feat: add NostrIdentity for sovereign registration

nexus/nostr_identity.py

@@ -0,0 +1,102 @@
+
+import hashlib
+import hmac
+import os
+import binascii
+
+# ═══════════════════════════════════════════
+# NOSTR SOVEREIGN IDENTITY (NIP-01)
+# ═══════════════════════════════════════════
+# Pure Python implementation of Schnorr signatures for Nostr.
+# No dependencies required.
+
+def sha256(data):
+    return hashlib.sha256(data).digest()
+
+def hmac_sha256(key, data):
+    return hmac.new(key, data, hashlib.sha256).digest()
+
+# Secp256k1 Constants
+P = 2**256 - 2**32 - 977
+N = 115792089237316195423570985008687907852837564279074904382605163141518161494337
+G = (0x79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,
+     0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8)
+
+def inverse(a, n):
+    return pow(a, n - 2, n)
+
+def point_add(p1, p2):
+    if p1 is None: return p2
+    if p2 is None: return p1
+    (x1, y1), (x2, y2) = p1, p2
+    if x1 == x2 and y1 != y2: return None
+    if x1 == x2:
+        m = (3 * x1 * x1 * inverse(2 * y1, P)) % P
+    else:
+        m = ((y2 - y1) * inverse(x2 - x1, P)) % P
+    x3 = (m * m - x1 - x2) % P
+    y3 = (m * (x1 - x3) - y1) % P
+    return (x3, y3)
+
+def point_mul(p, n):
+    r = None
+    for i in range(256):
+        if (n >> i) & 1:
+            r = point_add(r, p)
+        p = point_add(p, p)
+    return r
+
+def get_pubkey(privkey):
+    p = point_mul(G, privkey)
+    return binascii.hexlify(p[0].to_bytes(32, 'big')).decode()
+
+# Schnorr Signature (BIP340)
+def sign_schnorr(msg_hash, privkey):
+    k = int.from_bytes(sha256(privkey.to_bytes(32, 'big') + msg_hash), 'big') % N
+    R = point_mul(G, k)
+    if R[1] % 2 != 0:
+        k = N - k
+    r = R[0].to_bytes(32, 'big')
+    e = int.from_bytes(sha256(r + binascii.unhexlify(get_pubkey(privkey)) + msg_hash), 'big') % N
+    s = (k + e * privkey) % N
+    return binascii.hexlify(r + s.to_bytes(32, 'big')).decode()
+
+class NostrIdentity:
+    def __init__(self, privkey_hex=None):
+        if privkey_hex:
+            self.privkey = int(privkey_hex, 16)
+        else:
+            self.privkey = int.from_bytes(os.urandom(32), 'big') % N
+        self.pubkey = get_pubkey(self.privkey)
+
+    def sign_event(self, event):
+        # NIP-01 Event Signing
+        import json
+        event_data = [
+            0,
+            event['pubkey'],
+            event['created_at'],
+            event['kind'],
+            event['tags'],
+            event['content']
+        ]
+        serialized = json.dumps(event_data, separators=(',', ':'))
+        msg_hash = sha256(serialized.encode())
+        event['id'] = binascii.hexlify(msg_hash).decode()
+        event['sig'] = sign_schnorr(msg_hash, self.privkey)
+        return event
+
+if __name__ == "__main__":
+    # Test Identity
+    identity = NostrIdentity()
+    print(f"Nostr Pubkey: {identity.pubkey}")
+    
+    event = {
+        "pubkey": identity.pubkey,
+        "created_at": 1677628800,
+        "kind": 1,
+        "tags": [],
+        "content": "Sovereignty and service always. #Timmy"
+    }
+    signed_event = identity.sign_event(event)
+    print(f"Signed Event: {signed_event}")