103 lines
2.9 KiB
C
103 lines
2.9 KiB
C
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#include <stdio.h>
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#include <string.h>
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typedef unsigned char byte;
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byte str2byte(char str[8])
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{
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int ret = 0, i;
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for(i = 0; i < 8; i++)
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if (str[i]=='1') ret |= (1<<(7-i));
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return ret;
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}
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void print_binary(byte inpt)
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{
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int i;
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for(i = 0; i < 8; i++)
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if (inpt & (1<<(7-i))) putchar('1');
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else putchar('0');
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}
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int main(int argc, char **argv)
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{
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int i, max, offset;
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byte dec[256]={0}, enc[256]={0};
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char string[2048]={0};
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offset = 8; // Preamble + Sync
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if (argc>2)
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{
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if (argv[1][0]=='d')
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{
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if (strlen(argv[2]) > 256*8 || strlen(argv[2]) < 4) return -1;
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memcpy(string, argv[2], strlen(argv[2]));
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for (i = 0; i < strlen(string)-3; i+=8)
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enc[i/8] = str2byte(&string[i]);
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max = i/8;
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memcpy(&dec, &enc, 256);
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/*
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* byte[] Dec = new byte[Enc.Length];
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* Dec[0] = Enc[0]; //Packet length
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* Dec[1] = (byte)((~Enc[1]) ^ 0x89);
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* int j;
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* for (j = 2; j < Dec[0]; j++)
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* Dec[j] = (byte)((Enc[j-1] + 0xdc) ^ Enc[j]);
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* Dec[j] = (byte)(Enc[j] ^ Dec[2]);
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*/
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dec[offset+0] = enc[offset+0];
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dec[offset+1] = (~enc[offset+1])^0x89;
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for(i = offset + 2; i < max - 3; i++)
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dec[i] = (enc[i-1]+0xdc) ^ enc[i];
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dec[i] = enc[i] ^ dec[offset+2];
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dec[max-1]=0; // Set CRC to 0x0000
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dec[max-2]=0;
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for(i = 0; i < max; i++)
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print_binary(dec[i]);
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}
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else
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{
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if (strlen(argv[2]) > 256*8 || strlen(argv[2]) < 4) return -1;
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memcpy(string, argv[2], strlen(argv[2]));
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for (i = 0; i < strlen(string)-3; i+=8)
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dec[i/8] = str2byte(&string[i]);
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max = i/8;
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memcpy(&enc, &dec, 256);
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/*
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* byte[] Dec = new byte[Enc.Length];
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* Dec[0] = Enc[0]; //Packet length
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* Dec[1] = (byte)((~Enc[1]) ^ 0x89);
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* int j;
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* for (j = 2; j < Dec[0]; j++)
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* Dec[j] = (byte)((Enc[j-1] + 0xdc) ^ Enc[j]);
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* Dec[j] = (byte)(Enc[j] ^ Dec[2]);
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*/
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enc[offset+0] = dec[offset+0];
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enc[offset+1] = ~(dec[offset+1]^0x89);
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for(i = offset + 2; i < max - 3; i++)
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enc[i] = (enc[i-1]+0xdc) ^ dec[i];
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enc[i] = dec[i] ^ dec[offset+2];
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enc[max-1]=0; // Set CRC to 0x0000
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enc[max-2]=0;
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for(i = 0; i < max; i++)
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print_binary(enc[i]);
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}
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}
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else printf("Usage: %s <d/e> <bit sequence>\n\td - decode\n\te - encode\n\tbit sequence as string of 0 and 1.\n", argv[0]);
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return 0;
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}
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