Switch to coincurve for Windows compatibility

src/nostr/coincurve_keys.py

@@ -0,0 +1,45 @@
+from __future__ import annotations
+
+from bech32 import bech32_encode, bech32_decode, convertbits
+from coincurve import PrivateKey, PublicKey
+
+
+class Keys:
+    """Minimal replacement for monstr.encrypt.Keys using coincurve."""
+
+    def __init__(self, priv_k: str | None = None, pub_k: str | None = None):
+        if priv_k is not None:
+            if priv_k.startswith("nsec"):
+                priv_k = self.bech32_to_hex(priv_k)
+            self._priv_k = priv_k
+            priv = PrivateKey(bytes.fromhex(priv_k))
+        else:
+            priv = PrivateKey()
+            self._priv_k = priv.to_hex()
+
+        pub = priv.public_key.format(compressed=True).hex()[2:]
+        if pub_k:
+            if pub_k.startswith("npub"):
+                pub_k = self.bech32_to_hex(pub_k)
+            self._pub_k = pub_k
+        else:
+            self._pub_k = pub
+
+    @staticmethod
+    def hex_to_bech32(key_str: str, prefix: str = "npub") -> str:
+        data = convertbits(bytes.fromhex(key_str), 8, 5)
+        return bech32_encode(prefix, data)
+
+    @staticmethod
+    def bech32_to_hex(key: str) -> str:
+        hrp, data = bech32_decode(key)
+        if data is None:
+            raise ValueError("Invalid bech32 key")
+        decoded = convertbits(data, 5, 8, False)
+        return bytes(decoded).hex()
+
+    def private_key_hex(self) -> str:
+        return self._priv_k
+
+    def public_key_hex(self) -> str:
+        return self._pub_k