Merge b2e621cafc into 06ebdbd0fe

* Switch connect_ex result checks to errno lookups

* Return errno strings, clean up comment

README.md

@@ -220,6 +220,7 @@ For convenience, a web front-end on top of the command-line tool is available at
  - Added LANcom LCOS server recognition and Ed448 key extraction; credit [Daniel Lenski](https://github.com/dlenskiSB).
  - Fixed crash when running with `-P` and `-T` options simultaneously.
  - Fixed host key tests from only reporting a key type at most once despite multiple hosts supporting it; credit [Daniel Lenski](https://github.com/dlenskiSB).
+ - Fixed DHEat connection rate testing on MacOS X and BSD platforms; credit [Drew Noel](https://github.com/drewmnoel) and [Michael Osipov](https://github.com/michael-o).
 
 ### v3.2.0 (2024-04-22)
  - Added implementation of the DHEat denial-of-service attack (see `--dheat` option; [CVE-2002-20001](https://nvd.nist.gov/vuln/detail/CVE-2002-20001)).

src/ssh_audit/dheat.py

@@ -21,6 +21,7 @@
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    THE SOFTWARE.
 """
+import errno
 import multiprocessing
 import os
 import queue
@@ -442,10 +443,10 @@ class DHEat:
                 # out.d("Creating socket (%u of %u already exist)..." % (len(socket_dict), concurrent_sockets), write_now=True)
                 ret = s.connect_ex((target_ip_address, aconf.port))
                 num_attempted_connections += 1
-                if ret in [0, 115]:  # Check if connection is successful or EINPROGRESS.
+                if ret in [0, errno.EINPROGRESS]:
                     socket_dict[s] = now
                 else:
-                    out.d("connect_ex() returned: %d" % ret, write_now=True)
+                    out.d("connect_ex() returned: %s (%d)" % (os.strerror(ret), ret), write_now=True)
 
             # out.d("Calling select() on %u sockets..." % len(socket_dict), write_now=True)
             socket_list: List[socket.socket] = [*socket_dict]  # Get a list of sockets from the dictionary.

src/ssh_audit/gextest.py

@@ -110,7 +110,7 @@ class GEXTest:
                 # before continuing to issue reconnects.
                 modulus_size_returned, reconnect_failed = GEXTest._send_init(out, s, kex_group, kex, gex_alg, bits_min, bits_pref, bits_max)
                 if reconnect_failed:
-                    out.fail('Reconnect failed.')
+                    out.error('Reconnect failed.')
                     return exitcodes.FAILURE
 
                 if modulus_size_returned > 0:

src/ssh_audit/outputbuffer.py

@@ -54,6 +54,14 @@ class OutputBuffer:
         self.__is_color_supported = ('colorama' in sys.modules) or (os.name == 'posix')
         self.line_ended = True
 
+    def error(self, msg, line_ended=True):
+        """
+        Writes an error message to stderr.
+        """
+        end = '' if line_ended else '\n'
+        sys.stderr.write(f'{msg}{end}')
+        sys.stderr.flush()
+        
     def _print(self, level: str, s: str = '', line_ended: bool = True) -> None:
         '''Saves output to buffer (if in buffered mode), or immediately prints to stdout otherwise.'''
 

src/ssh_audit/ssh2_kex.py

@@ -1,7 +1,7 @@
 """
    The MIT License (MIT)
 
-   Copyright (C) 2017-2020 Joe Testa (jtesta@positronsecurity.com)
+   Copyright (C) 2017-2024 Joe Testa (jtesta@positronsecurity.com)
    Copyright (C) 2017 Andris Raugulis (moo@arthepsy.eu)
 
    Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -132,3 +132,16 @@ class SSH2_Kex:
         srv = SSH2_KexParty(srv_enc, srv_mac, srv_compression, srv_languages)
         kex = cls(outputbuffer, cookie, kex_algs, key_algs, cli, srv, follows, unused)
         return kex
+
+    def __str__(self) -> str:
+        ret = "----\nSSH2_Kex object:"
+        ret += "\nHost keys: "
+        ret += ", ".join(self.__key_algs)
+        ret += "\nKey exchanges: "
+        ret += ", ".join(self.__kex_algs)
+        ret += "\nClient SSH2_KexParty:"
+        ret += "\n" + str(self.__client)
+        ret += "\nServer SSH2_KexParty:"
+        ret += "\n" + str(self.__server)
+        ret += "\n----"
+        return ret

src/ssh_audit/ssh2_kexparty.py

@@ -1,6 +1,7 @@
 """
    The MIT License (MIT)
 
+   Copyright (C) 2024 Joe Testa (jtesta@positronsecurity.com)
    Copyright (C) 2017 Andris Raugulis (moo@arthepsy.eu)
 
    Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -48,3 +49,10 @@ class SSH2_KexParty:
     @property
     def languages(self) -> List[str]:
         return self.__languages
+
+    def __str__(self) -> str:
+        ret = "Ciphers: " + ", ".join(self.__enc)
+        ret += "\nMACs: " + ", ".join(self.__mac)
+        ret += "\nCompressions: " + ", ".join(self.__compression)
+        ret += "\nLanguages: " + ", ".join(self.__languages)
+        return ret

src/ssh_audit/ssh_audit.py

@@ -2,7 +2,7 @@
 """
    The MIT License (MIT)
 
-   Copyright (C) 2017-2023 Joe Testa (jtesta@positronsecurity.com)
+   Copyright (C) 2017-2024 Joe Testa (jtesta@positronsecurity.com)
    Copyright (C) 2017 Andris Raugulis (moo@arthepsy.eu)
 
    Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -88,7 +88,7 @@ def usage(uout: OutputBuffer, err: Optional[str] = None) -> None:
     p = os.path.basename(sys.argv[0])
     uout.head('# {} {}, https://github.com/jtesta/ssh-audit\n'.format(p, VERSION))
     if err is not None and len(err) > 0:
-        uout.fail(err + '\n')
+        uout.error(err + '\n')
         retval = exitcodes.UNKNOWN_ERROR
     uout.info('usage: {0} [options] <host>\n'.format(p))
     uout.info('   -h,  --help             print this help')
@@ -835,7 +835,7 @@ def list_policies(out: OutputBuffer, verbose: bool) -> None:
 
     out.sep()
     if len(server_policy_names) == 0 and len(client_policy_names) == 0:
-        out.fail("Error: no built-in policies found!")
+        out.error("Error: no built-in policies found!")
     else:
         out.info("\nHint: Use -P and provide the full name of a policy to run a policy scan with.\n")
         out.info("Hint: Use -L -v to also see the change log for each policy.\n")
@@ -1051,19 +1051,19 @@ def process_commandline(out: OutputBuffer, args: List[str], usage_cb: Callable[.
             try:
                 aconf.policy = Policy(policy_file=aconf.policy_file, json_output=aconf.json)
             except Exception as e:
-                out.fail("Error while loading policy file: %s: %s" % (str(e), traceback.format_exc()))
+                out.error("Error while loading policy file: %s: %s" % (str(e), traceback.format_exc()))
                 out.write()
                 sys.exit(exitcodes.UNKNOWN_ERROR)
 
         # If the user wants to do a client audit, but provided a server policy, terminate.
         if aconf.client_audit and aconf.policy.is_server_policy():
-            out.fail("Error: client audit selected, but server policy provided.")
+            out.error("Error: client audit selected, but server policy provided.")
             out.write()
             sys.exit(exitcodes.UNKNOWN_ERROR)
 
         # If the user wants to do a server audit, but provided a client policy, terminate.
         if aconf.client_audit is False and aconf.policy.is_server_policy() is False:
-            out.fail("Error: server audit selected, but client policy provided.")
+            out.error("Error: server audit selected, but client policy provided.")
             out.write()
             sys.exit(exitcodes.UNKNOWN_ERROR)
 
@@ -1262,7 +1262,7 @@ def audit(out: OutputBuffer, aconf: AuditConf, sshv: Optional[int] = None, print
         err = s.connect()
 
         if err is not None:
-            out.fail(err)
+            out.error(err)
 
             # If we're running against multiple targets, return a connection error to the calling worker thread.  Otherwise, write the error message to the console and exit.
             if len(aconf.target_list) > 0:
@@ -1310,15 +1310,16 @@ def audit(out: OutputBuffer, aconf: AuditConf, sshv: Optional[int] = None, print
                 err = fmt.format(err_pair[0], err_pair[1], packet_type)
     if err is not None:
         output(out, aconf, banner, header)
-        out.fail(err)
+        out.error(err)
         return exitcodes.CONNECTION_ERROR
     if sshv == 1:
         program_retval = output(out, aconf, banner, header, pkm=SSH1_PublicKeyMessage.parse(payload))
     elif sshv == 2:
         try:
             kex = SSH2_Kex.parse(out, payload)
+            out.d(str(kex))
         except Exception:
-            out.fail("Failed to parse server's kex.  Stack trace:\n%s" % str(traceback.format_exc()))
+            out.error("Failed to parse server's kex.  Stack trace:\n%s" % str(traceback.format_exc()))
             return exitcodes.CONNECTION_ERROR
 
         if aconf.dheat is not None:

src/ssh_audit/ssh_socket.py

@@ -108,7 +108,8 @@ class SSH_Socket(ReadBuf, WriteBuf):
             s.listen()
             self.__sock_map[s.fileno()] = s
         except Exception as e:
-            print("Warning: failed to listen on any IPv4 interfaces: %s" % str(e))
+            self.__outputbuffer.error("Warning: failed to listen on any IPv4 interfaces: %s" % str(e))
+            sys.exit(exitcodes.CONNECTION_ERROR)
 
         try:
             # Socket to listen on all IPv6 addresses.
@@ -119,11 +120,12 @@ class SSH_Socket(ReadBuf, WriteBuf):
             s.listen()
             self.__sock_map[s.fileno()] = s
         except Exception as e:
-            print("Warning: failed to listen on any IPv6 interfaces: %s" % str(e))
+            self.__outputbuffer.error("Warning: failed to listen on any IPv6 interfaces: %s" % str(e))
+            sys.exit(exitcodes.CONNECTION_ERROR)
 
         # If we failed to listen on any interfaces, terminate.
         if len(self.__sock_map.keys()) == 0:
-            print("Error: failed to listen on any IPv4 and IPv6 interfaces!")
+            self.__outputbuffer.error("Error: failed to listen on any IPv4 and IPv6 interfaces!")
             sys.exit(exitcodes.CONNECTION_ERROR)
 
         # Wait for an incoming connection.  If a timeout was explicitly
@@ -141,7 +143,7 @@ class SSH_Socket(ReadBuf, WriteBuf):
                 break
 
             if self.__timeout_set and time_elapsed >= self.__timeout:
-                print("Timeout elapsed.  Terminating...")
+                self.__outputbuffer.error("Timeout elapsed.  Terminating...")
                 sys.exit(exitcodes.CONNECTION_ERROR)
 
         # Accept the connection.
@@ -275,7 +277,7 @@ class SSH_Socket(ReadBuf, WriteBuf):
                 payload_length = packet_length - padding_length - 1
                 check_size = 4 + 1 + payload_length + padding_length
             if check_size % self.__block_size != 0:
-                self.__outputbuffer.fail('[exception] invalid ssh packet (block size)').write()
+                self.__outputbuffer.error('[exception] invalid ssh packet (block size)').write()
                 sys.exit(exitcodes.CONNECTION_ERROR)
             self.ensure_read(payload_length)
             if sshv == 1:
@@ -290,7 +292,7 @@ class SSH_Socket(ReadBuf, WriteBuf):
             if sshv == 1:
                 rcrc = SSH1.crc32(padding + payload)
                 if crc != rcrc:
-                    self.__outputbuffer.fail('[exception] packet checksum CRC32 mismatch.').write()
+                    self.__outputbuffer.error('[exception] packet checksum CRC32 mismatch.').write()
                     sys.exit(exitcodes.CONNECTION_ERROR)
             else:
                 self.ensure_read(padding_length)