From 5fdca2ffb2460045b9920739ca481b397ced5946 Mon Sep 17 00:00:00 2001
From: Alex Stokes <r.alex.stokes@gmail.com>
Date: Mon, 9 Sep 2019 20:23:44 -0400
Subject: [PATCH] Add public key implementation

---
 libp2p/crypto/ed25519.py | 45 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 40 insertions(+), 5 deletions(-)

diff --git a/libp2p/crypto/ed25519.py b/libp2p/crypto/ed25519.py
index 1b34a705..61c46311 100644
--- a/libp2p/crypto/ed25519.py
+++ b/libp2p/crypto/ed25519.py
@@ -1,13 +1,15 @@
 from Crypto.Hash import SHA256
 
-from libp2p.crypto.keys import KeyType, PublicKey
+from libp2p.crypto.keys import KeyPair, KeyType, PrivateKey, PublicKey
 from nacl.exceptions import BadSignatureError
-from nacl.public import PublicKey as Ed255129PublicKeyImpl
-from nacl.signing import VerifyKey
+from nacl.public import PrivateKey as PrivateKeyImpl
+from nacl.public import PublicKey as PublicKeyImpl
+from nacl.signing import SigningKey, VerifyKey
+import nacl.utils as utils
 
 
 class Ed25519PublicKey(PublicKey):
-    def __init__(self, impl: Ed255129PublicKeyImpl) -> None:
+    def __init__(self, impl: PublicKeyImpl) -> None:
         self.impl = impl
 
     def to_bytes(self) -> bytes:
@@ -15,7 +17,7 @@ class Ed25519PublicKey(PublicKey):
 
     @classmethod
     def from_bytes(cls, key_bytes: bytes) -> "Ed25519PublicKey":
-        return cls(Ed255129PublicKeyImpl(key_bytes))
+        return cls(PublicKeyImpl(key_bytes))
 
     def get_type(self) -> KeyType:
         return KeyType.Ed25519
@@ -28,3 +30,36 @@ class Ed25519PublicKey(PublicKey):
         except BadSignatureError:
             return False
         return True
+
+
+class Ed25519PrivateKey(PrivateKey):
+    def __init__(self, impl: PrivateKeyImpl) -> None:
+        self.impl = impl
+
+    @classmethod
+    def new(cls, seed: bytes = None) -> "Ed25519PrivateKey":
+        if not seed:
+            seed = utils.random()
+
+        private_key_impl = PrivateKeyImpl.from_seed(seed)
+        return cls(private_key_impl)
+
+    def to_bytes(self) -> bytes:
+        return bytes(self.impl)
+
+    def get_type(self) -> KeyType:
+        return KeyType.Ed25519
+
+    def sign(self, data: bytes) -> bytes:
+        h = SHA256.new(data)
+        signing_key = SigningKey(self.to_bytes())
+        return signing_key.sign(h)
+
+    def get_public_key(self) -> PublicKey:
+        return Ed25519PublicKey(self.impl.public_key)
+
+
+def create_new_key_pair(seed: bytes = None) -> KeyPair:
+    private_key = Ed25519PrivateKey.new(seed)
+    public_key = private_key.get_public_key()
+    return KeyPair(private_key, public_key)