cjh0613 · April 27, 2022 02:39 · Oct 24, 2018 · Oct 24, 2018
diff --git a/nianfo.py b/nianfo.py
@@ -32,7 +32,7 @@ def Encrypt(plaintext):
     # 1. Encode Plaintext in UTF-16 Little Endian
     data = plaintext.encode('utf-16le')
     # 2. Add Paddings (PKCS7)
-    pads = 16 - len(data) % 16
+    pads = (- len(data)) % 16
     data = data + bytes(pads * [pads])
     # 3. Use AES-256-CBC to Encrypt
     cryptor = AES.new(KEY, AES.MODE_CBC, IV)
@@ -58,7 +58,7 @@ def Decrypt(ciphertext):
         result = cryptor.decrypt(data)
         # 3. Remove Paddings (PKCS7)
         flag = result[-1]
-        if flag == 1 or (flag < 16 and result[-flag] == flag):
+        if flag < 16 and result[-flag] == flag:
             result = result[:-flag]
         # 4. Decode Plaintext with UTF-16 Little Endian
         return result.decode('utf-16le')

diff --git a/nianfo.py b/nianfo.py
@@ -0,0 +1,70 @@
+# !/usr/bin/env python3
+#
+# nianfo.py - TudouCode Demo in Python 3
+# Credit: https://github.com/lersh/TudouCode/
+#
+# Note:
+#  
+#     This is the first version('佛曰') of TudouCode('与佛论禅').
+#     The second version('如是我闻') needs compression and I can't debug.
+# 
+# Dependency: pycrypto
+
+from Crypto.Cipher import AES
+from random import choice
+
+KEY = b'XDXDtudou@KeyFansClub^_^Encode!!'
+IV = b'Potato@Key@_@=_='
+
+TUDOU = [
+    '滅', '苦', '婆', '娑', '耶', '陀', '跋', '多', '漫', '都', '殿', '悉', '夜', '爍', '帝', '吉',
+    '利', '阿', '無', '南', '那', '怛', '喝', '羯', '勝', '摩', '伽', '謹', '波', '者', '穆', '僧',
+    '室', '藝', '尼', '瑟', '地', '彌', '菩', '提', '蘇', '醯', '盧', '呼', '舍', '佛', '參', '沙',
+    '伊', '隸', '麼', '遮', '闍', '度', '蒙', '孕', '薩', '夷', '迦', '他', '姪', '豆', '特', '逝',
+    '朋', '輸', '楞', '栗', '寫', '數', '曳', '諦', '羅', '曰', '咒', '即', '密', '若', '般', '故',
+    '不', '實', '真', '訶', '切', '一', '除', '能', '等', '是', '上', '明', '大', '神', '知', '三',
+    '藐', '耨', '得', '依', '諸', '世', '槃', '涅', '竟', '究', '想', '夢', '倒', '顛', '離', '遠',
+    '怖', '恐', '有', '礙', '心', '所', '以', '亦', '智', '道', '。', '集', '盡', '死', '老', '至']
+
+BYTEMARK = ['冥', '奢', '梵', '呐', '俱', '哆', '怯', '諳', '罰', '侄', '缽', '皤']
+
+def Encrypt(plaintext):
+    # 1. Encode Plaintext in UTF-16 Little Endian
+    data = plaintext.encode('utf-16le')
+    # 2. Add Paddings (PKCS7)
+    pads = 16 - len(data) % 16
+    data = data + bytes(pads * [pads])
+    # 3. Use AES-256-CBC to Encrypt
+    cryptor = AES.new(KEY, AES.MODE_CBC, IV)
+    result = cryptor.encrypt(data)
+    # 4. Encode and Add Header
+    return '佛曰：' + ''.join([TUDOU[i] if i < 128 else choice(BYTEMARK) + TUDOU[i-128] for i in result])
+
+def Decrypt(ciphertext):
+    # 1. Remove Header and Decode
+    if ciphertext.startswith('佛曰：'):
+        ciphertext = ciphertext[3:]
+        data = b''
+        i = 0
+        while i < len(ciphertext):
+            if ciphertext[i] in BYTEMARK:
+                i = i + 1
+                data = data + bytes([TUDOU.index(ciphertext[i]) + 128])
+            else:
+                data = data + bytes([TUDOU.index(ciphertext[i])])
+            i = i + 1
+        # 2. Use AES-256-CBC to Decrypt
+        cryptor = AES.new(KEY, AES.MODE_CBC, IV)
+        result = cryptor.decrypt(data)
+        # 3. Remove Paddings (PKCS7)
+        flag = result[-1]
+        if flag == 1 or (flag < 16 and result[-flag] == flag):
+            result = result[:-flag]
+        # 4. Decode Plaintext with UTF-16 Little Endian
+        return result.decode('utf-16le')
+    else:
+        return ''
+
+print(Encrypt('test测试测试测试'))
+print(Decrypt('佛曰：梵依沙若罰怖諳羅怯大罰波除諳室若若奢伽涅怯究皤苦冥逝冥曳麼梵咒離除奢咒梵夷有怯神倒所滅俱孕盡等呐佛'))
+