Merge e3e3657f2b into ea117b203b

Because the `HostKeyTest` class was mutating its static/global
`HOST_KEY_TYPES` dict, this class could not actually be used more than once
in a single thread!

Rather than mutate this dict after parsing each key type
(`HOST_KEY_TYPES[host_key_type]['parsed'] = True`), the `perform_test`
method should simple add the parsed key types to a local `set()`.

README.md

@@ -202,7 +202,7 @@ To install from Dockerhub:
 ```
 $ docker pull positronsecurity/ssh-audit
 ```
-(Then run with: `docker run -it -p 2222:2222 positronsecurity/ssh-audit 10.1.1.1`)
+(Then run with: `docker run -it --rm -p 2222:2222 positronsecurity/ssh-audit 10.1.1.1`)
 
 The status of various other platform packages can be found below (via Repology):
 
@@ -213,6 +213,12 @@ For convenience, a web front-end on top of the command-line tool is available at
 
 ## ChangeLog
 
+### v3.3.0-dev (???)
+ - Added built-in policies for Ubuntu 24.04 LTS server and client, and OpenSSH 9.8.
+ - Added IPv6 support for DHEat and connection rate tests.
+ - 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).
+
 ### 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)).
  - Expanded filter of CBC ciphers to flag for the Terrapin vulnerability.  It now includes more rarely found ciphers.

src/ssh_audit/builtin_policies.py

@@ -49,6 +49,7 @@ BUILTIN_POLICIES: Dict[str, Dict[str, Union[Optional[str], Optional[List[str]],
 
     'Hardened Ubuntu Server 22.04 LTS (version 5)': {'version': '5', 'changelog': 'Added kex-strict-s-v00@openssh.com to kex list.', 'banner': None, 'compressions': None, 'host_keys': ['rsa-sha2-512', 'rsa-sha2-256', 'ssh-ed25519'], 'optional_host_keys': ['sk-ssh-ed25519@openssh.com', 'ssh-ed25519-cert-v01@openssh.com', 'sk-ssh-ed25519-cert-v01@openssh.com', 'rsa-sha2-256-cert-v01@openssh.com', 'rsa-sha2-512-cert-v01@openssh.com'], 'kex': ['sntrup761x25519-sha512@openssh.com', 'curve25519-sha256', 'curve25519-sha256@libssh.org', 'diffie-hellman-group16-sha512', 'diffie-hellman-group18-sha512', 'diffie-hellman-group-exchange-sha256', 'kex-strict-s-v00@openssh.com'], 'ciphers': ['chacha20-poly1305@openssh.com', 'aes256-gcm@openssh.com', 'aes128-gcm@openssh.com', 'aes256-ctr', 'aes192-ctr', 'aes128-ctr'], 'macs': ['hmac-sha2-256-etm@openssh.com', 'hmac-sha2-512-etm@openssh.com', 'umac-128-etm@openssh.com'], 'hostkey_sizes': {"rsa-sha2-256": {"hostkey_size": 4096}, "rsa-sha2-256-cert-v01@openssh.com": {"ca_key_size": 4096, "ca_key_type": "ssh-rsa", "hostkey_size": 4096}, "rsa-sha2-512": {"hostkey_size": 4096}, "rsa-sha2-512-cert-v01@openssh.com": {"ca_key_size": 4096, "ca_key_type": "ssh-rsa", "hostkey_size": 4096}, "sk-ssh-ed25519-cert-v01@openssh.com": {"ca_key_size": 256, "ca_key_type": "ssh-ed25519", "hostkey_size": 256}, "sk-ssh-ed25519@openssh.com": {"hostkey_size": 256}, "ssh-ed25519": {"hostkey_size": 256}, "ssh-ed25519-cert-v01@openssh.com": {"ca_key_size": 256, "ca_key_type": "ssh-ed25519", "hostkey_size": 256}}, 'dh_modulus_sizes': {'diffie-hellman-group-exchange-sha256': 3072}, 'server_policy': True},
 
+    'Hardened Ubuntu Server 24.04 LTS (version 1)': {'version': '1', 'changelog': 'Initial version.', 'banner': None, 'compressions': None, 'host_keys': ['ssh-ed25519', 'rsa-sha2-512', 'rsa-sha2-256'], 'optional_host_keys': ['sk-ssh-ed25519@openssh.com', 'ssh-ed25519-cert-v01@openssh.com', 'sk-ssh-ed25519-cert-v01@openssh.com', 'rsa-sha2-256-cert-v01@openssh.com', 'rsa-sha2-512-cert-v01@openssh.com'], 'kex': ['sntrup761x25519-sha512@openssh.com', 'curve25519-sha256', 'curve25519-sha256@libssh.org', 'diffie-hellman-group18-sha512', 'diffie-hellman-group-exchange-sha256', 'diffie-hellman-group16-sha512', 'ext-info-s', 'kex-strict-s-v00@openssh.com'], 'ciphers': ['chacha20-poly1305@openssh.com', 'aes256-gcm@openssh.com', 'aes256-ctr', 'aes192-ctr', 'aes128-gcm@openssh.com', 'aes128-ctr'], 'macs': ['hmac-sha2-512-etm@openssh.com', 'hmac-sha2-256-etm@openssh.com', 'umac-128-etm@openssh.com'], 'hostkey_sizes': {"rsa-sha2-256": {"hostkey_size": 4096}, "rsa-sha2-256-cert-v01@openssh.com": {"ca_key_size": 4096, "ca_key_type": "ssh-rsa", "hostkey_size": 4096}, "rsa-sha2-512": {"hostkey_size": 4096}, "rsa-sha2-512-cert-v01@openssh.com": {"ca_key_size": 4096, "ca_key_type": "ssh-rsa", "hostkey_size": 4096}, "sk-ssh-ed25519-cert-v01@openssh.com": {"ca_key_size": 256, "ca_key_type": "ssh-ed25519", "hostkey_size": 256}, "sk-ssh-ed25519@openssh.com": {"hostkey_size": 256}, "ssh-ed25519": {"hostkey_size": 256}, "ssh-ed25519-cert-v01@openssh.com": {"ca_key_size": 256, "ca_key_type": "ssh-ed25519", "hostkey_size": 256}}, 'dh_modulus_sizes': {'diffie-hellman-group-exchange-sha256': 3072}, 'server_policy': True},
 
     # Generic OpenSSH Server policies
 
@@ -94,6 +95,8 @@ BUILTIN_POLICIES: Dict[str, Dict[str, Union[Optional[str], Optional[List[str]],
 
     'Hardened OpenSSH Server v9.7 (version 1)': {'version': '1', 'changelog': 'Initial version.', 'banner': None, 'compressions': None, 'host_keys': ['rsa-sha2-512', 'rsa-sha2-256', 'ssh-ed25519'], 'optional_host_keys': ['sk-ssh-ed25519@openssh.com', 'ssh-ed25519-cert-v01@openssh.com', 'sk-ssh-ed25519-cert-v01@openssh.com', 'rsa-sha2-256-cert-v01@openssh.com', 'rsa-sha2-512-cert-v01@openssh.com'], 'kex': ['sntrup761x25519-sha512@openssh.com', 'curve25519-sha256', 'curve25519-sha256@libssh.org', 'diffie-hellman-group16-sha512', 'diffie-hellman-group18-sha512', 'diffie-hellman-group-exchange-sha256', 'ext-info-s', 'kex-strict-s-v00@openssh.com'], 'ciphers': ['chacha20-poly1305@openssh.com', 'aes256-gcm@openssh.com', 'aes128-gcm@openssh.com', 'aes256-ctr', 'aes192-ctr', 'aes128-ctr'], 'macs': ['hmac-sha2-256-etm@openssh.com', 'hmac-sha2-512-etm@openssh.com', 'umac-128-etm@openssh.com'], 'hostkey_sizes': {"rsa-sha2-256": {"hostkey_size": 4096}, "rsa-sha2-256-cert-v01@openssh.com": {"ca_key_size": 4096, "ca_key_type": "ssh-rsa", "hostkey_size": 4096}, "rsa-sha2-512": {"hostkey_size": 4096}, "rsa-sha2-512-cert-v01@openssh.com": {"ca_key_size": 4096, "ca_key_type": "ssh-rsa", "hostkey_size": 4096}, "sk-ssh-ed25519-cert-v01@openssh.com": {"ca_key_size": 256, "ca_key_type": "ssh-ed25519", "hostkey_size": 256}, "sk-ssh-ed25519@openssh.com": {"hostkey_size": 256}, "ssh-ed25519": {"hostkey_size": 256}, "ssh-ed25519-cert-v01@openssh.com": {"ca_key_size": 256, "ca_key_type": "ssh-ed25519", "hostkey_size": 256}}, 'dh_modulus_sizes': {'diffie-hellman-group-exchange-sha256': 3072}, 'server_policy': True},
 
+    'Hardened OpenSSH Server v9.8 (version 1)': {'version': '1', 'changelog': 'Initial version.', 'banner': None, 'compressions': None, 'host_keys': ['rsa-sha2-512', 'rsa-sha2-256', 'ssh-ed25519'], 'optional_host_keys': ['sk-ssh-ed25519@openssh.com', 'ssh-ed25519-cert-v01@openssh.com', 'sk-ssh-ed25519-cert-v01@openssh.com', 'rsa-sha2-256-cert-v01@openssh.com', 'rsa-sha2-512-cert-v01@openssh.com'], 'kex': ['sntrup761x25519-sha512@openssh.com', 'curve25519-sha256', 'curve25519-sha256@libssh.org', 'diffie-hellman-group16-sha512', 'diffie-hellman-group18-sha512', 'diffie-hellman-group-exchange-sha256', 'ext-info-s', 'kex-strict-s-v00@openssh.com'], 'ciphers': ['chacha20-poly1305@openssh.com', 'aes256-gcm@openssh.com', 'aes128-gcm@openssh.com', 'aes256-ctr', 'aes192-ctr', 'aes128-ctr'], 'macs': ['hmac-sha2-256-etm@openssh.com', 'hmac-sha2-512-etm@openssh.com', 'umac-128-etm@openssh.com'], 'hostkey_sizes': {"rsa-sha2-256": {"hostkey_size": 4096}, "rsa-sha2-256-cert-v01@openssh.com": {"ca_key_size": 4096, "ca_key_type": "ssh-rsa", "hostkey_size": 4096}, "rsa-sha2-512": {"hostkey_size": 4096}, "rsa-sha2-512-cert-v01@openssh.com": {"ca_key_size": 4096, "ca_key_type": "ssh-rsa", "hostkey_size": 4096}, "sk-ssh-ed25519-cert-v01@openssh.com": {"ca_key_size": 256, "ca_key_type": "ssh-ed25519", "hostkey_size": 256}, "sk-ssh-ed25519@openssh.com": {"hostkey_size": 256}, "ssh-ed25519": {"hostkey_size": 256}, "ssh-ed25519-cert-v01@openssh.com": {"ca_key_size": 256, "ca_key_type": "ssh-ed25519", "hostkey_size": 256}}, 'dh_modulus_sizes': {'diffie-hellman-group-exchange-sha256': 3072}, 'server_policy': True},
+
 
     # Amazon Linux Policies
 
@@ -109,7 +112,6 @@ BUILTIN_POLICIES: Dict[str, Dict[str, Union[Optional[str], Optional[List[str]],
 
     'Hardened Rocky Linux Client 9 (version 1)': {'version': '1', 'changelog': 'Initial version.', 'banner': None, 'compressions': None, 'host_keys': ['sk-ssh-ed25519-cert-v01@openssh.com', 'ssh-ed25519-cert-v01@openssh.com', 'rsa-sha2-512-cert-v01@openssh.com', 'rsa-sha2-256-cert-v01@openssh.com', 'sk-ssh-ed25519@openssh.com', 'ssh-ed25519', 'rsa-sha2-512', 'rsa-sha2-256'], 'optional_host_keys': None, 'kex': ['sntrup761x25519-sha512@openssh.com', 'curve25519-sha256', 'curve25519-sha256@libssh.org', 'diffie-hellman-group16-sha512', 'diffie-hellman-group18-sha512', 'diffie-hellman-group-exchange-sha256', 'ext-info-c', 'kex-strict-c-v00@openssh.com'], 'ciphers': ['chacha20-poly1305@openssh.com', 'aes256-gcm@openssh.com', 'aes128-gcm@openssh.com', 'aes256-ctr', 'aes192-ctr', 'aes128-ctr'], 'macs': ['hmac-sha2-256-etm@openssh.com', 'hmac-sha2-512-etm@openssh.com', 'umac-128-etm@openssh.com'], 'hostkey_sizes': None, 'dh_modulus_sizes': None, 'server_policy': False},
 
-
     # Ubuntu Client policies
 
     'Hardened Ubuntu Client 16.04 LTS (version 2)': {'version': '2', 'changelog': 'No change log available.', 'banner': None, 'compressions': None, 'host_keys': ['ssh-ed25519', 'ssh-ed25519-cert-v01@openssh.com', 'rsa-sha2-256', 'rsa-sha2-512'], 'optional_host_keys': None, 'kex': ['curve25519-sha256@libssh.org', 'diffie-hellman-group-exchange-sha256', 'ext-info-c'], 'ciphers': ['chacha20-poly1305@openssh.com', 'aes256-gcm@openssh.com', 'aes128-gcm@openssh.com', 'aes256-ctr', 'aes192-ctr', 'aes128-ctr'], 'macs': ['hmac-sha2-256-etm@openssh.com', 'hmac-sha2-512-etm@openssh.com', 'umac-128-etm@openssh.com'], 'hostkey_sizes': None, 'dh_modulus_sizes': None, 'server_policy': False},
@@ -120,5 +122,6 @@ BUILTIN_POLICIES: Dict[str, Dict[str, Union[Optional[str], Optional[List[str]],
 
     'Hardened Ubuntu Client 22.04 LTS (version 4)': {'version': '4', 'changelog': 'Added kex-strict-c-v00@openssh.com to kex list.', 'banner': None, 'compressions': None, 'host_keys': ['sk-ssh-ed25519-cert-v01@openssh.com', 'ssh-ed25519-cert-v01@openssh.com', 'rsa-sha2-512-cert-v01@openssh.com', 'rsa-sha2-256-cert-v01@openssh.com', 'sk-ssh-ed25519@openssh.com', 'ssh-ed25519', 'rsa-sha2-512', 'rsa-sha2-256'], 'optional_host_keys': None, 'kex': ['sntrup761x25519-sha512@openssh.com', 'curve25519-sha256', 'curve25519-sha256@libssh.org', 'diffie-hellman-group16-sha512', 'diffie-hellman-group18-sha512', 'diffie-hellman-group-exchange-sha256', 'ext-info-c', 'kex-strict-c-v00@openssh.com'], 'ciphers': ['chacha20-poly1305@openssh.com', 'aes256-gcm@openssh.com', 'aes128-gcm@openssh.com', 'aes256-ctr', 'aes192-ctr', 'aes128-ctr'], 'macs': ['hmac-sha2-256-etm@openssh.com', 'hmac-sha2-512-etm@openssh.com', 'umac-128-etm@openssh.com'], 'hostkey_sizes': None, 'dh_modulus_sizes': None, 'server_policy': False},
 
+    'Hardened Ubuntu Client 24.04 LTS (version 1)': {'version': '1', 'changelog': 'Initial version.', 'banner': None, 'compressions': None, 'host_keys': ['sk-ssh-ed25519-cert-v01@openssh.com', 'ssh-ed25519-cert-v01@openssh.com', 'rsa-sha2-512-cert-v01@openssh.com', 'rsa-sha2-256-cert-v01@openssh.com', 'sk-ssh-ed25519@openssh.com', 'ssh-ed25519', 'rsa-sha2-512', 'rsa-sha2-256'], 'optional_host_keys': None, 'kex': ['sntrup761x25519-sha512@openssh.com', 'curve25519-sha256', 'curve25519-sha256@libssh.org', 'diffie-hellman-group18-sha512', 'diffie-hellman-group-exchange-sha256', 'diffie-hellman-group16-sha512', 'ext-info-c', 'kex-strict-c-v00@openssh.com'], 'ciphers': ['chacha20-poly1305@openssh.com', 'aes256-gcm@openssh.com', 'aes256-ctr', 'aes192-ctr', 'aes128-gcm@openssh.com', 'aes128-ctr'], 'macs': ['hmac-sha2-512-etm@openssh.com', 'hmac-sha2-256-etm@openssh.com', 'umac-128-etm@openssh.com'], 'hostkey_sizes': None, 'dh_modulus_sizes': None, 'server_policy': False},
 
 }

src/ssh_audit/dheat.py

@@ -160,6 +160,11 @@ class DHEat:
         # The SSH2_Kex object that we recieved from the server in a prior connection.  We'll use it as a template to craft our own kex.
         self.kex = kex
 
+        # Resolve the target to an IP address depending on the user preferences (IPv4 or IPv6).
+        self.debug("Resolving target %s..." % self.target)
+        self.target_address_family, self.target_ip_address = DHEat._resolve_hostname(self.target, aconf.ip_version_preference)
+        self.debug("Resolved %s to %s (address family %u)" % (self.target, self.target_ip_address, self.target_address_family))
+
         # The connection and read timeouts.
         self.connect_timeout = aconf.timeout
         self.read_timeout = aconf.timeout
@@ -324,6 +329,11 @@ class DHEat:
             print("\n%sUnfortunately, this feature is not currently functional under Windows.%s  This should get fixed in a future release.  See: <https://github.com/jtesta/ssh-audit/issues/261>" % (DHEat.YELLOWB, DHEat.CLEAR))
             return ""
 
+        # Resolve the target into an IP address
+        out.d("Resolving target %s..." % aconf.host)
+        target_address_family, target_ip_address = DHEat._resolve_hostname(aconf.host, aconf.ip_version_preference)
+        out.d("Resolved %s to %s (address family %u)" % (aconf.host, target_ip_address, target_address_family))
+
         spinner = ["-", "\\", "|", "/"]
         spinner_index = 0
 
@@ -349,7 +359,7 @@ class DHEat:
                 rate_str = " at a max rate of %s%u%s connections per second" % (DHEat.WHITEB, aconf.conn_rate_test_target_rate, DHEat.CLEAR)
 
             print()
-            print("Performing non-disruptive rate test against %s[%s]:%u%s with %s%u%s concurrent sockets%s.  No Diffie-Hellman requests will be sent." % (DHEat.WHITEB, aconf.host, aconf.port, DHEat.CLEAR, DHEat.WHITEB, concurrent_sockets, DHEat.CLEAR, rate_str))
+            print("Performing non-disruptive rate test against %s[%s]:%u%s with %s%u%s concurrent sockets%s.  No Diffie-Hellman requests will be sent." % (DHEat.WHITEB, target_ip_address, aconf.port, DHEat.CLEAR, DHEat.WHITEB, concurrent_sockets, DHEat.CLEAR, rate_str))
             print()
 
             # Make room for the multi-line output.
@@ -426,11 +436,11 @@ class DHEat:
 
             # Open new sockets until we've hit the number of concurrent sockets, or if we exceeded the number of maximum connections.
             while (len(socket_dict) < concurrent_sockets) and (len(socket_dict) + num_opened_connections < max_connections):
-                s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+                s = socket.socket(target_address_family, socket.SOCK_STREAM)
                 s.setblocking(False)
 
                 # out.d("Creating socket (%u of %u already exist)..." % (len(socket_dict), concurrent_sockets), write_now=True)
-                ret = s.connect_ex((aconf.host, aconf.port))
+                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.
                     socket_dict[s] = now
@@ -743,6 +753,22 @@ class DHEat:
         print()
 
 
+    @staticmethod
+    def _resolve_hostname(host: str, ip_version_preference: List[int]) -> Tuple[int, str]:
+        '''Resolves a hostname to its IPv4 or IPv6 address, depending on user preference.'''
+
+        family = socket.AF_UNSPEC
+        if len(ip_version_preference) == 1:
+            family = socket.AF_INET if ip_version_preference[0] == 4 else socket.AF_INET6
+
+        r = socket.getaddrinfo(host, 0, family, socket.SOCK_STREAM)
+        for address_family, socktype, _, _, addr in r:
+            if socktype == socket.SOCK_STREAM:
+                return address_family, addr[0]
+
+        return -1, ''
+
+
     def _run(self) -> bool:
         '''Where all the magic happens.'''
 
@@ -751,7 +777,7 @@ class DHEat:
         if sys.platform == "win32":
             self.output("%sWARNING:%s this feature has not been thoroughly tested on Windows.  It may perform worse than on UNIX OSes." % (self.YELLOWB, self.CLEAR))
 
-        self.output("Running DHEat test against %s[%s]:%u%s with %s%u%s concurrent sockets..." % (self.WHITEB, self.target, self.port, self.CLEAR, self.WHITEB, self.concurrent_connections, self.CLEAR))
+        self.output("Running DHEat test against %s[%s]:%u%s with %s%u%s concurrent sockets..." % (self.WHITEB, self.target_ip_address, self.port, self.CLEAR, self.WHITEB, self.concurrent_connections, self.CLEAR))
 
         # If the user didn't specify an exact kex algorithm to test, check our prioritized list against what the server supports.  Larger p-values (such as group18: 8192-bits) cause the most strain on the server.
         chosen_alg = ""
@@ -894,7 +920,8 @@ class DHEat:
 
         # Copy variables from the object (which might exist in another process?).  This might cut down on inter-process overhead.
         connect_timeout = self.connect_timeout
-        target = self.target
+        target_ip_address = self.target_ip_address
+        target_address_family = self.target_address_family
         port = self.port
 
         # Determine if we are attacking with a GEX.
@@ -945,17 +972,17 @@ class DHEat:
                 num_socket_exceptions = 0
                 num_openssh_throttled_connections = 0
 
-            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            s = socket.socket(target_address_family, socket.SOCK_STREAM)
             s.settimeout(connect_timeout)
 
             # Loop until a successful TCP connection is made.
             connected = False
             while not connected:
 
-                # self.debug("Connecting to %s:%d" % (self.target, self.port))
+                # self.debug("Connecting to %s:%d" % (self.target_ip_address, self.port))
                 try:
                     num_attempted_tcp_connections += 1
-                    s.connect((target, port))
+                    s.connect((target_ip_address, port))
                     connected = True
                 except OSError as e:
                     self.debug("Failed to connect: %s" % str(e))

src/ssh_audit/globals.py

@@ -22,7 +22,7 @@
    THE SOFTWARE.
 """
 # The version to display.
-VERSION = 'v3.2.0'
+VERSION = 'v3.3.0-dev'
 
 # SSH software to impersonate
 SSH_HEADER = 'SSH-{0}-OpenSSH_8.2'

src/ssh_audit/hostkeytest.py

@@ -40,7 +40,7 @@ class HostKeyTest:
     # Tracks the RSA host key types.  As of this writing, testing one in this family yields valid results for the rest.
     RSA_FAMILY = ['ssh-rsa', 'rsa-sha2-256', 'rsa-sha2-512']
 
-    # Dict holding the host key types we should extract & parse.  'cert' is True to denote that a host key type handles certificates (thus requires additional parsing).  'variable_key_len' is True for host key types that can have variable sizes (True only for RSA types, as the rest are of fixed-size).  After the host key type is fully parsed, the key 'parsed' is added with a value of True.
+    # Dict holding the host key types we should extract & parse.  'cert' is True to denote that a host key type handles certificates (thus requires additional parsing).  'variable_key_len' is True for host key types that can have variable sizes (True only for RSA types, as the rest are of fixed-size).
     HOST_KEY_TYPES = {
         'ssh-rsa':      {'cert': False, 'variable_key_len': True},
         'rsa-sha2-256': {'cert': False, 'variable_key_len': True},
@@ -93,6 +93,7 @@ class HostKeyTest:
     def perform_test(out: 'OutputBuffer', s: 'SSH_Socket', server_kex: 'SSH2_Kex', kex_str: str, kex_group: 'KexDH', host_key_types: Dict[str, Dict[str, bool]]) -> None:
         hostkey_modulus_size = 0
         ca_modulus_size = 0
+        parsed_host_key_types = set()
 
         # If the connection still exists, close it so we can test
         # using a clean slate (otherwise it may exist in a non-testable
@@ -106,7 +107,7 @@ class HostKeyTest:
             key_warn_comments = []
 
             # Skip those already handled (i.e.: those in the RSA family, as testing one tests them all).
-            if 'parsed' in host_key_types[host_key_type] and host_key_types[host_key_type]['parsed']:
+            if host_key_type in parsed_host_key_types:
                 continue
 
             # If this host key type is supported by the server, we test it.
@@ -216,7 +217,7 @@ class HostKeyTest:
                 # If this host key type is in the RSA family, then mark them all as parsed (since results in one are valid for them all).
                 if host_key_type in HostKeyTest.RSA_FAMILY:
                     for rsa_type in HostKeyTest.RSA_FAMILY:
-                        host_key_types[rsa_type]['parsed'] = True
+                        parsed_host_key_types.add(rsa_type)
 
                         # If the current key is a member of the RSA family, then populate all RSA family members with the same
                         # failure and/or warning comments.
@@ -228,7 +229,7 @@ class HostKeyTest:
                         db['key'][rsa_type][2].extend(key_warn_comments)
 
                 else:
-                    host_key_types[host_key_type]['parsed'] = True
+                    parsed_host_key_types.add(host_key_type)
                     db = SSH2_KexDB.get_db()
                     while len(db['key'][host_key_type]) < 3:
                         db['key'][host_key_type].append([])

src/ssh_audit/policy.py

@@ -605,3 +605,29 @@ macs = %s
             dh_modulus_sizes_str = str(self._dh_modulus_sizes)
 
         return "Name: %s\nVersion: %s\nAllow Algorithm Subset and/or Reordering: %r\nBanner: %s\nCompressions: %s\nHost Keys: %s\nOptional Host Keys: %s\nKey Exchanges: %s\nCiphers: %s\nMACs: %s\nHost Key Sizes: %s\nDH Modulus Sizes: %s\nServer Policy: %r" % (name, version, self._allow_algorithm_subset_and_reordering, banner, compressions_str, host_keys_str, optional_host_keys_str, kex_str, ciphers_str, macs_str, hostkey_sizes_str, dh_modulus_sizes_str, self._server_policy)
+
+
+    def __getstate__(self) -> Dict[str, Any]:
+        '''Called when pickling this object.  The file descriptor isn't serializable, so we'll remove it from the state and include a string representation.'''
+
+        state = self.__dict__.copy()
+
+        if state['_warning_target'] == sys.stdout:
+            state['_warning_target_type'] = 'stdout'
+        else:
+            state['_warning_target_type'] = 'stderr'
+
+        del state['_warning_target']
+        return state
+
+
+    def __setstate__(self, state: Dict[str, Any]) -> None:
+        '''Called when unpickling this object.  Based on the string representation of the file descriptor, we'll restore the right handle.'''
+
+        if state['_warning_target_type'] == 'stdout':
+            state['_warning_target'] = sys.stdout
+        else:
+            state['_warning_target'] = sys.stderr
+
+        del state['_warning_target_type']
+        self.__dict__.update(state)

src/ssh_audit/ssh_audit.py

@@ -421,6 +421,8 @@ def output_recommendations(out: OutputBuffer, algs: Algorithms, algorithm_recomm
 
                         fn = level_to_output[level]
 
+                        an = '?'
+                        sg = '?'
                         if action == 'del':
                             an, sg = 'remove', '-'
                             ret = False
@@ -456,7 +458,7 @@ def output_info(out: OutputBuffer, software: Optional['Software'], client_audit:
 
         # If any warnings or failures were given, print a link to the hardening guides.
         if any_problems:
-            out.warn('(nfo) For hardening guides on common OSes, please see: <https://www.ssh-audit.com/hardening_guides.html>')
+            out.warn('(nfo) For hardening guides on common OSes, please see: < https://www.ssh-audit.com/hardening_guides.html >')
 
         # Add any additional notes.
         for additional_note in additional_notes:
@@ -721,7 +723,7 @@ def output(out: OutputBuffer, aconf: AuditConf, banner: Optional[Banner], header
         # Build & write the JSON struct.
         out.info(json.dumps(build_struct(aconf.host + ":" + str(aconf.port), banner, cves, kex=kex, client_host=client_host, software=software, algorithms=algs, algorithm_recommendation_suppress_list=algorithm_recommendation_suppress_list, additional_notes=additional_notes), indent=4 if aconf.json_print_indent else None, sort_keys=True))
     elif len(unknown_algorithms) > 0:  # If we encountered any unknown algorithms, ask the user to report them.
-        out.warn("\n\n!!! WARNING: unknown algorithm(s) found!: %s.  Please email the full output above to the maintainer (jtesta@positronsecurity.com), or create a Github issue at <https://github.com/jtesta/ssh-audit/issues>.\n" % ','.join(unknown_algorithms))
+        out.warn("\n\n!!! WARNING: unknown algorithm(s) found!: %s.  Please email the full output above to the maintainer (jtesta@positronsecurity.com), or create a Github issue at < https://github.com/jtesta/ssh-audit/issues >.\n" % ','.join(unknown_algorithms))
 
     return program_retval