godot-docs/classes/class_crypto.rst

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.. Generated automatically from Godot engine sources.
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.. _class_Crypto:

Crypto
======

**Inherits:** :ref:`RefCounted<class_RefCounted>` **<** :ref:`Object<class_Object>`

Provides access to advanced cryptographic functionalities.

.. rst-class:: classref-introduction-group

Description
-----------

The Crypto class provides access to advanced cryptographic functionalities.

Currently, this includes asymmetric key encryption/decryption, signing/verification, and generating cryptographically secure random bytes, RSA keys, HMAC digests, and self-signed :ref:`X509Certificate<class_X509Certificate>`\ s.


.. tabs::

 .. code-tab:: gdscript

    var crypto = Crypto.new()
    
    # Generate new RSA key.
    var key = crypto.generate_rsa(4096)
    
    # Generate new self-signed certificate with the given key.
    var cert = crypto.generate_self_signed_certificate(key, "CN=mydomain.com,O=My Game Company,C=IT")
    
    # Save key and certificate in the user folder.
    key.save("user://generated.key")
    cert.save("user://generated.crt")
    
    # Encryption
    var data = "Some data"
    var encrypted = crypto.encrypt(key, data.to_utf8_buffer())
    
    # Decryption
    var decrypted = crypto.decrypt(key, encrypted)
    
    # Signing
    var signature = crypto.sign(HashingContext.HASH_SHA256, data.sha256_buffer(), key)
    
    # Verifying
    var verified = crypto.verify(HashingContext.HASH_SHA256, data.sha256_buffer(), signature, key)
    
    # Checks
    assert(verified)
    assert(data.to_utf8_buffer() == decrypted)

 .. code-tab:: csharp

    using Godot;
    using System.Diagnostics;
    
    Crypto crypto = new Crypto();
    
    // Generate new RSA key.
    CryptoKey key = crypto.GenerateRsa(4096);
    
    // Generate new self-signed certificate with the given key.
    X509Certificate cert = crypto.GenerateSelfSignedCertificate(key, "CN=mydomain.com,O=My Game Company,C=IT");
    
    // Save key and certificate in the user folder.
    key.Save("user://generated.key");
    cert.Save("user://generated.crt");
    
    // Encryption
    string data = "Some data";
    byte[] encrypted = crypto.Encrypt(key, data.ToUtf8Buffer());
    
    // Decryption
    byte[] decrypted = crypto.Decrypt(key, encrypted);
    
    // Signing
    byte[] signature = crypto.Sign(HashingContext.HashType.Sha256, Data.Sha256Buffer(), key);
    
    // Verifying
    bool verified = crypto.Verify(HashingContext.HashType.Sha256, Data.Sha256Buffer(), signature, key);
    
    // Checks
    Debug.Assert(verified);
    Debug.Assert(data.ToUtf8Buffer() == decrypted);



.. rst-class:: classref-reftable-group

Methods
-------

.. table::
   :widths: auto

   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`                       | :ref:`constant_time_compare<class_Crypto_method_constant_time_compare>`\ (\ trusted\: :ref:`PackedByteArray<class_PackedByteArray>`, received\: :ref:`PackedByteArray<class_PackedByteArray>`\ )                                                                                                                                                       |
   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`PackedByteArray<class_PackedByteArray>` | :ref:`decrypt<class_Crypto_method_decrypt>`\ (\ key\: :ref:`CryptoKey<class_CryptoKey>`, ciphertext\: :ref:`PackedByteArray<class_PackedByteArray>`\ )                                                                                                                                                                                                 |
   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`PackedByteArray<class_PackedByteArray>` | :ref:`encrypt<class_Crypto_method_encrypt>`\ (\ key\: :ref:`CryptoKey<class_CryptoKey>`, plaintext\: :ref:`PackedByteArray<class_PackedByteArray>`\ )                                                                                                                                                                                                  |
   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`PackedByteArray<class_PackedByteArray>` | :ref:`generate_random_bytes<class_Crypto_method_generate_random_bytes>`\ (\ size\: :ref:`int<class_int>`\ )                                                                                                                                                                                                                                            |
   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`CryptoKey<class_CryptoKey>`             | :ref:`generate_rsa<class_Crypto_method_generate_rsa>`\ (\ size\: :ref:`int<class_int>`\ )                                                                                                                                                                                                                                                              |
   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`X509Certificate<class_X509Certificate>` | :ref:`generate_self_signed_certificate<class_Crypto_method_generate_self_signed_certificate>`\ (\ key\: :ref:`CryptoKey<class_CryptoKey>`, issuer_name\: :ref:`String<class_String>` = "CN=myserver,O=myorganisation,C=IT", not_before\: :ref:`String<class_String>` = "20140101000000", not_after\: :ref:`String<class_String>` = "20340101000000"\ ) |
   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`PackedByteArray<class_PackedByteArray>` | :ref:`hmac_digest<class_Crypto_method_hmac_digest>`\ (\ hash_type\: :ref:`HashType<enum_HashingContext_HashType>`, key\: :ref:`PackedByteArray<class_PackedByteArray>`, msg\: :ref:`PackedByteArray<class_PackedByteArray>`\ )                                                                                                                         |
   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`PackedByteArray<class_PackedByteArray>` | :ref:`sign<class_Crypto_method_sign>`\ (\ hash_type\: :ref:`HashType<enum_HashingContext_HashType>`, hash\: :ref:`PackedByteArray<class_PackedByteArray>`, key\: :ref:`CryptoKey<class_CryptoKey>`\ )                                                                                                                                                  |
   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`                       | :ref:`verify<class_Crypto_method_verify>`\ (\ hash_type\: :ref:`HashType<enum_HashingContext_HashType>`, hash\: :ref:`PackedByteArray<class_PackedByteArray>`, signature\: :ref:`PackedByteArray<class_PackedByteArray>`, key\: :ref:`CryptoKey<class_CryptoKey>`\ )                                                                                   |
   +-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Method Descriptions
-------------------

.. _class_Crypto_method_constant_time_compare:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **constant_time_compare**\ (\ trusted\: :ref:`PackedByteArray<class_PackedByteArray>`, received\: :ref:`PackedByteArray<class_PackedByteArray>`\ ) :ref:`🔗<class_Crypto_method_constant_time_compare>`

Compares two :ref:`PackedByteArray<class_PackedByteArray>`\ s for equality without leaking timing information in order to prevent timing attacks.

See `this blog post <https://paragonie.com/blog/2015/11/preventing-timing-attacks-on-string-comparison-with-double-hmac-strategy>`__ for more information.

.. rst-class:: classref-item-separator

----

.. _class_Crypto_method_decrypt:

.. rst-class:: classref-method

:ref:`PackedByteArray<class_PackedByteArray>` **decrypt**\ (\ key\: :ref:`CryptoKey<class_CryptoKey>`, ciphertext\: :ref:`PackedByteArray<class_PackedByteArray>`\ ) :ref:`🔗<class_Crypto_method_decrypt>`

Decrypt the given ``ciphertext`` with the provided private ``key``.

\ **Note:** The maximum size of accepted ciphertext is limited by the key size.

.. rst-class:: classref-item-separator

----

.. _class_Crypto_method_encrypt:

.. rst-class:: classref-method

:ref:`PackedByteArray<class_PackedByteArray>` **encrypt**\ (\ key\: :ref:`CryptoKey<class_CryptoKey>`, plaintext\: :ref:`PackedByteArray<class_PackedByteArray>`\ ) :ref:`🔗<class_Crypto_method_encrypt>`

Encrypt the given ``plaintext`` with the provided public ``key``.

\ **Note:** The maximum size of accepted plaintext is limited by the key size.

.. rst-class:: classref-item-separator

----

.. _class_Crypto_method_generate_random_bytes:

.. rst-class:: classref-method

:ref:`PackedByteArray<class_PackedByteArray>` **generate_random_bytes**\ (\ size\: :ref:`int<class_int>`\ ) :ref:`🔗<class_Crypto_method_generate_random_bytes>`

Generates a :ref:`PackedByteArray<class_PackedByteArray>` of cryptographically secure random bytes with given ``size``.

.. rst-class:: classref-item-separator

----

.. _class_Crypto_method_generate_rsa:

.. rst-class:: classref-method

:ref:`CryptoKey<class_CryptoKey>` **generate_rsa**\ (\ size\: :ref:`int<class_int>`\ ) :ref:`🔗<class_Crypto_method_generate_rsa>`

Generates an RSA :ref:`CryptoKey<class_CryptoKey>` that can be used for creating self-signed certificates and passed to :ref:`StreamPeerTLS.accept_stream()<class_StreamPeerTLS_method_accept_stream>`.

.. rst-class:: classref-item-separator

----

.. _class_Crypto_method_generate_self_signed_certificate:

.. rst-class:: classref-method

:ref:`X509Certificate<class_X509Certificate>` **generate_self_signed_certificate**\ (\ key\: :ref:`CryptoKey<class_CryptoKey>`, issuer_name\: :ref:`String<class_String>` = "CN=myserver,O=myorganisation,C=IT", not_before\: :ref:`String<class_String>` = "20140101000000", not_after\: :ref:`String<class_String>` = "20340101000000"\ ) :ref:`🔗<class_Crypto_method_generate_self_signed_certificate>`

Generates a self-signed :ref:`X509Certificate<class_X509Certificate>` from the given :ref:`CryptoKey<class_CryptoKey>` and ``issuer_name``. The certificate validity will be defined by ``not_before`` and ``not_after`` (first valid date and last valid date). The ``issuer_name`` must contain at least "CN=" (common name, i.e. the domain name), "O=" (organization, i.e. your company name), "C=" (country, i.e. 2 lettered ISO-3166 code of the country the organization is based in).

A small example to generate an RSA key and an X509 self-signed certificate.


.. tabs::

 .. code-tab:: gdscript

    var crypto = Crypto.new()
    # Generate 4096 bits RSA key.
    var key = crypto.generate_rsa(4096)
    # Generate self-signed certificate using the given key.
    var cert = crypto.generate_self_signed_certificate(key, "CN=example.com,O=A Game Company,C=IT")

 .. code-tab:: csharp

    var crypto = new Crypto();
    // Generate 4096 bits RSA key.
    CryptoKey key = crypto.GenerateRsa(4096);
    // Generate self-signed certificate using the given key.
    X509Certificate cert = crypto.GenerateSelfSignedCertificate(key, "CN=mydomain.com,O=My Game Company,C=IT");



.. rst-class:: classref-item-separator

----

.. _class_Crypto_method_hmac_digest:

.. rst-class:: classref-method

:ref:`PackedByteArray<class_PackedByteArray>` **hmac_digest**\ (\ hash_type\: :ref:`HashType<enum_HashingContext_HashType>`, key\: :ref:`PackedByteArray<class_PackedByteArray>`, msg\: :ref:`PackedByteArray<class_PackedByteArray>`\ ) :ref:`🔗<class_Crypto_method_hmac_digest>`

Generates an `HMAC <https://en.wikipedia.org/wiki/HMAC>`__ digest of ``msg`` using ``key``. The ``hash_type`` parameter is the hashing algorithm that is used for the inner and outer hashes.

Currently, only :ref:`HashingContext.HASH_SHA256<class_HashingContext_constant_HASH_SHA256>` and :ref:`HashingContext.HASH_SHA1<class_HashingContext_constant_HASH_SHA1>` are supported.

.. rst-class:: classref-item-separator

----

.. _class_Crypto_method_sign:

.. rst-class:: classref-method

:ref:`PackedByteArray<class_PackedByteArray>` **sign**\ (\ hash_type\: :ref:`HashType<enum_HashingContext_HashType>`, hash\: :ref:`PackedByteArray<class_PackedByteArray>`, key\: :ref:`CryptoKey<class_CryptoKey>`\ ) :ref:`🔗<class_Crypto_method_sign>`

Sign a given ``hash`` of type ``hash_type`` with the provided private ``key``.

.. rst-class:: classref-item-separator

----

.. _class_Crypto_method_verify:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **verify**\ (\ hash_type\: :ref:`HashType<enum_HashingContext_HashType>`, hash\: :ref:`PackedByteArray<class_PackedByteArray>`, signature\: :ref:`PackedByteArray<class_PackedByteArray>`, key\: :ref:`CryptoKey<class_CryptoKey>`\ ) :ref:`🔗<class_Crypto_method_verify>`

Verify that a given ``signature`` for ``hash`` of type ``hash_type`` against the provided public ``key``.

.. |virtual| replace:: :abbr:`virtual (This method should typically be overridden by the user to have any effect.)`
.. |const| replace:: :abbr:`const (This method has no side effects. It doesn't modify any of the instance's member variables.)`
.. |vararg| replace:: :abbr:`vararg (This method accepts any number of arguments after the ones described here.)`
.. |constructor| replace:: :abbr:`constructor (This method is used to construct a type.)`
.. |static| replace:: :abbr:`static (This method doesn't need an instance to be called, so it can be called directly using the class name.)`
.. |operator| replace:: :abbr:`operator (This method describes a valid operator to use with this type as left-hand operand.)`
.. |bitfield| replace:: :abbr:`BitField (This value is an integer composed as a bitmask of the following flags.)`
.. |void| replace:: :abbr:`void (No return value.)`