Merge branch 'x448'

Changelog.rst

@@ -9,6 +9,7 @@ Under development
 * GH#814: RSA keys for PSS can be imported.
 * GH#810: fixed negation of Ed25519 points
 * Add support for Curve25519 / X25519
+* Add support for Curve448 / X448
 * Add attribute ``curve`` to EccPoint and EccXPoint classes,
   with the canonical name of the curve.
 * GH#781: the label for the SP800_108_Counter KDF may now

Doc/src/features.rst

@@ -65,7 +65,7 @@ A list of useful resources in that area can be found on `Matthew Green's blog`_.
 * Asymmetric key generation:
 
   - RSA
-  - ECC (NIST P-curves; Ed25519, Ed448)
+  - ECC (NIST P-curves; Ed25519, Ed448, Curve25519, Curve448)
   - DSA
   - ElGamal (legacy)
 

Doc/src/public_key/ecc.rst

@@ -54,12 +54,13 @@ You can also export the public key, which is not sensitive::
    "Ed25519",    "``'Ed25519'``", "``'ed25519'``"
    "Ed448",      "``'Ed448'``", "``'ed448'``"
    "Curve25519", "``'Curve25519'``", "``'curve25519'``"
+   "Curve448", "``'Curve448'``", "``'curve448'``"
 
 For more information about each NIST curve see `FIPS 186-4`_, Section D.1.2.
 
-The Ed25519 and the Ed448 curves are defined in RFC8032_.
+Curves Ed25519 and Ed448 are defined in RFC8032_.
 
-The Curve25519 curve is defined in RFC7748_.
+Curves Curve25519 and Curve448 are defined in RFC7748_.
 
 The ECC keys can be used to perform or verify signatures, using the modules
 :mod:`Crypto.Signature.DSS` (ECDSA; NIST curves only)

README.rst

@@ -47,7 +47,7 @@ with respect to the last official version of PyCrypto (2.6.1):
 * Authenticated encryption modes (GCM, CCM, EAX, SIV, OCB)
 * Accelerated AES on Intel platforms via AES-NI
 * First class support for PyPy
-* Elliptic curves cryptography (NIST P-curves; Ed25519, Ed448, Curve25519)
+* Elliptic curves cryptography (NIST P-curves; Ed25519, Ed448, Curve25519, Curve448)
 * Better and more compact API (`nonce` and `iv` attributes for ciphers,
   automatic generation of random nonces and IVs, simplified CTR cipher mode,
   and more)

lib/Crypto/Protocol/DH.py

@@ -1,7 +1,8 @@
 from Crypto.Util.number import long_to_bytes
 from Crypto.PublicKey.ECC import (EccKey,
                                   construct,
-                                  _import_curve25519_public_key)
+                                  _import_curve25519_public_key,
+                                  _import_curve448_public_key)
 
 
 def _compute_ecdh(key_priv, key_pub):
@@ -11,6 +12,8 @@ def _compute_ecdh(key_priv, key_pub):
 
     if key_priv.curve == "Curve25519":
         z = bytearray(pointP.x.to_bytes(32, byteorder='little'))
+    elif key_priv.curve == "Curve448":
+        z = bytearray(pointP.x.to_bytes(56, byteorder='little'))
     else:
         # See Section 5.7.1.2 in NIST SP 800-56Ar3
         z = long_to_bytes(pointP.x, pointP.size_in_bytes())
@@ -58,6 +61,47 @@ def import_x25519_private_key(encoded):
     return construct(seed=encoded, curve="Curve25519")
 
 
+def import_x448_public_key(encoded):
+    """Create a new X448 public key object,
+    starting from the key encoded as raw ``bytes``,
+    in the format described in RFC7748.
+
+    Args:
+      encoded (bytes):
+        The x448 public key to import.
+        It must be 56 bytes.
+
+    Returns:
+      :class:`Crypto.PublicKey.EccKey` : a new ECC key object.
+
+    Raises:
+      ValueError: when the given key cannot be parsed.
+    """
+
+    x = _import_curve448_public_key(encoded)
+    return construct(curve='Curve448', point_x=x)
+
+
+def import_x448_private_key(encoded):
+    """Create a new X448 private key object,
+    starting from the key encoded as raw ``bytes``,
+    in the format described in RFC7748.
+
+    Args:
+      encoded (bytes):
+        The X448 private key to import.
+        It must be 56 bytes.
+
+    Returns:
+      :class:`Crypto.PublicKey.EccKey` : a new ECC key object.
+
+    Raises:
+      ValueError: when the given key cannot be parsed.
+    """
+
+    return construct(seed=encoded, curve="Curve448")
+
+
 def key_agreement(**kwargs):
     """Perform a Diffie-Hellman key agreement.
 

lib/Crypto/Protocol/DH.pyi

@@ -14,4 +14,6 @@ class RequestParams(TypedDict, Generic[T]):
 
 def import_x25519_public_key(encoded: bytes) -> EccKey: ...
 def import_x25519_private_key(encoded: bytes) -> EccKey: ...
+def import_x448_public_key(encoded: bytes) -> EccKey: ...
+def import_x448_private_key(encoded: bytes) -> EccKey: ...
 def key_agreement(**kwargs: Unpack[RequestParams[T]]) -> T: ...