diff options
Diffstat (limited to 'src/rfid_layer2_iso14443a.c')
-rw-r--r-- | src/rfid_layer2_iso14443a.c | 35 |
1 files changed, 17 insertions, 18 deletions
diff --git a/src/rfid_layer2_iso14443a.c b/src/rfid_layer2_iso14443a.c index cdd6b23..9bdd25a 100644 --- a/src/rfid_layer2_iso14443a.c +++ b/src/rfid_layer2_iso14443a.c @@ -85,35 +85,34 @@ iso14443a_code_nvb_bits(unsigned char *nvb, unsigned int bits) return 0; } -int random_bit(void) +static int random_bit(void) { - unsigned long e; + unsigned long e; - e = randctx[0]; - randctx[0]=randctx[1]; - randctx[1]=(randctx[2]<<19) + (randctx[2]>>13) + randctx[3]; - randctx[2]=randctx[3] ^ randctx[0]; - randctx[3]=e+randctx[1]; + e = randctx[0]; + randctx[0] = randctx[1]; + randctx[1] = (randctx[2]<<19) + (randctx[2]>>13) + randctx[3]; + randctx[2] = randctx[3] ^ randctx[0]; + randctx[3] = e+randctx[1]; - return randctx[1]&1; + return randctx[1]&1; } /* first bit is '1', second bit '2' */ static void rnd_toggle_bit_in_field(unsigned char *bitfield, unsigned int size, unsigned int bit) { - unsigned int byte,rnd; + unsigned int byte,rnd; - if(bit && (bit <= (size*8)) ) - { - rnd=random_bit(); + if (bit && (bit <= (size*8))) { + rnd = random_bit(); - DEBUGP("xor'ing bit %u with %u\n",bit,rnd); - bit--; - byte=bit/8; - bit=rnd<<(bit%8); - bitfield[byte] ^= bit; - } + DEBUGP("xor'ing bit %u with %u\n",bit,rnd); + bit--; + byte = bit/8; + bit = rnd << (bit % 8); + bitfield[byte] ^= bit; + } } |