Add chacha20 and salsa20 ciphers (#46)

* Add salsa20 and chacha20 ciphers

* Fix the hex escapes in documentation

docs/crypto.rst

@@ -56,6 +56,25 @@ Supported modes: ECB.
 .. autofunction:: malduck.blowfish.ecb.encrypt
 .. autofunction:: malduck.blowfish.ecb.decrypt
 
+ChaCha20
+--------
+
+ChaCha20 stream cipher.
+
+Assumes empty nonce if none given.
+
+.. code-block:: python
+
+    from malduck import chacha20
+
+    key = b'chachaKeyHereNow' * 2
+    nonce = b'\x01\x02\x03\x04\x05\0x6\0x7'
+    plaintext = b'data'*16
+    ciphertext = chacha20.decrypt(key, plaintext, nonce)
+
+.. autofunction:: malduck.chacha20.encrypt
+.. autofunction:: malduck.chacha20.decrypt
+
 DES/DES3 (CBC only)
 -------------------
 
@@ -71,12 +90,32 @@ Supported modes: CBC.
 
     key = b'des3des3'
     iv = b'3des3des'
-    plaintext = b'data'*16
-    ciphertext = des3.cbc.decrypt(key, plaintext)
+    plaintext = b'data' * 16
+    ciphertext = des3.cbc.encrypt(key, plaintext)
 
 .. autofunction:: malduck.des3.cbc.encrypt
 .. autofunction:: malduck.des3.cbc.decrypt
 
+Salsa20
+--------
+
+Salsa20 stream cipher.
+
+Assumes empty nonce if none given.
+
+.. code-block:: python
+
+    from malduck import salsa20
+
+    key = b'salsaFTW' * 4
+    nonce = b'\x01\x02\x03\x04\x05\0x6\0x7'
+    plaintext = b'data' * 16
+    ciphertext = salsa20.decrypt(key, plaintext, nonce)
+
+.. autofunction:: malduck.salsa20.encrypt
+.. autofunction:: malduck.salsa20.decrypt
+
+
 Serpent (CBC only)
 ------------------
 

malduck/__init__.py

@@ -6,7 +6,18 @@
 
 from .compression import aplib, gzip, lznt1
 
-from .crypto import aes, blowfish, des3, rabbit, rc4, rsa, serpent, xor
+from .crypto import (
+    aes,
+    blowfish,
+    chacha20,
+    des3,
+    rabbit,
+    rc4,
+    rsa,
+    salsa20,
+    serpent,
+    xor,
+)
 
 from .disasm import disasm, insn
 
@@ -125,10 +136,12 @@
     # crypto
     "aes",
     "blowfish",
+    "chacha20",
     "des3",
     "rabbit",
     "rc4",
     "rsa",
+    "salsa20",
     "serpent",
     "xor",
     # disasm

malduck/crypto/__init__.py

@@ -1,10 +1,23 @@
 from .aes import aes
 from .blowfish import blowfish
+from .chacha20 import chacha20
 from .des3 import des3
 from .rabbit import rabbit
 from .rc import rc4
 from .rsa import rsa
+from .salsa20 import salsa20
 from .serpent import serpent
 from .xor import xor
 
-__all__ = ["aes", "blowfish", "des3", "rabbit", "rc4", "rsa", "serpent", "xor"]
+__all__ = [
+    "aes",
+    "blowfish",
+    "chacha20",
+    "des3",
+    "rabbit",
+    "rc4",
+    "rsa",
+    "salsa20",
+    "serpent",
+    "xor",
+]

malduck/crypto/chacha20.py

@@ -0,0 +1,44 @@
+from typing import Optional
+from Cryptodome.Cipher import ChaCha20 as ChaCha20Cipher
+
+
+__all__ = ["chacha20"]
+
+
+class ChaCha20:
+    def encrypt(self, key: bytes, data: bytes, nonce: Optional[bytes] = None) -> bytes:
+        """
+        Encrypts buffer using ChaCha20 algorithm.
+
+        :param key: Cryptographic key (32 bytes)
+        :type key: bytes
+        :param data: Buffer to be encrypted
+        :type data: bytes
+        :param nonce: Nonce value (8/12 bytes, defaults to `b"\\\\x00"*8` )
+        :type nonce: bytes, optional
+        :return: Encrypted data
+        :rtype: bytes
+        """
+        if nonce is None:
+            nonce = b"\x00" * 8
+        return ChaCha20Cipher.new(key=key, nonce=nonce).encrypt(data)
+
+    def decrypt(self, key: bytes, data: bytes, nonce: Optional[bytes] = None) -> bytes:
+        """
+        Decrypts buffer using ChaCha20 algorithm.
+
+        :param key: Cryptographic key (32 bytes)
+        :type key: bytes
+        :param data: Buffer to be decrypted
+        :type data: bytes
+        :param nonce: Nonce value (8/12 bytes, defaults to `b"\\\\x00"*8` )
+        :type nonce: bytes, optional
+        :return: Decrypted data
+        :rtype: bytes
+        """
+        if nonce is None:
+            nonce = b"\x00" * 8
+        return ChaCha20Cipher.new(key=key, nonce=nonce).decrypt(data)
+
+
+chacha20 = ChaCha20()

malduck/crypto/salsa20.py

@@ -0,0 +1,44 @@
+from typing import Optional
+from Cryptodome.Cipher import Salsa20 as Salsa20Cipher
+
+
+__all__ = ["salsa20"]
+
+
+class Salsa20:
+    def encrypt(self, key: bytes, data: bytes, nonce: Optional[bytes] = None) -> bytes:
+        """
+        Encrypts buffer using Salsa20 algorithm.
+
+        :param key: Cryptographic key (16/32 bytes)
+        :type key: bytes
+        :param data: Buffer to be encrypted
+        :type data: bytes
+        :param nonce: Nonce value (8 bytes, defaults to `b"\\\\x00"*8` )
+        :type nonce: bytes, optional
+        :return: Encrypted data
+        :rtype: bytes
+        """
+        if nonce is None:
+            nonce = b"\x00" * 8
+        return Salsa20Cipher.new(key=key, nonce=nonce).encrypt(data)
+
+    def decrypt(self, key: bytes, data: bytes, nonce: Optional[bytes] = None) -> bytes:
+        """
+        Decrypts buffer using Salsa20 algorithm.
+
+        :param key: Cryptographic key (16/32 bytes)
+        :type key: bytes
+        :param data: Buffer to be decrypted
+        :type data: bytes
+        :param nonce: Nonce value (8 bytes, defaults to `b"\\\\x00"*8` )
+        :type nonce: bytes, optional
+        :return: Decrypted data
+        :rtype: bytes
+        """
+        if nonce is None:
+            nonce = b"\x00" * 8
+        return Salsa20Cipher.new(key=key, nonce=nonce).decrypt(data)
+
+
+salsa20 = Salsa20()

malduck/crypto/serpent.py

@@ -14,7 +14,7 @@ def encrypt(self, key: bytes, data: bytes, iv: Optional[bytes] = None) -> bytes:
         :type key: bytes
         :param data: Buffer to be encrypted
         :type data: bytes
-        :param iv: Initialization vector (defaults to `b"\x00" * 16`)
+        :param iv: Initialization vector (defaults to `b"\\\\x00" * 16`)
         :type iv: bytes, optional
         :return: Encrypted data
         :rtype: bytes
@@ -29,7 +29,7 @@ def decrypt(self, key: bytes, data: bytes, iv: Optional[bytes] = None) -> bytes:
         :type key: bytes
         :param data: Buffer to be decrypted
         :type data: bytes
-        :param iv: Initialization vector (defaults to `b"\x00" * 16`)
+        :param iv: Initialization vector (defaults to `b"\\\\x00" * 16`)
         :type iv: bytes, optional
         :return: Decrypted data
         :rtype: bytes

tests/test_crypto.py

@@ -2,7 +2,7 @@
 # This file is part of Roach - https://github.com/jbremer/roach.
 # See the file 'docs/LICENSE.txt' for copying permission.
 
-from malduck import aes, blowfish, des3, rc4, rsa, xor, base64, unhex, rabbit, p8, serpent
+from malduck import aes, blowfish, des3, rc4, rsa, xor, base64, unhex, rabbit, p8, serpent, chacha20, salsa20
 
 
 def test_aes():
@@ -65,6 +65,26 @@ def test_des():
     ) == b"\x1d\xed\xc37pV\x89S\xac\xaeT\xaf\xa1\xcfW\xa3"
 
 
+def test_chacha20():
+    assert chacha20.decrypt(
+        key=b"A"*32, data=b'P\xb6\x12W\xf4\xd7\x83|,\xea\x04n\xba\x08Kj', nonce=b"C"*8
+    ) == b"B"*16
+
+    assert chacha20.encrypt(
+        key=b"A"*32, data=b"B"*16, nonce=b"C"*8
+    ) == b'P\xb6\x12W\xf4\xd7\x83|,\xea\x04n\xba\x08Kj'
+
+
+def test_salsa20():
+    assert salsa20.decrypt(
+        key=b"A"*32, data=b'\x16\x0e\x8d\xe2\xef\x8d\xf1\xc0\xf1\x17\xdf3\xed\xc6\xb5y', nonce=b"C"*8
+    ) == b"B"*16
+
+    assert salsa20.encrypt(
+        key=b"A"*32, data=b"B"*16, nonce=b"C"*8
+    ) == b'\x16\x0e\x8d\xe2\xef\x8d\xf1\xc0\xf1\x17\xdf3\xed\xc6\xb5y'
+
+
 def test_rc4():
     assert rc4(b"Key", b"Plaintext") == unhex("bbf316e8d940af0ad3")
     assert rc4(b"Wiki", b"pedia") == unhex("1021bf0420")