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fix memmove if len=0

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This commit is contained in:
merlokk 2019-02-05 18:39:03 +02:00
parent 0e5d896893
commit 69f3e65dd0
1 changed files with 13 additions and 11 deletions
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24
armsrc/iso14443a.c
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@ -2266,32 +2266,34 @@ int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, bool send_chaining, void *data, u
iso14a_set_timeout(save_iso14a_timeout); iso14a_set_timeout(save_iso14a_timeout);
} }
// if we received an I- or R(ACK)-Block with a block number equal to the // if we received an I- or R(ACK)-Block with a block number equal to the
// current block number, toggle the current block number // current block number, toggle the current block number
if (len >= 3 // PCB+CRC = 3 bytes if (len >= 3 // PCB+CRC = 3 bytes
&& ((data_bytes[0] & 0xC0) == 0 // I-Block && ((data_bytes[0] & 0xC0) == 0 // I-Block
|| (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
&& (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
{ {
iso14_pcb_blocknum ^= 1; iso14_pcb_blocknum ^= 1;
} }
// if we received I-block with chaining we need to send ACK and receive another block of data // if we received I-block with chaining we need to send ACK and receive another block of data
if (res) if (res)
*res = data_bytes[0]; *res = data_bytes[0];
// crc check // crc check
if (len >=3 && !check_crc(CRC_14443_A, data_bytes, len)) { if (len >= 3 && !check_crc(CRC_14443_A, data_bytes, len)) {
return -1; return -1;
} }
} }
// cut frame byte if (len) {
len -= 1; // cut frame byte
// memmove(data_bytes, data_bytes + 1, len); len -= 1;
for (int i = 0; i < len; i++) // memmove(data_bytes, data_bytes + 1, len);
data_bytes[i] = data_bytes[i + 1]; for (int i = 0; i < len; i++)
data_bytes[i] = data_bytes[i + 1];
}
return len; return len;
} }