diff --git a/ROM2/crctest.c b/ROM2/crctest.c new file mode 100644 index 0000000000000000000000000000000000000000..bf48c894620a153edafbc9cb36d762e0e15995d2 --- /dev/null +++ b/ROM2/crctest.c @@ -0,0 +1,41 @@ +#include <stdio.h> +#include <stdlib.h> +typedef unsigned short u16; +typedef unsigned char bool; +#include "crctab.h" + +unsigned short +docrc (unsigned char *p, int len, bool pad, unsigned short crcstart) +{ + int len2 = len; + unsigned short crc = crcstart; + + while (len-- > 0) + crc = (crc << 8) ^ crctab[(crc >> 8) ^ *p++]; + if (pad && len2 < 128) { + len = 128-len; + while (len-- > 0) + crc = (crc << 8) ^ crctab[(crc >> 8) ^ 0x1a]; + } + + return crc; +} + +int main(int argc, char** argv) { + unsigned short crc; + unsigned short msgid; + char *password, *message; + if (argc != 4) { + fprintf(stderr, "Usage: %s <id> <password> <message>\n", argv[0]); + return 1; + } + msgid = strtol(argv[1], NULL, 16); + password = argv[2]; + message = argv[3]; + crc = docrc(((char*)&msgid)+1, 1, 0, 0); + crc = docrc(((char*)&msgid), 1, 0, crc); + crc = docrc(password, strlen(password), 0, crc); + crc = docrc(message, strlen(message), 0, crc); + printf("CRC is 0x%x\n", crc); + return 0; +}