initial support for P-256K and ES256K per RFC 8812

Author: jschlyter

src/cryptojwt/jwk/__init__.py

@@ -69,6 +69,7 @@ def __init__(
                     "RS384",
                     "RS512",
                     "ES256",
+                    "ES256K",
                     "ES384",
                     "ES512",
                     "PS256",
@@ -86,6 +87,7 @@ def __init__(
                     "RS384",
                     "RS512",
                     "ES256",
+                    "ES256K",
                     "ES384",
                     "ES512",
                     "PS256",

src/cryptojwt/jwk/ec.py

@@ -28,6 +28,7 @@
     "P-256": ec.SECP256R1,
     "P-224": ec.SECP224R1,
     "P-192": ec.SECP192R1,
+    "P-256K": ec.SECP256K1,
 }
 
 # Inverted NIST2SEC dictionary

src/cryptojwt/jws/dsa.py

@@ -16,6 +16,9 @@ def __init__(self, algorithm="ES256"):
         if algorithm == "ES256":
             self.hash_algorithm = hashes.SHA256
             self.curve_name = "secp256r1"
+        elif algorithm == "ES256K":
+            self.hash_algorithm = hashes.SHA256
+            self.curve_name = "secp256k1"
         elif algorithm == "ES384":
             self.hash_algorithm = hashes.SHA384
             self.curve_name = "secp384r1"

src/cryptojwt/jws/jws.py

@@ -41,6 +41,7 @@
     "RS384": RSASigner("RS384"),
     "RS512": RSASigner("RS512"),
     "ES256": ECDSASigner("ES256"),
+    "ES256K": ECDSASigner("ES256K"),
     "ES384": ECDSASigner("ES384"),
     "ES512": ECDSASigner("ES512"),
     "PS256": PSSSigner("SHA256"),

src/cryptojwt/key_bundle.py

@@ -1364,6 +1364,8 @@ def key_by_alg(alg: str):
     elif alg.startswith("ES"):
         if alg == "ES256":
             return key_gen("EC", crv="P-256")
+        elif alg == "ES256K":
+            return key_gen("EC", crv="P-256K")
         elif alg == "ES384":
             return key_gen("EC", crv="P-384")
         elif alg == "ES512":