127 lines
2.7 KiB
C
127 lines
2.7 KiB
C
#include <errno.h>
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#include <malloc.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mman.h>
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int reproduce(unsigned char *pic_address, int pic_size)
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{
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int return_value = 0;
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for (int iter = 0; iter < pic_size; iter++)
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{
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printf("%02X", pic_address[iter]);
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}
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printf("\n");
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return_value = 1;
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CLONE_CLEANUP:
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if (NULL != pic_address)
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{
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munmap(pic_address, pic_size);
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}
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exit(0);
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}
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int hex_ascii_to_bin(char *hex_string, int hex_len, unsigned char *hex_bin)
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{
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if (hex_bin == NULL || hex_string == NULL || hex_len % 2 != 0)
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{
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return 0;
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}
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char *position = hex_string;
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for (int index = 0; index - 1 < hex_len; index++)
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{
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if (*position == NULL) break;
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for (int offset = 0; offset < 2; offset++, position++)
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{
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unsigned char hex_sort = *position | 0x20;
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if (hex_sort >= '0' && hex_sort <= '9')
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{
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hex_sort -= 0x30;
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}
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else if (hex_sort <= 'f' && hex_sort >= 'a')
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{
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hex_sort -= 0x57;
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}
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else
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{
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return 0;
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}
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if (!offset)
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{
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hex_bin[index] = (hex_sort << 4);
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}
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else
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{
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hex_bin[index] |= hex_sort;
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}
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}
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}
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return 1;
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}
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int generation(char *parent_hex, int rand_offset, char rand_flip)
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{
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int return_value = 0;
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int parent_hex_len = strlen(parent_hex);
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int parent_bin_len = parent_hex_len / 2;
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int prot = (PROT_READ | PROT_WRITE | PROT_EXEC);
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int flags = (MAP_ANON | MAP_PRIVATE);
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unsigned char *pic_buffer = mmap(NULL, parent_bin_len, prot, flags, -1, 0);
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if (MAP_FAILED == pic_buffer)
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{
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return_value = errno;
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goto GEN_CLEANUP;
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}
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hex_ascii_to_bin(parent_hex, parent_hex_len, pic_buffer);
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pic_buffer[rand_offset] = pic_buffer[rand_offset] ^ rand_flip;
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int (*reproduce_function)(unsigned char *, int) = reproduce;
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void (*pic_function)(void *, int, void *) = pic_buffer;
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pic_function(pic_buffer, parent_bin_len, reproduce_function);
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return_value = 1;
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GEN_CLEANUP:
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if (NULL != pic_buffer)
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{
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munmap(pic_buffer, parent_bin_len);
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}
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return return_value;
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}
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int main(int argc, const char **argv)
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{
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if (3 > argc || argv[1] == NULL || argv[2] == NULL || argv[3] == NULL)
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{
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exit(1);
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}
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char *hex_string = argv[1];
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int rand_offset = atoi(argv[2]);
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char rand_flip = atoi(argv[3]);
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int return_value = 0;
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return_value = generation(hex_string, rand_offset, rand_flip);
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if (!return_value)
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{
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exit(1);
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}
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return 0;
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}
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