Strict DEFAULT check in evgen mode

[pyderasn.git] / pyderasn.py

diff --git a/pyderasn.py b/pyderasn.py
index 62e884ba9357bfc49f21f77c19c7cd90fe21f954..60d9cf0513f89503afeb749cab4e43c932c00993 100755 (executable)
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -665,6 +665,11 @@ parse the CRL above with fully assembled ``RevokedCertificate``::
         ):
             print("serial number:", int(obj["userCertificate"]))
 
+.. note::
+
+   SEQUENCE/SET values with DEFAULT specified are automatically decoded
+   without evgen mode.
+
 .. _mmap:
 
 mmap-ed file
@@ -1180,7 +1185,7 @@ except ImportError:  # pragma: no cover
     def colored(what, *args, **kwargs):
         return what
 
-__version__ = "7.2"
+__version__ = "7.3"
 
 __all__ = (
     "agg_octet_string",
@@ -6195,11 +6200,10 @@ class Sequence(SequenceEncode1stMixing, Obj):
     defaulted values existence validation by setting
     ``"allow_default_values": True`` :ref:`context <ctx>` option.
 
-    .. warning::
-
-       Check for default value existence is not performed in
-       ``evgen_mode``, because previously decoded values are not stored
-       in memory, to be able to compare them.
+    All values with DEFAULT specified are decoded atomically in
+    :ref:`evgen mode <evgen_mode>`. If DEFAULT value is some kind of
+    SEQUENCE, then it will be yielded as a single element, not
+    disassembled. That is required for DEFAULT existence check.
 
     Two sequences are equal if they have equal specification (schema),
     implicit/explicit tagging and the same values.
@@ -6425,9 +6429,10 @@ class Sequence(SequenceEncode1stMixing, Obj):
                     len(v) == 0
             ):
                 continue
+            spec_defaulted = spec.default is not None
             sub_decode_path = decode_path + (name,)
             try:
-                if evgen_mode:
+                if evgen_mode and not spec_defaulted:
                     for _decode_path, value, v_tail in spec.decode_evgen(
                             v,
                             sub_offset,
@@ -6505,9 +6510,10 @@ class Sequence(SequenceEncode1stMixing, Obj):
             vlen += value_len
             sub_offset += value_len
             v = v_tail
-            if not evgen_mode:
-                if spec.default is not None and value == spec.default:
-                    # This will not work in evgen_mode
+            if spec_defaulted:
+                if evgen_mode:
+                    yield sub_decode_path, value, v_tail
+                if value == spec.default:
                     if ctx_bered or ctx_allow_default_values:
                         ber_encoded = True
                     else:
@@ -6517,6 +6523,7 @@ class Sequence(SequenceEncode1stMixing, Obj):
                             decode_path=sub_decode_path,
                             offset=sub_offset,
                         )
+            if not evgen_mode:
                 values[name] = value
                 spec_defines = getattr(spec, "defines", ())
                 if len(spec_defines) == 0:
@@ -6716,7 +6723,8 @@ class Set(Sequence, SequenceEncode1stMixing):
                     decode_path=decode_path,
                     offset=offset,
                 )
-            if evgen_mode:
+            spec_defaulted = spec.default is not None
+            if evgen_mode and not spec_defaulted:
                 for _decode_path, value, v_tail in spec.decode_evgen(
                         v,
                         sub_offset,
@@ -6748,17 +6756,20 @@ class Set(Sequence, SequenceEncode1stMixing):
                         decode_path=sub_decode_path,
                         offset=sub_offset,
                     )
-            if spec.default is None or value != spec.default:
-                pass
-            elif ctx_bered or ctx_allow_default_values:
-                ber_encoded = True
-            else:
-                raise DecodeError(
-                    "DEFAULT value met",
-                    klass=self.__class__,
-                    decode_path=sub_decode_path,
-                    offset=sub_offset,
-                )
+            if spec_defaulted:
+                if evgen_mode:
+                    yield sub_decode_path, value, v_tail
+                if value != spec.default:
+                    pass
+                elif ctx_bered or ctx_allow_default_values:
+                    ber_encoded = True
+                else:
+                    raise DecodeError(
+                        "DEFAULT value met",
+                        klass=self.__class__,
+                        decode_path=sub_decode_path,
+                        offset=sub_offset,
+                    )
             values[name] = value
             del _specs_items[name]
             tag_order_prev = value_tag_order