Danger

This is a “Hazardous Materials” module. You should ONLY use it if you’re 100% absolutely sure that you know what you’re doing because this module is full of land mines, dragons, and dinosaurs with laser guns.

Ed25519 signing

Ed25519 is an elliptic curve signing algorithm using EdDSA and Curve25519. If you do not have legacy interoperability concerns then you should strongly consider using this signature algorithm.

Signing & Verification

>>> from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
>>> private_key = Ed25519PrivateKey.generate()
>>> signature = private_key.sign(b"my authenticated message")
>>> public_key = private_key.public_key()
>>> # Raises InvalidSignature if verification fails
>>> public_key.verify(signature, b"my authenticated message")

Key interfaces

class cryptography.hazmat.primitives.asymmetric.ed25519.Ed25519PrivateKey

New in version 2.6.

classmethod generate()

Generate an Ed25519 private key.

Returns:

Ed25519PrivateKey

classmethod from_private_bytes(data)

Parameters:

data (bytes-like) – 32 byte private key.

Returns:

Ed25519PrivateKey

Raises:

• ValueError – This is raised if the private key is not 32 bytes long.

• cryptography.exceptions.UnsupportedAlgorithm – If Ed25519 is not supported by the OpenSSL version cryptography is using.

>>> from cryptography.hazmat.primitives import serialization
>>> from cryptography.hazmat.primitives.asymmetric import ed25519
>>> private_key = ed25519.Ed25519PrivateKey.generate()
>>> private_bytes = private_key.private_bytes(
...     encoding=serialization.Encoding.Raw,
...     format=serialization.PrivateFormat.Raw,
...     encryption_algorithm=serialization.NoEncryption()
... )
>>> loaded_private_key = ed25519.Ed25519PrivateKey.from_private_bytes(private_bytes)

public_key()

Returns:

Ed25519PublicKey

sign(data)

Parameters:

data (bytes) – The data to sign.

Returns bytes:

The 64 byte signature.

private_bytes(encoding, format, encryption_algorithm)

Allows serialization of the key to bytes. Encoding ( PEM, DER, or Raw) and format ( PKCS8, OpenSSH or Raw ) are chosen to define the exact serialization.

Parameters:

• encoding – A value from the Encoding enum.

• format – A value from the PrivateFormat enum. If the encoding is Raw then format must be Raw , otherwise it must be PKCS8 or OpenSSH.

• encryption_algorithm – An instance of an object conforming to the KeySerializationEncryption interface.

Return bytes:

Serialized key.

class cryptography.hazmat.primitives.asymmetric.ed25519.Ed25519PublicKey

New in version 2.6.

classmethod from_public_bytes(data)

Parameters:

data (bytes) – 32 byte public key.

Returns:

Ed25519PublicKey

Raises:

• ValueError – This is raised if the public key is not 32 bytes long.

• cryptography.exceptions.UnsupportedAlgorithm – If Ed25519 is not supported by the OpenSSL version cryptography is using.

>>> from cryptography.hazmat.primitives import serialization
>>> from cryptography.hazmat.primitives.asymmetric import ed25519
>>> private_key = ed25519.Ed25519PrivateKey.generate()
>>> public_key = private_key.public_key()
>>> public_bytes = public_key.public_bytes(
...     encoding=serialization.Encoding.Raw,
...     format=serialization.PublicFormat.Raw
... )
>>> loaded_public_key = ed25519.Ed25519PublicKey.from_public_bytes(public_bytes)

public_bytes(encoding, format)

Allows serialization of the key to bytes. Encoding ( PEM, DER, OpenSSH, or Raw) and format ( SubjectPublicKeyInfo, OpenSSH , or Raw ) are chosen to define the exact serialization.

Parameters:

• encoding – A value from the Encoding enum.

• format – A value from the PublicFormat enum. If the encoding is Raw then format must be Raw. If encoding is OpenSSH then format must be OpenSSH. In all other cases format must be SubjectPublicKeyInfo.

Returns bytes:

The public key bytes.

verify(signature, data)

Parameters:

• signature (bytes) – The signature to verify.

• data (bytes) – The data to verify.

Raises:

cryptography.exceptions.InvalidSignature – Raised when the signature cannot be verified.