Add sign and verify capability to Identity

earthsnake/identity.py

@@ -4,7 +4,7 @@ import re
 from typing import Optional
 
 import bip39
-from ed25519 import SigningKey, VerifyingKey, create_keypair
+from ed25519 import BadSignatureError, SigningKey, VerifyingKey, create_keypair
 
 from .base32 import base32_bytes_to_string, base32_string_to_bytes
 from .exc import ValidationError
@@ -23,8 +23,8 @@ class Identity:
 
     _KEY_PATTERN = f'b[{B32_CHAR}]{{52}}'
     _NAME_PATTERN = f'[{ALPHA_LOWER}][{ALPHA_LOWER_OR_DIGIT}]{{3}}'
-    _PATTERN = f'^@{_NAME_PATTERN}\\.{_KEY_PATTERN}$'
     _SECRET_PATTERN = f'^{_KEY_PATTERN}$'
+    PATTERN = f'^@{_NAME_PATTERN}\\.{_KEY_PATTERN}$'
 
     def __init__(
         self,
@@ -143,3 +143,23 @@ class Identity:
         mnemonic = bip39.encode_bytes(seed)
 
         return f'{self.name} {mnemonic}'
+
+    def sign(self, data: str) -> str:
+        """Sign data"""
+
+        if not self.sign_key:
+            raise TypeError('This identity doesn’t have a signing key')
+
+        return base32_bytes_to_string(self.sign_key.sign(data.encode('utf-8')))
+
+    def verify(self, data: str, signature: str) -> bool:
+        """Verify if data is signed by us"""
+
+        signature_bytes = base32_string_to_bytes(signature)
+
+        try:
+            self.verify_key.verify(signature_bytes, data.encode('utf-8'))
+        except BadSignatureError:
+            return False
+
+        return True