From bbbdf71e50211e2dd8c1fc5a8c2ff85150e1dd54 Mon Sep 17 00:00:00 2001 From: Daniel Lenski Date: Sat, 6 Jul 2024 17:56:24 -0700 Subject: [PATCH] Recognize LANcom LCOS software and support ed448 key extraction (#277) * Include raw hostkey bytes in debug output * Recognize LANcom LCOS software and support extraction of ssh-ed448 key type LANcom router devices appear to be primarily used in Germany (see [1] for examples on the public Internet), and they appear to support the `ssh-ed448` key type which is documented in [2], but which has never been supported by any as-yet-released version of OpenSSH. [1] https://www.shodan.io/search?query=ssh+%22ed448%22 [2] https://datatracker.ietf.org/doc/html/rfc8709#name-public-key-format --- src/ssh_audit/hostkeytest.py | 4 ++++ src/ssh_audit/kexdh.py | 3 +++ src/ssh_audit/software.py | 4 ++++ 3 files changed, 11 insertions(+) diff --git a/src/ssh_audit/hostkeytest.py b/src/ssh_audit/hostkeytest.py index b01b8d2..18f786f 100644 --- a/src/ssh_audit/hostkeytest.py +++ b/src/ssh_audit/hostkeytest.py @@ -52,6 +52,9 @@ class HostKeyTest: 'ssh-ed25519': {'cert': False, 'variable_key_len': False}, 'ssh-ed25519-cert-v01@openssh.com': {'cert': True, 'variable_key_len': False}, + + 'ssh-ed448': {'cert': False, 'variable_key_len': False}, + # 'ssh-ed448-cert-v01@openssh.com': {'cert': True, 'variable_key_len': False}, } TWO2K_MODULUS_WARNING = '2048-bit modulus only provides 112-bits of symmetric strength' @@ -158,6 +161,7 @@ class HostKeyTest: ca_key_type = kex_group.get_ca_type() ca_modulus_size = kex_group.get_ca_size() out.d("Hostkey type: [%s]; hostkey size: %u; CA type: [%s]; CA modulus size: %u" % (host_key_type, hostkey_modulus_size, ca_key_type, ca_modulus_size), write_now=True) + out.d("Raw hostkey bytes (%d): [%s]" % (len(raw_hostkey_bytes), raw_hostkey_bytes.hex()), write_now=True) # Record all the host key info. server_kex.set_host_key(host_key_type, raw_hostkey_bytes, hostkey_modulus_size, ca_key_type, ca_modulus_size) diff --git a/src/ssh_audit/kexdh.py b/src/ssh_audit/kexdh.py index 85beb8e..7335334 100644 --- a/src/ssh_audit/kexdh.py +++ b/src/ssh_audit/kexdh.py @@ -134,6 +134,9 @@ class KexDH: # pragma: nocover if self.__hostkey_type == 'ssh-ed25519': self.out.d("%s has a fixed host key modulus of 32." % self.__hostkey_type) self.__hostkey_n_len = 32 + elif self.__hostkey_type == 'ssh-ed448': + self.out.d("%s has a fixed host key modulus of 57." % self.__hostkey_type) + self.__hostkey_n_len = 57 else: # Here is the modulus size & actual modulus of the host key public key. hostkey_n, self.__hostkey_n_len, ptr = KexDH.__get_bytes(hostkey, ptr) diff --git a/src/ssh_audit/software.py b/src/ssh_audit/software.py index f13ebeb..21e22ca 100644 --- a/src/ssh_audit/software.py +++ b/src/ssh_audit/software.py @@ -224,4 +224,8 @@ class Software: mx = re.match(r'^PuTTY_Release_(.*)', software) if mx: return cls(None, Product.PuTTY, mx.group(1), None, None) + mx = re.match(r'^lancom(.*)', software) + if mx: + v, p = 'LANcom', 'LCOS sshd' + return cls(v, p, mx.group(1), None, None) return None