Styjun

I'm trying to send a file through WinRM/PowerShell but it seems that I'm facing a 3000 bytes limit and I don't know how to get rid of it.

From a local powershell, I can run this command and send chunks of BASE64 data successfully, I'm not limited :

while ($l=[System.Convert]::FromBase64String((Read-Host)))add-content -value ($l) -encoding byte -path 'tstfile.txt'

However, if I try to send data remotely (from a python script), the transfert starts successfully and the server stops after 3000 bytes have been written to tstfile.txt...

Here is my "simplified" code ( Python 3.5.3 + pywinrm 0.3.0 ), inspired from Ansible (https://github.com/ansible/ansible/blob/devel/lib/ansible/plugins/connection/winrm.py) :

import winrm

class TestUpload() :

 def put_file(self, location, contents):

 # start shell
 self._shell_id = self._conn.open_shell()
 ps_script='while ($l=[System.Convert]::FromBase64String((Read-Host)))add-content -value ($l) -encoding byte -path ' + location + ''
 command_id = self._conn.run_command(self._shell_id, "powershell -Command %s " % (ps_script))

 # send data
 b64contents = base64.b64encode(contents.encode('utf-8')).decode('ascii')
 for i in range(0, len(b64contents), self._step):
 self._raw_send_data(self._shell_id, command_id, b64contents[i:i+self._step] )
 self._raw_send_data(self._shell_id, command_id, '', eof=True)

 # close shell
 self._conn.cleanup_command(self._shell_id, command_id)
 self._conn.close_shell(self._shell_id)


 def _raw_send_data(self, shell_id, command_id,content, eof=False):
 req = 'env:Envelope': self._conn._get_soap_header(
 resource_uri='http://schemas.microsoft.com/wbem/wsman/1/windows/shell/cmd',
 action='http://schemas.microsoft.com/wbem/wsman/1/windows/shell/Send',
 shell_id=shell_id)

 stream = req['env:Envelope'].setdefault('env:Body', ).setdefault(
 'rsp:Send', ).setdefault('rsp:Stream', )
 stream['@CommandId'] = command_id
 stream['@Name'] = 'stdin'
 content += 'rn'
 stream['#text'] = base64.b64encode(content.encode('utf-8'))
 stream['@xmlns:rsp'] = 'http://schemas.microsoft.com/wbem/wsman/1/windows/shell'

 if eof:
 stream['@End'] = 'true'

 res = self._conn.send_message(xmltodict.unparse(req))

This works :

t=TestUpload(step=100)
t.put_file('tstfile.txt',open('900bytesfile.txt').read())

This fails :

t=TestUpload(step=100)
t.put_file('tstfile.txt',open('9000bytesfile.txt').read())
Traceback (most recent call last):
 File "/opt/environments/pypy/site-packages/winrm/transport.py", line 262, in _send_message_request
 response.raise_for_status()
 File "/opt/environments/pypy/site-packages/requests/models.py", line 940, in raise_for_status
 raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 500 Server Error: for url: https://win-srv1.local.activcloud.eu:5986/wsman

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
 File "/opt/environments/pypy/site-packages/winrm/protocol.py", line 234, in send_message
 resp = self.transport.send_message(message)
 File "/opt/environments/pypy/site-packages/winrm/transport.py", line 256, in send_message
 response = self._send_message_request(prepared_request, message)
 File "/opt/environments/pypy/site-packages/winrm/transport.py", line 273, in _send_message_request
 raise WinRMTransportError('http', ex.response.status_code, response_text)
winrm.exceptions.WinRMTransportError: Bad HTTP response returned from server. Code 500

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
 File "<console>", line 1, in <module>
 File "/opt/repos/poc4/tst.py", line 158, in put_file
 self._raw_send_data(self._shell_id, command_id, b64contents[i:i+self._step] )
 File "/opt/repos/poc4/tst.py", line 332, in _raw_send_data
 res = self._conn.send_message(xmltodict.unparse(req))
 File "/opt/environments/pypy/site-packages/winrm/protocol.py", line 256, in send_message
 raise WinRMOperationTimeoutError()
winrm.exceptions.WinRMOperationTimeoutError

I've got no error messages (except the timeout), I didn't find anything in the server logs, my only clue is that the file is 3000 bytes length on the server side (the data inside are correct) :

Mode LastWriteTime Length Name
---- ------------- ------ ----
-a---- 3/28/2019 2:52 PM 3000 tstfile.txt

Does anybody have an an idea ?
Maybe check if ansible is able to run that command with more than 3000 bytes of data ?