diff options
Diffstat (limited to 'pyasn1/codec/ber/decoder.py')
| -rw-r--r-- | pyasn1/codec/ber/decoder.py | 85 |
1 files changed, 65 insertions, 20 deletions
diff --git a/pyasn1/codec/ber/decoder.py b/pyasn1/codec/ber/decoder.py index 0dc7d01..0f90e26 100644 --- a/pyasn1/codec/ber/decoder.py +++ b/pyasn1/codec/ber/decoder.py @@ -38,12 +38,15 @@ class AbstractSimpleDecoder(AbstractDecoder): def _createComponent(self, asn1Spec, tagSet, value=noValue, nativeMode=False, **options): - if nativeMode: + if nativeMode and value is not noValue: return value - if asn1Spec is None: + + elif asn1Spec is None: return self.protoComponent.clone(value, tagSet=tagSet) + elif value is noValue: return asn1Spec + else: return asn1Spec.clone(value) @@ -119,61 +122,103 @@ class BooleanDecoder(IntegerDecoder): if nativeMode: return value and True or False - return IntegerDecoder._createComponent(self, asn1Spec, tagSet, value and 1 or 0, **options) + return IntegerDecoder._createComponent(self, asn1Spec, tagSet, + value and 1 or 0, nativeMode, **options) class BitStringDecoder(AbstractSimpleDecoder): protoComponent = univ.BitString(()) supportConstructedForm = True + def _createComponent(self, asn1Spec, tagSet, value=noValue, + nativeMode=False, **options): + if nativeMode and value is not noValue: + return str(value) + + return AbstractSimpleDecoder._createComponent(self, asn1Spec, tagSet, value, + nativeMode, **options) + def valueDecoder(self, substrate, asn1Spec, tagSet=None, length=None, state=None, decodeFun=None, substrateFun=None, **options): head, tail = substrate[:length], substrate[length:] + + if substrateFun: + asn1Object = self._createComponent(asn1Spec, tagSet, **options) + return substrateFun(asn1Object, substrate, length) + if tagSet[0].tagFormat == tag.tagFormatSimple: # XXX what tag to check? if not head: raise error.PyAsn1Error('Empty substrate') + trailingBits = oct2int(head[0]) if trailingBits > 7: raise error.PyAsn1Error( 'Trailing bits overflow %s' % trailingBits ) + head = head[1:] - value = self.protoComponent.fromOctetString(head, trailingBits) + value = univ.BitString.SizedInteger.fromOctetString(head, trailingBits) + return self._createComponent(asn1Spec, tagSet, value, **options), tail if not self.supportConstructedForm: raise error.PyAsn1Error('Constructed encoding form prohibited at %s' % self.__class__.__name__) - bitString = self._createComponent(asn1Spec, tagSet, **options) + # All inner fragments are of the same type, treat them as octet string + # TODO: nested constructed encoding won't work + substrateFun = self.substrateCollector - if substrateFun: - return substrateFun(bitString, substrate, length) + bitString = univ.BitString.SizedInteger() while head: - component, head = decodeFun(head, self.protoComponent, **options) - bitString += component + chunk, head = decodeFun(head, self.protoComponent, + substrateFun=substrateFun, + **options) + trailingBits = oct2int(chunk[0]) + if trailingBits > 7: + raise error.PyAsn1Error( + 'Trailing bits overflow %s' % trailingBits + ) + + value = univ.BitString.SizedInteger.fromOctetString(chunk[1:], trailingBits) - return bitString, tail + bitString = (bitString << value.bitLength) | value + + return self._createComponent(asn1Spec, tagSet, bitString, **options), tail def indefLenValueDecoder(self, substrate, asn1Spec, tagSet=None, length=None, state=None, decodeFun=None, substrateFun=None, **options): - bitString = self._createComponent(asn1Spec, tagSet, **options) - if substrateFun: - return substrateFun(bitString, substrate, length) + asn1Object = self._createComponent(asn1Spec, tagSet, **options) + return substrateFun(asn1Object, substrate, length) + + # All inner fragments are of the same type, treat them as octet string + substrateFun = self.substrateCollector + + bitString = univ.BitString.SizedInteger() while substrate: - component, substrate = decodeFun(substrate, self.protoComponent, - allowEoo=True, **options) - if component is eoo.endOfOctets: + chunk, substrate = decodeFun(substrate, self.protoComponent, + substrateFun=substrateFun, + allowEoo=True, **options) + + if chunk is eoo.endOfOctets: break - bitString += component + trailingBits = oct2int(chunk[0]) + if trailingBits > 7: + raise error.PyAsn1Error( + 'Trailing bits overflow %s' % trailingBits + ) + + value = univ.BitString.SizedInteger.fromOctetString(chunk[1:], trailingBits) + + bitString = (bitString << value.bitLength) | value else: raise error.SubstrateUnderrunError('No EOO seen before substrate ends') @@ -192,8 +237,8 @@ class OctetStringDecoder(AbstractSimpleDecoder): head, tail = substrate[:length], substrate[length:] if substrateFun: - return substrateFun(self._createComponent(asn1Spec, tagSet, **options), - substrate, length) + asn1Object = self._createComponent(asn1Spec, tagSet, **options) + return substrateFun(asn1Object, substrate, length) if tagSet[0].tagFormat == tag.tagFormatSimple: # XXX what tag to check? return self._createComponent(asn1Spec, tagSet, head, **options), tail @@ -256,7 +301,7 @@ class NullDecoder(AbstractSimpleDecoder): head, tail = substrate[:length], substrate[length:] - component = self._createComponent(asn1Spec, tagSet, **options) + component = self._createComponent(asn1Spec, tagSet, None, **options) if head: raise error.PyAsn1Error('Unexpected %d-octet substrate for Null' % length) |