From 424812432ce13e4402864e0b72fc0a819dcc3493 Mon Sep 17 00:00:00 2001
From: raphael <raphael@maenle.net>
Date: Fri, 10 Dec 2021 17:46:53 +0100
Subject: [PATCH] adds all initial communication functionality

- adds rest server wraper
- adds secret generation
- adds secret visualization
---
 .gitignore |   2 +
 README.md  |  22 ++++++++
 main.py    | 144 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 168 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 README.md
 create mode 100644 main.py

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..beb9746
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+__pycache__/*
+.bump*
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..a2f8dfb
--- /dev/null
+++ b/README.md
@@ -0,0 +1,22 @@
+## Bump Python Client
+
+This Bump client enables easy access to the bump service through a python api.
+Bump any other client anywhere through an easy to use API.
+
+## working functions
+
+- peek
+- pop
+- push
+- list
+- clear
+- generate new cryptographicaly safe secret
+- visualize with rudimentary qr code to share with other clients
+
+## missing
+
+- add an existing secret
+- scan existing qr code
+- sync 'read' to other clients
+- alert function that shows any new notifications
+
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..b9fa735
--- /dev/null
+++ b/main.py
@@ -0,0 +1,144 @@
+import random
+import qrcode
+import requests
+import base64
+import re
+
+SENDER_LENGTH = 4 
+PASSWORD_LENGTH = 8 
+
+from random_word import RandomWords
+
+import secrets
+from base64 import urlsafe_b64encode as b64e, urlsafe_b64decode as b64d
+
+from cryptography.fernet import Fernet
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
+
+r = RandomWords()
+
+backend = default_backend()
+iterations = 100_000
+
+def _derive_key(password: bytes, salt: bytes, iterations: int = iterations) -> bytes:
+    """Derive a secret key from a given password and salt"""
+    kdf = PBKDF2HMAC(
+        algorithm=hashes.SHA256(), length=32, salt=salt,
+        iterations=iterations, backend=backend)
+    return b64e(kdf.derive(password))
+
+def password_encrypt(message: bytes, password: str, iterations: int = iterations) -> bytes:
+    salt = secrets.token_bytes(16)
+    key = _derive_key(password.encode(), salt, iterations)
+    return b64e(
+        b'%b%b%b' % (
+            salt,
+            iterations.to_bytes(4, 'big'),
+            b64d(Fernet(key).encrypt(message)),
+        )
+    )
+
+def password_decrypt(token: bytes, password: str) -> bytes:
+    decoded = b64d(token)
+    salt, iter, token = decoded[:16], decoded[16:20], b64e(decoded[20:])
+    iterations = int.from_bytes(iter, 'big')
+    key = _derive_key(password.encode(), salt, iterations)
+    return Fernet(key).decrypt(token)
+
+class Bump:
+    def __init__(self, secret=None, secret_file='.bump_secrets'):
+        self.secrets = self.load_secrets(secret, secret_file)
+        if self.secrets == []:
+            self.generate_secret(secret_file)
+            self.show_secrets()
+
+        self.URL = "http://0.0.0.0:4000/api/"
+
+
+
+    def load_secrets(self, secret, secrets_file='.bump_secrets'):
+        try:
+            with open(secrets_file, 'r') as f:
+                secrets = f.read().splitlines()
+        except FileNotFoundError:
+            secrets = []
+        if secret is not None and secret not in self.secrets:
+            secrets.append(secret)
+
+        return secrets
+
+    def generate_secret(self, secret_file):
+        WORDS = r.get_random_words()
+        secret = ""
+        for _ in range(SENDER_LENGTH + PASSWORD_LENGTH):
+            secret += random.choice(WORDS) + "-"
+        while len(secret[SENDER_LENGTH:]) < 32:
+            secret += random.choice(WORDS) + "-"
+        secret = secret[:-1]
+
+        self.secrets.append(secret)
+
+        with open(secret_file, 'a+') as f:
+            f.write(secret + '\n')
+
+
+    def show_secrets(self):
+        for secret in self.secrets:
+           qrcode.make(secret).show()
+           print(secret)
+
+    def get_password(self, index=0):
+        secret = self.secrets[index].split('-')
+        return "-".join(secret[SENDER_LENGTH:])
+
+
+    def get_sender(self, index=0):
+        words = self.secrets[index].split('-')
+        return "-".join(words[0:SENDER_LENGTH])
+
+    def encrypt(self, data):
+        password = self.get_password()
+        return password_encrypt(data.encode(), password)
+
+    def decrypt(self, data):
+        password = self.get_password()
+        return password_decrypt(data, password).decode()
+
+    def push(self, data):
+        url = self.URL + "push"
+        params = {
+            'sender': self.get_sender(),
+            'data': self.encrypt(data)
+        }
+
+        print(url)
+        r = requests.post(url, params)
+        print(r.json())
+        
+            
+    def peak(self):
+        return self.get_post("peak")
+
+    def pop(self):
+        return self.get_post("pop")
+
+    def list(self):
+        return self.get_post("list")
+
+    def clear(self):
+        return self.get_post("clear")
+
+    def get_post(self, mechanism):
+        url = self.URL + mechanism
+        params = {
+            'sender': self.get_sender()
+        }
+        r = requests.post(url, params)
+        if r.json() == {}:
+            return {}
+        return self.decrypt(r.json().get('data'))
+
+if __name__ == '__main__':
+    b = Bump()