Initial bip340 reference code copy pasta

3 files changed, 174 insertions, 0 deletions

diff --git a/nostr/bip340.py b/nostr/bip340.py
new file mode 100644
index 0000000..7712500
--- /dev/null
+++ b/nostr/bip340.py
@@ -0,0 +1,170 @@
+### Reference implementatoin copy pasta from https://github.com/bitcoin/bips/blob/02de475efc528058bd04a0c4ad31b6422aed5f5f/bip-0340/reference.py
+
+from typing import Tuple, Optional, Any
+import hashlib
+import binascii
+
+# Set DEBUG to True to get a detailed debug output including
+# intermediate values during key generation, signing, and
+# verification. This is implemented via calls to the
+# debug_print_vars() function.
+#
+# If you want to print values on an individual basis, use
+# the pretty() function, e.g., print(pretty(foo)).
+DEBUG = False
+
+p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F
+n = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141
+
+# Points are tuples of X and Y coordinates and the point at infinity is
+# represented by the None keyword.
+G = (
+    0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798,
+    0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8,
+)
+
+Point = Tuple[int, int]
+
+# This implementation can be sped up by storing the midstate after hashing
+# tag_hash instead of rehashing it all the time.
+def tagged_hash(tag: str, msg: bytes) -> bytes:
+    tag_hash = hashlib.sha256(tag.encode()).digest()
+    return hashlib.sha256(tag_hash + tag_hash + msg).digest()
+
+
+def is_infinite(P: Optional[Point]) -> bool:
+    return P is None
+
+
+def x(P: Point) -> int:
+    assert not is_infinite(P)
+    return P[0]
+
+
+def y(P: Point) -> int:
+    assert not is_infinite(P)
+    return P[1]
+
+
+def point_add(P1: Optional[Point], P2: Optional[Point]) -> Optional[Point]:
+    if P1 is None:
+        return P2
+    if P2 is None:
+        return P1
+    if (x(P1) == x(P2)) and (y(P1) != y(P2)):
+        return None
+    if P1 == P2:
+        lam = (3 * x(P1) * x(P1) * pow(2 * y(P1), p - 2, p)) % p
+    else:
+        lam = ((y(P2) - y(P1)) * pow(x(P2) - x(P1), p - 2, p)) % p
+    x3 = (lam * lam - x(P1) - x(P2)) % p
+    return (x3, (lam * (x(P1) - x3) - y(P1)) % p)
+
+
+def point_mul(P: Optional[Point], n: int) -> Optional[Point]:
+    R = None
+    for i in range(256):
+        if (n >> i) & 1:
+            R = point_add(R, P)
+        P = point_add(P, P)
+    return R
+
+
+def bytes_from_int(x: int) -> bytes:
+    return x.to_bytes(32, byteorder="big")
+
+
+def bytes_from_point(P: Point) -> bytes:
+    return bytes_from_int(x(P))
+
+
+def xor_bytes(b0: bytes, b1: bytes) -> bytes:
+    return bytes(x ^ y for (x, y) in zip(b0, b1))
+
+
+def lift_x(b: bytes) -> Optional[Point]:
+    x = int_from_bytes(b)
+    if x >= p:
+        return None
+    y_sq = (pow(x, 3, p) + 7) % p
+    y = pow(y_sq, (p + 1) // 4, p)
+    if pow(y, 2, p) != y_sq:
+        return None
+    return (x, y if y & 1 == 0 else p - y)
+
+
+def int_from_bytes(b: bytes) -> int:
+    return int.from_bytes(b, byteorder="big")
+
+
+def hash_sha256(b: bytes) -> bytes:
+    return hashlib.sha256(b).digest()
+
+
+def has_even_y(P: Point) -> bool:
+    assert not is_infinite(P)
+    return y(P) % 2 == 0
+
+
+def pubkey_gen(seckey: bytes) -> bytes:
+    d0 = int_from_bytes(seckey)
+    if not (1 <= d0 <= n - 1):
+        raise ValueError("The secret key must be an integer in the range 1..n-1.")
+    P = point_mul(G, d0)
+    assert P is not None
+    return bytes_from_point(P)
+
+
+def schnorr_sign(msg: bytes, seckey: bytes, aux_rand: bytes) -> bytes:
+    if len(msg) != 32:
+        raise ValueError("The message must be a 32-byte array.")
+    d0 = int_from_bytes(seckey)
+    if not (1 <= d0 <= n - 1):
+        raise ValueError("The secret key must be an integer in the range 1..n-1.")
+    if len(aux_rand) != 32:
+        raise ValueError("aux_rand must be 32 bytes instead of %i." % len(aux_rand))
+    P = point_mul(G, d0)
+    assert P is not None
+    d = d0 if has_even_y(P) else n - d0
+    t = xor_bytes(bytes_from_int(d), tagged_hash("BIP0340/aux", aux_rand))
+    k0 = int_from_bytes(tagged_hash("BIP0340/nonce", t + bytes_from_point(P) + msg)) % n
+    if k0 == 0:
+        raise RuntimeError("Failure. This happens only with negligible probability.")
+    R = point_mul(G, k0)
+    assert R is not None
+    k = n - k0 if not has_even_y(R) else k0
+    e = (
+        int_from_bytes(
+            tagged_hash(
+                "BIP0340/challenge", bytes_from_point(R) + bytes_from_point(P) + msg
+            )
+        )
+        % n
+    )
+    sig = bytes_from_point(R) + bytes_from_int((k + e * d) % n)
+    debug_print_vars()
+    if not schnorr_verify(msg, bytes_from_point(P), sig):
+        raise RuntimeError("The created signature does not pass verification.")
+    return sig
+
+
+def schnorr_verify(msg: bytes, pubkey: bytes, sig: bytes) -> bool:
+    if len(msg) != 32:
+        raise ValueError("The message must be a 32-byte array.")
+    if len(pubkey) != 32:
+        raise ValueError("The public key must be a 32-byte array.")
+    if len(sig) != 64:
+        raise ValueError("The signature must be a 64-byte array.")
+    P = lift_x(pubkey)
+    r = int_from_bytes(sig[0:32])
+    s = int_from_bytes(sig[32:64])
+    if (P is None) or (r >= p) or (s >= n):
+        debug_print_vars()
+        return False
+    e = int_from_bytes(tagged_hash("BIP0340/challenge", sig[0:32] + pubkey + msg)) % n
+    R = point_add(point_mul(G, s), point_mul(P, n - e))
+    if (R is None) or (not has_even_y(R)) or (x(R) != r):
+        debug_print_vars()
+        return False
+    debug_print_vars()
+    return True
diff --git a/nostr/event.py b/nostr/event.py
index 9cf363a..3dfe638 100644
--- a/nostr/event.py
+++ b/nostr/event.py
@@ -9,6 +9,9 @@ class EventKind(Enum):
     SET_METADATA = 0
     TEXT_NOTE = 1
     RECOMMEND_SERVER = 2
+    CONTACT_LIST = 3
+    ENCRYPTED_DIRECT_MESSAGE = 4
+    DELETION = 5
 
 
 class Event:
@@ -24,4 +27,5 @@ class Event:
     def id(self):
         data = [0, self.pubkey, self.created_at, self.kind, self.tags, self.content]
         jd = json.dumps(data).encode("utf-8")
+        print(jd)
         return hashlib.sha256(jd).hexdigest()
diff --git a/nostr/keys.py b/nostr/keys.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/nostr/keys.py