feat: 完善AES加密实现和多个问题的解决方案

- 在common库中添加了完整的AES-128加密解密实现
- 实现了AES-ECB和AES-CBC模式的加密解密函数
- 添加了密钥扩展和所有必要的AES操作函数
- 完成了问题10的AES-CBC模式实现
- 修复了问题11的加密oracle实现，使用正确的ECB检测
- 改进了代码风格，使用现代Rust格式化语法
- 为多个问题添加了common库的依赖

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

problems/p11/Cargo.toml

@@ -4,4 +4,5 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+common = { path = "../../common" }
 rand = "0.9.1"

problems/p11/src/main.rs

@@ -1,4 +1,5 @@
-use rand::{Rng, seq::IndexedRandom};
+use common::{aes_cbc_enc, aes_ecb_enc, is_ecb, pkcs7_padding};
+use rand::prelude::*;
 
 fn gen_random_key() -> [u8; 16] {
     let mut rng = rand::rng();
@@ -24,22 +25,23 @@ fn encryption_oracle(plaintext: &[u8]) -> Vec<u8> {
     data.extend(plaintext);
     data.extend(random_suffix);
 
-    pkcs7_padding(&mut data, 16); // in p9
+    pkcs7_padding(&mut data, 16);
 
     if enc_mode == 0 {
         // ECB mode in p7
-        ecb_encrypt(&data, &key)
+        println!("Using ECB mode.");
+        aes_ecb_enc(&data, &key).unwrap()
     } else {
         // CBC mode in p10
         let iv = [0u8; 16];
-        cbc_encrypt(&data, &key, &iv)
+        println!("Using CBC mode.");
+        aes_cbc_enc(&data, &key, &iv).unwrap()
     }
-    data
 }
 
 fn main() {
-    let plaintext = b"YELLOW SUBMARINE";
-    let encrypted_data = encryption_oracle(plaintext);
+    let plaintext = b"YELLOW SUBMARINE".repeat(32);
+    let encrypted_data = encryption_oracle(&plaintext);
     // in p8
     if is_ecb(&encrypted_data) {
         println!("ECB mode detected.");