pymonocypher

4.0.2.6 verified Fri May 01 auth: no python

Python ctypes bindings to the Monocypher library. Current version: 4.0.2.6, requires Python ~=3.10. Release cadence: irregular, tied to Monocypher updates.

pip install pymonocypher

Common errors

error AttributeError: module 'pymonocypher' has no attribute 'crypto_sign_keypair' ↓

cause Incorrect import: using 'import pymonocypher' without accessing the inner module.

fix

Import correctly: from pymonocypher import pymonocypher as m; then use m.crypto_sign_keypair().

error TypeError: compute_signing_public_key() takes exactly 1 argument (0 given) ↓

cause Passing a 32-byte key instead of 64-byte secret key (deprecated 32-byte variant removed).

fix

Pass the full 64-byte secret key returned by crypto_sign_keypair().

error ValueError: nb_block is not a valid parameter for argon2i_32 ↓

cause Using the old parameter name nb_block instead of nb_blocks (fixed in v4.0.2.4).

fix

Use nb_blocks instead of nb_block.

Warnings

breaking Upgraded from Monocypher 3.1.3 to 4.0.2 in v4.0.2.1; incremental SignatureVerify removed. ↓

fix Use crypto_sign_verify instead of IncrementalSignatureVerify.

breaking compute_signing_public_key now requires a 64-byte secret key (full keypair output). The 32-byte variant is deprecated as of v4.0.2.3. ↓

fix Pass the full 64-byte secret key (sk) to compute_signing_public_key. For the deprecated 32-byte variant, update your code to use the full key.

deprecated compute_signing_public_key 32-byte variant deprecated in v4.0.2.3 and will be removed in a future release. ↓

fix Use the 64-byte secret key variant.

gotcha argon2i_32 had incorrect parameter nb_block (should be nb_blocks) fixed in v4.0.2.4. ↓

fix Use nb_blocks instead of nb_block when calling argon2i_32.

gotcha Python 3.10 support dropped as of v4.0.2.6/v3.1.3.5. ↓

fix Use Python >=3.11 or pin to an older version (v4.0.2.5 supports 3.10).

Imports

pymonocypher
wrong
```
import pymonocypher
```
correct
```
from pymonocypher import pymonocypher as m
```
The main module is nested; direct import misses the bindings.
crypto_sign
wrong
```
pymonocypher.crypto_sign(msg, sk)
```
correct
```
m.crypto_sign(msg, sk)
```
Must use the imported module alias after correct import.

Quickstart

Generate a signing keypair, sign a message, and verify the signature.

from pymonocypher import pymonocypher as m
key = m.crypto_sign_keypair()
print('Public key:', key.pk.hex())
msg = b'Hello'
sig = m.crypto_sign(msg, key.sk)
print('Signature:', sig.hex())
# Verify
m.crypto_sign_verify(sig, msg, key.pk)
print('Verified OK')