From e588ed13aa2d3e621e2605e20bb417d2bed8ac25 Mon Sep 17 00:00:00 2001
From: beneth <bmauduit@beneth.fr>
Date: Mon, 13 Apr 2020 17:39:08 +0200
Subject: [PATCH] Move base64 encode to a function

---
 set1/chal1/src/main.rs | 107 ++++++++++++++++++++++-------------------
 1 file changed, 58 insertions(+), 49 deletions(-)

diff --git a/set1/chal1/src/main.rs b/set1/chal1/src/main.rs
index 5c9b7cd..3b74cb7 100644
--- a/set1/chal1/src/main.rs
+++ b/set1/chal1/src/main.rs
@@ -5,11 +5,6 @@
 ////
 
 use std::env;
-use std::convert::TryInto;
-
-static BASE64_TABLE: &'static [char] = &['A','B','C','D','E','F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V' ,'W' ,'X' ,'Y' ,'Z',
-                                         'a','b','c','d','e','f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v' ,'w' ,'x' ,'y' ,'z',
-                                         '0','1','2','3','4','5', '6', '7', '8', '9', '+', '/'];
 
 /// Convert Hex String to char
 ///
@@ -23,6 +18,63 @@ fn hex_to_char(s: &str) -> Result<char, std::num::ParseIntError> {
   u8::from_str_radix(s, 16).map(|n| n as char)
 }
 
+/// Encode a Vector of bytes to Base64 and return the base 64 String
+fn base64_encode(input: &Vec<u8>) -> String {
+  static BASE64_TABLE: &'static [char] = &['A','B','C','D','E','F', 'G', 'H',
+                                           'I', 'J', 'K', 'L', 'M', 'N', 'O',
+                                           'P', 'Q', 'R', 'S', 'T', 'U', 'V',
+                                           'W' ,'X' ,'Y' ,'Z',
+                                           'a','b','c','d','e','f', 'g', 'h',
+                                           'i', 'j', 'k', 'l', 'm', 'n', 'o',
+                                           'p', 'q', 'r', 's', 't', 'u', 'v',
+                                           'w' ,'x' ,'y' ,'z',
+                                           '0','1','2','3','4','5', '6', '7',
+                                           '8', '9', '+', '/'];
+  let mut output = String::new();
+  for j in (0..input.len()).step_by(3) {
+    let mut pad = 0;
+    let mut arr = [0u8;4];
+    arr[0] = 0;
+
+    for i in 0..3 {
+      if i+j == input.len() {
+        arr[i+1] = 0;
+        pad = 1;
+      } else if i+j > input.len() {
+        arr[i+1] = 0;
+        pad = 2;
+      } else {
+        arr[i+1] = input[i+j];
+      }
+    }
+    let tmp = u32::from_be_bytes(arr);
+
+    let tmp1 = (tmp>>18) & 0x3F;
+    let tmp2 = (tmp>>12) & 0x3F;
+
+    output.push(BASE64_TABLE[tmp1 as usize]);
+    output.push(BASE64_TABLE[tmp2 as usize]);
+
+    if pad == 2 {
+      output.push_str("==");
+      break
+    } else {
+      let tmp3 = (tmp>>6) & 0x3F;
+      output.push(BASE64_TABLE[tmp3 as usize]);
+    }
+
+    if pad == 1 {
+      output.push_str("=");
+      break
+    } else {
+      let tmp4 = (tmp) & 0x3F;
+      output.push(BASE64_TABLE[tmp4 as usize]);
+    }
+  }
+
+  output
+}
+
 fn main() {
   let mut input_str = String::new();
   let args: Vec<String> = env::args().collect();
@@ -51,50 +103,7 @@ fn main() {
     .map(|i| u8::from_str_radix(i, 16).unwrap())
     .collect();
 
-  // TODO !
-  // TODO: Make not ugly and move to function b64_encode(Vec<u8>) -> str
-  // TODO !
-  let mut output = String::new();
-  for j in (0..hex.len()).step_by(3) {
-    let mut pad = 0;
-    let mut arr = [0u8;4];
-    arr[0] = 0;
-
-    for i in 0..3 {
-      if i+j == hex.len() {
-        arr[i+1] = 0;
-        pad = 1;
-      } else if i+j > hex.len() {
-        arr[i+1] = 0;
-        pad = 2;
-      } else {
-        arr[i+1] = hex[i+j];
-      }
-    }
-    let tmp = u32::from_be_bytes(arr);
-
-    let tmp1:usize = ((tmp>>18) & 0x3F).try_into().unwrap();
-    let tmp2:usize = ((tmp>>12) & 0x3F).try_into().unwrap();
-
-    output.push(BASE64_TABLE[tmp1]);
-    output.push(BASE64_TABLE[tmp2]);
-
-    if pad == 2 {
-      output.push_str("==");
-      break
-    } else {
-      let tmp3:usize = ((tmp>>6) & 0x3F).try_into().unwrap();
-      output.push(BASE64_TABLE[tmp3]);
-    }
-
-    if pad == 1 {
-      output.push_str("=");
-      break
-    } else {
-      let tmp4:usize = ((tmp) & 0x3F).try_into().unwrap();
-      output.push(BASE64_TABLE[tmp4]);
-    }
-  }
+  let output = base64_encode(&hex);
 
   println!("→ Input string is « {} »", input);
   println!("→ Hex String to ASCII « {} »", &input_str);