ed25519.rst

Ed25519 signing

cryptography.hazmat.primitives.asymmetric.ed25519

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

2.6

generate()

Generate an Ed25519 private key.

returns

Ed25519PrivateKey

from_private_bytes(data)

param data

32 byte private key.

type data

bytes-like

returns

Ed25519PrivateKey

raises ValueError

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

raises 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)

param bytes data

The data to sign.

returns bytes

The 64 byte signature.

private_bytes(encoding, format, encryption_algorithm)

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

param encoding

A value from the ~cryptography.hazmat.primitives.serialization.Encoding enum.

param format

A value from the ~cryptography.hazmat.primitives.serialization.PrivateFormat enum. If the encoding is ~cryptography.hazmat.primitives.serialization.Encoding.Raw then format must be ~cryptography.hazmat.primitives.serialization.PrivateFormat.Raw , otherwise it must be ~cryptography.hazmat.primitives.serialization.PrivateFormat.PKCS8 or ~cryptography.hazmat.primitives.serialization.PrivateFormat.OpenSSH.

param encryption_algorithm

An instance of an object conforming to the ~cryptography.hazmat.primitives.serialization.KeySerializationEncryption interface.

return bytes

Serialized key.

2.6

from_public_bytes(data)

param bytes data

32 byte public key.

returns

Ed25519PublicKey

raises ValueError

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

raises 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 ( ~cryptography.hazmat.primitives.serialization.Encoding.PEM, ~cryptography.hazmat.primitives.serialization.Encoding.DER, ~cryptography.hazmat.primitives.serialization.Encoding.OpenSSH, or ~cryptography.hazmat.primitives.serialization.Encoding.Raw) and format ( ~cryptography.hazmat.primitives.serialization.PublicFormat.SubjectPublicKeyInfo, ~cryptography.hazmat.primitives.serialization.PublicFormat.OpenSSH , or ~cryptography.hazmat.primitives.serialization.PublicFormat.Raw ) are chosen to define the exact serialization.

param encoding

A value from the ~cryptography.hazmat.primitives.serialization.Encoding enum.

param format

A value from the ~cryptography.hazmat.primitives.serialization.PublicFormat enum. If the encoding is ~cryptography.hazmat.primitives.serialization.Encoding.Raw then format must be ~cryptography.hazmat.primitives.serialization.PublicFormat.Raw. If encoding is ~cryptography.hazmat.primitives.serialization.Encoding.OpenSSH then format must be ~cryptography.hazmat.primitives.serialization.PublicFormat.OpenSSH. In all other cases format must be ~cryptography.hazmat.primitives.serialization.PublicFormat.SubjectPublicKeyInfo.

returns bytes

The public key bytes.

verify(signature, data)

param bytes signature

The signature to verify.

param bytes data

The data to verify.

raises cryptography.exceptions.InvalidSignature

Raised when the signature cannot be verified.