decoder.py 文件源码

def valueDecoder(self, substrate, asn1Spec,
                     tagSet=None, length=None, state=None,
                     decodeFun=None, substrateFun=None,
                     **options):

        if tagSet[0].tagFormat != tag.tagFormatSimple:
            raise error.PyAsn1Error('Simple tag format expected')

        head, tail = substrate[:length], substrate[length:]

        component = self._createComponent(asn1Spec, tagSet)

        if head:
            raise error.PyAsn1Error('Unexpected %d-octet substrate for Null' % length)

        return component, tail