, datalen ), datalen );
+
+	/* Add ICV */
+	icv = ~crc32_le ( ~0, iob->data + hdrlen, datalen );
+	cipher_encrypt ( &arc4_algorithm, &ctx->arc4, &icv,
+			 iob_put ( eiob, WEP_ICV_LEN ), WEP_ICV_LEN );
+
+	return eiob;
+}
+
+/**
+ * Decrypt packet using WEP
+ *
+ * @v crypto	802.11 cryptographic algorithm
+ * @v eiob	I/O buffer of encrypted packet
+ * @ret iob	Newly allocated I/O buffer for plaintext packet, or NULL
+ *
+ * If a consistency check for the decryption fails (usually indicating
+ * an invalid key), @c NULL is returned.
+ */
+static struct io_buffer * wep_decrypt ( struct net80211_crypto *crypto,
+					struct io_buffer *eiob )
+{
+	struct wep_ctx *ctx = crypto->priv;
+	struct io_buffer *iob;
+	struct ieee80211_frame *hdr;
+	const int hdrlen = IEEE80211_TYP_FRAME_HEADER_LEN;
+	int datalen = iob_len ( eiob ) - hdrlen - WEP_OVERHEAD;
+	int newlen = hdrlen + datalen;
+	u32 iv, icv, crc;
+
+	iob = alloc_iob ( newlen );
+	if ( ! iob )
+		return NULL;
+
+	memcpy ( iob_put ( iob, hdrlen ), eiob->data, hdrlen );
+	hdr = iob->data;
+	hdr->fc &= ~IEEE80211_FC_PROTECTED;
+
+	/* Strip off IV and use it to initialize cryptosystem */
+	memcpy ( &iv, eiob->data + hdrlen, 4 );
+	iv &= 0xffffff;		/* ignore key ID byte */
+	memcpy ( ctx->key, &iv, WEP_IV_LEN );
+
+	/* Decrypt the data using RC4 */
+	cipher_setkey ( &arc4_algorithm, &ctx->arc4, ctx->key,
+			ctx->keylen + WEP_IV_LEN );
+	cipher_decrypt ( &arc4_algorithm, &ctx->arc4, eiob->data + hdrlen +
+			 WEP_HEADER_LEN, iob_put ( iob, datalen ), datalen );
+
+	/* Strip off ICV and verify it */
+	cipher_decrypt ( &arc4_algorithm, &ctx->arc4, eiob->data + hdrlen +
+			 WEP_HEADER_LEN + datalen, &icv, WEP_ICV_LEN );
+	crc = ~crc32_le ( ~0, iob->data + hdrlen, datalen );
+	if ( crc != icv ) {
+		DBGC ( crypto, "WEP %p CRC mismatch: expect %08x, get %08x\n",
+		       crypto, icv, crc );
+		free_iob ( iob );
+		return NULL;
+	}
+	return iob;
+}
+
+/** WEP cryptosystem for 802.11 */
+struct net80211_crypto wep_crypto __net80211_crypto = {
+	.algorithm = NET80211_CRYPT_WEP,
+	.init = wep_init,
+	.encrypt = wep_encrypt,
+	.decrypt = wep_decrypt,
+	.priv_len = sizeof ( struct wep_ctx ),
+};
+
+/**
+ * Initialize trivial 802.11 security handshaker
+ *
+ * @v dev	802.11 device
+ * @v ctx	Security handshaker
+ *
+ * This simply fetches a WEP key from netX/key, and if it exists,
+ * installs WEP cryptography on the 802.11 device. No real handshaking
+ * is performed.
+ */
+static int trivial_init ( struct net80211_device *dev )
+{
+	u8 key[WEP_MAX_KEY];	/* support up to 128-bit keys */
+	int len;
+	int rc;
+
+	if ( dev->associating &&
+	     dev->associating->crypto == NET80211_CRYPT_NONE )
+		return 0;	/* no crypto? OK. */
+
+	len = fetch_setting ( netdev_settings ( dev->netdev ),
+			      &net80211_key_setting, key, WEP_MAX_KEY );
+
+	if ( len <= 0 ) {
+		DBGC ( dev, "802.11 %p cannot do WEP without a key\n", dev );
+		return -EACCES;
+	}
+
+	/* Full 128-bit keys are a nonstandard extension, but they're
+	   utterly trivial to support, so we do. */
+	if ( len != 5 && len != 13 && len != 16 ) {
+		DBGC ( dev, "802.11 %p invalid WEP key length %d\n",
+		       dev, len );
+		return -EINVAL;
+	}
+
+	DBGC ( dev, "802.11 %p installing %d-bit WEP\n", dev, len * 8 );
+
+	rc = sec80211_install ( &dev->crypto, NET80211_CRYPT_WEP, key, len,
+				NULL );
+	if ( rc < 0 )
+		return rc;
+
+	return 0;
+}
+
+/**
+ * Check for key change on trivial 802.11 security handshaker
+ *
+ * @v dev	802.11 device
+ * @v ctx	Security handshaker
+ */
+static int trivial_change_key ( struct net80211_device *dev )
+{
+	u8 key[WEP_MAX_KEY];
+	int len;
+	int change = 0;
+
+	/* If going from WEP to clear, or something else to WEP, reassociate. */
+	if ( ! dev->crypto || ( dev->crypto->init != wep_init ) )
+		change ^= 1;
+
+	len = fetch_setting ( netdev_settings ( dev->netdev ),
+			      &net80211_key_setting, key, WEP_MAX_KEY );
+	if ( len <= 0 )
+		change ^= 1;
+
+	/* Changing crypto type => return nonzero to reassociate. */
+	if ( change )
+		return -EINVAL;
+
+	/* Going from no crypto to still no crypto => nothing to do. */
+	if ( len <= 0 )
+		return 0;
+
+	/* Otherwise, reinitialise WEP with new key. */
+	return wep_init ( dev->crypto, key, len, NULL );
+}
+
+/** Trivial 802.11 security handshaker */
+struct net80211_handshaker trivial_handshaker __net80211_handshaker = {
+	.protocol = NET80211_SECPROT_NONE,
+	.init = trivial_init,
+	.change_key = trivial_change_key,
+	.priv_len = 0,
+};