Remove duplicated code and make base64 error handling better

src/set1.rs

@@ -1,8 +1,8 @@
 #![allow(dead_code)]
 use crate::bytes::Bytes;
 use crate::bytes_base64::BytesBase64;
-use crate::ecb;
-use std::io::{BufRead, BufReader, Write};
+use crate::{ecb, utils};
+use std::io::Write;
 use std::str;
 
 pub fn challenge1() {
@@ -38,15 +38,7 @@ pub fn challenge3() {
 }
 
 pub fn challenge4() {
-    fn read(path: &str) -> Vec<Bytes> {
-        let file = std::fs::File::open(path).unwrap();
-        let br = BufReader::new(file);
-        br.lines()
-            .map(|line| Bytes::from_hex(&line.unwrap()))
-            .collect()
-    }
-
-    let bytes_vector = read("data/4.txt");
+    let bytes_vector = utils::read_hex_lines("data/4.txt");
     let mut xored_bytes_vector: Vec<Bytes> = vec![];
     for i in 32..=127 {
         for bytes in bytes_vector.iter() {
@@ -73,11 +65,6 @@ pub fn challenge5() {
 }
 
 pub fn challenge6() {
-    fn read(path: &str) -> Bytes {
-        let s = std::fs::read_to_string(path).unwrap();
-        BytesBase64::from_base64(&s).to_bytes()
-    }
-
     fn _write(path: &str, bytes_base64: &BytesBase64) {
         let width = 60;
         let bytes = bytes_base64.to_string();
@@ -96,7 +83,7 @@ pub fn challenge6() {
 
     fn _test_roundtrip() {
         // Test that conversion from to bytes and back works
-        let bytes = read("data/6.txt");
+        let bytes = utils::read_base64("data/6.txt");
         let bytes_base64 = BytesBase64::from_bytes(bytes);
         _write("data/6.txt", &bytes_base64);
     }
@@ -139,7 +126,7 @@ pub fn challenge6() {
     }
 
     _test_roundtrip();
-    let bytes = read("data/6.txt");
+    let bytes = utils::read_base64("data/6.txt");
     let key_size = guess_key_size(&bytes);
     let bytes_tranposed = transpose(&bytes, key_size);
     let key = Bytes(
@@ -155,10 +142,6 @@ pub fn challenge6() {
 }
 
 pub fn challenge7() {
-    fn read(path: &str) -> Bytes {
-        let s = std::fs::read_to_string(path).unwrap();
-        BytesBase64::from_base64(&s).to_bytes()
-    }
     let text = Bytes::from_utf8("We meet at burger king!");
     let key = Bytes::from_utf8("YELLOW SUBMARINE");
     let ciphertext = ecb::encrypt(&key, &text);
@@ -166,21 +149,13 @@ pub fn challenge7() {
     if text != roundtrip {
         panic!("ECB roundtrip not working.");
     }
-    let ciphertext = read("data/7.txt");
+    let ciphertext = utils::read_base64("data/7.txt");
     let data = ecb::decrypt(&key, &ciphertext);
     let partial_msg = data.to_utf8()[..20].to_string();
     println!("[okay] Challenge 7: {}...", partial_msg);
 }
 
 pub fn challenge8() {
-    fn read(path: &str) -> Vec<Bytes> {
-        let file = std::fs::File::open(path).unwrap();
-        let br = BufReader::new(file);
-        br.lines()
-            .map(|line| Bytes::from_hex(&line.unwrap()))
-            .collect()
-    }
-
     fn rate(Bytes(v): &Bytes, size: usize) -> u32 {
         let mut rating = 0;
         let chunks: Vec<&[u8]> = v.chunks(size).collect();
@@ -193,7 +168,7 @@ pub fn challenge8() {
     }
 
     let expected_index: usize = 132;
-    let bytes_vector = read("data/8.txt");
+    let bytes_vector = utils::read_hex_lines("data/8.txt");
     let ratings: Vec<u32> = bytes_vector.iter().map(|b| rate(&b, 16)).collect();
     let min_rating = ratings.iter().min().unwrap();
     let index = ratings.iter().position(|e| e == min_rating).unwrap();
@@ -208,7 +183,7 @@ pub fn challenge8() {
     );
 
     // More elegant solution.
-    let bytes_vector = read("data/8.txt");
+    let bytes_vector = utils::read_hex_lines("data/8.txt");
     let ix: Vec<usize> = bytes_vector
         .iter()
         .enumerate()