new: fixed rsa identity generation and implemented api enrollment plugin

pwnagotchi/identity.py

@@ -0,0 +1,47 @@
+from Crypto.Signature import PKCS1_PSS
+from Crypto.PublicKey import RSA
+import Crypto.Hash.SHA256 as SHA256
+import base64
+import hashlib
+import os
+import logging
+
+DefaultPath = "/etc/pwnagotchi/"
+
+
+class KeyPair(object):
+    def __init__(self, path=DefaultPath):
+        self.path = path
+        self.priv_path = os.path.join(path, "id_rsa")
+        self.priv_key = None
+        self.pub_path = "%s.pub" % self.priv_path
+        self.pub_key = None
+
+        if not os.path.exists(self.path):
+            os.makedirs(self.path)
+
+        if not os.path.exists(self.priv_path) or not os.path.exists(self.pub_path):
+            logging.info("generating %s ..." % self.priv_path)
+            os.system("/usr/bin/ssh-keygen -t rsa -m PEM -b 4096 -N '' -f '%s'" % self.priv_path)
+
+        with open(self.priv_path) as fp:
+            self.priv_key = RSA.importKey(fp.read())
+
+        with open(self.pub_path) as fp:
+            self.pub_key = RSA.importKey(fp.read())
+            self.pub_key_pem = self.pub_key.exportKey('PEM').decode("ascii")
+            # python is special
+            if 'RSA PUBLIC KEY' not in self.pub_key_pem:
+                self.pub_key_pem = self.pub_key_pem.replace('PUBLIC KEY', 'RSA PUBLIC KEY')
+
+        pem = self.pub_key_pem.encode("ascii")
+
+        self.pub_key_pem_b64 = base64.b64encode(pem).decode("ascii")
+        self.fingerprint = hashlib.sha256(pem).hexdigest()
+
+    def sign(self, message):
+        hasher = SHA256.new(message.encode("ascii"))
+        signer = PKCS1_PSS.new(self.priv_key, saltLen=16)
+        signature = signer.sign(hasher)
+        signature_b64 = base64.b64encode(signature).decode("ascii")
+        return signature, signature_b64