shellcode_executor.c

// Shellcode executor
// Expects hex as a command line parameter
//
// Compile with:  gcc -fno-stack-protector -z execstack main.c

#include <string.h>
#include <stddef.h>
#include <stdlib.h>

int main(int argc, char* argv[])
{
	if (argc == 2)
	{
		char code[32000] = { 0 };	// may overflow
		int codeindex = 0;

		char temp[3] = { 0 };
		int length = strlen(argv[1]);

		for (int i = 0; i < length; i += 2)
		{
			strncpy(temp, argv[1] + i, 2);
			code[codeindex] = strtol(temp, NULL, 16);
			codeindex++;
		}

		int (*foo)() = (int(*)())code;
		foo();
	}
}