From da107e125605438c7cf739ad34bb6204b3d4b85e Mon Sep 17 00:00:00 2001 From: meri Date: Wed, 25 Apr 2007 01:36:28 +0000 Subject: fixed ISO 14443A anticollision git-svn-id: https://svn.gnumonks.org/trunk/librfid@1988 e0336214-984f-0b4b-a45f-81c69e1f0ede --- src/rfid_asic_rc632.c | 20 +++++++++-------- src/rfid_layer2_iso14443a.c | 52 +++++++++++++++++++++++++++++++++------------ 2 files changed, 49 insertions(+), 23 deletions(-) diff --git a/src/rfid_asic_rc632.c b/src/rfid_asic_rc632.c index 0d6824c..0560d09 100644 --- a/src/rfid_asic_rc632.c +++ b/src/rfid_asic_rc632.c @@ -875,7 +875,7 @@ rc632_iso14443a_transceive_acf(struct rfid_asic_handle *handle, int ret; u_int8_t rx_buf[64]; u_int8_t rx_len = sizeof(rx_buf); - u_int8_t rx_align = 0, tx_last_bits, tx_bytes; + u_int8_t rx_align = 0, tx_last_bits, tx_bytes, tx_bytes_total; u_int8_t boc; u_int8_t error_flag; *bit_of_col = ISO14443A_BITOFCOL_NONE; @@ -899,14 +899,14 @@ rc632_iso14443a_transceive_acf(struct rfid_asic_handle *handle, if (ret < 0) return ret; - tx_last_bits = acf->nvb & 0x0f; /* lower nibble indicates bits */ - tx_bytes = acf->nvb >> 4; + tx_last_bits = acf->nvb & 0x07; /* lower nibble indicates bits */ + tx_bytes = ( acf->nvb >> 4 ) & 0x07; if (tx_last_bits) { - tx_bytes++; - rx_align = (tx_last_bits+1) % 8;/* rx frame complements tx */ + tx_bytes_total = tx_bytes+1; + rx_align = tx_last_bits & 0x07; /* rx frame complements tx */ } - - //rx_align = 8 - tx_last_bits;/* rx frame complements tx */ + else + tx_bytes_total = tx_bytes; /* set RxAlign and TxLastBits*/ ret = rc632_reg_write(handle, RC632_REG_BIT_FRAMING, @@ -914,7 +914,7 @@ rc632_iso14443a_transceive_acf(struct rfid_asic_handle *handle, if (ret < 0) return ret; - ret = rc632_transceive(handle, (u_int8_t *)acf, tx_bytes, + ret = rc632_transceive(handle, (u_int8_t *)acf, tx_bytes_total, rx_buf, &rx_len, 0x32, 0); if (ret < 0) return ret; @@ -923,8 +923,10 @@ rc632_iso14443a_transceive_acf(struct rfid_asic_handle *handle, acf->uid_bits[tx_bytes-2] = ( (acf->uid_bits[tx_bytes-2] & (0xff >> (8-tx_last_bits))) | rx_buf[0]); + /* copy the rest */ - memcpy(&acf->uid_bits[tx_bytes+1-2], &rx_buf[1], rx_len-1); + if(rx_len) + memcpy(&acf->uid_bits[tx_bytes-1], &rx_buf[1], rx_len-1); /* determine whether there was a collission */ ret = rc632_reg_read(handle, RC632_REG_ERROR_FLAG, &error_flag); diff --git a/src/rfid_layer2_iso14443a.c b/src/rfid_layer2_iso14443a.c index 4716018..2c4cb1e 100644 --- a/src/rfid_layer2_iso14443a.c +++ b/src/rfid_layer2_iso14443a.c @@ -23,6 +23,8 @@ #include #include #include + +// #define DEBUG_LIBRFID #include #include @@ -32,6 +34,8 @@ #define TIMEOUT 1236 +unsigned long randctx[4]={0x22d4a017,0x773a1f44,0xc39e1460,0x9cde8801}; + /* Transceive a 7-bit short frame */ int iso14443a_transceive_sf(struct rfid_layer2_handle *handle, @@ -80,20 +84,38 @@ iso14443a_code_nvb_bits(unsigned char *nvb, unsigned int bits) return 0; } +int random_bit(void) +{ + 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]; + + return randctx[1]&1; +} + /* first bit is '1', second bit '2' */ static void -set_bit_in_field(unsigned char *bitfield, unsigned int bit) +rnd_toggle_bit_in_field(unsigned char *bitfield, unsigned int size, unsigned int bit) { - unsigned int byte_count = bit / 8; - unsigned int bit_count = bit % 8; - - DEBUGP("bitfield=%p, byte_count=%u, bit_count=%u\n", - bitfield, byte_count, bit_count); - DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count)); - *(bitfield+byte_count) |= 1 << (bit_count-1); - DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count)); + unsigned int byte,rnd; + + 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; + } } + static int iso14443a_anticol(struct rfid_layer2_handle *handle) { @@ -122,7 +144,7 @@ iso14443a_anticol(struct rfid_layer2_handle *handle) return ret; } h->state = ISO14443A_STATE_ATQA_RCVD; - + DEBUGP("ATQA: 0x%02x 0x%02x\n", *aqptr, *(aqptr+1)); if (!atqa->bf_anticol) { @@ -150,18 +172,20 @@ cascade: ret = iso14443a_transceive_acf(handle, &acf, &bit_of_col); if (ret < 0) return ret; - DEBUGP("bit_of_col = %u\n", bit_of_col); while (bit_of_col != ISO14443A_BITOFCOL_NONE) { - set_bit_in_field(&acf.uid_bits[0], bit_of_col-16); + DEBUGP("collision at pos %u\n", bit_of_col); + iso14443a_code_nvb_bits(&acf.nvb, bit_of_col); + rnd_toggle_bit_in_field(acf.uid_bits, sizeof(acf.uid_bits), bit_of_col); + DEBUGP("acf: nvb=0x%02X uid_bits=%s\n",acf.nvb,rfid_hexdump(acf.uid_bits,sizeof(acf.uid_bits))); ret = iso14443a_transceive_acf(handle, &acf, &bit_of_col); - DEBUGP("bit_of_col = %u\n", bit_of_col); if (ret < 0) return ret; } iso14443a_code_nvb_bits(&acf.nvb, 7*8); + ret = iso14443a_transceive(handle, RFID_14443A_FRAME_REGULAR, (unsigned char *)&acf, 7, (unsigned char *) &sak, &rx_len, @@ -325,7 +349,7 @@ iso14443a_init(struct rfid_reader_handle *rh) return NULL; memset(h, 0, sizeof(*h)); - + h->l2 = &rfid_layer2_iso14443a; h->rh = rh; h->priv.iso14443a.state = ISO14443A_STATE_NONE; -- cgit v1.2.3