I love C. It was my first language I learned. Any other security professional will tell you, C is the bomb, but on the same token, a source for a lot of head ache.
To anyone out there aspiring to be a security professional, get to know C and assembly. C lets you inline assembly which makes it awesome. The key is to practice your programming and practice often. Its too easy to forget.
#include <windows.h> #include <stdio.h> char *ppt(char *); long GetFS(FILE *); int main(int argc, char *argv[]) { if(argc < 3) { printf("Usage is %s filename xorcount",argv[0]); return 0; } const int xorcount = atoi(argv[2]); char *derp = ppt(argv[1]); FILE *pFile = fopen ( argv[1] , "rb" ); unsigned int fsg = GetFS(pFile); fclose(pFile); int x; for(x=0;x<fsg;x++) { int vg = derp[x]; __asm { mov eax,xorcount xor vg,eax } printf("Hex pos: %d \tHex Value: %2X\tAscii Char Value: %c\tXor'd value of char: %d\r\n",x,derp[x],derp[x],vg); vg=0; } __asm { sar fsg,3 } printf("File size shifted right 3: %i \r\n",fsg); __asm { sal fsg,3 mov eax,1024 crc32 eax,fsg } printf("File size shifted left 3: %i \r\n",fsg); } char* ppt(char *filename) // load file into buffer and return { FILE * pFile; long lSize; char * buffer; size_t result; pFile = fopen ( filename , "rb" ); if (pFile==NULL) {fputs ("File error",stderr); exit (1);} fseek (pFile , 0 , SEEK_END); lSize = ftell (pFile); rewind (pFile); buffer = (char*) malloc (sizeof(char)*lSize); if (buffer == NULL) {fputs ("Memory error",stderr); exit (2);} result = fread (buffer,1,lSize,pFile); if (result != lSize) {fputs ("Reading error",stderr); exit (3);} fclose (pFile); return buffer; } long GetFS(FILE *lol) // get file size { long lSize = 0; fseek (lol , 0 , SEEK_END); lSize = ftell (lol); rewind (lol); return lSize; }
This is kind of a filler post. I just feel like updating the blog with something. On that note, I’m split on what i want to do next. Was thinking of making a segway into hardware hacking for a little while as I had a project in mind, but we shall see. 