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1 | from __future__ import unicode_literals | |
2 | ||
3 | from math import ceil | |
4 | ||
5 | from .compat import compat_b64decode, compat_pycrypto_AES | |
6 | from .utils import bytes_to_intlist, intlist_to_bytes | |
7 | ||
8 | ||
9 | if compat_pycrypto_AES: | |
10 | def aes_cbc_decrypt_bytes(data, key, iv): | |
11 | """ Decrypt bytes with AES-CBC using pycryptodome """ | |
12 | return compat_pycrypto_AES.new(key, compat_pycrypto_AES.MODE_CBC, iv).decrypt(data) | |
13 | ||
14 | def aes_gcm_decrypt_and_verify_bytes(data, key, tag, nonce): | |
15 | """ Decrypt bytes with AES-GCM using pycryptodome """ | |
16 | return compat_pycrypto_AES.new(key, compat_pycrypto_AES.MODE_GCM, nonce).decrypt_and_verify(data, tag) | |
17 | ||
18 | else: | |
19 | def aes_cbc_decrypt_bytes(data, key, iv): | |
20 | """ Decrypt bytes with AES-CBC using native implementation since pycryptodome is unavailable """ | |
21 | return intlist_to_bytes(aes_cbc_decrypt(*map(bytes_to_intlist, (data, key, iv)))) | |
22 | ||
23 | def aes_gcm_decrypt_and_verify_bytes(data, key, tag, nonce): | |
24 | """ Decrypt bytes with AES-GCM using native implementation since pycryptodome is unavailable """ | |
25 | return intlist_to_bytes(aes_gcm_decrypt_and_verify(*map(bytes_to_intlist, (data, key, tag, nonce)))) | |
26 | ||
27 | ||
28 | BLOCK_SIZE_BYTES = 16 | |
29 | ||
30 | ||
31 | def aes_ctr_decrypt(data, key, iv): | |
32 | """ | |
33 | Decrypt with aes in counter mode | |
34 | ||
35 | @param {int[]} data cipher | |
36 | @param {int[]} key 16/24/32-Byte cipher key | |
37 | @param {int[]} iv 16-Byte initialization vector | |
38 | @returns {int[]} decrypted data | |
39 | """ | |
40 | return aes_ctr_encrypt(data, key, iv) | |
41 | ||
42 | ||
43 | def aes_ctr_encrypt(data, key, iv): | |
44 | """ | |
45 | Encrypt with aes in counter mode | |
46 | ||
47 | @param {int[]} data cleartext | |
48 | @param {int[]} key 16/24/32-Byte cipher key | |
49 | @param {int[]} iv 16-Byte initialization vector | |
50 | @returns {int[]} encrypted data | |
51 | """ | |
52 | expanded_key = key_expansion(key) | |
53 | block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES)) | |
54 | counter = iter_vector(iv) | |
55 | ||
56 | encrypted_data = [] | |
57 | for i in range(block_count): | |
58 | counter_block = next(counter) | |
59 | block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES] | |
60 | block += [0] * (BLOCK_SIZE_BYTES - len(block)) | |
61 | ||
62 | cipher_counter_block = aes_encrypt(counter_block, expanded_key) | |
63 | encrypted_data += xor(block, cipher_counter_block) | |
64 | encrypted_data = encrypted_data[:len(data)] | |
65 | ||
66 | return encrypted_data | |
67 | ||
68 | ||
69 | def aes_cbc_decrypt(data, key, iv): | |
70 | """ | |
71 | Decrypt with aes in CBC mode | |
72 | ||
73 | @param {int[]} data cipher | |
74 | @param {int[]} key 16/24/32-Byte cipher key | |
75 | @param {int[]} iv 16-Byte IV | |
76 | @returns {int[]} decrypted data | |
77 | """ | |
78 | expanded_key = key_expansion(key) | |
79 | block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES)) | |
80 | ||
81 | decrypted_data = [] | |
82 | previous_cipher_block = iv | |
83 | for i in range(block_count): | |
84 | block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES] | |
85 | block += [0] * (BLOCK_SIZE_BYTES - len(block)) | |
86 | ||
87 | decrypted_block = aes_decrypt(block, expanded_key) | |
88 | decrypted_data += xor(decrypted_block, previous_cipher_block) | |
89 | previous_cipher_block = block | |
90 | decrypted_data = decrypted_data[:len(data)] | |
91 | ||
92 | return decrypted_data | |
93 | ||
94 | ||
95 | def aes_cbc_encrypt(data, key, iv): | |
96 | """ | |
97 | Encrypt with aes in CBC mode. Using PKCS#7 padding | |
98 | ||
99 | @param {int[]} data cleartext | |
100 | @param {int[]} key 16/24/32-Byte cipher key | |
101 | @param {int[]} iv 16-Byte IV | |
102 | @returns {int[]} encrypted data | |
103 | """ | |
104 | expanded_key = key_expansion(key) | |
105 | block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES)) | |
106 | ||
107 | encrypted_data = [] | |
108 | previous_cipher_block = iv | |
109 | for i in range(block_count): | |
110 | block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES] | |
111 | remaining_length = BLOCK_SIZE_BYTES - len(block) | |
112 | block += [remaining_length] * remaining_length | |
113 | mixed_block = xor(block, previous_cipher_block) | |
114 | ||
115 | encrypted_block = aes_encrypt(mixed_block, expanded_key) | |
116 | encrypted_data += encrypted_block | |
117 | ||
118 | previous_cipher_block = encrypted_block | |
119 | ||
120 | return encrypted_data | |
121 | ||
122 | ||
123 | def aes_gcm_decrypt_and_verify(data, key, tag, nonce): | |
124 | """ | |
125 | Decrypt with aes in GBM mode and checks authenticity using tag | |
126 | ||
127 | @param {int[]} data cipher | |
128 | @param {int[]} key 16-Byte cipher key | |
129 | @param {int[]} tag authentication tag | |
130 | @param {int[]} nonce IV (recommended 12-Byte) | |
131 | @returns {int[]} decrypted data | |
132 | """ | |
133 | ||
134 | # XXX: check aes, gcm param | |
135 | ||
136 | hash_subkey = aes_encrypt([0] * BLOCK_SIZE_BYTES, key_expansion(key)) | |
137 | ||
138 | if len(nonce) == 12: | |
139 | j0 = nonce + [0, 0, 0, 1] | |
140 | else: | |
141 | fill = (BLOCK_SIZE_BYTES - (len(nonce) % BLOCK_SIZE_BYTES)) % BLOCK_SIZE_BYTES + 8 | |
142 | ghash_in = nonce + [0] * fill + bytes_to_intlist((8 * len(nonce)).to_bytes(8, 'big')) | |
143 | j0 = ghash(hash_subkey, ghash_in) | |
144 | ||
145 | # TODO: add nonce support to aes_ctr_decrypt | |
146 | ||
147 | # nonce_ctr = j0[:12] | |
148 | iv_ctr = inc(j0) | |
149 | ||
150 | decrypted_data = aes_ctr_decrypt(data, key, iv_ctr + [0] * (BLOCK_SIZE_BYTES - len(iv_ctr))) | |
151 | pad_len = len(data) // 16 * 16 | |
152 | s_tag = ghash( | |
153 | hash_subkey, | |
154 | data | |
155 | + [0] * (BLOCK_SIZE_BYTES - len(data) + pad_len) # pad | |
156 | + bytes_to_intlist((0 * 8).to_bytes(8, 'big') # length of associated data | |
157 | + ((len(data) * 8).to_bytes(8, 'big'))) # length of data | |
158 | ) | |
159 | ||
160 | if tag != aes_ctr_encrypt(s_tag, key, j0): | |
161 | raise ValueError("Mismatching authentication tag") | |
162 | ||
163 | return decrypted_data | |
164 | ||
165 | ||
166 | def aes_encrypt(data, expanded_key): | |
167 | """ | |
168 | Encrypt one block with aes | |
169 | ||
170 | @param {int[]} data 16-Byte state | |
171 | @param {int[]} expanded_key 176/208/240-Byte expanded key | |
172 | @returns {int[]} 16-Byte cipher | |
173 | """ | |
174 | rounds = len(expanded_key) // BLOCK_SIZE_BYTES - 1 | |
175 | ||
176 | data = xor(data, expanded_key[:BLOCK_SIZE_BYTES]) | |
177 | for i in range(1, rounds + 1): | |
178 | data = sub_bytes(data) | |
179 | data = shift_rows(data) | |
180 | if i != rounds: | |
181 | data = list(iter_mix_columns(data, MIX_COLUMN_MATRIX)) | |
182 | data = xor(data, expanded_key[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES]) | |
183 | ||
184 | return data | |
185 | ||
186 | ||
187 | def aes_decrypt(data, expanded_key): | |
188 | """ | |
189 | Decrypt one block with aes | |
190 | ||
191 | @param {int[]} data 16-Byte cipher | |
192 | @param {int[]} expanded_key 176/208/240-Byte expanded key | |
193 | @returns {int[]} 16-Byte state | |
194 | """ | |
195 | rounds = len(expanded_key) // BLOCK_SIZE_BYTES - 1 | |
196 | ||
197 | for i in range(rounds, 0, -1): | |
198 | data = xor(data, expanded_key[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES]) | |
199 | if i != rounds: | |
200 | data = list(iter_mix_columns(data, MIX_COLUMN_MATRIX_INV)) | |
201 | data = shift_rows_inv(data) | |
202 | data = sub_bytes_inv(data) | |
203 | data = xor(data, expanded_key[:BLOCK_SIZE_BYTES]) | |
204 | ||
205 | return data | |
206 | ||
207 | ||
208 | def aes_decrypt_text(data, password, key_size_bytes): | |
209 | """ | |
210 | Decrypt text | |
211 | - The first 8 Bytes of decoded 'data' are the 8 high Bytes of the counter | |
212 | - The cipher key is retrieved by encrypting the first 16 Byte of 'password' | |
213 | with the first 'key_size_bytes' Bytes from 'password' (if necessary filled with 0's) | |
214 | - Mode of operation is 'counter' | |
215 | ||
216 | @param {str} data Base64 encoded string | |
217 | @param {str,unicode} password Password (will be encoded with utf-8) | |
218 | @param {int} key_size_bytes Possible values: 16 for 128-Bit, 24 for 192-Bit or 32 for 256-Bit | |
219 | @returns {str} Decrypted data | |
220 | """ | |
221 | NONCE_LENGTH_BYTES = 8 | |
222 | ||
223 | data = bytes_to_intlist(compat_b64decode(data)) | |
224 | password = bytes_to_intlist(password.encode('utf-8')) | |
225 | ||
226 | key = password[:key_size_bytes] + [0] * (key_size_bytes - len(password)) | |
227 | key = aes_encrypt(key[:BLOCK_SIZE_BYTES], key_expansion(key)) * (key_size_bytes // BLOCK_SIZE_BYTES) | |
228 | ||
229 | nonce = data[:NONCE_LENGTH_BYTES] | |
230 | cipher = data[NONCE_LENGTH_BYTES:] | |
231 | ||
232 | decrypted_data = aes_ctr_decrypt(cipher, key, nonce + [0] * (BLOCK_SIZE_BYTES - NONCE_LENGTH_BYTES)) | |
233 | plaintext = intlist_to_bytes(decrypted_data) | |
234 | ||
235 | return plaintext | |
236 | ||
237 | ||
238 | RCON = (0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36) | |
239 | SBOX = (0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76, | |
240 | 0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0, | |
241 | 0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15, | |
242 | 0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75, | |
243 | 0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84, | |
244 | 0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF, | |
245 | 0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8, | |
246 | 0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2, | |
247 | 0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73, | |
248 | 0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB, | |
249 | 0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79, | |
250 | 0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08, | |
251 | 0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A, | |
252 | 0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E, | |
253 | 0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF, | |
254 | 0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16) | |
255 | SBOX_INV = (0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, | |
256 | 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, | |
257 | 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, | |
258 | 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25, | |
259 | 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, | |
260 | 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84, | |
261 | 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06, | |
262 | 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b, | |
263 | 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73, | |
264 | 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e, | |
265 | 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, | |
266 | 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4, | |
267 | 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, | |
268 | 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, | |
269 | 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, | |
270 | 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d) | |
271 | MIX_COLUMN_MATRIX = ((0x2, 0x3, 0x1, 0x1), | |
272 | (0x1, 0x2, 0x3, 0x1), | |
273 | (0x1, 0x1, 0x2, 0x3), | |
274 | (0x3, 0x1, 0x1, 0x2)) | |
275 | MIX_COLUMN_MATRIX_INV = ((0xE, 0xB, 0xD, 0x9), | |
276 | (0x9, 0xE, 0xB, 0xD), | |
277 | (0xD, 0x9, 0xE, 0xB), | |
278 | (0xB, 0xD, 0x9, 0xE)) | |
279 | RIJNDAEL_EXP_TABLE = (0x01, 0x03, 0x05, 0x0F, 0x11, 0x33, 0x55, 0xFF, 0x1A, 0x2E, 0x72, 0x96, 0xA1, 0xF8, 0x13, 0x35, | |
280 | 0x5F, 0xE1, 0x38, 0x48, 0xD8, 0x73, 0x95, 0xA4, 0xF7, 0x02, 0x06, 0x0A, 0x1E, 0x22, 0x66, 0xAA, | |
281 | 0xE5, 0x34, 0x5C, 0xE4, 0x37, 0x59, 0xEB, 0x26, 0x6A, 0xBE, 0xD9, 0x70, 0x90, 0xAB, 0xE6, 0x31, | |
282 | 0x53, 0xF5, 0x04, 0x0C, 0x14, 0x3C, 0x44, 0xCC, 0x4F, 0xD1, 0x68, 0xB8, 0xD3, 0x6E, 0xB2, 0xCD, | |
283 | 0x4C, 0xD4, 0x67, 0xA9, 0xE0, 0x3B, 0x4D, 0xD7, 0x62, 0xA6, 0xF1, 0x08, 0x18, 0x28, 0x78, 0x88, | |
284 | 0x83, 0x9E, 0xB9, 0xD0, 0x6B, 0xBD, 0xDC, 0x7F, 0x81, 0x98, 0xB3, 0xCE, 0x49, 0xDB, 0x76, 0x9A, | |
285 | 0xB5, 0xC4, 0x57, 0xF9, 0x10, 0x30, 0x50, 0xF0, 0x0B, 0x1D, 0x27, 0x69, 0xBB, 0xD6, 0x61, 0xA3, | |
286 | 0xFE, 0x19, 0x2B, 0x7D, 0x87, 0x92, 0xAD, 0xEC, 0x2F, 0x71, 0x93, 0xAE, 0xE9, 0x20, 0x60, 0xA0, | |
287 | 0xFB, 0x16, 0x3A, 0x4E, 0xD2, 0x6D, 0xB7, 0xC2, 0x5D, 0xE7, 0x32, 0x56, 0xFA, 0x15, 0x3F, 0x41, | |
288 | 0xC3, 0x5E, 0xE2, 0x3D, 0x47, 0xC9, 0x40, 0xC0, 0x5B, 0xED, 0x2C, 0x74, 0x9C, 0xBF, 0xDA, 0x75, | |
289 | 0x9F, 0xBA, 0xD5, 0x64, 0xAC, 0xEF, 0x2A, 0x7E, 0x82, 0x9D, 0xBC, 0xDF, 0x7A, 0x8E, 0x89, 0x80, | |
290 | 0x9B, 0xB6, 0xC1, 0x58, 0xE8, 0x23, 0x65, 0xAF, 0xEA, 0x25, 0x6F, 0xB1, 0xC8, 0x43, 0xC5, 0x54, | |
291 | 0xFC, 0x1F, 0x21, 0x63, 0xA5, 0xF4, 0x07, 0x09, 0x1B, 0x2D, 0x77, 0x99, 0xB0, 0xCB, 0x46, 0xCA, | |
292 | 0x45, 0xCF, 0x4A, 0xDE, 0x79, 0x8B, 0x86, 0x91, 0xA8, 0xE3, 0x3E, 0x42, 0xC6, 0x51, 0xF3, 0x0E, | |
293 | 0x12, 0x36, 0x5A, 0xEE, 0x29, 0x7B, 0x8D, 0x8C, 0x8F, 0x8A, 0x85, 0x94, 0xA7, 0xF2, 0x0D, 0x17, | |
294 | 0x39, 0x4B, 0xDD, 0x7C, 0x84, 0x97, 0xA2, 0xFD, 0x1C, 0x24, 0x6C, 0xB4, 0xC7, 0x52, 0xF6, 0x01) | |
295 | RIJNDAEL_LOG_TABLE = (0x00, 0x00, 0x19, 0x01, 0x32, 0x02, 0x1a, 0xc6, 0x4b, 0xc7, 0x1b, 0x68, 0x33, 0xee, 0xdf, 0x03, | |
296 | 0x64, 0x04, 0xe0, 0x0e, 0x34, 0x8d, 0x81, 0xef, 0x4c, 0x71, 0x08, 0xc8, 0xf8, 0x69, 0x1c, 0xc1, | |
297 | 0x7d, 0xc2, 0x1d, 0xb5, 0xf9, 0xb9, 0x27, 0x6a, 0x4d, 0xe4, 0xa6, 0x72, 0x9a, 0xc9, 0x09, 0x78, | |
298 | 0x65, 0x2f, 0x8a, 0x05, 0x21, 0x0f, 0xe1, 0x24, 0x12, 0xf0, 0x82, 0x45, 0x35, 0x93, 0xda, 0x8e, | |
299 | 0x96, 0x8f, 0xdb, 0xbd, 0x36, 0xd0, 0xce, 0x94, 0x13, 0x5c, 0xd2, 0xf1, 0x40, 0x46, 0x83, 0x38, | |
300 | 0x66, 0xdd, 0xfd, 0x30, 0xbf, 0x06, 0x8b, 0x62, 0xb3, 0x25, 0xe2, 0x98, 0x22, 0x88, 0x91, 0x10, | |
301 | 0x7e, 0x6e, 0x48, 0xc3, 0xa3, 0xb6, 0x1e, 0x42, 0x3a, 0x6b, 0x28, 0x54, 0xfa, 0x85, 0x3d, 0xba, | |
302 | 0x2b, 0x79, 0x0a, 0x15, 0x9b, 0x9f, 0x5e, 0xca, 0x4e, 0xd4, 0xac, 0xe5, 0xf3, 0x73, 0xa7, 0x57, | |
303 | 0xaf, 0x58, 0xa8, 0x50, 0xf4, 0xea, 0xd6, 0x74, 0x4f, 0xae, 0xe9, 0xd5, 0xe7, 0xe6, 0xad, 0xe8, | |
304 | 0x2c, 0xd7, 0x75, 0x7a, 0xeb, 0x16, 0x0b, 0xf5, 0x59, 0xcb, 0x5f, 0xb0, 0x9c, 0xa9, 0x51, 0xa0, | |
305 | 0x7f, 0x0c, 0xf6, 0x6f, 0x17, 0xc4, 0x49, 0xec, 0xd8, 0x43, 0x1f, 0x2d, 0xa4, 0x76, 0x7b, 0xb7, | |
306 | 0xcc, 0xbb, 0x3e, 0x5a, 0xfb, 0x60, 0xb1, 0x86, 0x3b, 0x52, 0xa1, 0x6c, 0xaa, 0x55, 0x29, 0x9d, | |
307 | 0x97, 0xb2, 0x87, 0x90, 0x61, 0xbe, 0xdc, 0xfc, 0xbc, 0x95, 0xcf, 0xcd, 0x37, 0x3f, 0x5b, 0xd1, | |
308 | 0x53, 0x39, 0x84, 0x3c, 0x41, 0xa2, 0x6d, 0x47, 0x14, 0x2a, 0x9e, 0x5d, 0x56, 0xf2, 0xd3, 0xab, | |
309 | 0x44, 0x11, 0x92, 0xd9, 0x23, 0x20, 0x2e, 0x89, 0xb4, 0x7c, 0xb8, 0x26, 0x77, 0x99, 0xe3, 0xa5, | |
310 | 0x67, 0x4a, 0xed, 0xde, 0xc5, 0x31, 0xfe, 0x18, 0x0d, 0x63, 0x8c, 0x80, 0xc0, 0xf7, 0x70, 0x07) | |
311 | ||
312 | ||
313 | def key_expansion(data): | |
314 | """ | |
315 | Generate key schedule | |
316 | ||
317 | @param {int[]} data 16/24/32-Byte cipher key | |
318 | @returns {int[]} 176/208/240-Byte expanded key | |
319 | """ | |
320 | data = data[:] # copy | |
321 | rcon_iteration = 1 | |
322 | key_size_bytes = len(data) | |
323 | expanded_key_size_bytes = (key_size_bytes // 4 + 7) * BLOCK_SIZE_BYTES | |
324 | ||
325 | while len(data) < expanded_key_size_bytes: | |
326 | temp = data[-4:] | |
327 | temp = key_schedule_core(temp, rcon_iteration) | |
328 | rcon_iteration += 1 | |
329 | data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes]) | |
330 | ||
331 | for _ in range(3): | |
332 | temp = data[-4:] | |
333 | data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes]) | |
334 | ||
335 | if key_size_bytes == 32: | |
336 | temp = data[-4:] | |
337 | temp = sub_bytes(temp) | |
338 | data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes]) | |
339 | ||
340 | for _ in range(3 if key_size_bytes == 32 else 2 if key_size_bytes == 24 else 0): | |
341 | temp = data[-4:] | |
342 | data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes]) | |
343 | data = data[:expanded_key_size_bytes] | |
344 | ||
345 | return data | |
346 | ||
347 | ||
348 | def iter_vector(iv): | |
349 | while True: | |
350 | yield iv | |
351 | iv = inc(iv) | |
352 | ||
353 | ||
354 | def sub_bytes(data): | |
355 | return [SBOX[x] for x in data] | |
356 | ||
357 | ||
358 | def sub_bytes_inv(data): | |
359 | return [SBOX_INV[x] for x in data] | |
360 | ||
361 | ||
362 | def rotate(data): | |
363 | return data[1:] + [data[0]] | |
364 | ||
365 | ||
366 | def key_schedule_core(data, rcon_iteration): | |
367 | data = rotate(data) | |
368 | data = sub_bytes(data) | |
369 | data[0] = data[0] ^ RCON[rcon_iteration] | |
370 | ||
371 | return data | |
372 | ||
373 | ||
374 | def xor(data1, data2): | |
375 | return [x ^ y for x, y in zip(data1, data2)] | |
376 | ||
377 | ||
378 | def iter_mix_columns(data, matrix): | |
379 | for i in (0, 4, 8, 12): | |
380 | for row in matrix: | |
381 | mixed = 0 | |
382 | for j in range(4): | |
383 | # xor is (+) and (-) | |
384 | mixed ^= (0 if data[i:i + 4][j] == 0 or row[j] == 0 else | |
385 | RIJNDAEL_EXP_TABLE[(RIJNDAEL_LOG_TABLE[data[i + j]] + RIJNDAEL_LOG_TABLE[row[j]]) % 0xFF]) | |
386 | yield mixed | |
387 | ||
388 | ||
389 | def shift_rows(data): | |
390 | return [data[((column + row) & 0b11) * 4 + row] for column in range(4) for row in range(4)] | |
391 | ||
392 | ||
393 | def shift_rows_inv(data): | |
394 | return [data[((column - row) & 0b11) * 4 + row] for column in range(4) for row in range(4)] | |
395 | ||
396 | ||
397 | def shift_block(data): | |
398 | data_shifted = [] | |
399 | ||
400 | bit = 0 | |
401 | for n in data: | |
402 | if bit: | |
403 | n |= 0x100 | |
404 | bit = n & 1 | |
405 | n >>= 1 | |
406 | data_shifted.append(n) | |
407 | ||
408 | return data_shifted | |
409 | ||
410 | ||
411 | def inc(data): | |
412 | data = data[:] # copy | |
413 | for i in range(len(data) - 1, -1, -1): | |
414 | if data[i] == 255: | |
415 | data[i] = 0 | |
416 | else: | |
417 | data[i] = data[i] + 1 | |
418 | break | |
419 | return data | |
420 | ||
421 | ||
422 | def block_product(block_x, block_y): | |
423 | # NIST SP 800-38D, Algorithm 1 | |
424 | ||
425 | if len(block_x) != BLOCK_SIZE_BYTES or len(block_y) != BLOCK_SIZE_BYTES: | |
426 | raise ValueError("Length of blocks need to be %d bytes" % BLOCK_SIZE_BYTES) | |
427 | ||
428 | block_r = [0xE1] + [0] * (BLOCK_SIZE_BYTES - 1) | |
429 | block_v = block_y[:] | |
430 | block_z = [0] * BLOCK_SIZE_BYTES | |
431 | ||
432 | for i in block_x: | |
433 | for bit in range(7, -1, -1): | |
434 | if i & (1 << bit): | |
435 | block_z = xor(block_z, block_v) | |
436 | ||
437 | do_xor = block_v[-1] & 1 | |
438 | block_v = shift_block(block_v) | |
439 | if do_xor: | |
440 | block_v = xor(block_v, block_r) | |
441 | ||
442 | return block_z | |
443 | ||
444 | ||
445 | def ghash(subkey, data): | |
446 | # NIST SP 800-38D, Algorithm 2 | |
447 | ||
448 | if len(data) % BLOCK_SIZE_BYTES: | |
449 | raise ValueError("Length of data should be %d bytes" % BLOCK_SIZE_BYTES) | |
450 | ||
451 | last_y = [0] * BLOCK_SIZE_BYTES | |
452 | for i in range(0, len(data), BLOCK_SIZE_BYTES): | |
453 | block = data[i : i + BLOCK_SIZE_BYTES] # noqa: E203 | |
454 | last_y = block_product(xor(last_y, block), subkey) | |
455 | ||
456 | return last_y | |
457 | ||
458 | ||
459 | __all__ = [ | |
460 | 'aes_ctr_decrypt', | |
461 | 'aes_cbc_decrypt', | |
462 | 'aes_cbc_decrypt_bytes', | |
463 | 'aes_decrypt_text', | |
464 | 'aes_encrypt', | |
465 | 'aes_gcm_decrypt_and_verify', | |
466 | 'aes_gcm_decrypt_and_verify_bytes', | |
467 | 'key_expansion' | |
468 | ] |