refactor table into a single cipher plugin

mifaa · Nov 5, 2014 · cbf8c67 · cbf8c67
1 parent 2519fb9
commit cbf8c67
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Showing 7 changed files with 237 additions and 104 deletions.
diff --git a/.travis.yml b/.travis.yml
@@ -24,6 +24,7 @@ script:
   - python tests/test.py -c tests/aes-cfb8.json
   - python tests/test.py -c tests/rc4-md5.json
   - python tests/test.py -c tests/salsa20.json
+  - python tests/test.py -c tests/table.json
   - python tests/test.py -c tests/server-multi-ports.json
   - python tests/test.py -c tests/server-multi-passwd.json tests/server-multi-passwd-client-side.json
   - python tests/test.py -c tests/workers.json
diff --git a/shadowsocks/crypto/rc4_md5.py b/shadowsocks/crypto/rc4_md5.py
@@ -55,7 +55,7 @@ def test():
     from shadowsocks.crypto import util
 
     cipher = create_cipher(b'rc4-md5', b'k' * 32, b'i' * 16, 1)
-    decipher = create_cipher(b'rc4-md5', b'k' * 32, b'i' * 16, 1)
+    decipher = create_cipher(b'rc4-md5', b'k' * 32, b'i' * 16, 0)
 
     util.run_cipher(cipher, decipher)
 

diff --git a/shadowsocks/crypto/table.py b/shadowsocks/crypto/table.py
@@ -0,0 +1,178 @@
+# !/usr/bin/env python
+
+# Copyright (c) 2014 clowwindy
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+from __future__ import absolute_import, division, print_function, \
+    with_statement
+
+import string
+import struct
+import hashlib
+
+
+__all__ = ['ciphers']
+
+cached_tables = {}
+
+if hasattr(string, 'maketrans'):
+    maketrans = string.maketrans
+    translate = string.translate
+else:
+    maketrans = bytes.maketrans
+    translate = bytes.translate
+
+
+def get_table(key):
+    m = hashlib.md5()
+    m.update(key)
+    s = m.digest()
+    a, b = struct.unpack('<QQ', s)
+    table = maketrans(b'', b'')
+    table = [table[i: i + 1] for i in range(len(table))]
+    for i in range(1, 1024):
+        table.sort(key=lambda x: int(a % (ord(x) + i)))
+    return table
+
+
+def init_table(key):
+    if key not in cached_tables:
+        encrypt_table = b''.join(get_table(key))
+        decrypt_table = maketrans(encrypt_table, maketrans(b'', b''))
+        cached_tables[key] = [encrypt_table, decrypt_table]
+    return cached_tables[key]
+
+
+class TableCipher(object):
+    def __init__(self, cipher_name, key, iv, op):
+        self._encrypt_table, self._decrypt_table = init_table(key)
+        self._op = op
+
+    def update(self, data):
+        if self._op:
+            return translate(data, self._encrypt_table)
+        else:
+            return translate(data, self._decrypt_table)
+
+
+ciphers = {
+    b'table': (0, 0, TableCipher)
+}
+
+
+def test_table_result():
+    target1 = [
+        [60, 53, 84, 138, 217, 94, 88, 23, 39, 242, 219, 35, 12, 157, 165, 181,
+         255, 143, 83, 247, 162, 16, 31, 209, 190, 171, 115, 65, 38, 41, 21,
+         245, 236, 46, 121, 62, 166, 233, 44, 154, 153, 145, 230, 49, 128, 216,
+         173, 29, 241, 119, 64, 229, 194, 103, 131, 110, 26, 197, 218, 59, 204,
+         56, 27, 34, 141, 221, 149, 239, 192, 195, 24, 155, 170, 183, 11, 254,
+         213, 37, 137, 226, 75, 203, 55, 19, 72, 248, 22, 129, 33, 175, 178,
+         10, 198, 71, 77, 36, 113, 167, 48, 2, 117, 140, 142, 66, 199, 232,
+         243, 32, 123, 54, 51, 82, 57, 177, 87, 251, 150, 196, 133, 5, 253,
+         130, 8, 184, 14, 152, 231, 3, 186, 159, 76, 89, 228, 205, 156, 96,
+         163, 146, 18, 91, 132, 85, 80, 109, 172, 176, 105, 13, 50, 235, 127,
+         0, 189, 95, 98, 136, 250, 200, 108, 179, 211, 214, 106, 168, 78, 79,
+         74, 210, 30, 73, 201, 151, 208, 114, 101, 174, 92, 52, 120, 240, 15,
+         169, 220, 182, 81, 224, 43, 185, 40, 99, 180, 17, 212, 158, 42, 90, 9,
+         191, 45, 6, 25, 4, 222, 67, 126, 1, 116, 124, 206, 69, 61, 7, 68, 97,
+         202, 63, 244, 20, 28, 58, 93, 134, 104, 144, 227, 147, 102, 118, 135,
+         148, 47, 238, 86, 112, 122, 70, 107, 215, 100, 139, 223, 225, 164,
+         237, 111, 125, 207, 160, 187, 246, 234, 161, 188, 193, 249, 252],
+        [151, 205, 99, 127, 201, 119, 199, 211, 122, 196, 91, 74, 12, 147, 124,
+         180, 21, 191, 138, 83, 217, 30, 86, 7, 70, 200, 56, 62, 218, 47, 168,
+         22, 107, 88, 63, 11, 95, 77, 28, 8, 188, 29, 194, 186, 38, 198, 33,
+         230, 98, 43, 148, 110, 177, 1, 109, 82, 61, 112, 219, 59, 0, 210, 35,
+         215, 50, 27, 103, 203, 212, 209, 235, 93, 84, 169, 166, 80, 130, 94,
+         164, 165, 142, 184, 111, 18, 2, 141, 232, 114, 6, 131, 195, 139, 176,
+         220, 5, 153, 135, 213, 154, 189, 238, 174, 226, 53, 222, 146, 162,
+         236, 158, 143, 55, 244, 233, 96, 173, 26, 206, 100, 227, 49, 178, 34,
+         234, 108, 207, 245, 204, 150, 44, 87, 121, 54, 140, 118, 221, 228,
+         155, 78, 3, 239, 101, 64, 102, 17, 223, 41, 137, 225, 229, 66, 116,
+         171, 125, 40, 39, 71, 134, 13, 193, 129, 247, 251, 20, 136, 242, 14,
+         36, 97, 163, 181, 72, 25, 144, 46, 175, 89, 145, 113, 90, 159, 190,
+         15, 183, 73, 123, 187, 128, 248, 252, 152, 24, 197, 68, 253, 52, 69,
+         117, 57, 92, 104, 157, 170, 214, 81, 60, 133, 208, 246, 172, 23, 167,
+         160, 192, 76, 161, 237, 45, 4, 58, 10, 182, 65, 202, 240, 185, 241,
+         79, 224, 132, 51, 42, 126, 105, 37, 250, 149, 32, 243, 231, 67, 179,
+         48, 9, 106, 216, 31, 249, 19, 85, 254, 156, 115, 255, 120, 75, 16]]
+
+    target2 = [
+        [124, 30, 170, 247, 27, 127, 224, 59, 13, 22, 196, 76, 72, 154, 32,
+         209, 4, 2, 131, 62, 101, 51, 230, 9, 166, 11, 99, 80, 208, 112, 36,
+         248, 81, 102, 130, 88, 218, 38, 168, 15, 241, 228, 167, 117, 158, 41,
+         10, 180, 194, 50, 204, 243, 246, 251, 29, 198, 219, 210, 195, 21, 54,
+         91, 203, 221, 70, 57, 183, 17, 147, 49, 133, 65, 77, 55, 202, 122,
+         162, 169, 188, 200, 190, 125, 63, 244, 96, 31, 107, 106, 74, 143, 116,
+         148, 78, 46, 1, 137, 150, 110, 181, 56, 95, 139, 58, 3, 231, 66, 165,
+         142, 242, 43, 192, 157, 89, 175, 109, 220, 128, 0, 178, 42, 255, 20,
+         214, 185, 83, 160, 253, 7, 23, 92, 111, 153, 26, 226, 33, 176, 144,
+         18, 216, 212, 28, 151, 71, 206, 222, 182, 8, 174, 205, 201, 152, 240,
+         155, 108, 223, 104, 239, 98, 164, 211, 184, 34, 193, 14, 114, 187, 40,
+         254, 12, 67, 93, 217, 6, 94, 16, 19, 82, 86, 245, 24, 197, 134, 132,
+         138, 229, 121, 5, 235, 238, 85, 47, 103, 113, 179, 69, 250, 45, 135,
+         156, 25, 61, 75, 44, 146, 189, 84, 207, 172, 119, 53, 123, 186, 120,
+         171, 68, 227, 145, 136, 100, 90, 48, 79, 159, 149, 39, 213, 236, 126,
+         52, 60, 225, 199, 105, 73, 233, 252, 118, 215, 35, 115, 64, 37, 97,
+         129, 161, 177, 87, 237, 141, 173, 191, 163, 140, 234, 232, 249],
+        [117, 94, 17, 103, 16, 186, 172, 127, 146, 23, 46, 25, 168, 8, 163, 39,
+         174, 67, 137, 175, 121, 59, 9, 128, 179, 199, 132, 4, 140, 54, 1, 85,
+         14, 134, 161, 238, 30, 241, 37, 224, 166, 45, 119, 109, 202, 196, 93,
+         190, 220, 69, 49, 21, 228, 209, 60, 73, 99, 65, 102, 7, 229, 200, 19,
+         82, 240, 71, 105, 169, 214, 194, 64, 142, 12, 233, 88, 201, 11, 72,
+         92, 221, 27, 32, 176, 124, 205, 189, 177, 246, 35, 112, 219, 61, 129,
+         170, 173, 100, 84, 242, 157, 26, 218, 20, 33, 191, 155, 232, 87, 86,
+         153, 114, 97, 130, 29, 192, 164, 239, 90, 43, 236, 208, 212, 185, 75,
+         210, 0, 81, 227, 5, 116, 243, 34, 18, 182, 70, 181, 197, 217, 95, 183,
+         101, 252, 248, 107, 89, 136, 216, 203, 68, 91, 223, 96, 141, 150, 131,
+         13, 152, 198, 111, 44, 222, 125, 244, 76, 251, 158, 106, 24, 42, 38,
+         77, 2, 213, 207, 249, 147, 113, 135, 245, 118, 193, 47, 98, 145, 66,
+         160, 123, 211, 165, 78, 204, 80, 250, 110, 162, 48, 58, 10, 180, 55,
+         231, 79, 149, 74, 62, 50, 148, 143, 206, 28, 15, 57, 159, 139, 225,
+         122, 237, 138, 171, 36, 56, 115, 63, 144, 154, 6, 230, 133, 215, 41,
+         184, 22, 104, 254, 234, 253, 187, 226, 247, 188, 156, 151, 40, 108,
+         51, 83, 178, 52, 3, 31, 255, 195, 53, 235, 126, 167, 120]]
+
+    encrypt_table = ''.join(get_table('foobar!'))
+    decrypt_table = string.maketrans(encrypt_table, string.maketrans('', ''))
+
+    for i in range(0, 256):
+        assert (target1[0][i] == ord(encrypt_table[i]))
+        assert (target1[1][i] == ord(decrypt_table[i]))
+
+    encrypt_table = ''.join(get_table('barfoo!'))
+    decrypt_table = string.maketrans(encrypt_table, string.maketrans('', ''))
+
+    for i in range(0, 256):
+        assert (target2[0][i] == ord(encrypt_table[i]))
+        assert (target2[1][i] == ord(decrypt_table[i]))
+
+
+def test_encryption():
+    from shadowsocks.crypto import util
+
+    cipher = TableCipher(b'table', b'test', b'', 1)
+    decipher = TableCipher(b'rc4-md5', b'test', b'', 0)
+
+    util.run_cipher(cipher, decipher)
+
+
+if __name__ == '__main__':
+    test_encryption()