From 7c94e5d8fb36334abe507390e99b3059f834e04f Mon Sep 17 00:00:00 2001
From: 0xalivecow <mail@ta-lotz.de>
Date: Tue, 22 Oct 2024 20:22:42 +0200
Subject: [PATCH] refactor: Externalise AES and SEA functions

---
 src/tasks/tasks01/sea128.rs | 39 ++++--------------------
 src/utils/ciphers.rs        | 59 +++++++++++++++++++++++++++++++++++++
 src/utils/math.rs           |  9 ++++++
 src/utils/mod.rs            |  2 ++
 4 files changed, 76 insertions(+), 33 deletions(-)
 create mode 100644 src/utils/ciphers.rs
 create mode 100644 src/utils/math.rs

diff --git a/src/tasks/tasks01/sea128.rs b/src/tasks/tasks01/sea128.rs
index b6e6135..09b090a 100644
--- a/src/tasks/tasks01/sea128.rs
+++ b/src/tasks/tasks01/sea128.rs
@@ -1,9 +1,11 @@
 use anyhow::{anyhow, Result};
 use base64::prelude::*;
-use openssl::symm::{Cipher, Crypter, Mode};
 use serde_json::Value;
 
-use crate::utils::poly::b64_2_num;
+use crate::utils::{
+    ciphers::{sea_128_decrypt, sea_128_encrypt},
+    poly::b64_2_num,
+};
 
 pub fn sea128(args: &Value) -> Result<String> {
     let key_string: String = serde_json::from_value(args["key"].clone())?;
@@ -19,42 +21,13 @@ pub fn sea128(args: &Value) -> Result<String> {
     match mode.as_str() {
         "encrypt" => {
             //eprintln!("{:?}", plaintexts);
-            let mut encrypter = Crypter::new(Cipher::aes_128_ecb(), Mode::Encrypt, &key, None)?;
-            encrypter.pad(false);
 
-            let mut ciphertext = [0; 32].to_vec();
-
-            let mut count = encrypter.update(&input, &mut ciphertext)?;
-            count += encrypter.finalize(&mut ciphertext)?;
-            ciphertext.truncate(count);
-
-            //eprintln!("{:?}", &ciphertext[..]);
-
-            let mut bytes: [u8; 16] = [0u8; 16];
-            bytes.copy_from_slice(&ciphertext);
-            let number: u128 = <u128>::from_be_bytes(bytes);
-
-            let output = BASE64_STANDARD.encode((number ^ xor_val).to_be_bytes());
+            let output = BASE64_STANDARD.encode(sea_128_encrypt(&key, &input)?);
 
             Ok(output)
         }
         "decrypt" => {
-            let mut decrypter = Crypter::new(Cipher::aes_128_ecb(), Mode::Decrypt, &key, None)?;
-            decrypter.pad(false);
-
-            let mut bytes: [u8; 16] = [0u8; 16];
-            bytes.copy_from_slice(&input);
-            let input_num: u128 = <u128>::from_be_bytes(bytes);
-
-            let input_afer_xor = (input_num ^ xor_val).to_be_bytes();
-
-            let mut plaintext = [0; 32].to_vec();
-
-            let mut count = decrypter.update(&input_afer_xor, &mut plaintext)?;
-            count += decrypter.finalize(&mut plaintext)?;
-            plaintext.truncate(count);
-
-            let output = BASE64_STANDARD.encode(plaintext);
+            let output = BASE64_STANDARD.encode(sea_128_decrypt(&key, &input)?);
 
             Ok(output)
         }
diff --git a/src/utils/ciphers.rs b/src/utils/ciphers.rs
new file mode 100644
index 0000000..d82be86
--- /dev/null
+++ b/src/utils/ciphers.rs
@@ -0,0 +1,59 @@
+use anyhow::Result;
+use openssl::symm::{Cipher, Crypter, Mode};
+
+use super::math::xor_bytes;
+
+pub fn aes_128_encrypt(key: &Vec<u8>, input: &Vec<u8>) -> Result<Vec<u8>> {
+    let mut encrypter = Crypter::new(Cipher::aes_128_ecb(), Mode::Encrypt, &key, None)?;
+    encrypter.pad(false);
+
+    let mut ciphertext = [0; 32].to_vec();
+
+    let mut count = encrypter.update(input, &mut ciphertext)?;
+    count += encrypter.finalize(&mut ciphertext)?;
+    ciphertext.truncate(count);
+
+    //eprintln!("{:?}", &ciphertext[..]);
+
+    Ok(ciphertext)
+}
+
+pub fn aes_128_decrypt(key: &Vec<u8>, input: &Vec<u8>) -> Result<Vec<u8>> {
+    let mut decrypter = Crypter::new(Cipher::aes_128_ecb(), Mode::Decrypt, key, None)?;
+    decrypter.pad(false);
+
+    let mut plaintext = [0; 32].to_vec();
+
+    let mut count = decrypter.update(input, &mut plaintext)?;
+    count += decrypter.finalize(&mut plaintext)?;
+    plaintext.truncate(count);
+
+    let mut bytes: [u8; 16] = [0u8; 16];
+    bytes.copy_from_slice(&plaintext);
+    let number: u128 = <u128>::from_be_bytes(bytes);
+
+    Ok(plaintext)
+}
+
+pub fn sea_128_encrypt(key: &Vec<u8>, input: &Vec<u8>) -> Result<Vec<u8>> {
+    let xor_val: u128 = 0xc0ffeec0ffeec0ffeec0ffeec0ffee11;
+    let sea128_out = xor_bytes(
+        &aes_128_encrypt(key, input)?,
+        xor_val.to_be_bytes().to_vec(),
+    )?;
+    Ok(sea128_out)
+}
+
+pub fn sea_128_decrypt(key: &Vec<u8>, input: &Vec<u8>) -> Result<Vec<u8>> {
+    let xor_val: u128 = 0xc0ffeec0ffeec0ffeec0ffeec0ffee11;
+
+    let intermediate = xor_bytes(input, xor_val.to_be_bytes().to_vec())?;
+    Ok(aes_128_decrypt(&key, &intermediate)?)
+}
+
+/*
+* let mut bytes: [u8; 16] = [0u8; 16];
+    bytes.copy_from_slice(&ciphertext);
+    let number: u128 = <u128>::from_be_bytes(bytes);
+
+* */
diff --git a/src/utils/math.rs b/src/utils/math.rs
new file mode 100644
index 0000000..b9c8f84
--- /dev/null
+++ b/src/utils/math.rs
@@ -0,0 +1,9 @@
+use anyhow::Result;
+
+pub fn xor_bytes(vec1: &Vec<u8>, mut vec2: Vec<u8>) -> Result<Vec<u8>> {
+    for (byte1, byte2) in vec1.iter().zip(vec2.iter_mut()) {
+        *byte2 ^= byte1;
+    }
+
+    Ok(vec2)
+}
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
index b8568f9..fcbb75b 100644
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@@ -1,2 +1,4 @@
+pub mod ciphers;
+pub mod math;
 pub mod parse;
 pub mod poly;