Add intro-crypto exercise 03

school/intro-crypto/uebung/03/u03/src/main.rs

@@ -0,0 +1,101 @@
+// use std::fs;
+struct Prng {
+    a: u16,
+    b: u16,
+    c: u16,
+    s0: u16,
+    s1: u16,
+}
+
+impl Iterator for Prng {
+    type Item = u8;
+
+    fn next(&mut self) -> Option<u8> {
+        let r = self.s0;
+        self.s0 = self.s1;
+        self.s1 = ((self.a * self.s1) % 257 + (self.b * r) % 257 + self.c) % 257;
+        Some((r % 256) as u8)
+    }
+}
+
+impl Prng {
+    fn new(s0: u16, s1: u16) -> Self {
+        Self {
+            s0: s0 % 257,
+            s1: s1 % 257,
+            a: 97,
+            b: 212,
+            c: 42,
+        }
+    }
+}
+
+fn main() {
+    // let c: &[u8] = &[0x4E, 0x7E, 0x3D, 0x88, 0x8E, 0x01, 0x0D, 0x84];
+    // let p: &[u8] = &[0x68, 0x74, 0x74, 0x70, 0x73, 0x3A, 0x2F, 0x2F];
+    // c.iter()
+    //     .zip(p.iter())
+    //     .map(|(c, p)| c ^ p)
+    //     .for_each(|k| print!("{:02X} ", k));
+
+    let c: &[u8] = &[
+        0x4E, 0x7E, 0x3D, 0x88, 0x8E, 0x01, 0x0D, 0x84, 0xB8, 0x7E, 0xBF, 0x1A, 0x25, 0x37, 0xFA,
+        0x4D, 0x89, 0x87, 0x91, 0xFA, 0x50, 0x51, 0xFC, 0x42, 0x7A, 0x9A, 0x6A, 0xE4,
+    ];
+    let p = Prng::new(0x26, 0x0a);
+
+    c.into_iter()
+        .zip(p)
+        .map(|(c, k)| c ^ k)
+        .map(|c| c as char)
+        .for_each(|c| print!("{}", c));
+    println!();
+
+    // let key: &[u8] = &[0xba, 0xad, 0xa5, 0x55, 0xc0, 0x00, 0x10, 0xff];
+    // // let cipher: &[u8] = &[0x33, 0xfd, 0xeb, 0x12, 0xcd, 0x0a, 0x0a, 0xf5];
+    // // let key: &[u8] = &[0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a];
+    // // cipher
+    // //     .iter()
+    // //     .zip(key.iter())
+    // //     .map(|(c, k)| c ^ k)
+    // //     .for_each(|p| print!("0x{:x} ", p));
+
+    // let args: Vec<_> = std::env::args().skip(1).collect();
+    // let data = fs::read(&args[0]).expect("Cannot read");
+    // let plain: Vec<_> = data
+    //     .into_iter()
+    //     .zip(key.into_iter().cycle())
+    //     .map(|(c, k)| c ^ k)
+    //     .collect();
+
+    // fs::write(&args[1], plain).expect("Cannot write");
+}
+
+// fn main() {
+//     let cipher: &[u8] = &[
+//         0xDC, 0x48, 0x13, 0x3B, 0x9C, 0x4C, 0x49, 0x80, 0xAC, 0xA7, 0xB9, 0x54, 0xF2, 0x7C, 0x2B,
+//         0x9E, 0xD5, 0xDF, 0x0D, 0x05, 0xB3, 0x1D, 0x4E, 0xF8,
+//     ];
+//     let key: &[u8] = &[
+//         0x98, 0x29, 0x60, 0x72, 0xF2, 0x38, 0x2C, 0xF2, 0xC2, 0xC2, 0xCD, 0x1D, 0x81, 0x08, 0x65,
+//         0xFB, 0xA0, 0xB3, 0x6C, 0x6B, 0xD7, 0x3C, 0x6F, 0xD9,
+//     ];
+//     cipher.iter().for_each(|c| print!("0x{:X} ", c));
+//     println!();
+//     key.iter().for_each(|c| print!("0x{:X} ", c));
+//     println!();
+//     cipher
+//         .iter()
+//         .zip(key.iter())
+//         .map(|(c, k)| c ^ k)
+//         .for_each(|p| print!("{:X} ", p));
+//     println!();
+
+//     cipher
+//         .iter()
+//         .zip(key.iter())
+//         .map(|(c, k)| c ^ k)
+//         .map(|c| c as char)
+//         .for_each(|p| print!("{} ", p));
+//     println!();
+// }