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Fixed bad zero-padding in BitString.

This commit is contained in:
Josef 2020-09-09 13:39:33 +02:00
parent 978e7e066d
commit f5a2cba1f9
1 changed files with 52 additions and 26 deletions
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78
pycrate_asn1rt/asnobj_str.py
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@ -1062,18 +1062,24 @@ Specific constraints attributes:
Cont._val = self._val[1]
buf = Cont.to_oer()
l_val = len(buf) * 8
pad_bits = 0
_gen = [(T_BYTES, buf, l_val)]
if Cont == self._const_cont:
return _gen
else:
# 2) value is the standard (uint, bit length)
if self._val[1]:
buf, l_val = uint_to_bytes(self._val[0], self._val[1]), self._val[1]
l_val = self._val[1]
_gen = [(T_UINT, self._val[0], l_val)]
# padding bits
pad_bits = (l_val % 8)
pad_bits = (8 - pad_bits) if pad_bits else 0
_gen.append((T_UINT, 0, pad_bits))
else:
# empty bit string
buf = b''
pad_bits = 0
l_val = 0
_gen = [(T_BYTES, buf, len(buf)*8)]
_gen = [(T_BYTES, b'', l_val)]
if self._const_sz:
if (self._const_sz._ev is None) and (self._const_sz.ra == 1):
@ -1081,8 +1087,9 @@ Specific constraints attributes:
return _gen
# Variable size constrains
GEN = ASN1CodecOER.encode_length_determinant(len(buf)+1)
GEN.append((T_UINT, (len(buf) * 8) - l_val, 8)) # Initial octet
GEN = ASN1CodecOER.encode_length_determinant(((l_val + pad_bits) // 8)
+ 1)
GEN.append((T_UINT, pad_bits, 8)) # Initial octet
GEN.extend(_gen)
return GEN
@ -1102,40 +1109,49 @@ Specific constraints attributes:
Cont._val = self._val[1]
buf = Cont.to_oer()
l_val = len(buf) * 8
_gen = (Buf('V', val=buf, bl=l_val),)
pad_bits = 0
_gen = [Buf('V', val=buf, bl=l_val)]
if Cont == self._const_cont:
self._struct = Envelope(self._name, GEN=_gen)
self._struct = Envelope(self._name, GEN=tuple(_gen))
return self._struct
else:
# 2) value is the standard (uint, bit length)
if self._val[1]:
buf, l_val = uint_to_bytes(self._val[0], self._val[1]), \
self._val[1]
l_val = self._val[1]
_gen = [Uint('V', val=self._val[0], bl=l_val)]
# padding bits
pad_bits = (l_val % 8)
pad_bits = (8 - pad_bits) if pad_bits else 0
_gen.append(Uint('Zero-pad', val=0, bl=pad_bits))
else:
# empty bit string
buf = b''
pad_bits = 0
l_val = 0
_gen = (Buf('V', val=buf, bl=len(buf)*8),)
_gen = [Buf('V', b'', l_val)]
if self._const_sz:
if (self._const_sz._ev is None) and (self._const_sz.ra == 1):
# Fixed size constrains
self._struct = Envelope(self._name, GEN=_gen)
self._struct = Envelope(self._name, GEN=tuple(_gen))
return self._struct
# Variable size constrains
GEN = ASN1CodecOER.encode_length_determinant_ws(len(buf) + 1)
GEN.append(Uint('Initial octet', val=(len(buf) * 8) - l_val, bl=8))
GEN = [ASN1CodecOER.encode_length_determinant_ws(
((l_val + pad_bits) // 8) + 1)]
GEN.append(Uint('Initial octet', val=pad_bits, bl=8))
GEN.extend(_gen)
self._struct = Envelope(self._name, GEN=(GEN,))
self._struct = Envelope(self._name, GEN=tuple(GEN))
return self._struct
def _from_oer(self, char):
if self._const_sz:
if (self._const_sz._ev is None) and (self._const_sz.ra == 1):
# Fixed
buf = char.get_uint(self._const_sz.lb)
self._val = (buf, self._const_sz.lb)
l_val = self._const_sz.lb
pad_bits = (l_val % 8)
pad_bits = (8 - pad_bits) if pad_bits else 0
buf = char.get_uint(l_val+pad_bits)
self._val = (buf >> pad_bits, l_val)
return
elif self._const_cont:
# Contained by constraint
@ -1146,18 +1162,23 @@ Specific constraints attributes:
# Variable size constraints
l_det = ASN1CodecOER.decode_length_determinant(char)
i_oct = char.get_uint(8)
l_val = 8*(l_det - 1) - i_oct
self._val = (char.get_uint(l_val), l_val)
pad_bits = char.get_uint(8)
l_val = 8*(l_det - 1) - pad_bits
self._val = (char.get_uint(l_val+pad_bits) >> pad_bits, l_val)
def _from_oer_ws(self, char):
if self._const_sz:
if (self._const_sz._ev is None) and (self._const_sz.ra == 1):
# Fixed
val = Uint('V', bl=self._const_sz.lb)
l_val = self._const_sz.lb
pad_bits = (l_val % 8)
pad_bits = (8 - pad_bits) if pad_bits else 0
val = Uint('V', bl=l_val)
val._from_char(char)
zero_pad = Uint('Zero-pad', bl=pad_bits)
zero_pad._from_char(char)
self._val = (val.get_val(), val.get_bl())
self._struct = Envelope(self._name, GEN=(val,))
self._struct = Envelope(self._name, GEN=(val, zero_pad))
return
elif self._const_cont:
# Contained by constraint
@ -1169,14 +1190,19 @@ Specific constraints attributes:
return
# Variable size constraints
l_val, _gen = ASN1CodecOER.decode_length_determinant_ws(char)
l_det, _gen = ASN1CodecOER.decode_length_determinant_ws(char)
_gen = [_gen]
i_oct = Uint('Initial octet', bl=8)
i_oct._from_char(char)
val = Uint('V', bl=8*(l_val - 1) - i_oct.get_val())
pad_bits = i_oct.get_val()
l_val = 8*(l_det - 1) - pad_bits
val = Uint('V', bl=l_val)
val._from_char(char)
_gen.extend((i_oct, val))
zero_pad = Uint('Zero-pad', bl=pad_bits)
zero_pad._from_char(char)
_gen.extend((i_oct, val, zero_pad))
self._val = (val.get_val(), val.get_bl())
self._struct = Envelope(self._name, GEN=(_gen,))
self._struct = Envelope(self._name, GEN=tuple(_gen))
class OCT_STR(ASN1Obj):