Implement encryption oracle for challenge 11.

src/set1.rs

@@ -1,7 +1,7 @@
 #![allow(dead_code)]
 use crate::bytes::Bytes;
 use crate::bytes_base64::BytesBase64;
-use openssl::symm::{decrypt, Cipher};
+use crate::ecb;
 use std::io::{BufRead, BufReader, Write};
 use std::str;
 
@@ -160,15 +160,16 @@ pub fn challenge7() {
         let s = std::fs::read_to_string(path).unwrap();
         BytesBase64::from_base64(&s).to_bytes()
     }
-    let ciphertext = &read("data/7.txt").0;
-    let key = b"YELLOW SUBMARINE";
-    let cipher = Cipher::aes_128_ecb();
-    let data = decrypt(cipher, key, None, ciphertext);
-    let result = match data {
-        Ok(data) => Bytes(data).to_utf8(),
-        Err(err) => err.to_string(),
-    };
-    let partial_msg = result[..20].to_string();
+    let text = Bytes::from_utf8("We meet at burger king!");
+    let key = Bytes::from_utf8("YELLOW SUBMARINE");
+    let ciphertext = ecb::encrypt(&key, &text);
+    let roundtrip = ecb::decrypt(&key, &ciphertext);
+    if text != roundtrip {
+        panic!("ECB roundtrip not working.");
+    }
+    let ciphertext = read("data/7.txt");
+    let data = ecb::decrypt(&key, &ciphertext);
+    let partial_msg = data.to_utf8()[..20].to_string();
     println!("[okay] Challenge 7: {}...", partial_msg);
 }
 
@@ -198,6 +199,9 @@ pub fn challenge8() {
     let index = ratings.iter().position(|e| e == min_rating).unwrap();
     let average = ratings.iter().sum::<u32>() as f32 / ratings.len() as f32;
     let partial_cipher = bytes_vector[index].to_hex()[..10].to_string();
+    if index != 132 {
+        panic!("Regression in challenge 8.");
+    }
     println!(
         "[okay] Challenge 8: Cipher {} [{}...] with rating {} (average = {}) is the solution.",
         index, partial_cipher, min_rating, average