v_41: Add an error if period exceeds the limit

This release adds a new error message to Key.activate that will be thrown if the period exceeds the permitted limit in Python. The problem is described in https://github.com/Cryptolens/cryptolens-python/tree/master#the-expiration-date-cannot-be-converted-to-a-datetime-object-please-try-setting-the-period-to-a-lower-value, but in essence, the issue is that the timestamp representation of the expiration date causes an overflow in Python, and thus an error is thrown.

v_40: Improvements to the signature verification method

Use constant time comparison when available (#59)

* Use constant time comparison when available

* Update setup.py

v_39: Add GetKeys method and fix cmd window from showing up when computing machine code

Minor fix and update version number

v_38: Add Decrement Int Value to Key

Add DecrementIntValueToKey (#56)

* Update methods.py

* Update setup.py

v_37: Fix an issue in HasFeature method

In this update we fixed an issue that could occur if a license did not have the data object required for feature templates or if the content of it was empty.

v_36: Support for proxy servers

In this release, we have added support for proxy servers defined on OS level. To enable it, you can add the following command before calling any other API method such as Key.activate.

HelperMethods.proxy_experimental = True

v_35: Update return value in GetMachineCode upon error

This updates changes the behaviour of Helpers.GetMachineCode when the library is unable to retrieve the UUID. If this occurs, None will be returned.

v_34: Update UUID source for Windows

When the machine code, we rely on the UUID that is provided by the OS. On Windows, we used to use wmic to obtain the UUID. As pointed out by @pmnforce in #50, it will be deprecated in Windows 11. We are thus switching to a different method to compute it, i.e., as follows:

cmd /c powershell.exe -Command "(Get-CimInstance -Class Win32_ComputerSystemProduct).UUID"

Based on our tests, this will not affect the value of the machine code, i.e., this update is backwards compatible.

v_33: Update the API endpoint

The base address of the API was changed from app.cryptolens.io to api.cryptolens.io.

Note: for corporate clients or those with strict firewall rules, please notify them to whitelist the IPs on the following page: https://help.cryptolens.io/security/api-ip[](https://github.com/)

v_32: Event registration and data object methods

Add the following methods:

• get_events
• register_event
• add_data_object_to_key
• remove_data_object_to_key
• add_data_object_to_machine
• remove_data_object_to_machine
• list_machine_data_objects
• list_key_data_objects

Thanks to @synominit for the data object related methods.