pure25519

0.0.1 verified Fri May 01 auth: no python

Pure-Python implementation of Curve25519 and Ed25519 cryptographic routines. Current version is 0.0.1, with no recent releases. Provides low-level functions for DH key exchange (Curve25519) and digital signatures (Ed25519). It is a reference implementation not recommended for production use due to lack of constant-time security.

pip install pure25519

Common errors

error cannot import name 'dh_start' from 'pure25519' ↓

cause Incorrect import path; pure25519 has submodules 'dh' and 'ed25519'.

fix

Use 'from pure25519.dh import dh_start'.

error AttributeError: 'bytes' object has no attribute 'sign' ↓

cause Attempting to sign a message by calling .sign() on the message bytes instead of on a SigningKey object.

fix

Use 'signature = sk.sign(message)' where sk is a SigningKey instance.

error TypeError: expected 32 bytes, got 64 ↓

cause Incorrect seed length for SigningKey.from_seed(). Seed must be exactly 32 bytes.

fix

Ensure the seed is 32 bytes long.

Warnings

gotcha This is a pure-python implementation intended for educational/reference purposes. It does NOT implement constant-time operations and is vulnerable to timing side-channel attacks. Do not use in production. ↓

fix Use a production-grade library like PyNaCl or cryptography.

deprecated The library is essentially unmaintained (last release 2014). Issues may never be fixed. ↓

fix Consider migrating to a maintained library such as PyNaCl or ed25519.

gotcha The ed25519 module uses a custom key object, not the standard bytes interface. Signing with bytes directly will fail. ↓

fix Always use SigningKey.generate() or SigningKey.from_seed() to create keys.

Imports

dh_start
```
from pure25519.dh import dh_start
```
Correct import for Diffie-Hellman functions.
SigningKey
```
from pure25519.ed25519 import SigningKey
```
Correct import for Ed25519 signing.
VerifyingKey
```
from pure25519.ed25519 import VerifyingKey
```
Correct import for Ed25519 verification.

Quickstart

Generate an Ed25519 key pair, sign a message, and verify the signature.

from pure25519.ed25519 import SigningKey, VerifyingKey

sk = SigningKey.generate()
vk = sk.get_verifying_key()
message = b"test message"
signature = sk.sign(message)
assert vk.verify(signature, message)
print("Ed25519 signature roundtrip OK")