wifi: cleanup
cleanup wifiencrypt()/wifidecrypt() routines moving tkip and ccmp in separate routines so we dont use less stack space.
This commit is contained in:
cinap_lenrek
parent
33d00fce10
commit
b9214d6662
1 changed files with 127 additions and 109 deletions
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@ -664,54 +664,23 @@ wifistat(Wifi *wifi, void *buf, long n, ulong off)
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return n;
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}
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static void tkipk2tk(uchar key[16], u16int tk[8]);
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static void tkipphase1(u32int tscu, uchar ta[Eaddrlen], u16int tk[8], u16int p1k[5]);
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static void tkipphase2(u16int tscl, u16int p1k[5], u16int tk[8], uchar rc4key[16]);
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typedef struct MICstate MICstate;
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struct MICstate
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{
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u32int l;
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u32int r;
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u32int m;
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u32int n;
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};
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static void micsetup(MICstate *s, uchar key[8]);
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static void micupdate(MICstate *s, uchar *data, ulong len);
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static void micfinish(MICstate *s, uchar mic[8]);
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static uchar pad4[4] = { 0x00, 0x00, 0x00, 0x00, };
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static int setupCCMP(Wkey *k, Wifipkt *w, uvlong tsc, uchar nonce[13], uchar auth[30], AESstate *as);
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void aesCCMencrypt(int L, int M, uchar *N /* N[15-L] */,
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uchar *a /* a[la] */, int la,
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uchar *m /* m[lm+M] */, int lm,
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AESstate *s);
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int aesCCMdecrypt(int L, int M, uchar *N /* N[15-L] */,
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uchar *a /* a[la] */, int la,
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uchar *m /* m[lm+M] */, int lm,
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AESstate *s);
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static void tkipencrypt(Wkey *k, Wifipkt *w, Block *b, uvlong tsc);
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static int tkipdecrypt(Wkey *k, Wifipkt *w, Block *b, uvlong tsc);
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static void ccmpencrypt(Wkey *k, Wifipkt *w, Block *b, uvlong tsc);
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static int ccmpdecrypt(Wkey *k, Wifipkt *w, Block *b, uvlong tsc);
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static Block*
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wifiencrypt(Wifi *, Wnode *wn, Block *b)
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{
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uchar auth[32], seed[16];
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u16int tk[8], p1k[5];
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uvlong tsc;
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ulong crc;
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AESstate as;
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RC4state rs;
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MICstate ms;
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Wifipkt *w;
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int n, kid;
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Wifipkt *w;
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Wkey *k;
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kid = 0;
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k = &wn->txkey[kid];
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if(k->cipher == 0)
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goto pass;
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return b;
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n = wifihdrlen((Wifipkt*)b->rp);
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@ -735,30 +704,9 @@ wifiencrypt(Wifi *, Wnode *wn, Block *b)
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b->rp[6] = tsc>>32;
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b->rp[7] = tsc>>40;
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b->rp += 8;
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if(k->len != 32)
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goto drop;
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micsetup(&ms, k->key+24);
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micupdate(&ms, dstaddr(w), Eaddrlen);
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micupdate(&ms, srcaddr(w), Eaddrlen);
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micupdate(&ms, pad4, 4);
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micupdate(&ms, b->rp, BLEN(b));
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micfinish(&ms, b->wp);
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b->wp += 8;
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crc = ethercrc(b->rp, BLEN(b));
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crc = ~crc;
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b->wp[0] = crc;
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b->wp[1] = crc>>8;
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b->wp[2] = crc>>16;
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b->wp[3] = crc>>24;
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b->wp += 4;
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tkipk2tk(k->key, tk);
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tkipphase1(tsc >> 16, w->a2, tk, p1k);
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tkipphase2(tsc & 0xFFFF, p1k, tk, seed);
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setupRC4state(&rs, seed, sizeof(seed));
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rc4(&rs, b->rp, BLEN(b));
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tkipencrypt(k, w, b, tsc);
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break;
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case CCMP:
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b->rp[0] = tsc;
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@ -770,39 +718,27 @@ wifiencrypt(Wifi *, Wnode *wn, Block *b)
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b->rp[6] = tsc>>32;
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b->rp[7] = tsc>>40;
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b->rp += 8;
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if(k->len != 16)
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goto drop;
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aesCCMencrypt(2, 8, seed, auth, setupCCMP(k, w, tsc, seed, auth, &as),
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b->rp, BLEN(b), &as);
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b->wp += 8;
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ccmpencrypt(k, w, b, tsc);
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break;
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default:
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goto drop;
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drop:
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free(b);
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return nil;
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}
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b->rp = (uchar*)w;
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w->fc[1] |= 0x40;
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pass:
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return b;
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drop:
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free(b);
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return nil;
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}
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static Block*
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wifidecrypt(Wifi *, Wnode *wn, Block *b)
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{
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uchar auth[32], seed[16], mic[8];
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u16int tk[8], p1k[5];
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RC4state rs;
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AESstate as;
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MICstate ms;
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uvlong tsc;
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ulong crc;
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Wifipkt *w;
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int n, kid;
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Wifipkt *w;
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Wkey *k;
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w = (Wifipkt*)b->rp;
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@ -830,31 +766,9 @@ wifidecrypt(Wifi *, Wnode *wn, Block *b)
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(uvlong)b->rp[0]<<8 |
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(uvlong)b->rp[2];
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b->rp += 8;
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if(tsc <= k->tsc || BLEN(b) < 8+4 || k->len != 32)
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if(tsc <= k->tsc || k->len != 32)
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goto drop;
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tkipk2tk(k->key, tk);
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tkipphase1(tsc >> 16, w->a2, tk, p1k);
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tkipphase2(tsc & 0xFFFF, p1k, tk, seed);
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setupRC4state(&rs, seed, sizeof(seed));
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rc4(&rs, b->rp, BLEN(b));
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b->wp -= 4;
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crc = (ulong)b->wp[0] |
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(ulong)b->wp[1]<<8 |
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(ulong)b->wp[2]<<16 |
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(ulong)b->wp[3]<<24;
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crc = ~crc;
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if(ethercrc(b->rp, BLEN(b)) != crc)
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goto drop;
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b->wp -= 8;
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micsetup(&ms, k->key+16);
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micupdate(&ms, dstaddr(w), Eaddrlen);
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micupdate(&ms, srcaddr(w), Eaddrlen);
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micupdate(&ms, pad4, 4);
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micupdate(&ms, b->rp, BLEN(b));
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micfinish(&ms, mic);
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if(memcmp(b->wp, mic, 8) != 0)
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if(tkipdecrypt(k, w, b, tsc) != 0)
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goto drop;
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break;
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case CCMP:
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@ -867,13 +781,13 @@ wifidecrypt(Wifi *, Wnode *wn, Block *b)
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b->rp += 8;
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if(tsc <= k->tsc || k->len != 16)
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goto drop;
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b->wp -= 8;
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if(aesCCMdecrypt(2, 8, seed, auth, setupCCMP(k, w, tsc, seed, auth, &as),
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b->rp, BLEN(b), &as) != 0)
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if(ccmpdecrypt(k, w, b, tsc) != 0)
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goto drop;
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break;
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default:
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goto drop;
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drop:
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freeb(b);
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return nil;
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}
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k->tsc = tsc;
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@ -882,9 +796,6 @@ wifidecrypt(Wifi *, Wnode *wn, Block *b)
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w = (Wifipkt*)b->rp;
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w->fc[1] &= ~0x40;
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return b;
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drop:
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freeb(b);
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return nil;
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}
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static u16int Sbox[256] = {
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@ -1043,6 +954,14 @@ tkipphase2(u16int tscl, u16int p1k[5], u16int tk[8], uchar rc4key[16])
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rc4key[15] = ppk[5] >> 8;
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}
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typedef struct MICstate MICstate;
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struct MICstate
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{
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u32int l;
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u32int r;
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u32int m;
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u32int n;
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};
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static void
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micsetup(MICstate *s, uchar key[8])
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@ -1107,6 +1026,78 @@ micfinish(MICstate *s, uchar mic[8])
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mic[7] = s->r>>24;
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}
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static uchar pad4[4] = { 0x00, 0x00, 0x00, 0x00, };
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static void
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tkipencrypt(Wkey *k, Wifipkt *w, Block *b, uvlong tsc)
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{
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u16int tk[8], p1k[5];
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uchar seed[16];
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RC4state rs;
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MICstate ms;
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ulong crc;
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micsetup(&ms, k->key+24);
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micupdate(&ms, dstaddr(w), Eaddrlen);
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micupdate(&ms, srcaddr(w), Eaddrlen);
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micupdate(&ms, pad4, 4);
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micupdate(&ms, b->rp, BLEN(b));
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micfinish(&ms, b->wp);
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b->wp += 8;
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crc = ethercrc(b->rp, BLEN(b));
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crc = ~crc;
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b->wp[0] = crc;
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b->wp[1] = crc>>8;
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b->wp[2] = crc>>16;
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b->wp[3] = crc>>24;
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b->wp += 4;
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tkipk2tk(k->key, tk);
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tkipphase1(tsc >> 16, w->a2, tk, p1k);
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tkipphase2(tsc & 0xFFFF, p1k, tk, seed);
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setupRC4state(&rs, seed, sizeof(seed));
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rc4(&rs, b->rp, BLEN(b));
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}
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static int
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tkipdecrypt(Wkey *k, Wifipkt *w, Block *b, uvlong tsc)
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{
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uchar seed[16], mic[8];
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u16int tk[8], p1k[5];
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RC4state rs;
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MICstate ms;
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ulong crc;
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if(BLEN(b) < 8+4)
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return -1;
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tkipk2tk(k->key, tk);
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tkipphase1(tsc >> 16, w->a2, tk, p1k);
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tkipphase2(tsc & 0xFFFF, p1k, tk, seed);
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setupRC4state(&rs, seed, sizeof(seed));
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rc4(&rs, b->rp, BLEN(b));
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b->wp -= 4;
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crc = (ulong)b->wp[0] |
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(ulong)b->wp[1]<<8 |
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(ulong)b->wp[2]<<16 |
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(ulong)b->wp[3]<<24;
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crc = ~crc;
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if(ethercrc(b->rp, BLEN(b)) != crc)
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return -1;
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b->wp -= 8;
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micsetup(&ms, k->key+16);
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micupdate(&ms, dstaddr(w), Eaddrlen);
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micupdate(&ms, srcaddr(w), Eaddrlen);
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micupdate(&ms, pad4, 4);
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micupdate(&ms, b->rp, BLEN(b));
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micfinish(&ms, mic);
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return memcmp(b->wp, mic, 8) != 0;
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}
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static uchar*
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putbe(uchar *p, int L, uint v)
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{
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@ -1150,7 +1141,7 @@ sblock(int L, uchar *N, uint i, uchar b[16], AESstate *s)
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return b;
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};
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void
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static void
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aesCCMencrypt(int L, int M, uchar *N /* N[15-L] */,
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uchar *a /* a[la] */, int la,
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uchar *m /* m[lm+M] */, int lm,
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@ -1189,7 +1180,7 @@ aesCCMencrypt(int L, int M, uchar *N /* N[15-L] */,
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memmove(m, t, M);
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}
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int
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static int
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aesCCMdecrypt(int L, int M, uchar *N /* N[15-L] */,
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uchar *a /* a[la] */, int la,
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uchar *m /* m[lm+M] */, int lm,
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@ -1255,3 +1246,30 @@ setupCCMP(Wkey *k, Wifipkt *w, uvlong tsc, uchar nonce[13], uchar auth[32], AESs
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return p - auth;
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}
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static void
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ccmpencrypt(Wkey *k, Wifipkt *w, Block *b, uvlong tsc)
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{
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uchar auth[32], nonce[13];
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AESstate as;
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aesCCMencrypt(2, 8, nonce, auth,
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setupCCMP(k, w, tsc, nonce, auth, &as),
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b->rp, BLEN(b), &as);
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b->wp += 8;
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}
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static int
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ccmpdecrypt(Wkey *k, Wifipkt *w, Block *b, uvlong tsc)
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{
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uchar auth[32], nonce[13];
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AESstate as;
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if(BLEN(b) < 8)
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return -1;
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b->wp -= 8;
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return aesCCMdecrypt(2, 8, nonce, auth,
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setupCCMP(k, w, tsc, nonce, auth, &as),
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b->rp, BLEN(b), &as);
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}
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