devkanan 0.2.2

Cliente Python para DevKanan — validación local + API online de licencias firmadas RSA

devkanan

Lightweight Python client to activate and validate RSA-signed licenses issued by the DevKanan platform or an on-premise DevKananServer.

Installation

pip install devkanan

Usage

Online activation

from devkanan import Key, Helpers

result, msg = Key.activate(
    token=ACCESS_TOKEN,
    rsa_pub_key=RSA_PUBLIC_KEY,
    product_id=100000,
    key="ABCD-EFGH-IJKL-MNOP",
    machine_code=Helpers.GetMachineCode(v=2),
    # floating_time_interval=300,  # optional floating lease
    server_url="https://devkanan.dev",  # optional
)

if result is None:
    print(f"Activation failed: {msg}")
    exit(1)

if result.is_on_right_machine(Helpers.GetMachineCode(v=2)) and result.has_not_expired():
    print("License valid — app can start")

Offline validation (signed .dat file)

from devkanan import LicenseKey, Helpers

RSA_PUB_KEY = """-----BEGIN PUBLIC KEY-----
... your tenant's RSA public key ...
-----END PUBLIC KEY-----"""

with open("license.dat", encoding="utf-8-sig") as f:
    lk = LicenseKey.load_from_string(RSA_PUB_KEY, f.read(), max_age_days=1)

if lk is None:
    print("Invalid license (corrupt signature, expired or blocked)")
    exit(1)

if not lk.is_on_right_machine(Helpers.GetMachineCode(v=2)):
    print("This machine is not authorized")
    exit(1)

# Features
if lk.F1:
    enable_pro_features()

Usage credits

from devkanan import Credits

# Consume credits when a premium feature is used
ok, balance, msg = Credits.record(
    token=ACCESS_TOKEN, product_id=100000, key=LICENSE_KEY,
    amount=10, feature="export_pdf",
)

# Check current balance
enabled, balance, msg = Credits.balance(
    token=ACCESS_TOKEN, product_id=100000, key=LICENSE_KEY,
)

API

Helpers.GetMachineCode(v=2)

Generates a unique machine code based on hardware properties. v=2 (default) uses BIOS UUID via PowerShell on Windows or /etc/machine-id on Linux. Produces the same hash as the Cryptolens SDK.

LicenseKey.load_from_string(rsa_pub_key, content, max_age_days=0)

Parses a .dat, verifies the RSA signature and freshness.

Parameter	Type	Description
rsa_pub_key	str	XML (.NET) or PEM (standard). Auto-detected.
content	str	.dat file contents
max_age_days	int	Max days since signDate before re-validation is required. 0 = no limit.

Returns a LicenseKey object or None if any check fails.

LicenseKey methods

• is_on_right_machine(machine_code) — verifies the machine is authorized
• has_not_expired() — verifies expires > now
• has_feature(n) — shortcut for getattr(lk, f'f{n}') (n = 1..8)

LicenseKey attributes

Attribute	Type
product_id, id, key, notes	basic data
created, expires, sign_date	unix timestamps
period, max_no_of_machines	integers
F1..F8, block, trial_activation	flags
activated_machines	List[ActivatedMachine]
data_objects	List[DataObject]
customer	Customer or None
offline_mode	"FloatingLease" / "FloatingManual" / "Locked"

Comparison with Cryptolens SDK

	Cryptolens SDK	devkanan
Online activation	✅	✅
Offline .dat / .skm validation	✅	✅
Helpers.GetMachineCode	✅	✅ (same hash)
LicenseKey.load_from_string	✅	✅
Size	~2 MB with deps	~10 KB
Dependencies	pycryptodome, requests	cryptography, requests

Documentation

• DevKanan docs
• API reference
• Offline mode guide

License

Apache 2.0. Partially based on Cryptolens Python SDK (also Apache 2.0).