cryptography is always available

asyncua/common/connection.py

@@ -7,13 +7,7 @@ import copy
 from asyncua import ua
 from asyncua.ua.uaerrors import UaInvalidParameterError
 from ..ua.ua_binary import struct_from_binary, struct_to_binary, header_from_binary, header_to_binary
-
-try:
-    from ..crypto.uacrypto import InvalidSignature
-except ImportError:
-
-    class InvalidSignature(Exception):  # type: ignore
-        pass
+from ..crypto.uacrypto import InvalidSignature
 
 
 _logger = logging.getLogger("asyncua.uaprotocol")

asyncua/crypto/security_policies.py

@@ -4,28 +4,13 @@ import time
 
 from abc import ABCMeta, abstractmethod
 from ..ua import CryptographyNone, SecurityPolicy, MessageSecurityMode, UaError
-
-try:
-    from ..crypto import uacrypto
-
-    CRYPTOGRAPHY_AVAILABLE = True
-except ImportError:
-    CRYPTOGRAPHY_AVAILABLE = False
+from ..crypto import uacrypto
 
 
 POLICY_NONE_URI = "http://opcfoundation.org/UA/SecurityPolicy#None"
 _logger = logging.getLogger(__name__)
 
 
-def require_cryptography(obj):
-    """
-    Raise exception if cryptography module is not available.
-    Call this function in constructors.
-    """
-    if not CRYPTOGRAPHY_AVAILABLE:
-        raise UaError(f"Can't use {obj.__class__.__name__}, cryptography module is not installed")
-
-
 class Signer:
     """
     Abstract base class for cryptographic signature algorithm
@@ -237,7 +222,6 @@ class Cryptography(CryptographyNone):
 
 class SignerRsa(Signer):
     def __init__(self, client_pk):
-        require_cryptography(self)
         self.client_pk = client_pk
         self.key_size = self.client_pk.key_size // 8
 
@@ -250,7 +234,6 @@ class SignerRsa(Signer):
 
 class VerifierRsa(Verifier):
     def __init__(self, server_cert):
-        require_cryptography(self)
         self.server_cert = server_cert
         self.key_size = self.server_cert.public_key().key_size // 8
 
@@ -263,7 +246,6 @@ class VerifierRsa(Verifier):
 
 class EncryptorRsa(Encryptor):
     def __init__(self, server_cert, enc_fn, padding_size):
-        require_cryptography(self)
         self.server_cert = server_cert
         self.key_size = self.server_cert.public_key().key_size // 8
         self.encryptor = enc_fn
@@ -285,7 +267,6 @@ class EncryptorRsa(Encryptor):
 
 class DecryptorRsa(Decryptor):
     def __init__(self, client_pk, dec_fn, padding_size):
-        require_cryptography(self)
         self.client_pk = client_pk
         self.key_size = self.client_pk.key_size // 8
         self.decryptor = dec_fn
@@ -307,7 +288,6 @@ class DecryptorRsa(Decryptor):
 
 class SignerAesCbc(Signer):
     def __init__(self, key):
-        require_cryptography(self)
         self.key = key
 
     def signature_size(self):
@@ -319,7 +299,6 @@ class SignerAesCbc(Signer):
 
 class VerifierAesCbc(Verifier):
     def __init__(self, key):
-        require_cryptography(self)
         self.key = key
 
     def signature_size(self):
@@ -333,7 +312,6 @@ class VerifierAesCbc(Verifier):
 
 class EncryptorAesCbc(Encryptor):
     def __init__(self, key, init_vec):
-        require_cryptography(self)
         self.cipher = uacrypto.cipher_aes_cbc(key, init_vec)
 
     def plain_block_size(self):
@@ -348,7 +326,6 @@ class EncryptorAesCbc(Encryptor):
 
 class DecryptorAesCbc(Decryptor):
     def __init__(self, key, init_vec):
-        require_cryptography(self)
         self.cipher = uacrypto.cipher_aes_cbc(key, init_vec)
 
     def plain_block_size(self):
@@ -363,7 +340,6 @@ class DecryptorAesCbc(Decryptor):
 
 class SignerSha256(Signer):
     def __init__(self, client_pk):
-        require_cryptography(self)
         self.client_pk = client_pk
         self.key_size = self.client_pk.key_size // 8
 
@@ -376,7 +352,6 @@ class SignerSha256(Signer):
 
 class VerifierSha256(Verifier):
     def __init__(self, server_cert):
-        require_cryptography(self)
         self.server_cert = server_cert
         self.key_size = self.server_cert.public_key().key_size // 8
 
@@ -389,7 +364,6 @@ class VerifierSha256(Verifier):
 
 class SignerHMac256(Signer):
     def __init__(self, key):
-        require_cryptography(self)
         self.key = key
 
     def signature_size(self):
@@ -401,7 +375,6 @@ class SignerHMac256(Signer):
 
 class VerifierHMac256(Verifier):
     def __init__(self, key):
-        require_cryptography(self)
         self.key = key
 
     def signature_size(self):
@@ -415,7 +388,6 @@ class VerifierHMac256(Verifier):
 
 class SignerPssSha256(Signer):
     def __init__(self, client_pk):
-        require_cryptography(self)
         self.client_pk = client_pk
         self.key_size = self.client_pk.key_size // 8
 
@@ -428,7 +400,6 @@ class SignerPssSha256(Signer):
 
 class VerifierPssSha256(Verifier):
     def __init__(self, server_cert):
-        require_cryptography(self)
         self.server_cert = server_cert
         self.key_size = self.server_cert.public_key().key_size // 8
 
@@ -476,7 +447,6 @@ class SecurityPolicyAes128Sha256RsaOaep(SecurityPolicy):
         return uacrypto.encrypt_rsa_oaep(pubkey, data)
 
     def __init__(self, peer_cert, host_cert, client_pk, mode, permission_ruleset=None):
-        require_cryptography(self)
         if isinstance(peer_cert, bytes):
             peer_cert = uacrypto.x509_from_der(peer_cert)
         # even in Sign mode we need to asymmetrically encrypt secrets
@@ -550,7 +520,6 @@ class SecurityPolicyAes256Sha256RsaPss(SecurityPolicy):
         return uacrypto.encrypt_rsa_oaep_sha256(pubkey, data)
 
     def __init__(self, peer_cert, host_cert, client_pk, mode, permission_ruleset=None):
-        require_cryptography(self)
         if isinstance(peer_cert, bytes):
             peer_cert = uacrypto.x509_from_der(peer_cert)
         # even in Sign mode we need to asymmetrically encrypt secrets
@@ -632,7 +601,6 @@ class SecurityPolicyBasic128Rsa15(SecurityPolicy):
     def __init__(self, peer_cert, host_cert, client_pk, mode, permission_ruleset=None):
         _logger.warning("DEPRECATED! Do not use SecurityPolicyBasic128Rsa15 anymore!")
 
-        require_cryptography(self)
         if isinstance(peer_cert, bytes):
             peer_cert = uacrypto.x509_from_der(peer_cert)
         # even in Sign mode we need to asymmetrically encrypt secrets
@@ -712,7 +680,6 @@ class SecurityPolicyBasic256(SecurityPolicy):
     def __init__(self, peer_cert, host_cert, client_pk, mode, permission_ruleset=None):
         _logger.warning("DEPRECATED! Do not use SecurityPolicyBasic256 anymore!")
 
-        require_cryptography(self)
         if isinstance(peer_cert, bytes):
             peer_cert = uacrypto.x509_from_der(peer_cert)
         # even in Sign mode we need to asymmetrically encrypt secrets
@@ -790,7 +757,6 @@ class SecurityPolicyBasic256Sha256(SecurityPolicy):
         return uacrypto.encrypt_rsa_oaep(pubkey, data)
 
     def __init__(self, peer_cert, host_cert, client_pk, mode, permission_ruleset=None):
-        require_cryptography(self)
         if isinstance(peer_cert, bytes):
             peer_cert = uacrypto.x509_from_der(peer_cert)
         # even in Sign mode we need to asymmetrically encrypt secrets

asyncua/server/internal_server.py

@@ -24,12 +24,7 @@ from .users import User, UserRole
 from .internal_session import InternalSession
 from .event_generator import EventGenerator
 from ..crypto.validator import CertificateValidatorMethod
-
-try:
-    from asyncua.crypto import uacrypto
-except ImportError:
-    logging.getLogger(__name__).warning("cryptography is not installed, use of crypto disabled")
-    uacrypto = False
+from ..crypto import uacrypto
 
 _logger = logging.getLogger(__name__)
 
@@ -403,9 +398,6 @@ class InternalServer:
 
         # decrypt password if we can
         if str(token.EncryptionAlgorithm) != "None":
-            if not uacrypto:
-                # raise  # Should I raise a significant exception?
-                return False
             try:
                 if token.EncryptionAlgorithm == "http://www.w3.org/2001/04/xmlenc#rsa-1_5":
                     raw_pw = uacrypto.decrypt_rsa15(self.private_key, password)

asyncua/tools.py

@@ -513,10 +513,8 @@ def application_to_strings(app):
 def cert_to_string(der):
     if not der:
         return "[no certificate]"
-    try:
     from .crypto import uacrypto
-    except ImportError:
-        return f"{len(der)} bytes"
+
     cert = uacrypto.x509_from_der(der)
     return uacrypto.x509_to_string(cert)
 

tests/test_crypto_connect.py

@@ -13,15 +13,7 @@ from asyncua import ua
 from asyncua.server.user_managers import CertificateUserManager
 from asyncua.crypto.security_policies import Verifier, Decryptor
 from asyncua.crypto.validator import CertificateValidator, CertificateValidatorOptions
-
-try:
-    from asyncua.crypto import uacrypto
-    from asyncua.crypto import security_policies
-except ImportError:
-    print("WARNING: CRYPTO NOT AVAILABLE, CRYPTO TESTS DISABLED!!")
-    disable_crypto_tests = True
-else:
-    disable_crypto_tests = False
+from asyncua.crypto import uacrypto, security_policies
 
 pytestmark = pytest.mark.asyncio
 

tests/test_permissions.py

@@ -6,14 +6,7 @@ from asyncua import Server
 from asyncua import ua
 from asyncua.server.users import UserRole
 from asyncua.server.user_managers import CertificateUserManager
-
-try:
-    from asyncua.crypto import security_policies
-except ImportError:
-    print("WARNING: CRYPTO NOT AVAILABLE, CRYPTO TESTS DISABLED!!")
-    disable_crypto_tests = True
-else:
-    disable_crypto_tests = False
+from asyncua.crypto import security_policies
 
 pytestmark = pytest.mark.asyncio