first commit

projecten1/lib/python3.6/site-packages/wheel/signatures/ed25519py.py

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+import os
+import warnings
+from collections import namedtuple
+
+from . import djbec
+
+__all__ = ['crypto_sign', 'crypto_sign_open', 'crypto_sign_keypair', 'Keypair',
+           'PUBLICKEYBYTES', 'SECRETKEYBYTES', 'SIGNATUREBYTES']
+
+PUBLICKEYBYTES = 32
+SECRETKEYBYTES = 64
+SIGNATUREBYTES = 64
+
+Keypair = namedtuple('Keypair', ('vk', 'sk'))  # verifying key, secret key
+
+
+def crypto_sign_keypair(seed=None):
+    """Return (verifying, secret) key from a given seed, or os.urandom(32)"""
+    if seed is None:
+        seed = os.urandom(PUBLICKEYBYTES)
+    else:
+        warnings.warn("ed25519ll should choose random seed.",
+                      RuntimeWarning)
+    if len(seed) != 32:
+        raise ValueError("seed must be 32 random bytes or None.")
+    skbytes = seed
+    vkbytes = djbec.publickey(skbytes)
+    return Keypair(vkbytes, skbytes+vkbytes)
+
+
+def crypto_sign(msg, sk):
+    """Return signature+message given message and secret key.
+    The signature is the first SIGNATUREBYTES bytes of the return value.
+    A copy of msg is in the remainder."""
+    if len(sk) != SECRETKEYBYTES:
+        raise ValueError("Bad signing key length %d" % len(sk))
+    vkbytes = sk[PUBLICKEYBYTES:]
+    skbytes = sk[:PUBLICKEYBYTES]
+    sig = djbec.signature(msg, skbytes, vkbytes)
+    return sig + msg
+
+
+def crypto_sign_open(signed, vk):
+    """Return message given signature+message and the verifying key."""
+    if len(vk) != PUBLICKEYBYTES:
+        raise ValueError("Bad verifying key length %d" % len(vk))
+    rc = djbec.checkvalid(signed[:SIGNATUREBYTES], signed[SIGNATUREBYTES:], vk)
+    if not rc:
+        raise ValueError("rc != True", rc)
+    return signed[SIGNATUREBYTES:]