update(ycb2025): add a missing aes.py

Author: RocketMaDev

source/_posts/ycb2025/hello_iot.md

@@ -58,6 +58,114 @@ excerpt: 通过自定义AES换S盒加密登录验证、利用`/log`泄露libc和
 
 ## EXPLOIT
 
+```python aes.py
+from pwn import u64
+# ========================================================
+#  纯 Python 实现 AES-128 加密 (支持自定义 S-box)
+# ========================================================
+
+# 默认 AES S-box，可自行修改实现「换表 AES」
+S_BOX = [
+    0x29, 0x40, 0x57, 0x6e, 0x85, 0x9c, 0xb3, 0xca, 0xe1, 0xf8,  0xf, 0x26, 0x3d, 0x54, 0x6b, 0x82,
+    0x99, 0xb0, 0xc7, 0xde, 0xf5,  0xc, 0x23, 0x3a, 0x51, 0x68, 0x7f, 0x96, 0xad, 0xc4, 0xdb, 0xf2,
+     0x9, 0x20, 0x37, 0x4e, 0x65, 0x7c, 0x93, 0xaa, 0xc1, 0xd8, 0xef,  0x6, 0x1d, 0x34, 0x4b, 0x62,
+    0x79, 0x90, 0xa7, 0xbe, 0xd5, 0xec,  0x3, 0x1a, 0x31, 0x48, 0x5f, 0x76, 0x8d, 0xa4, 0xbb, 0xd2,
+    0xe9,  0x0, 0x17, 0x2e, 0x45, 0x5c, 0x73, 0x8a, 0xa1, 0xb8, 0xcf, 0xe6, 0xfd, 0x14, 0x2b, 0x42,
+    0x59, 0x70, 0x87, 0x9e, 0xb5, 0xcc, 0xe3, 0xfa, 0x11, 0x28, 0x3f, 0x56, 0x6d, 0x84, 0x9b, 0xb2,
+    0xc9, 0xe0, 0xf7,  0xe, 0x25, 0x3c, 0x53, 0x6a, 0x81, 0x98, 0xaf, 0xc6, 0xdd, 0xf4,  0xb, 0x22,
+    0x39, 0x50, 0x67, 0x7e, 0x95, 0xac, 0xc3, 0xda, 0xf1,  0x8, 0x1f, 0x36, 0x4d, 0x64, 0x7b, 0x92,
+    0xa9, 0xc0, 0xd7, 0xee,  0x5, 0x1c, 0x33, 0x4a, 0x61, 0x78, 0x8f, 0xa6, 0xbd, 0xd4, 0xeb,  0x2,
+    0x19, 0x30, 0x47, 0x5e, 0x75, 0x8c, 0xa3, 0xba, 0xd1, 0xe8, 0xff, 0x16, 0x2d, 0x44, 0x5b, 0x72,
+    0x89, 0xa0, 0xb7, 0xce, 0xe5, 0xfc, 0x13, 0x2a, 0x41, 0x58, 0x6f, 0x86, 0x9d, 0xb4, 0xcb, 0xe2,
+    0xf9, 0x10, 0x27, 0x3e, 0x55, 0x6c, 0x83, 0x9a, 0xb1, 0xc8, 0xdf, 0xf6,  0xd, 0x24, 0x3b, 0x52,
+    0x69, 0x80, 0x97, 0xae, 0xc5, 0xdc, 0xf3,  0xa, 0x21, 0x38, 0x4f, 0x66, 0x7d, 0x94, 0xab, 0xc2,
+    0xd9, 0xf0,  0x7, 0x1e, 0x35, 0x4c, 0x63, 0x7a, 0x91, 0xa8, 0xbf, 0xd6, 0xed,  0x4, 0x1b, 0x32,
+    0x49, 0x60, 0x77, 0x8e, 0xa5, 0xbc, 0xd3, 0xea,  0x1, 0x18, 0x2f, 0x46, 0x5d, 0x74, 0x8b, 0xa2,
+    0xb9, 0xd0, 0xe7, 0xfe, 0x15, 0x2c, 0x43, 0x5a, 0x71, 0x88, 0x9f, 0xb6, 0xcd, 0xe4, 0xfb, 0x12,
+]
+
+R_CON = [
+    0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36
+]
+
+
+def sub_bytes(state):
+    return [S_BOX[b] for b in state]
+
+
+def shift_rows(s):
+    return [
+        s[0], s[5], s[10], s[15],
+        s[4], s[9], s[14], s[3],
+        s[8], s[13], s[2], s[7],
+        s[12], s[1], s[6], s[11]
+    ]
+
+
+def xtime(a):
+    return ((a << 1) ^ 0x1B) & 0xFF if a & 0x80 else (a << 1)
+
+
+def mix_single_column(a):
+    t = a[0] ^ a[1] ^ a[2] ^ a[3]
+    u = a[0]
+    a[0] ^= t ^ xtime(a[0] ^ a[1])
+    a[1] ^= t ^ xtime(a[1] ^ a[2])
+    a[2] ^= t ^ xtime(a[2] ^ a[3])
+    a[3] ^= t ^ xtime(a[3] ^ u)
+    return a
+
+
+def mix_columns(s):
+    for i in range(4):
+        col = s[i * 4:(i + 1) * 4]
+        s[i * 4:(i + 1) * 4] = mix_single_column(col)
+    return s
+
+
+def add_round_key(s, k):
+    return [a ^ b for a, b in zip(s, k)]
+
+
+def key_expansion(key):
+    key_symbols = list(key)
+    assert len(key_symbols) == 16
+    expanded = key_symbols[:]
+    for i in range(4, 44):
+        t = expanded[(i - 1) * 4:i * 4]
+        if i % 4 == 0:
+            t = t[1:] + t[:1]
+            t = [S_BOX[b] for b in t]
+            t[0] ^= R_CON[i // 4]
+        for j in range(4):
+            expanded.append(expanded[(i - 4) * 4 + j] ^ t[j])
+    return expanded
+
+
+def aes_encrypt_block(block, key):
+    state = list(block)
+    w = key_expansion(key)
+    state = add_round_key(state, w[:16])
+    for round in range(1, 10):
+        state = sub_bytes(state)
+        state = shift_rows(state)
+        state = mix_columns(state)
+        state = add_round_key(state, w[round * 16:(round + 1) * 16])
+    state = sub_bytes(state)
+    state = shift_rows(state)
+    state = add_round_key(state, w[160:176])
+    return bytes(state)
+
+
+# ====== 示例 ======
+if __name__ == "__main__":
+    key = b"0123456789ABCDEF"
+    plaintext = b"A" * 16
+    ciphertext = aes_encrypt_block(plaintext, key)
+    print("Plain :", plaintext)
+    print("Cipher:", hex(u64(ciphertext[:8])), hex(u64(ciphertext[8:])))
+```
+
 ```python
 from pwn import *
 from aes import aes_encrypt_block