diff options
Diffstat (limited to 'pyasn1/codec/ber/encoder.py')
| -rw-r--r-- | pyasn1/codec/ber/encoder.py | 166 |
1 files changed, 134 insertions, 32 deletions
diff --git a/pyasn1/codec/ber/encoder.py b/pyasn1/codec/ber/encoder.py index f213d5b..142e167 100644 --- a/pyasn1/codec/ber/encoder.py +++ b/pyasn1/codec/ber/encoder.py @@ -33,29 +33,39 @@ class AbstractItemEncoder(object): encodedTag = tagClass | tagFormat if isConstructed: encodedTag |= tag.tagFormatConstructed + if tagId < 31: return encodedTag | tagId, + else: substrate = tagId & 0x7f, + tagId >>= 7 + while tagId: substrate = (0x80 | (tagId & 0x7f),) + substrate tagId >>= 7 + return (encodedTag | 0x1F,) + substrate def encodeLength(self, length, defMode): if not defMode and self.supportIndefLenMode: return (0x80,) + if length < 0x80: return length, + else: substrate = () while length: substrate = (length & 0xff,) + substrate length >>= 8 + substrateLen = len(substrate) + if substrateLen > 126: raise error.PyAsn1Error('Length octets overflow (%d)' % substrateLen) + return (0x80 | substrateLen,) + substrate def encodeValue(self, value, asn1Spec, encodeFun, **options): @@ -87,16 +97,32 @@ class AbstractItemEncoder(object): value, asn1Spec, encodeFun, **options ) + if LOG: + LOG('encoded %svalue %s into %s' % ( + isConstructed and 'constructed ' or '', value, substrate + )) + if not substrate and isConstructed and options.get('ifNotEmpty', False): return substrate - # primitive form implies definite mode if not isConstructed: defModeOverride = True + if LOG: + LOG('overridden encoding mode into definitive for primitive type') + header = self.encodeTag(singleTag, isConstructed) + + if LOG: + LOG('encoded %stag %s into %s' % (isConstructed and 'constructed ' or '', + singleTag, debug.hexdump(header))) + header += self.encodeLength(len(substrate), defModeOverride) + if LOG: + LOG('encoded %s octets (tag + payload) into %s' % ( + len(substrate), debug.hexdump(header))) + if isOctets: substrate = ints2octs(header) + substrate @@ -133,6 +159,11 @@ class IntegerEncoder(AbstractItemEncoder): def encodeValue(self, value, asn1Spec, encodeFun, **options): if value == 0: + if LOG: + LOG('encoding %spayload for zero INTEGER' % ( + self.supportCompactZero and 'no ' or '' + )) + # de-facto way to encode zero if self.supportCompactZero: return (), False, False @@ -159,11 +190,15 @@ class BitStringEncoder(AbstractItemEncoder): substrate = alignedValue.asOctets() return int2oct(len(substrate) * 8 - valueLength) + substrate, False, True + if LOG: + LOG('encoding into up to %s-octet chunks' % maxChunkSize) + baseTag = value.tagSet.baseTag # strip off explicit tags if baseTag: tagSet = tag.TagSet(baseTag, baseTag) + else: tagSet = tag.TagSet() @@ -197,44 +232,47 @@ class OctetStringEncoder(AbstractItemEncoder): if not maxChunkSize or len(substrate) <= maxChunkSize: return substrate, False, True - else: + if LOG: + LOG('encoding into up to %s-octet chunks' % maxChunkSize) - # strip off explicit tags for inner chunks + # strip off explicit tags for inner chunks - if asn1Spec is None: - baseTag = value.tagSet.baseTag + if asn1Spec is None: + baseTag = value.tagSet.baseTag - # strip off explicit tags - if baseTag: - tagSet = tag.TagSet(baseTag, baseTag) - else: - tagSet = tag.TagSet() + # strip off explicit tags + if baseTag: + tagSet = tag.TagSet(baseTag, baseTag) - asn1Spec = value.clone(tagSet=tagSet) + else: + tagSet = tag.TagSet() + + asn1Spec = value.clone(tagSet=tagSet) - elif not isOctetsType(value): - baseTag = asn1Spec.tagSet.baseTag + elif not isOctetsType(value): + baseTag = asn1Spec.tagSet.baseTag - # strip off explicit tags - if baseTag: - tagSet = tag.TagSet(baseTag, baseTag) - else: - tagSet = tag.TagSet() + # strip off explicit tags + if baseTag: + tagSet = tag.TagSet(baseTag, baseTag) + + else: + tagSet = tag.TagSet() - asn1Spec = asn1Spec.clone(tagSet=tagSet) + asn1Spec = asn1Spec.clone(tagSet=tagSet) - pos = 0 - substrate = null + pos = 0 + substrate = null - while True: - chunk = value[pos:pos + maxChunkSize] - if not chunk: - break + while True: + chunk = value[pos:pos + maxChunkSize] + if not chunk: + break - substrate += encodeFun(chunk, asn1Spec, **options) - pos += maxChunkSize + substrate += encodeFun(chunk, asn1Spec, **options) + pos += maxChunkSize - return substrate, True, True + return substrate, True, True class NullEncoder(AbstractItemEncoder): @@ -270,8 +308,10 @@ class ObjectIdentifierEncoder(AbstractItemEncoder): oid = (second + 80,) + oid[2:] else: raise error.PyAsn1Error('Impossible first/second arcs at %s' % (value,)) + elif first == 2: oid = (second + 80,) + oid[2:] + else: raise error.PyAsn1Error('Impossible first/second arcs at %s' % (value,)) @@ -282,15 +322,19 @@ class ObjectIdentifierEncoder(AbstractItemEncoder): if 0 <= subOid <= 127: # Optimize for the common case octets += (subOid,) + elif subOid > 127: # Pack large Sub-Object IDs res = (subOid & 0x7f,) subOid >>= 7 + while subOid: res = (0x80 | (subOid & 0x7f),) + res subOid >>= 7 + # Add packed Sub-Object ID to resulted Object ID octets += res + else: raise error.PyAsn1Error('Negative OID arc %s at %s' % (subOid, value)) @@ -306,12 +350,16 @@ class RealEncoder(AbstractItemEncoder): ms, es = 1, 1 if m < 0: ms = -1 # mantissa sign + if e < 0: es = -1 # exponent sign + m *= ms + if encbase == 8: m *= 2 ** (abs(e) % 3 * es) e = abs(e) // 3 * es + elif encbase == 16: m *= 2 ** (abs(e) % 4 * es) e = abs(e) // 4 * es @@ -322,6 +370,7 @@ class RealEncoder(AbstractItemEncoder): e -= 1 continue break + return ms, int(m), encbase, e def _chooseEncBase(self, value): @@ -329,23 +378,32 @@ class RealEncoder(AbstractItemEncoder): encBase = [2, 8, 16] if value.binEncBase in encBase: return self._dropFloatingPoint(m, value.binEncBase, e) + elif self.binEncBase in encBase: return self._dropFloatingPoint(m, self.binEncBase, e) - # auto choosing base 2/8/16 + + # auto choosing base 2/8/16 mantissa = [m, m, m] exponent = [e, e, e] sign = 1 encbase = 2 e = float('inf') + for i in range(3): (sign, mantissa[i], encBase[i], exponent[i]) = self._dropFloatingPoint(mantissa[i], encBase[i], exponent[i]) + if abs(exponent[i]) < abs(e) or (abs(exponent[i]) == abs(e) and mantissa[i] < m): e = exponent[i] m = int(mantissa[i]) encbase = encBase[i] + + if LOG: + LOG('automatically chosen REAL encoding base %s, sign %s, mantissa %s, ' + 'exponent %s' % (encbase, sign, m, e)) + return sign, m, encbase, e def encodeValue(self, value, asn1Spec, encodeFun, **options): @@ -354,69 +412,98 @@ class RealEncoder(AbstractItemEncoder): if value.isPlusInf: return (0x40,), False, False + if value.isMinusInf: return (0x41,), False, False + m, b, e = value + if not m: return null, False, True + if b == 10: + if LOG: + LOG('encoding REAL into character form') + return str2octs('\x03%dE%s%d' % (m, e == 0 and '+' or '', e)), False, True + elif b == 2: fo = 0x80 # binary encoding ms, m, encbase, e = self._chooseEncBase(value) + if ms < 0: # mantissa sign fo |= 0x40 # sign bit + # exponent & mantissa normalization if encbase == 2: while m & 0x1 == 0: m >>= 1 e += 1 + elif encbase == 8: while m & 0x7 == 0: m >>= 3 e += 1 fo |= 0x10 + else: # encbase = 16 while m & 0xf == 0: m >>= 4 e += 1 fo |= 0x20 + sf = 0 # scale factor + while m & 0x1 == 0: m >>= 1 sf += 1 + if sf > 3: raise error.PyAsn1Error('Scale factor overflow') # bug if raised + fo |= sf << 2 eo = null if e == 0 or e == -1: eo = int2oct(e & 0xff) + else: while e not in (0, -1): eo = int2oct(e & 0xff) + eo e >>= 8 + if e == 0 and eo and oct2int(eo[0]) & 0x80: eo = int2oct(0) + eo + if e == -1 and eo and not (oct2int(eo[0]) & 0x80): eo = int2oct(0xff) + eo + n = len(eo) if n > 0xff: raise error.PyAsn1Error('Real exponent overflow') + if n == 1: pass + elif n == 2: fo |= 1 + elif n == 3: fo |= 2 + else: fo |= 3 eo = int2oct(n & 0xff) + eo + po = null + while m: po = int2oct(m & 0xff) + po m >>= 8 + substrate = int2oct(fo) + eo + po + return substrate, False, True + else: raise error.PyAsn1Error('Prohibited Real base %s' % b) @@ -441,10 +528,14 @@ class SequenceEncoder(AbstractItemEncoder): namedType = namedTypes[idx] if namedType.isOptional and not component.isValue: - continue + if LOG: + LOG('not encoding OPTIONAL component %r' % (namedType,)) + continue if namedType.isDefaulted and component == namedType.asn1Object: - continue + if LOG: + LOG('not encoding DEFAULT component %r' % (namedType,)) + continue if self.omitEmptyOptionals: options.update(ifNotEmpty=namedType.isOptional) @@ -457,6 +548,9 @@ class SequenceEncoder(AbstractItemEncoder): if wrapType.tagSet and not wrapType.isSameTypeWith(component): chunk = encodeFun(chunk, wrapType, **options) + if LOG: + LOG('wrapped open type with wrap type %r' % (wrapType,)) + substrate += chunk else: @@ -467,12 +561,17 @@ class SequenceEncoder(AbstractItemEncoder): component = value[namedType.name] except KeyError: - raise error.PyAsn1Error('Component name "%s" not found in %r' % (namedType.name, value)) + raise error.PyAsn1Error('Component name "%s" not found in %r' % ( + namedType.name, value)) if namedType.isOptional and namedType.name not in value: + if LOG: + LOG('not encoding OPTIONAL component %r' % (namedType,)) continue if namedType.isDefaulted and component == namedType.asn1Object: + if LOG: + LOG('not encoding DEFAULT component %r' % (namedType,)) continue if self.omitEmptyOptionals: @@ -486,6 +585,9 @@ class SequenceEncoder(AbstractItemEncoder): if wrapType.tagSet and not wrapType.isSameTypeWith(component): chunk = encodeFun(chunk, wrapType, **options) + if LOG: + LOG('wrapped open type with wrap type %r' % (wrapType,)) + substrate += chunk return substrate, True, True |