断言错误：使用dm.xmlsec.binding加密SOAP正文内容时，未知的节点类型：3

Question

尝试使用https://pypi.org/project/dm.xmlsec.binding/加密soapxml消息体时出错。你知道吗

Traceback (most recent call last):
  File "./manage.py", line 14, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/romeroqj/.virtualenv/lib/python2.7/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
    utility.execute()
  File "/Users/romeroqj/.virtualenv/lib/python2.7/site-packages/django/core/management/__init__.py", line 356, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/romeroqj/.virtualenv/lib/python2.7/site-packages/django/core/management/base.py", line 283, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/romeroqj/.virtualenv/lib/python2.7/site-packages/django/core/management/base.py", line 330, in execute
    output = self.handle(*args, **options)
  File "/Users/romeroqj/Desktop/management/commands/encrypt.py", line 63, in handle
    encrypted_xml = enc_ctx.encryptXml(enc_data, doc.getroot())
  File "_xmlsec.pyx", line 555, in dm.xmlsec.binding._xmlsec.EncCtx.encryptXml (src/_xmlsec.c:7336)
  File "_xmlsec.pyx", line 637, in dm.xmlsec.binding._xmlsec.lxml_safe_dealloc (src/_xmlsec.c:8132)
  File "src/lxml/public-api.pxi", line 29, in lxml.etree.elementFactory
  File "src/lxml/etree.pyx", line 1607, in lxml.etree._elementFactory
  File "src/lxml/classlookup.pxi", line 403, in lxml.etree._parser_class_lookup
  File "src/lxml/nsclasses.pxi", line 174, in lxml.etree._find_nselement_class
  File "src/lxml/classlookup.pxi", line 257, in lxml.etree._callLookupFallback
  File "src/lxml/classlookup.pxi", line 336, in lxml.etree._lookupDefaultElementClass
AssertionError: Unknown node type: 3

尝试加密正文内容时出错(xmlsec.TypeEncContent内容)，但当我尝试加密body元素时，它会起作用(xmlsec.typencement元素). 代码如下：

import dm.xmlsec.binding as xmlsec
from dm.xmlsec.binding.tmpl import EncData, fromstring

key_mngr = xmlsec.KeysMngr()
key = xmlsec.Key.load('cert.pem', xmlsec.KeyDataFormatCertPem)
key.name = 'cert.pem'
key_mngr.addKey(key)
enc_data = EncData(
    xmlsec.TransformAes128Cbc, type=xmlsec.TypeEncContent
)
enc_data.ensureCipherValue()  # target for encryption result
enc_ctx = xmlsec.EncCtx(key_mngr)
enc_ctx.encKey = xmlsec.Key.generate(
    xmlsec.KeyDataAes, 192, xmlsec.KeyDataTypeSession
)
doc = fromstring(xml_data)
body = doc.find('soap:Body', namespaces=NAMESPACES)  # NAMESPACES is redacted for brevity
encrypted_xml = enc_ctx.encryptXml(enc_data, doc.getroot())

XML数据如下所示：

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
    <soap:Header>
    ...
    </soap:Header>
    <soap:Body Id="Body">
    ...
    </soap:Body>
</soap:Envelope>

这里可能有什么问题？你知道吗

我不确定这是相关的还是相关的，但是我尝试使用不同的库https://github.com/mehcode/python-xmlsec/issues/83来做同样的事情，我得到了一个分段错误，但是，当我尝试加密元素时，它工作了。这种模式让我相信这种方法有问题。你知道吗

如有任何提示，我们将不胜感激。提前谢谢！你知道吗