Initial commit

venv/Lib/site-packages/jose/backends/_asn1.py

@@ -0,0 +1,83 @@
+"""ASN1 encoding helpers for converting between PKCS1 and PKCS8.
+
+Required by rsa_backend but not cryptography_backend.
+"""
+from pyasn1.codec.der import decoder, encoder
+from pyasn1.type import namedtype, univ
+
+RSA_ENCRYPTION_ASN1_OID = "1.2.840.113549.1.1.1"
+
+
+class RsaAlgorithmIdentifier(univ.Sequence):
+    """ASN1 structure for recording RSA PrivateKeyAlgorithm identifiers."""
+
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType("rsaEncryption", univ.ObjectIdentifier()), namedtype.NamedType("parameters", univ.Null())
+    )
+
+
+class PKCS8PrivateKey(univ.Sequence):
+    """ASN1 structure for recording PKCS8 private keys."""
+
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType("version", univ.Integer()),
+        namedtype.NamedType("privateKeyAlgorithm", RsaAlgorithmIdentifier()),
+        namedtype.NamedType("privateKey", univ.OctetString()),
+    )
+
+
+class PublicKeyInfo(univ.Sequence):
+    """ASN1 structure for recording PKCS8 public keys."""
+
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType("algorithm", RsaAlgorithmIdentifier()), namedtype.NamedType("publicKey", univ.BitString())
+    )
+
+
+def rsa_private_key_pkcs8_to_pkcs1(pkcs8_key):
+    """Convert a PKCS8-encoded RSA private key to PKCS1."""
+    decoded_values = decoder.decode(pkcs8_key, asn1Spec=PKCS8PrivateKey())
+
+    try:
+        decoded_key = decoded_values[0]
+    except IndexError:
+        raise ValueError("Invalid private key encoding")
+
+    return decoded_key["privateKey"]
+
+
+def rsa_private_key_pkcs1_to_pkcs8(pkcs1_key):
+    """Convert a PKCS1-encoded RSA private key to PKCS8."""
+    algorithm = RsaAlgorithmIdentifier()
+    algorithm["rsaEncryption"] = RSA_ENCRYPTION_ASN1_OID
+
+    pkcs8_key = PKCS8PrivateKey()
+    pkcs8_key["version"] = 0
+    pkcs8_key["privateKeyAlgorithm"] = algorithm
+    pkcs8_key["privateKey"] = pkcs1_key
+
+    return encoder.encode(pkcs8_key)
+
+
+def rsa_public_key_pkcs1_to_pkcs8(pkcs1_key):
+    """Convert a PKCS1-encoded RSA private key to PKCS8."""
+    algorithm = RsaAlgorithmIdentifier()
+    algorithm["rsaEncryption"] = RSA_ENCRYPTION_ASN1_OID
+
+    pkcs8_key = PublicKeyInfo()
+    pkcs8_key["algorithm"] = algorithm
+    pkcs8_key["publicKey"] = univ.BitString.fromOctetString(pkcs1_key)
+
+    return encoder.encode(pkcs8_key)
+
+
+def rsa_public_key_pkcs8_to_pkcs1(pkcs8_key):
+    """Convert a PKCS8-encoded RSA private key to PKCS1."""
+    decoded_values = decoder.decode(pkcs8_key, asn1Spec=PublicKeyInfo())
+
+    try:
+        decoded_key = decoded_values[0]
+    except IndexError:
+        raise ValueError("Invalid public key encoding.")
+
+    return decoded_key["publicKey"].asOctets()