update

src/nostr/key_manager.py

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+# nostr/key_manager.py
+
+import base64
+import traceback
+from typing import Optional
+
+from bip_utils import Bip39SeedGenerator
+from bip85.bip85 import BIP85
+from cryptography.fernet import Fernet, InvalidToken
+from bech32 import bech32_encode, convertbits
+
+from .logging_config import configure_logging
+from utils.key_derivation import derive_key_from_parent_seed
+
+# Add the missing import for Keys and NIP4Encrypt
+from monstr.encrypt import Keys, NIP4Encrypt  # Ensure monstr.encrypt is installed and accessible
+
+logger = configure_logging()
+
+def encode_bech32(prefix: str, key_hex: str) -> str:
+    """
+    Encodes a hex key into Bech32 format with the given prefix.
+
+    :param prefix: The Bech32 prefix (e.g., 'nsec', 'npub').
+    :param key_hex: The key in hexadecimal format.
+    :return: The Bech32-encoded string.
+    """
+    try:
+        key_bytes = bytes.fromhex(key_hex)
+        data = convertbits(key_bytes, 8, 5, pad=True)
+        return bech32_encode(prefix, data)
+    except Exception as e:
+        logger.error(f"Failed to encode {prefix}: {e}")
+        logger.error(traceback.format_exc())
+        raise
+
+class KeyManager:
+    """
+    Manages key generation, encoding, and derivation for NostrClient.
+    """
+
+    def __init__(self, parent_seed: str):
+        self.parent_seed = parent_seed
+        self.keys = None
+        self.nsec = None
+        self.npub = None
+        self.initialize_keys()
+
+    def initialize_keys(self):
+        """
+        Derives Nostr keys using BIP85 and initializes Keys.
+        """
+        try:
+            logger.debug("Starting key initialization")
+            seed_bytes = Bip39SeedGenerator(self.parent_seed).Generate()
+            bip85 = BIP85(seed_bytes)
+            entropy = bip85.derive_entropy(app_no=1237, language_code=0, words_num=24, index=0)
+
+            if len(entropy) != 32:
+                logger.error(f"Derived entropy length is {len(entropy)} bytes; expected 32 bytes.")
+                raise ValueError("Invalid entropy length.")
+
+            privkey_hex = entropy.hex()
+            self.keys = Keys(priv_k=privkey_hex)  # Now Keys is defined via the import
+            logger.debug("Nostr Keys initialized successfully.")
+
+            self.nsec = encode_bech32('nsec', privkey_hex)
+            logger.debug(f"Nostr Private Key (nsec): {self.nsec}")
+
+            public_key_hex = self.keys.public_key_hex()
+            self.npub = encode_bech32('npub', public_key_hex)
+            logger.debug(f"Nostr Public Key (npub): {self.npub}")
+
+        except Exception as e:
+            logger.error(f"Key initialization failed: {e}")
+            logger.error(traceback.format_exc())
+            raise
+
+    def get_npub(self) -> str:
+        """
+        Returns the Nostr public key (npub).
+
+        :return: The npub as a string.
+        """
+        if self.npub:
+            logger.debug(f"Returning npub: {self.npub}")
+            return self.npub
+        else:
+            logger.error("Nostr public key (npub) is not available.")
+            raise ValueError("Nostr public key (npub) is not available.")
+
+    def derive_encryption_key(self) -> bytes:
+        """
+        Derives the encryption key using the parent seed.
+
+        :return: The derived encryption key.
+        """
+        try:
+            key = derive_key_from_parent_seed(self.parent_seed)
+            logger.debug("Encryption key derived successfully.")
+            return key
+        except Exception as e:
+            logger.error(f"Failed to derive encryption key: {e}")
+            logger.error(traceback.format_exc())
+            raise