题
我在寻找一个解决分析。1的规范文件,并产生一种解码器。
理想情况下,我愿与Python模块,但是如果没有什么可我会用C++库和接口他们与蟒蛇,与过多的解决方案。
在过去我一直在使用pyasn1和建筑的一切方面,但已成为太unwieldly.
我还看了看表面上看来libtasn1和asn1c.第一一个有问题的分析,即使是最简单的文件。第二具有良好分析器而产生的C代码,用于解码看起来太复杂;该方案的工作以及有直接规范,但是窒息复杂的。
任何其他良好的替代办法我可能忽略了?
其他提示
我几年前写了这样的解析器。它产生pyasn1库Python类。我用爱立信DOC使解析器为他们的CDR。
我会尝试,现在在这里张贴的代码。
import sys
from pyparsing import *
OpenBracket = Regex("[({]").suppress()
CloseBracket = Regex("[)}]").suppress()
def Enclose(val):
return OpenBracket + val + CloseBracket
def SetDefType(typekw):
def f(a, b, c):
c["defType"] = typekw
return f
def NoDashes(a, b, c):
return c[0].replace("-", "_")
def DefineTypeDef(typekw, typename, typedef):
return typename.addParseAction(SetDefType(typekw)).setResultsName("definitionType") - \
Optional(Enclose(typedef).setResultsName("definition"))
SizeConstraintBodyOpt = Word(nums).setResultsName("minSize") - \
Optional(Suppress(Literal("..")) - Word(nums + "n").setResultsName("maxSize"))
SizeConstraint = Group(Keyword("SIZE").suppress() - Enclose(SizeConstraintBodyOpt)).setResultsName("sizeConstraint")
Constraints = Group(delimitedList(SizeConstraint)).setResultsName("constraints")
DefinitionBody = Forward()
TagPrefix = Enclose(Word(nums).setResultsName("tagID")) - Keyword("IMPLICIT").setResultsName("tagFormat")
OptionalSuffix = Optional(Keyword("OPTIONAL").setResultsName("isOptional"))
JunkPrefix = Optional("--F--").suppress()
AName = Word(alphanums + "-").setParseAction(NoDashes).setResultsName("name")
SingleElement = Group(JunkPrefix - AName - Optional(TagPrefix) - DefinitionBody.setResultsName("typedef") - OptionalSuffix)
NamedTypes = Dict(delimitedList(SingleElement)).setResultsName("namedTypes")
SetBody = DefineTypeDef("Set", Keyword("SET"), NamedTypes)
SequenceBody = DefineTypeDef("Sequence", Keyword("SEQUENCE"), NamedTypes)
ChoiceBody = DefineTypeDef("Choice", Keyword("CHOICE"), NamedTypes)
SetOfBody = (Keyword("SET") + Optional(SizeConstraint) + Keyword("OF")).setParseAction(SetDefType("SetOf")) + Group(DefinitionBody).setResultsName("typedef")
SequenceOfBody = (Keyword("SEQUENCE") + Optional(SizeConstraint) + Keyword("OF")).setParseAction(SetDefType("SequenceOf")) + Group(DefinitionBody).setResultsName("typedef")
CustomBody = DefineTypeDef("constructed", Word(alphanums + "-").setParseAction(NoDashes), Constraints)
NullBody = DefineTypeDef("Null", Keyword("NULL"), Constraints)
OctetStringBody = DefineTypeDef("OctetString", Regex("OCTET STRING"), Constraints)
IA5StringBody = DefineTypeDef("IA5String", Keyword("IA5STRING"), Constraints)
EnumElement = Group(Word(printables).setResultsName("name") - Enclose(Word(nums).setResultsName("value")))
NamedValues = Dict(delimitedList(EnumElement)).setResultsName("namedValues")
EnumBody = DefineTypeDef("Enum", Keyword("ENUMERATED"), NamedValues)
BitStringBody = DefineTypeDef("BitString", Keyword("BIT") + Keyword("STRING"), NamedValues)
DefinitionBody << (OctetStringBody | SetOfBody | SetBody | ChoiceBody | SequenceOfBody | SequenceBody | EnumBody | BitStringBody | IA5StringBody | NullBody | CustomBody)
Definition = AName - Literal("::=").suppress() - Optional(TagPrefix) - DefinitionBody
Definitions = Dict(ZeroOrMore(Group(Definition)))
pf = Definitions.parseFile(sys.argv[1])
TypeDeps = {}
TypeDefs = {}
def SizeConstraintHelper(size):
s2 = s1 = size.get("minSize")
s2 = size.get("maxSize", s2)
try:
return("constraint.ValueSizeConstraint(%s, %s)" % (int(s1), int(s2)))
except ValueError:
pass
ConstraintMap = {
'sizeConstraint' : SizeConstraintHelper,
}
def ConstraintHelper(c):
result = []
for key, value in c.items():
r = ConstraintMap[key](value)
if r:
result.append(r)
return result
def GenerateConstraints(c, ancestor, element, level=1):
result = ConstraintHelper(c)
if result:
return [ "subtypeSpec = %s" % " + ".join(["%s.subtypeSpec" % ancestor] + result) ]
return []
def GenerateNamedValues(definitions, ancestor, element, level=1):
result = [ "namedValues = namedval.NamedValues(" ]
for kw in definitions:
result.append(" ('%s', %s)," % (kw["name"], kw["value"]))
result.append(")")
return result
OptMap = {
False: "",
True: "Optional",
}
def GenerateNamedTypesList(definitions, element, level=1):
result = []
for val in definitions:
name = val["name"]
typename = None
isOptional = bool(val.get("isOptional"))
subtype = []
constraints = val.get("constraints")
if constraints:
cg = ConstraintHelper(constraints)
subtype.append("subtypeSpec=%s" % " + ".join(cg))
tagId = val.get("tagID")
if tagId:
subtype.append("implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatConstructed, %s)" % tagId)
if subtype:
subtype = ".subtype(%s)" % ", ".join(subtype)
else:
subtype = ""
cbody = []
if val["defType"] == "constructed":
typename = val["typedef"]
element["_d"].append(typename)
elif val["defType"] == "Null":
typename = "univ.Null"
elif val["defType"] == "SequenceOf":
typename = "univ.SequenceOf"
print val.items()
cbody = [ " componentType=%s()" % val["typedef"]["definitionType"] ]
elif val["defType"] == "Choice":
typename = "univ.Choice"
indef = val.get("definition")
if indef:
cbody = [ " %s" % x for x in GenerateClassDefinition(indef, name, typename, element) ]
construct = [ "namedtype.%sNamedType('%s', %s(" % (OptMap[isOptional], name, typename), ")%s)," % subtype ]
if not cbody:
result.append("%s%s%s" % (" " * level, construct[0], construct[1]))
else:
result.append(" %s" % construct[0])
result.extend(cbody)
result.append(" %s" % construct[1])
return result
def GenerateNamedTypes(definitions, ancestor, element, level=1):
result = [ "componentType = namedtype.NamedTypes(" ]
result.extend(GenerateNamedTypesList(definitions, element))
result.append(")")
return result
defmap = {
'constraints' : GenerateConstraints,
'namedValues' : GenerateNamedValues,
'namedTypes' : GenerateNamedTypes,
}
def GenerateClassDefinition(definition, name, ancestor, element, level=1):
result = []
for defkey, defval in definition.items():
if defval:
fn = defmap.get(defkey)
if fn:
result.extend(fn(defval, ancestor, element, level))
return [" %s" % x for x in result]
def GenerateClass(element, ancestor):
name = element["name"]
top = "class %s(%s):" % (name, ancestor)
definition = element.get("definition")
body = []
if definition:
body = GenerateClassDefinition(definition, name, ancestor, element)
else:
typedef = element.get("typedef")
if typedef:
element["_d"].append(typedef["definitionType"])
body.append(" componentType = %s()" % typedef["definitionType"])
szc = element.get('sizeConstraint')
if szc:
body.extend(GenerateConstraints({ 'sizeConstraint' : szc }, ancestor, element))
if not body:
body.append(" pass")
TypeDeps[name] = list(frozenset(element["_d"]))
return "\n".join([top] + body)
StaticMap = {
"Null" : "univ.Null",
"Enum" : "univ.Enumerated",
"OctetString" : "univ.OctetString",
"IA5String" : "char.IA5String",
"Set" : "univ.Set",
"Sequence" : "univ.Sequence",
"Choice" : "univ.Choice",
"SetOf" : "univ.SetOf",
"BitString" : "univ.BitString",
"SequenceOf" : "univ.SequenceOf",
}
def StaticConstructor(x):
x["_d"] = []
if x["defType"] == "constructed":
dt = x["definitionType"]
x["_d"].append(dt)
else:
dt = StaticMap[x["defType"]]
return GenerateClass(x, dt)
for element in pf:
TypeDefs[element["name"]] = StaticConstructor(element)
while TypeDefs:
ready = [ k for k, v in TypeDeps.items() if len(v) == 0 ]
if not ready:
x = list()
for a in TypeDeps.values():
x.extend(a)
x = frozenset(x) - frozenset(TypeDeps.keys())
print TypeDefs
raise ValueError, sorted(x)
for t in ready:
for v in TypeDeps.values():
try:
v.remove(t)
except ValueError:
pass
del TypeDeps[t]
print TypeDefs[t]
print
print
del TypeDefs[t]
此将采取与语法的文件,与此类似:
CarrierInfo ::= OCTET STRING (SIZE(2..3))
ChargeAreaCode ::= OCTET STRING (SIZE(3))
ChargeInformation ::= OCTET STRING (SIZE(2..33))
ChargedParty ::= ENUMERATED
(chargingOfCallingSubscriber (0),
chargingOfCalledSubscriber (1),
noCharging (2))
ChargingOrigin ::= OCTET STRING (SIZE(1))
Counter ::= OCTET STRING (SIZE(1..4))
Date ::= OCTET STRING (SIZE(3..4))
您将需要添加所生成的文件的顶部一行:
from pyasn1.type import univ, namedtype, namedval, constraint, tag, char
和命名结果defs.py.然后,我连着一串prettyprinters到DEFS(如果你没有跳过它)
import defs, parsers
def rplPrettyOut(self, value):
return repr(self.decval(value))
for name in dir(parsers):
if (not name.startswith("_")) and hasattr(defs, name):
target = getattr(defs, name)
target.prettyOut = rplPrettyOut
target.decval = getattr(parsers, name)
然后,它下降到:
def ParseBlock(self, block):
while block and block[0] != '\x00':
result, block = pyasn1.codec.ber.decoder.decode(block, asn1Spec=parserimp.defs.CallDataRecord())
yield result
如果你仍然有兴趣我会在某个地方把代码。事实上,我把它放在任何情况下 - 但如果你有兴趣让我知道,我会在那儿点你
。有一个 ANTLR ASN.1语法;使用ANTLR,你应该能够作出ASN.1语法分析器出来。产生用于pyasn1码留给读者作为练习到海报: - )
我有 pyasn1 经验,这足以解析相当复杂的语法。文法表示用蟒结构,所以没有必要运行代码生成器。
我是作者的LEPL、分析器Python编写的,什么你想要做的一件事情在我的"TODO"列表。
我不会这样做很快,但是你可以考虑使用LEPL构造你的解决方案,因为:
1-这是一个纯粹的蟒蛇解决方案(这使生活更简单)
2-它已经可以分析二进制数据以及文本,所以你只需要使用一个单一的工具相同的分析器使用的分析ASN1规范将被用于分析的二进制数据
主要缺点是:
1-这是一个相当新的软件包,因此它可以buggier于一些,并支持社区不是很大
2-它被限制向Python2.6和(二进制析程序只适用Python3)。
欲了解更多信息,请看 http://www.acooke.org/lepl -特别是二进制的分析请参阅有关章节的手册(我无法直接链接到,如栈溢出似乎认为我是垃圾邮件)
安德鲁
PS的主要原因,这并不是东西,我已经开始,ASN1规格是不免费提供的,我知道。如果你有对它们的访问,这不是非法的(!), 一个复制将大大理解的(不幸的是,我目前正在另一个项目,因此这将仍然需要时间来实现,但它会帮助我得到这工作的迟早...).
我已经做了使用ASN1C和建筑周围有高硼硅扩展了类似的工作。将缠绕的结构在 3GPP TS 32.401 说明。
使用耐热玻璃,你可以写够厚,原生的Python数据类型和正确的ASN.1之间转换的包装(包装发生器,例如SWIG,往往不会对类型进行复杂的操作)。我写的包装器还追踪底层的C数据结构的所有权(例如,接入到一个分体结构,返回Python对象,但没有基础数据的复制,只能引用共享)。
在包装最终被写在一种半自动化的方式,但因为这是我用ASN.1唯一的工作我从来没有台阶的完全使自动化代码生成。
您可以尝试使用其他Python-C包装和执行完全自动转换:工作会少些,但你会移动的复杂性(和重复容易出错的操作)的结构的用户:这个原因我首选耐热玻璃的方式。 ASN1C肯定是很好的选择。
我最近创建的Python包称为 asn1tools 其编译的ASN.1规范成Python对象,其可用于编码和解码的消息。
>>> import asn1tools
>>> foo = asn1tools.compile_file('tests/files/foo.asn')
>>> encoded = foo.encode('Question', {'id': 1, 'question': 'Is 1+1=3?'})
>>> encoded
bytearray(b'0\x0e\x02\x01\x01\x16\x09Is 1+1=3?')
>>> foo.decode('Question', encoded)
{'id': 1, 'question': 'Is 1+1=3?'}