Documentation

Author: mauricelambert

README.md

@@ -0,0 +1,64 @@
+# FastRC4 - LibARC4
+
+> **This RC4 implementation is not secure, it is a POC for an optimized RC4 implementation in ASM. You should never use this implementation for TLS, WEP, ... or other old protocols using RC4. You should never use it to encrypt secrets or very large file.**
+
+## Description
+
+This repository implements RC4 encryption with IV, written in ASM with few optimizations.
+
+## Requirements
+
+ - To use the shared library you don't need any requirements.
+ - To use the python interface you need Python3 and the standard library.
+
+## Compilation
+
+```bash
+nasm -felf64 ARC4.asm
+ld -shared ARC4.o -o librc4.so
+strip librc4.so
+```
+
+## Usages
+
+### Exported functions
+
+```c
+char *get_iv();
+void *encrypt(char *key, char *data, unsigned long long length);
+void *decrypt(char *key, char iv[256], char *data, unsigned long long length);
+void *generate_iv();
+void *xor_key_iv();
+void *generate_key(char *key);
+void *arc4_null_byte(char *data);
+void *arc4(char *data, unsigned long long length);
+void *reset_key();
+void *set_iv(char *iv);
+```
+
+```
+arc4_null_byte([IN/OUT] char *data) -> NULL
+arc4([IN/OUT] char *data, [IN] unsigned long long length) -> NULL
+generate_iv() -> NULL
+xor_key_iv() -> NULL
+generate_key(char *key) -> NULL
+reset_key() -> NULL
+get_iv() -> char[256] // null byte terminate string
+set_iv([IN] char iv[256]) -> NULL
+encrypt([IN] char *key, [IN/OUT] char *data, [IN] unsigned long long length) -> NULL  // if length is 0 call arc4_null_byte
+decrypt([IN] char *key, [IN] char iv[256], [IN/OUT] char *data, [IN] unsigned long long length) -> NULL // there is no way to decrypt string terminating by null byte because encrypted data can contains null byte
+```
+
+### Python interface
+
+```python
+from librc4 import RC4
+
+rc4 = RC4(b'my key')
+cipher = rc4.encrypt(b'my data')
+secret = rc4.decrypt(cipher)
+```
+
+## Licence
+
+Licensed under the [GPL, version 3](https://www.gnu.org/licenses/).

librc4.py

@@ -211,7 +211,7 @@ def tests():
     analyzer = DataAnalysis(data)
     analyze = list(analyzer.keys_frequences())
     analyzer.statistictypes_printer(analyze)
-    analyzer.statistictypes_chart(analyze)
+    # analyzer.statistictypes_chart(analyze)
 
     from binascii import hexlify
     key = b'This is my secret key !'