From 3beda995566e7301629c7cfed6395874be225197 Mon Sep 17 00:00:00 2001 From: Dan <14043624+delivrance@users.noreply.github.com> Date: Thu, 13 Jun 2019 00:52:31 +0200 Subject: [PATCH] Update README.md --- README.md | 45 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 40 insertions(+), 5 deletions(-) diff --git a/README.md b/README.md index a984f70..c42703e 100644 --- a/README.md +++ b/README.md @@ -6,19 +6,23 @@ **TgCrypto** is a high-performance, easy-to-install Telegram Crypto Library written in C as a Python extension. TgCrypto is intended for [Pyrogram](//github.com/pyrogram/pyrogram) and implements the crypto algorithms Telegram -requires, namely **AES-IGE 256 bit** (used in MTProto v2.0) and **AES-CTR 256 bit** (used for CDN encrypted files). +requires, namely: + +- **AES256-IGE** - used in [MTProto v2.0](https://core.telegram.org/mtproto). +- **AES256-CTR** - used for [CDN encrypted files](https://core.telegram.org/cdn). +- **AES256-CBC** - used for [encrypted passport credentials](https://core.telegram.org/passport). ## Installation ``` bash -$ pip3 install --upgrade tgcrypto +$ pip3 install -U tgcrypto ``` More info: https://docs.pyrogram.org/topics/tgcrypto ## API -TgCrypto API consists of these four methods: +TgCrypto API consists of these six methods: ```python def ige256_encrypt(data: bytes, key: bytes, iv: bytes) -> bytes: @@ -28,6 +32,10 @@ def ige256_decrypt(data: bytes, key: bytes, iv: bytes) -> bytes: def ctr256_encrypt(data: bytes, key: bytes, iv: bytes, state: bytes) -> bytes: def ctr256_decrypt(data: bytes, key: bytes, iv: bytes, state: bytes) -> bytes: + +def cbc256_encrypt(data: bytes, key: bytes, iv: bytes) -> bytes: + +def cbc256_decrypt(data: bytes, key: bytes, iv: bytes) -> bytes: ``` ## Usage @@ -38,6 +46,7 @@ def ctr256_decrypt(data: bytes, key: bytes, iv: bytes, state: bytes) -> bytes: ``` python import os + import tgcrypto data = os.urandom(10 * 1024 * 1024 + 7) # 10 MB of random data + 7 bytes to show padding @@ -57,6 +66,7 @@ print(data == ige_decrypted) # True ``` python import os + import tgcrypto data = os.urandom(10 * 1024 * 1024) # 10 MB of random data @@ -76,9 +86,10 @@ print(data == ctr_decrypted) # True ``` python import os -import tgcrypto from io import BytesIO +import tgcrypto + data = BytesIO(os.urandom(10 * 1024 * 1024)) # 10 MB of random data key = os.urandom(32) # Random Key @@ -116,6 +127,30 @@ while True: print(data.getvalue() == decrypted_data.getvalue()) # True ``` +### CBC Mode + +**Note**: Data must be padded to match a multiple of the block size (16 bytes). + +``` python +import os + +import tgcrypto + +data = os.urandom(10 * 1024 * 1024 + 7) # 10 MB of random data + 7 bytes to show padding +key = os.urandom(32) # Random Key + +enc_iv = bytearray(os.urandom(16)) # Random IV +dec_iv = enc_iv.copy() # Keep a copy for decryption + +# Pad with zeroes: -7 % 16 = 9 +data += bytes(-len(data) % 16) + +cbc_encrypted = tgcrypto.cbc256_encrypt(data, key, enc_iv) +cbc_decrypted = tgcrypto.cbc256_decrypt(cbc_encrypted, key, dec_iv) + +print(data == cbc_decrypted) # True +``` + ## Testing 1. Install the package: `pip3 install -U tgcrypto`. @@ -123,7 +158,7 @@ print(data.getvalue() == decrypted_data.getvalue()) # True 3. Enter the directory: `cd tgcrypto`. 4. Run tests: `python3 -m unittest`. -**Note**: I haven't found any public test vectors for AES-IGE 256 bit, yet. +**Note**: I haven't found any public test vectors for AES256-IGE, yet. ## License