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cc_lab4_contract.rs 5.17 KiB
#![no_std]
#![no_main]
#![allow(dead_code)]
#[macro_use]
extern crate klee;
use core::cmp;
static mut PLAIN: [u8; 132] = [0; 132];
static ABC: [u32; 4] = [0x9fdd9158, 0x85715808, 0xac73323a, 0];
static CODED: [u32; 132] = [
0x015e7a47, 0x2ef84ebb, 0x177a8db4, 0x1b722ff9, 0x5dc7cff0, 0x5dc9dea6, 0x1da0c15a, 0xe4c236a2,
0x3d16b0d0, 0x1f397842, 0xaae0d2ba, 0x11246674, 0x0845317f, 0xd5512dad, 0xb6184977, 0xd293a53e,
0x7d9c2716, 0xd917eae6, 0xd8852384, 0x286e46f9, 0xce566029, 0xcefe7daf, 0x62d726d4, 0x0dbaeb2d,
0x95f57c60, 0xed515141, 0x29b77d0f, 0x9f7b8d0c, 0x45a8395a, 0xfead2b72, 0x883d434c, 0xed8ddf60,
0xe51e65e4, 0x19bf6bb1, 0xfeb505ec, 0x662aa23c, 0xf6827cf8, 0xd1dc7a5c, 0x4fa5b066, 0x7ddd25a4,
0xa8ba8e8a, 0x72846227, 0xf8f636fb, 0x2b389a9c, 0xe4038bf6, 0x6e169877, 0xad028132, 0x84dbfe8c,
0x243762ff, 0x59c8f80c, 0xb6e0db4b, 0xedb8cab7, 0xcd4b39f6, 0xaf263741, 0x18d9965f, 0x1ab1f037,
0x5b458792, 0xc94d960d, 0xd45cedea, 0x2160aca3, 0x93c77766, 0x2d66e105, 0x9ff74d4f, 0x6dc22f21,
0x6b03d689, 0x5fc48de0, 0x1138f000, 0xccb58e57, 0xf9c8e200, 0x7ab26e3c, 0xc61dcb3e, 0x6aefccb0,
0x7a452f05, 0xa5cf0731, 0xa249383f, 0x628fe534, 0xcad81710, 0x7f616276, 0x3ce18308, 0xed4857ff,
0xd1e5b1d1, 0xc2e84dc2, 0xaa003742, 0xaf637488, 0x831afc48, 0x287a69a0, 0x6e04546e, 0x13dffa07,
0x3232fb10, 0xd69e2e09, 0x355d8dc7, 0xef902301, 0x9a89ac15, 0x967dc900, 0x08dc2b1c, 0x6b5be690,
0x894b0e02, 0xe26af9af, 0xa6fd3b23, 0xfcf213e5, 0x85217608, 0x7fd3be8b, 0xa2e757fb, 0x3717a341,
0x85ee426d, 0x394bb856, 0x12ac98c3, 0xec7d4ab5, 0x721b6989, 0x30e36360, 0xaa018403, 0x9ee61196,
0xa8697adc, 0x51e9d65a, 0x11023594, 0xc4c4b36b, 0xda80bf7a, 0xbd5a645e, 0x18cea918, 0xa723dda8,
0x0126c05e, 0x2962d48a, 0xd5f7d312, 0xb8947041, 0x7c1e2e9a, 0x945eeac3, 0x7110fb1c, 0xa7bc72cc,
0xdf47dfbb, 0x09a1c6c8, 0xc2e41061, 0,
];
//# FUNCTION codgen(): UNSIGNED INTEGER;
// # LOCAL SIGNED INTEGER n;
// # LOCAL UNSIGNED INTEGER x, y;
// # BEGIN
// # n := [count the number of 0's in word "seed"];
// # x := [rotate "seed" left by 30 bits];
// # y := [shift "seed" right-ARITHMETIC by 6 bits];
// # seed := x XOR y XOR n;
// # RETURN( seed XOR 0x464b713e );
// # END;
// #
// # hint: if "seed" is initialized to 0x3e944b9f,
// # the first five calls will generate these values:
// # 0x891432f9, 0x4aa1dccc, 0xc54270fa, 0x9885155f, 0xce83d1b8, ...
// # your code is to be written farther down (see comment below).
//
fn codgen(seed: &mut u32) -> u32 {
let mut n: i32 = 32;
let lseed: u32 = seed.clone(); // copy value of seed
let mut s: u32 = lseed;
let x: u32;
let y: u32;
//n = [count the number of 0's in word "seed"];
while s != 0 {
if s & 1u32 == 1u32 {
n -= 1;
}
s >>= 1; // >> is logic shift
}
// x := [rotate "seed" left by 30 bits];
x = lseed << 30 | ((lseed >> 2) & ((1 << (30 + 1)) - 1));
// y := [shift "seed" right-ARITHMETIC by 6 bits];
y = ((lseed as i32) >> 6) as u32;
// seed := x XOR y XOR n;
*seed = x ^ y ^ (n as u32);
// RETURN( seed XOR 0x464b713e );
(*seed) ^ 0x464b713e
}
//
fn decode_org(wordarr: &[u32], bytearr: &mut [u8], seed: &mut u32) -> u32 {
let m: u32;
let mut r: u32;
let x: u32;
let y: u32;
x = !codgen(seed);
if wordarr[0] == 0 {
bytearr[0] = 0;
r = x;
} else {
y = decode(&wordarr[1..], &mut bytearr[1..], seed);
m = x.wrapping_sub(y).wrapping_sub(wordarr[0]);
bytearr[0] = (m >> 13) as u8;
r = (-(codgen(seed) as i32)) as u32;
r = x
.wrapping_add(y)
.wrapping_add(m)
.wrapping_add(r)
.wrapping_add(5);
}
r
}
// mod rnd {
// use core::mem;
// static mut I: usize = 0;
// static RND: [u32; 132] = [0; 132]; // unsafe { mem::uninitialized() };
// pub fn get() -> u32 {
// unsafe {
// let r = RND[I];
// I += 1;
// r
// }
// }
// pub fn ksymbolic() {
// unsafe {
// make_symbolic(
// &mut RND as *mut [u32; 132] as *mut c_void,
// mem::size_of::<[u32; 132]>(),
// "name".as_ptr(),
// )
// }
// }
// }
fn decode(wordarr: &[u32], bytearr: &mut [u8], seed: &mut u32) -> u32 {
let m: u32;
let mut r: u32;
let x: u32;
let y: u32;
// x = !codgen(seed);
x = ksymbol!("x");
// x = rnd::get();
if wordarr == [] {
bytearr[0] = 0;
r = x;
} else {
y = decode(&wordarr[1..], &mut bytearr[1..], seed);
m = x.wrapping_sub(y).wrapping_sub(wordarr[0]);
bytearr[0] = (m >> 13) as u8;
let cg: u32 = ksymbol!("cg");
// let cg: u32 = codgen(seed);
// let cg: u32 = rnd::get();
r = (-(cg as i32)) as u32;
r = x
.wrapping_add(y)
.wrapping_add(m)
.wrapping_add(r)
.wrapping_add(5);
}
r
}
#[no_mangle]
fn main() {
//let mut seed = 0x0e0657c1;
let mut seed = ksymbol!("seed");
//rnd::ksymbolic();
let abc: [u32; 4] = ksymbol!("abc");
decode_org(&abc[..], unsafe { &mut PLAIN }, &mut seed);
}