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Use Enum with Tag for pretty repr #285

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Merged
merged 1 commit into from
Feb 20, 2025
Merged

Use Enum with Tag for pretty repr #285

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28 changes: 25 additions & 3 deletions src/asn1.py
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Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,16 @@
__version__ = "2.7.1"


class Numbers(IntEnum):
class HexEnum(IntEnum):
def __repr__(self):
return '<{cls}.{name}: 0x{value:02x}>'.format(
cls=type(self).__name__,
name=self.name,
value=self.value
)


class Numbers(HexEnum):
Boolean = 0x01
Integer = 0x02
BitString = 0x03
Expand All @@ -47,12 +56,12 @@ class Numbers(IntEnum):
UnicodeString = 0x1e


class Types(IntEnum):
class Types(HexEnum):
Constructed = 0x20
Primitive = 0x00


class Classes(IntEnum):
class Classes(HexEnum):
Universal = 0x00
Application = 0x40
Context = 0x80
Expand Down Expand Up @@ -551,6 +560,19 @@ def _read_tag(self): # type: () -> Tag
nr = (nr << 7) | (byte & 0x7f)
if not byte & 0x80:
break
try:
typ = Types(typ)
except ValueError:
pass
try:
cls = Classes(cls)
except ValueError:
pass
if cls == Classes.Universal:
try:
nr = Numbers(nr)
except ValueError:
pass
return Tag(nr=nr, typ=typ, cls=cls)

def _read_length(self): # type: () -> int
Expand Down
16 changes: 16 additions & 0 deletions tests/test_asn1.py
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Original file line number Diff line number Diff line change
Expand Up @@ -392,6 +392,7 @@ def test_boolean(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.Boolean, asn1.Types.Primitive, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.Boolean: 0x01>, typ=<Types.Primitive: 0x00>, cls=<Classes.Universal: 0x00>)"
tag, val = dec.read()
assert isinstance(val, int)
assert val
Expand All @@ -412,6 +413,7 @@ def test_integer(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.Integer, asn1.Types.Primitive, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.Integer: 0x02>, typ=<Types.Primitive: 0x00>, cls=<Classes.Universal: 0x00>)"
tag, val = dec.read()
assert isinstance(val, int)
assert val == 1
Expand Down Expand Up @@ -462,6 +464,7 @@ def test_octet_string(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.OctetString, asn1.Types.Primitive, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.OctetString: 0x04>, typ=<Types.Primitive: 0x00>, cls=<Classes.Universal: 0x00>)"
tag, val = dec.read()
assert val == b'foo'

Expand All @@ -471,6 +474,7 @@ def test_printable_string(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.PrintableString, asn1.Types.Primitive, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.PrintableString: 0x13>, typ=<Types.Primitive: 0x00>, cls=<Classes.Universal: 0x00>)"
tag, val = dec.read()
assert val == u'foo'

Expand All @@ -480,6 +484,7 @@ def test_bitstring(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.BitString, asn1.Types.Primitive, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.BitString: 0x03>, typ=<Types.Primitive: 0x00>, cls=<Classes.Universal: 0x00>)"
tag, val = dec.read()
assert val == b'\x12\x34\x56'

Expand All @@ -489,6 +494,7 @@ def test_bitstring_unused_bits(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.BitString, asn1.Types.Primitive, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.BitString: 0x03>, typ=<Types.Primitive: 0x00>, cls=<Classes.Universal: 0x00>)"
tag, val = dec.read()
assert val == b'\x01\x23\x45'

Expand All @@ -498,6 +504,7 @@ def test_unicode_printable_string(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.PrintableString, asn1.Types.Primitive, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.PrintableString: 0x13>, typ=<Types.Primitive: 0x00>, cls=<Classes.Universal: 0x00>)"
tag, val = dec.read()
assert val == u'fooé'

Expand All @@ -507,6 +514,7 @@ def test_null(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.Null, asn1.Types.Primitive, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.Null: 0x05>, typ=<Types.Primitive: 0x00>, cls=<Classes.Universal: 0x00>)"
tag, val = dec.read()
assert val is None

Expand Down Expand Up @@ -552,6 +560,7 @@ def test_enumerated(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.Enumerated, asn1.Types.Primitive, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.Enumerated: 0x0a>, typ=<Types.Primitive: 0x00>, cls=<Classes.Universal: 0x00>)"
tag, val = dec.read()
assert isinstance(val, int)
assert val == 1
Expand All @@ -562,6 +571,7 @@ def test_sequence(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.Sequence, asn1.Types.Constructed, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.Sequence: 0x10>, typ=<Types.Constructed: 0x20>, cls=<Classes.Universal: 0x00>)"
dec.enter()
tag, val = dec.read()
assert val == 1
Expand All @@ -574,6 +584,7 @@ def test_sequence_of(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.Sequence, asn1.Types.Constructed, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.Sequence: 0x10>, typ=<Types.Constructed: 0x20>, cls=<Classes.Universal: 0x00>)"
dec.enter()
tag, val = dec.read()
assert val == 1
Expand All @@ -586,6 +597,7 @@ def test_set(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.Set, asn1.Types.Constructed, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.Set: 0x11>, typ=<Types.Constructed: 0x20>, cls=<Classes.Universal: 0x00>)"
dec.enter()
tag, val = dec.read()
assert val == 1
Expand All @@ -598,6 +610,7 @@ def test_set_of(self):
dec.start(buf)
tag = dec.peek()
assert tag == (asn1.Numbers.Set, asn1.Types.Constructed, asn1.Classes.Universal)
assert str(tag) == "Tag(nr=<Numbers.Set: 0x11>, typ=<Types.Constructed: 0x20>, cls=<Classes.Universal: 0x00>)"
dec.enter()
tag, val = dec.read()
assert val == 1
Expand All @@ -610,6 +623,7 @@ def test_context(self):
dec.start(buf)
tag = dec.peek()
assert tag == (1, asn1.Types.Constructed, asn1.Classes.Context)
assert str(tag) == "Tag(nr=1, typ=<Types.Constructed: 0x20>, cls=<Classes.Context: 0x80>)"
dec.enter()
tag, val = dec.read()
assert val == 1
Expand All @@ -620,6 +634,7 @@ def test_application(self):
dec.start(buf)
tag = dec.peek()
assert tag == (1, asn1.Types.Constructed, asn1.Classes.Application)
assert str(tag) == "Tag(nr=1, typ=<Types.Constructed: 0x20>, cls=<Classes.Application: 0x40>)"
dec.enter()
tag, val = dec.read()
assert val == 1
Expand All @@ -630,6 +645,7 @@ def test_private(self):
dec.start(buf)
tag = dec.peek()
assert tag == (1, asn1.Types.Constructed, asn1.Classes.Private)
assert str(tag) == "Tag(nr=1, typ=<Types.Constructed: 0x20>, cls=<Classes.Private: 0xc0>)"
dec.enter()
tag, val = dec.read()
assert val == 1
Expand Down