1 files changed, 70 insertions, 0 deletions
diff --git a/src/pycryptopp/publickey/ed25519/keys.py b/src/pycryptopp/publickey/ed25519/keys.py
new file mode 100644
index 0000000..5d7eafb
--- /dev/null
+++ b/src/pycryptopp/publickey/ed25519/keys.py
@@ -0,0 +1,70 @@
+import _ed25519
+BadSignatureError = _ed25519.BadSignatureError
+
+class SigningKey(object):
+    # this is how all keys are created
+    def __init__(self, sk_bytes):
+        if not isinstance(sk_bytes, type("")):
+            raise TypeError("must be bytes, not %s" % type(sk_bytes))
+        if len(sk_bytes) != 32:
+            raise ValueError("must be exactly 32 bytes")
+        vk_bytes, sk_and_vk = _ed25519.publickey(sk_bytes)
+        assert sk_and_vk[:32] == sk_bytes
+        assert vk_bytes == sk_and_vk[32:]
+        self.vk_bytes = vk_bytes
+        self.sk_and_vk = sk_and_vk
+
+    def __eq__(self, them):
+        if not isinstance(them, object): return False
+        return (them.__class__ == self.__class__
+                and them.sk_and_vk == self.sk_and_vk)
+
+    def get_verifying_key_bytes(self):
+        return self.vk_bytes
+
+    def sign(self, msg):
+        sig_and_msg = _ed25519.sign(msg, self.sk_and_vk)
+        # the response is R+S+msg
+        sig_R = sig_and_msg[0:32]
+        sig_S = sig_and_msg[32:64]
+        msg_out = sig_and_msg[64:]
+        sig_out = sig_R + sig_S
+        assert msg_out == msg
+        return sig_out
+
+class VerifyingKey(object):
+    def __init__(self, vk_bytes):
+        if not isinstance(vk_bytes, type("")):
+            raise TypeError("must be bytes, not %s" % type(vk_bytes))
+        if len(vk_bytes) != 32:
+            raise ValueError("must be exactly 32 bytes")
+        self.vk_bytes = vk_bytes
+
+    def __eq__(self, them):
+        if not isinstance(them, object): return False
+        return (them.__class__ == self.__class__
+                and them.vk_bytes == self.vk_bytes)
+
+    def verify(self, sig, msg):
+        assert isinstance(sig, type("")) # string, really bytes
+        assert len(sig) == 64
+        sig_R = sig[:32]
+        sig_S = sig[32:]
+        sig_and_msg = sig_R + sig_S + msg
+        # this might raise BadSignatureError
+        msg2 = _ed25519.open(sig_and_msg, self.vk_bytes)
+        assert msg2 == msg
+
+def selftest():
+    from binascii import unhexlify
+    message = "crypto libraries should always test themselves at powerup"
+    sk_bytes = unhexlify("548b1f9f938519ad3d527d8c47a1e6ec1439fbec61710b245363865c6f234899")
+    sk = SigningKey(sk_bytes)
+    vk_bytes = unhexlify("787162d9ad1ad571237681560c1ad653fb7df9e09e637e6a8072e4520fd288ca")
+    vk = VerifyingKey(vk_bytes)
+    assert sk.get_verifying_key_bytes() == vk_bytes
+    sig = sk.sign(message)
+    assert sig == "13f42bc2d485e76c7cfaad25e1a840ede25b44a73befb0a528d836d7b434cf87e260c09d980388fab4cb564885857ea4dc3fb04107ca74960cc5a4d415fbf50d".decode('hex'), sig
+    vk.verify(sig, message)
+
+selftest()