Various bug fixes (#1261)

* can't append bytes to strings
* log when people run funny execcmd's
* testing python-3.8-rc -> python-3.8

.circleci/config.yml

@@ -5,7 +5,7 @@ workflows:
     jobs:
       - test-3.6-buster
       - test-3.7-buster
-      - test-3.8-rc-buster
+      - test-3.8-buster
 jobs:
   test-3.7-buster: &test-template
     docker:
@@ -40,7 +40,7 @@ jobs:
     <<: *test-template
     docker:
       - image: circleci/python:3.6-buster
-  test-3.8-rc-buster:
+  test-3.8-buster:
     <<: *test-template
     docker:
-      - image: circleci/python:3.8-rc-buster
+      - image: circleci/python:3.8-buster

src/cowrie/commands/ls.py

@@ -88,6 +88,8 @@ def get_dir_files(self, path):
 
     def do_ls_normal(self, path):
         files = self.get_dir_files(path)
+        if not files:
+            return
 
         line = [x[fs.A_NAME] for x in files]
         if not line:
@@ -111,6 +113,8 @@ def do_ls_normal(self, path):
 
     def do_ls_l(self, path):
         files = self.get_dir_files(path)
+        if not files:
+            return
 
         filesize_str_extent = 0
         if len(files):

src/cowrie/shell/protocol.py

@@ -220,7 +220,11 @@ def __init__(self, avatar, execcmd):
         Before this, execcmd is 'bytes'. Here it converts to 'string' and
         commands work with string rather than bytes.
         """
-        self.execcmd = execcmd.decode('utf8')
+        try:
+            self.execcmd = execcmd.decode('utf8')
+        except UnicodeDecodeError:
+            log.err("Unusual execcmd: {}".format(repr(execcmd)))
+
         HoneyPotBaseProtocol.__init__(self, avatar)
 
     def connectionMade(self):

src/cowrie/ssh/forwarding.py

@@ -116,8 +116,8 @@ def channelOpen(self, specificData):
         Modifies the original to send a TCP tunnel request via the CONNECT method
         """
         forwarding.SSHConnectForwardingChannel.channelOpen(self, specificData)
-        dst = self.dstport[0] + b':' + str(self.dstport[1])
-        connect_hdr = b'CONNECT ' + dst + b" HTTP/1.1\r\n\r\n"
+        dst = self.dstport[0] + ':' + str(self.dstport[1])
+        connect_hdr = b'CONNECT ' + dst.encode('ascii') + b' HTTP/1.1\r\n\r\n'
         forwarding.SSHConnectForwardingChannel.dataReceived(self, connect_hdr)
 
     def dataReceived(self, data):
@@ -128,20 +128,20 @@ def dataReceived(self, data):
 
     def write(self, data):
         """
-        Modifies the original to stip off the TCP tunnel response
+        Modifies the original to strip off the TCP tunnel response
         """
         if not self.tunnel_established and data[:4].lower() == b'http':
             # Check proxy response code
             try:
-                res_code = int(data.split(' ')[1], 10)
+                res_code = int(data.split(b' ')[1], 10)
             except ValueError:
-                log.err('Failed to parse TCP tunnel response code')
+                log.err("Failed to parse TCP tunnel response code")
                 self._close("Connection refused")
             if res_code != 200:
-                log.err('Unexpected response code: {}'.format(res_code))
+                log.err("Unexpected response code: {}".format(res_code))
                 self._close("Connection refused")
             # Strip off rest of packet
-            eop = data.find("\r\n\r\n")
+            eop = data.find(b'\r\n\r\n')
             if eop > -1:
                 data = data[eop + 4:]
             # This only happens once when the channel is opened