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add experimental wpa2/ccmp support

--- a/sys/src/9/pc/wifi.c

+++ b/sys/src/9/pc/wifi.c

@@ -503,6 +503,7 @@

 static char *ciphers[] = {

 	[0]	"clear",

 	[TKIP]	"tkip",

+	[CCMP]	"ccmp",

 };

 static int

@@ -682,13 +683,25 @@

 static uchar pad4[4] = { 0x00, 0x00, 0x00, 0x00, };

+static int setupCCMP(Wkey *k, Wifipkt *w, uvlong tsc, uchar nonce[13], uchar auth[30], AESstate *as);

+

+void aesCCMencrypt(int L, int M, uchar *N /* N[15-L] */,

+	uchar *a /* a[la] */, int la,

+	uchar *m /* m[lm+M] */, int lm,

+	AESstate *s);

+int aesCCMdecrypt(int L, int M, uchar *N /* N[15-L] */,

+	uchar *a /* a[la] */, int la,

+	uchar *m /* m[lm+M] */, int lm,

+	AESstate *s);

+

 static Block*

 wifiencrypt(Wifi *, Wnode *wn, Block *b)

 {

+	uchar auth[32], seed[16];

 	u16int tk[8], p1k[5];

-	uchar seed[16];

 	uvlong tsc;

 	ulong crc;

+	AESstate as;

 	RC4state rs;

 	MICstate ms;

 	Wifipkt *w;

@@ -699,8 +712,6 @@

 	k = &wn->txkey[kid];

 	if(k->cipher == 0)

 		goto pass;

-	if(k->cipher != TKIP || k->len != 32)

-		goto drop;

 	n = wifihdrlen((Wifipkt*)b->rp);

@@ -712,38 +723,64 @@

 	b->rp += n;

 	tsc = ++k->tsc;

-	b->rp[0] = tsc>>8;

-	b->rp[1] = (b->rp[0] | 0x20) & 0x7f;

-	b->rp[2] = tsc;

-	b->rp[3] = kid<<6 | 0x20;

-	b->rp[4] = tsc>>16;

-	b->rp[5] = tsc>>24;

-	b->rp[6] = tsc>>32;

-	b->rp[7] = tsc>>40;

-	b->rp += 8;

-	micsetup(&ms, k->key+24);

-	micupdate(&ms, dstaddr(w), Eaddrlen);

-	micupdate(&ms, srcaddr(w), Eaddrlen);

-	micupdate(&ms, pad4, 4);

-	micupdate(&ms, b->rp, BLEN(b));

-	micfinish(&ms, b->wp);

-	b->wp += 8;

+	switch(k->cipher){

+	case TKIP:

+		b->rp[0] = tsc>>8;

+		b->rp[1] = (b->rp[0] | 0x20) & 0x7f;

+		b->rp[2] = tsc;

+		b->rp[3] = kid<<6 | 0x20;

+		b->rp[4] = tsc>>16;

+		b->rp[5] = tsc>>24;

+		b->rp[6] = tsc>>32;

+		b->rp[7] = tsc>>40;

+		b->rp += 8;

-	crc = ethercrc(b->rp, BLEN(b));

-	crc = ~crc;

-	b->wp[0] = crc;

-	b->wp[1] = crc>>8;

-	b->wp[2] = crc>>16;

-	b->wp[3] = crc>>24;

-	b->wp += 4;

+		if(k->len != 32)

+			goto drop;

+		micsetup(&ms, k->key+24);

+		micupdate(&ms, dstaddr(w), Eaddrlen);

+		micupdate(&ms, srcaddr(w), Eaddrlen);

+		micupdate(&ms, pad4, 4);

+		micupdate(&ms, b->rp, BLEN(b));

+		micfinish(&ms, b->wp);

+		b->wp += 8;

-	tkipk2tk(k->key, tk);

-	tkipphase1(tsc >> 16, w->a2, tk, p1k);

-	tkipphase2(tsc & 0xFFFF, p1k, tk, seed);

-	setupRC4state(&rs, seed, sizeof(seed));

-	rc4(&rs, b->rp, BLEN(b));

+		crc = ethercrc(b->rp, BLEN(b));

+		crc = ~crc;

+		b->wp[0] = crc;

+		b->wp[1] = crc>>8;

+		b->wp[2] = crc>>16;

+		b->wp[3] = crc>>24;

+		b->wp += 4;

+		tkipk2tk(k->key, tk);

+		tkipphase1(tsc >> 16, w->a2, tk, p1k);

+		tkipphase2(tsc & 0xFFFF, p1k, tk, seed);

+		setupRC4state(&rs, seed, sizeof(seed));

+		rc4(&rs, b->rp, BLEN(b));

+		break;

+	case CCMP:

+		b->rp[0] = tsc;

+		b->rp[1] = tsc>>8;

+		b->rp[2] = 0;

+		b->rp[3] = kid<<6 | 0x20;

+		b->rp[4] = tsc>>16;

+		b->rp[5] = tsc>>24;

+		b->rp[6] = tsc>>32;

+		b->rp[7] = tsc>>40;

+		b->rp += 8;

+

+		if(k->len != 16)

+			goto drop;

+		aesCCMencrypt(2, 8, seed, auth, setupCCMP(k, w, tsc, seed, auth, &as),

+			b->rp, BLEN(b), &as);

+		b->wp += 8;

+		break;

+	default:

+		goto drop;

+	}

+

 	b->rp = (uchar*)w;

 	w->fc[1] |= 0x40;

@@ -757,9 +794,10 @@

 static Block*

 wifidecrypt(Wifi *, Wnode *wn, Block *b)

 {

-	uchar seed[16], mic[8];

+	uchar auth[32], seed[16], mic[8];

 	u16int tk[8], p1k[5];

 	RC4state rs;

+	AESstate as;

 	MICstate ms;

 	uvlong tsc;

 	ulong crc;

@@ -773,8 +811,7 @@

 	n = wifihdrlen(w);

 	b->rp += n;

-

-	if(BLEN(b) < 8+8+4)

+	if(BLEN(b) < 8+8)

 		goto drop;

 	kid = b->rp[3]>>6;

@@ -784,45 +821,61 @@

 		kid = 4;	/* use peerwise key for non-unicast */

 	k = &wn->rxkey[kid];

-	if(k->cipher != TKIP || k->len != 32)

-		goto drop;

+	switch(k->cipher){

+	case TKIP:

+		tsc =	(uvlong)b->rp[7]<<40 |

+			(uvlong)b->rp[6]<<32 |

+			(uvlong)b->rp[5]<<24 |

+			(uvlong)b->rp[4]<<16 |

+			(uvlong)b->rp[0]<<8 |

+			(uvlong)b->rp[2];

+		b->rp += 8;

+		if(tsc <= k->tsc || BLEN(b) < 8+4 || k->len != 32)

+			goto drop;

+		tkipk2tk(k->key, tk);

+		tkipphase1(tsc >> 16, w->a2, tk, p1k);

+		tkipphase2(tsc & 0xFFFF, p1k, tk, seed);

+		setupRC4state(&rs, seed, sizeof(seed));

+		rc4(&rs, b->rp, BLEN(b));

-	tsc =	(uvlong)b->rp[7]<<40 |

-		(uvlong)b->rp[6]<<32 |

-		(uvlong)b->rp[5]<<24 |

-		(uvlong)b->rp[4]<<16 |

-		(uvlong)b->rp[0]<<8 |

-		(uvlong)b->rp[2];

-	b->rp += 8;

+		b->wp -= 4;

+		crc =	(ulong)b->wp[0] |

+			(ulong)b->wp[1]<<8 |

+			(ulong)b->wp[2]<<16 |

+			(ulong)b->wp[3]<<24;

+		crc = ~crc;

+		if(ethercrc(b->rp, BLEN(b)) != crc)

+			goto drop;

-	if(tsc <= k->tsc)

+		b->wp -= 8;

+		micsetup(&ms, k->key+16);

+		micupdate(&ms, dstaddr(w), Eaddrlen);

+		micupdate(&ms, srcaddr(w), Eaddrlen);

+		micupdate(&ms, pad4, 4);

+		micupdate(&ms, b->rp, BLEN(b));

+		micfinish(&ms, mic);

+		if(memcmp(b->wp, mic, 8) != 0)

+			goto drop;

+		break;

+	case CCMP:

+		tsc =	(uvlong)b->rp[7]<<40 |

+			(uvlong)b->rp[6]<<32 |

+			(uvlong)b->rp[5]<<24 |

+			(uvlong)b->rp[4]<<16 |

+			(uvlong)b->rp[1]<<8 |

+			(uvlong)b->rp[0];

+		b->rp += 8;

+		if(tsc <= k->tsc || k->len != 16)

+			goto drop;

+		b->wp -= 8;

+		if(aesCCMdecrypt(2, 8, seed, auth, setupCCMP(k, w, tsc, seed, auth, &as),

+			b->rp, BLEN(b), &as) != 0)

+			goto drop;

+		break;

+	default:

 		goto drop;

+	}

-	tkipk2tk(k->key, tk);

-	tkipphase1(tsc >> 16, w->a2, tk, p1k);

-	tkipphase2(tsc & 0xFFFF, p1k, tk, seed);

-	setupRC4state(&rs, seed, sizeof(seed));

-	rc4(&rs, b->rp, BLEN(b));

-

-	b->wp -= 4;

-	crc =	(ulong)b->wp[0] |

-		(ulong)b->wp[1]<<8 |

-		(ulong)b->wp[2]<<16 |

-		(ulong)b->wp[3]<<24;

-	crc = ~crc;

-	if(ethercrc(b->rp, BLEN(b)) != crc)

-		goto drop;

-

-	b->wp -= 8;

-	micsetup(&ms, k->key+16);

-	micupdate(&ms, dstaddr(w), Eaddrlen);

-	micupdate(&ms, srcaddr(w), Eaddrlen);

-	micupdate(&ms, pad4, 4);

-	micupdate(&ms, b->rp, BLEN(b));

-	micfinish(&ms, mic);

-	if(memcmp(b->wp, mic, 8) != 0)

-		goto drop;

-

 	k->tsc = tsc;

 	b->rp -= n;

 	memmove(b->rp, w, n);

@@ -1052,4 +1105,139 @@

 	mic[5] = s->r>>8;

 	mic[6] = s->r>>16;

 	mic[7] = s->r>>24;

+}

+

+static uchar*

+putbe(uchar *p, int L, uint v)

+{

+	while(--L >= 0)

+		*p++ = (v >> L*8) & 0xFF;

+	return p;

+}

+

+static void

+xblock(int L, int M, uchar *N, uchar *a, int la, int lm, uchar t[16], AESstate *s)

+{

+	uchar l[8], *p, *x, *e;

+

+	assert(M >= 4 && M <= 16);

+	assert(L >= 2 && L <= 4);

+

+	t[0] = ((la > 0)<<6) | ((M-2)/2)<<3 | (L-1);	/* flags */

+	memmove(&t[1], N, 15-L);

+	putbe(&t[16-L], L, lm);

+	aes_encrypt(s->ekey, s->rounds, t, t);

+	

+	if(la > 0){

+		assert(la < 0xFF00);

+		for(p = l, e = putbe(l, 2, la), x = t; p < e; x++, p++)

+			*x ^= *p;

+		for(e = a + la; a < e; x = t){

+			for(; a < e && x < &t[16]; x++, a++)

+				*x ^= *a;

+			aes_encrypt(s->ekey, s->rounds, t, t);

+		}

+	}

+}

+

+static uchar*

+sblock(int L, uchar *N, uint i, uchar b[16], AESstate *s)

+{

+	b[0] = L-1;	/* flags */

+	memmove(&b[1], N, 15-L);

+	putbe(&b[16-L], L, i);

+	aes_encrypt(s->ekey, s->rounds, b, b);

+	return b;

+};

+

+void

+aesCCMencrypt(int L, int M, uchar *N /* N[15-L] */,

+	uchar *a /* a[la] */, int la,

+	uchar *m /* m[lm+M] */, int lm,

+	AESstate *s)

+{

+	uchar t[16], b[16], *p, *x;

+	uint i;

+

+	xblock(L, M, N, a, la, lm, t, s);

+

+	for(i = 1; lm >= 16; i++, lm -= 16){

+		for(p = sblock(L, N, i, b, s), x = t; p < &b[16]; x++, m++, p++){

+			*x ^= *m;

+			*m ^= *p;

+		}

+		aes_encrypt(s->ekey, s->rounds, t, t);

+	}

+	if(lm > 0){

+		for(p = sblock(L, N, i, b, s), x = t; p < &b[lm]; x++, m++, p++){

+			*x ^= *m;

+			*m ^= *p;

+		}

+		aes_encrypt(s->ekey, s->rounds, t, t);

+	}

+

+	for(p = sblock(L, N, 0, b, s), x = t; p < &b[M]; x++, p++)

+		*x ^= *p;

+

+	memmove(m, t, M);

+}

+

+int

+aesCCMdecrypt(int L, int M, uchar *N /* N[15-L] */,

+	uchar *a /* a[la] */, int la,

+	uchar *m /* m[lm+M] */, int lm,

+	AESstate *s)

+{

+	uchar t[16], b[16], *p, *x;

+	uint i;

+

+	xblock(L, M, N, a, la, lm, t, s);

+

+	for(i = 1; lm >= 16; i++, lm -= 16){

+		for(p = sblock(L, N, i, b, s), x = t; p < &b[16]; x++, m++, p++){

+			*m ^= *p;

+			*x ^= *m;

+		}

+		aes_encrypt(s->ekey, s->rounds, t, t);

+	}

+	if(lm > 0){

+		for(p = sblock(L, N, i, b, s), x = t; p < &b[lm]; x++, m++, p++){

+			*m ^= *p;

+			*x ^= *m;

+		}

+		aes_encrypt(s->ekey, s->rounds, t, t);

+	}

+

+	for(p = sblock(L, N, 0, b, s), x = t; p < &b[M]; x++, p++)

+		*x ^= *p;

+

+	return memcmp(m, t, M) != 0;

+}

+

+static int

+setupCCMP(Wkey *k, Wifipkt *w, uvlong tsc, uchar nonce[13], uchar auth[32], AESstate *as)

+{

+	uchar *p;

+

+	setupAESstate(as, k->key, k->len, nil);

+

+	nonce[0] = ((w->fc[0] & 0x0c) == 0x00) << 4;

+	memmove(&nonce[1], w->a2, Eaddrlen);

+	nonce[7]  = tsc >> 40;

+	nonce[8]  = tsc >> 32;

+	nonce[9]  = tsc >> 24;

+	nonce[10] = tsc >> 16;

+	nonce[11] = tsc >> 8;

+	nonce[12] = tsc;

+

+	p = auth;

+	*p++ = (w->fc[0] & (((w->fc[0] & 0x0c) == 0x08) ? 0x0f : 0xff));

+	*p++ = (w->fc[1] & ~0x38) | 0x40;

+	memmove(p, w->a1, Eaddrlen); p += Eaddrlen;

+	memmove(p, w->a2, Eaddrlen); p += Eaddrlen;

+	memmove(p, w->a3, Eaddrlen); p += Eaddrlen;

+	*p++ = w->seq[0] & 0x0f;

+	*p++ = 0;

+

+	return p - auth;

 }

--- a/sys/src/cmd/aux/wpa.c

+++ b/sys/src/cmd/aux/wpa.c

@@ -44,6 +44,19 @@

 	uchar	data[];

 };

+typedef struct Cipher Cipher;

+struct Cipher

+{

+	char	*name;

+	int	keylen;

+};

+

+Cipher	tkip = { "tkip", 32 };

+Cipher	ccmp = { "ccmp", 16 };

+

+Cipher	*peercipher;

+Cipher	*groupcipher;

+

 int	prompt;

 int	debug;

 int	fd, cfd;

@@ -57,9 +70,9 @@

 	0x30,			/* RSN */

 	0x14,			/* length */

 	0x01, 0x00,		/* version 1 */

-	0x00, 0x0F, 0xAC, 0x02,	/* group cipher suite TKIP */

+	0x00, 0x0F, 0xAC, 0x04,	/* group cipher suite CCMP */

 	0x01, 0x00,		/* peerwise cipher suite count 1 */

-	0x00, 0x0F, 0xAC, 0x02,	/* peerwise cipher suite TKIP */

+	0x00, 0x0F, 0xAC, 0x04,	/* peerwise cipher suite CCMP */

 	0x01, 0x00,		/* authentication suite count 1 */

 	0x00, 0x0F, 0xAC, 0x02,	/* authentication suite PSK */

 	0x00, 0x00,		/* capabilities */

@@ -324,7 +337,7 @@

 void

 usage(void)

 {

-	fprint(2, "%s: [-dp] [-s essid] dev\n", argv0);

+	fprint(2, "%s: [-dp12] [-s essid] dev\n", argv0);

 	exits("usage");

 }

@@ -344,6 +357,8 @@

 	/* default is WPA */

 	rsne = wpaie;

 	rsnelen = sizeof(wpaie);

+	peercipher = &tkip;

+	groupcipher = &tkip;

 	ARGBEGIN {

 	case 'd':

@@ -358,10 +373,14 @@

 	case '1':

 		rsne = wpaie;

 		rsnelen = sizeof(wpaie);

+		peercipher = &tkip;

+		groupcipher = &tkip;

 		break;

 	case '2':

 		rsne = rsnie;

 		rsnelen = sizeof(rsnie);

+		peercipher = &ccmp;

+		groupcipher = &ccmp;

 		break;

 	default:

 		usage();

@@ -554,7 +573,8 @@

 			if((flags & (Fptk|Fack)) == (Fptk|Fack)){

 				/* install peerwise receive key */

-				if(fprint(cfd, "rxkey %.*H tkip:%.*H@%llux", Eaddrlen, amac, 32, ptk+32, rsc) < 0)

+				if(fprint(cfd, "rxkey %.*H %s:%.*H@%llux", Eaddrlen, amac,

+					peercipher->name, peercipher->keylen, ptk+32, rsc) < 0)

 					sysfatal("write rxkey: %r");

 				/* pick random 16bit tsc value for transmit */

@@ -568,7 +588,8 @@

 				sleep(100);

 				/* install peerwise transmit key */ 

-				if(fprint(cfd, "txkey %.*H tkip:%.*H@%llux", Eaddrlen, amac, 32, ptk+32, rsc) < 0)

+				if(fprint(cfd, "txkey %.*H %s:%.*H@%llux", Eaddrlen, amac,

+					peercipher->name, peercipher->keylen, ptk+32, rsc) < 0)

 					sysfatal("write txkey: %r");

 				/* reset rsc for group key */

@@ -593,10 +614,11 @@

 			} else

 				continue;

-			if(gtklen > 0 && gtkkid != -1){

+			if(gtklen >= groupcipher->keylen && gtkkid != -1){

 				/* install group key */

-				if(fprint(cfd, "rxkey%d %.*H tkip:%.*H@%llux",

-					gtkkid, Eaddrlen, amac, gtklen, gtk, rsc) < 0)

+				if(fprint(cfd, "rxkey%d %.*H %s:%.*H@%llux",

+					gtkkid, Eaddrlen, amac, 

+					groupcipher->name, groupcipher->keylen, gtk, rsc) < 0)

 					sysfatal("write rxkey%d: %r", gtkkid);

 			}

 		}

-- 

⑨