Adding upstream version 3.1.0.upstream/3.1.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 468 insertions, 0 deletions

diff --git a/src/ssh_audit/ssh2_kexdb.py b/src/ssh_audit/ssh2_kexdb.py
new file mode 100644
index 0000000..36130da
--- /dev/null
+++ b/src/ssh_audit/ssh2_kexdb.py
@@ -0,0 +1,468 @@
+"""
+   The MIT License (MIT)
+
+   Copyright (C) 2017-2023 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
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+"""
+# pylint: disable=unused-import
+import copy
+import threading
+
+from typing import Dict, List, Set, Sequence, Tuple, Iterable  # noqa: F401
+from typing import Callable, Optional, Union, Any  # noqa: F401
+
+
+class SSH2_KexDB:  # pylint: disable=too-few-public-methods
+    FAIL_1024BIT_MODULUS = 'using small 1024-bit modulus'
+    FAIL_3DES = 'using broken & deprecated 3DES cipher'
+    FAIL_BLOWFISH = 'using weak & deprecated Blowfish cipher'
+    FAIL_CAST = 'using weak & deprecated CAST cipher'
+    FAIL_DES = 'using broken DES cipher'
+    FAIL_IDEA = 'using deprecated IDEA cipher'
+    FAIL_LOGJAM_ATTACK = 'vulnerable to the Logjam attack: https://en.wikipedia.org/wiki/Logjam_(computer_security)'
+    FAIL_MD5 = 'using broken MD5 hash algorithm'
+    FAIL_NSA_BACKDOORED_CURVE = 'using elliptic curves that are suspected as being backdoored by the U.S. National Security Agency'
+    FAIL_PLAINTEXT = 'no encryption/integrity'
+    FAIL_RC4 = 'using broken RC4 cipher'
+    FAIL_RIJNDAEL = 'using deprecated & non-standardized Rijndael cipher'
+    FAIL_RIPEMD = 'using deprecated RIPEMD hash algorithm'
+    FAIL_SEED = 'using deprecated SEED cipher'
+    FAIL_SERPENT = 'using deprecated Serpent cipher'
+    FAIL_SHA1 = 'using broken SHA-1 hash algorithm'
+    FAIL_SMALL_ECC_MODULUS = 'using small ECC modulus'
+    FAIL_UNKNOWN = 'using unknown algorithm'
+    FAIL_UNPROVEN = 'using unproven algorithm'
+    FAIL_UNTRUSTED = 'using untrusted algorithm developed in secret by a government entity'
+
+    WARN_2048BIT_MODULUS = '2048-bit modulus only provides 112-bits of symmetric strength'
+    WARN_BLOCK_SIZE = 'using small 64-bit block size'
+    WARN_CIPHER_MODE = 'using weak cipher mode'
+    WARN_ENCRYPT_AND_MAC = 'using encrypt-and-MAC mode'
+    WARN_EXPERIMENTAL = 'using experimental algorithm'
+    WARN_RNDSIG_KEY = 'using weak random number generator could reveal the key'
+    WARN_TAG_SIZE = 'using small 64-bit tag size'
+    WARN_TAG_SIZE_96 = 'using small 96-bit tag size'
+
+    INFO_DEFAULT_OPENSSH_CIPHER = 'default cipher since OpenSSH 6.9'
+    INFO_DEFAULT_OPENSSH_KEX = 'default key exchange since OpenSSH 6.4'
+    INFO_DEPRECATED_IN_OPENSSH88 = 'deprecated in OpenSSH 8.8: https://www.openssh.com/txt/release-8.8'
+    INFO_DISABLED_IN_DBEAR67 = 'disabled in Dropbear SSH 2015.67'
+    INFO_DISABLED_IN_OPENSSH70 = 'disabled in OpenSSH 7.0: https://www.openssh.com/txt/release-7.0'
+    INFO_NEVER_IMPLEMENTED_IN_OPENSSH = 'despite the @openssh.com tag, this was never implemented in OpenSSH'
+    INFO_REMOVED_IN_OPENSSH61 = 'removed since OpenSSH 6.1, removed from specification'
+    INFO_REMOVED_IN_OPENSSH69 = 'removed in OpenSSH 6.9: https://www.openssh.com/txt/release-6.9'
+    INFO_REMOVED_IN_OPENSSH70 = 'removed in OpenSSH 7.0: https://www.openssh.com/txt/release-7.0'
+    INFO_WITHDRAWN_PQ_ALG = 'the sntrup4591761 algorithm was withdrawn, as it may not provide strong post-quantum security'
+    INFO_EXTENSION_NEGOTIATION = 'pseudo-algorithm that denotes the peer supports RFC8308 extensions'
+    INFO_STRICT_KEX = 'pseudo-algorithm that denotes the peer supports a stricter key exchange method as a counter-measure to the Terrapin attack (CVE-2023-48795)'
+
+    # Maintains a dictionary per calling thread that yields its own copy of MASTER_DB.  This prevents results from one thread polluting the results of another thread.
+    DB_PER_THREAD: Dict[int, Dict[str, Dict[str, List[List[Optional[str]]]]]] = {}
+
+    MASTER_DB: Dict[str, Dict[str, List[List[Optional[str]]]]] = {
+        # Format: 'algorithm_name': [['version_first_appeared_in'], [reason_for_failure1, reason_for_failure2, ...], [warning1, warning2, ...], [info1, info2, ...]]
+        'kex': {
+            'Curve25519SHA256': [[]],
+            'curve25519-sha256': [['7.4,d2018.76'], [], [], [INFO_DEFAULT_OPENSSH_KEX]],
+            'curve25519-sha256@libssh.org': [['6.4,d2013.62,l10.6.0'], [], [], [INFO_DEFAULT_OPENSSH_KEX]],
+            'curve448-sha512': [[]],
+            'curve448-sha512@libssh.org': [[]],
+            'diffie-hellman-group14-sha1': [['3.9,d0.53,l10.6.0'], [FAIL_SHA1], [WARN_2048BIT_MODULUS]],
+            'diffie-hellman-group14-sha224@ssh.com': [[]],
+            'diffie-hellman-group14-sha256': [['7.3,d2016.73'], [], [WARN_2048BIT_MODULUS]],
+            'diffie-hellman-group14-sha256@ssh.com': [[], [], [WARN_2048BIT_MODULUS]],
+            'diffie-hellman-group15-sha256': [[]],
+            'diffie-hellman-group15-sha256@ssh.com': [[]],
+            'diffie-hellman-group15-sha384@ssh.com': [[]],
+            'diffie-hellman-group15-sha512': [[]],
+            'diffie-hellman-group16-sha256': [[]],
+            'diffie-hellman-group16-sha384@ssh.com': [[]],
+            'diffie-hellman-group16-sha512': [['7.3,d2016.73']],
+            'diffie-hellman-group16-sha512@ssh.com': [[]],
+            'diffie-hellman-group17-sha512': [[]],
+            'diffie-hellman_group17-sha512': [[]],
+            'diffie-hellman-group18-sha512': [['7.3']],
+            'diffie-hellman-group18-sha512@ssh.com': [[]],
+            'diffie-hellman-group1-sha1': [['2.3.0,d0.28,l10.2', '6.6', '6.9'], [FAIL_1024BIT_MODULUS, FAIL_LOGJAM_ATTACK, FAIL_SHA1], [], [INFO_REMOVED_IN_OPENSSH69]],
+            'diffie-hellman-group1-sha256': [[], [FAIL_1024BIT_MODULUS]],
+            'diffie-hellman-group-exchange-sha1': [['2.3.0', '6.6', None], [FAIL_SHA1]],
+            'diffie-hellman-group-exchange-sha224@ssh.com': [[]],
+            'diffie-hellman-group-exchange-sha256': [['4.4']],
+            'diffie-hellman-group-exchange-sha256@ssh.com': [[]],
+            'diffie-hellman-group-exchange-sha384@ssh.com': [[]],
+            'diffie-hellman-group-exchange-sha512@ssh.com': [[]],
+            'ecdh-nistp256-kyber-512r3-sha256-d00@openquantumsafe.org': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'ecdh-nistp384-kyber-768r3-sha384-d00@openquantumsafe.org': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'ecdh-nistp521-kyber-1024r3-sha512-d00@openquantumsafe.org': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'ecdh-sha2-1.2.840.10045.3.1.1': [[], [FAIL_SMALL_ECC_MODULUS, FAIL_NSA_BACKDOORED_CURVE]],  # NIST P-192 / secp192r1
+            'ecdh-sha2-1.2.840.10045.3.1.7': [[], [FAIL_NSA_BACKDOORED_CURVE]],  # NIST P-256 / secp256r1
+            'ecdh-sha2-1.3.132.0.10': [[]],  # ECDH over secp256k1 (i.e.: the Bitcoin curve)
+            'ecdh-sha2-1.3.132.0.16': [[], [FAIL_UNPROVEN]],  # sect283k1
+            'ecdh-sha2-1.3.132.0.1': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS]],  # sect163k1
+            'ecdh-sha2-1.3.132.0.26': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS]],  # sect233k1
+            'ecdh-sha2-1.3.132.0.27': [[], [FAIL_SMALL_ECC_MODULUS, FAIL_NSA_BACKDOORED_CURVE]],  # sect233r1
+            'ecdh-sha2-1.3.132.0.33': [[], [FAIL_SMALL_ECC_MODULUS, FAIL_NSA_BACKDOORED_CURVE]],  # NIST P-224 / secp224r1
+            'ecdh-sha2-1.3.132.0.34': [[], [FAIL_NSA_BACKDOORED_CURVE]],  # NIST P-384 / secp384r1
+            'ecdh-sha2-1.3.132.0.35': [[], [FAIL_NSA_BACKDOORED_CURVE]],  # NIST P-521 / secp521r1
+            'ecdh-sha2-1.3.132.0.36': [[], [FAIL_UNPROVEN]],  # sect409k1
+            'ecdh-sha2-1.3.132.0.37': [[], [FAIL_NSA_BACKDOORED_CURVE]],  # sect409r1
+            'ecdh-sha2-1.3.132.0.38': [[], [FAIL_UNPROVEN]],  # sect571k1
+
+            # Note: the base64 strings, according to draft 6 of RFC5656, is Base64(MD5(DER(OID))).  The final RFC5656 dropped the base64 strings in favor of plain OID concatenation, but apparently some SSH servers implement them anyway.  See: https://datatracker.ietf.org/doc/html/draft-green-secsh-ecc-06#section-9.2
+            'ecdh-sha2-4MHB+NBt3AlaSRQ7MnB4cg==': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS]],  # sect163k1
+            'ecdh-sha2-5pPrSUQtIaTjUSt5VZNBjg==': [[], [FAIL_SMALL_ECC_MODULUS, FAIL_NSA_BACKDOORED_CURVE]],  # NIST P-192 / secp192r1
+            'ecdh-sha2-9UzNcgwTlEnSCECZa7V1mw==': [[], [FAIL_NSA_BACKDOORED_CURVE]],  # NIST P-256 / secp256r1
+            'ecdh-sha2-brainpoolp256r1@genua.de': [[], [FAIL_UNPROVEN]],
+            'ecdh-sha2-brainpoolp384r1@genua.de': [[], [FAIL_UNPROVEN]],
+            'ecdh-sha2-brainpoolp521r1@genua.de': [[], [FAIL_UNPROVEN]],
+            'ecdh-sha2-curve25519': [[], []],
+            'ecdh-sha2-D3FefCjYoJ/kfXgAyLddYA==': [[], [FAIL_NSA_BACKDOORED_CURVE]],  # sect409r1
+            'ecdh-sha2-h/SsxnLCtRBh7I9ATyeB3A==': [[], [FAIL_NSA_BACKDOORED_CURVE]],  # NIST P-521 / secp521r1
+            'ecdh-sha2-m/FtSAmrV4j/Wy6RVUaK7A==': [[], [FAIL_UNPROVEN]],  # sect409k1
+            'ecdh-sha2-mNVwCXAoS1HGmHpLvBC94w==': [[], [FAIL_UNPROVEN]],  # sect571k1
+            'ecdh-sha2-nistb233': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS]],
+            'ecdh-sha2-nistb409': [[], [FAIL_UNPROVEN]],
+            'ecdh-sha2-nistk163': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS]],
+            'ecdh-sha2-nistk233': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS]],
+            'ecdh-sha2-nistk283': [[], [FAIL_UNPROVEN]],
+            'ecdh-sha2-nistk409': [[], [FAIL_UNPROVEN]],
+            'ecdh-sha2-nistp192': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'ecdh-sha2-nistp224': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'ecdh-sha2-nistp256': [['5.7,d2013.62,l10.6.0'], [FAIL_NSA_BACKDOORED_CURVE]],
+            'ecdh-sha2-nistp384': [['5.7,d2013.62'], [FAIL_NSA_BACKDOORED_CURVE]],
+            'ecdh-sha2-nistp521': [['5.7,d2013.62'], [FAIL_NSA_BACKDOORED_CURVE]],
+            'ecdh-sha2-nistt571': [[], [FAIL_UNPROVEN]],
+            'ecdh-sha2-qCbG5Cn/jjsZ7nBeR7EnOA==': [[FAIL_SMALL_ECC_MODULUS, FAIL_NSA_BACKDOORED_CURVE]],  # sect233r1
+            'ecdh-sha2-qcFQaMAMGhTziMT0z+Tuzw==': [[], [FAIL_NSA_BACKDOORED_CURVE]],  # NIST P-384 / secp384r1
+            'ecdh-sha2-VqBg4QRPjxx1EXZdV0GdWQ==': [[], [FAIL_NSA_BACKDOORED_CURVE, FAIL_SMALL_ECC_MODULUS]],  # NIST P-224 / secp224r1
+            'ecdh-sha2-wiRIU8TKjMZ418sMqlqtvQ==': [[], [FAIL_UNPROVEN]],  # sect283k1
+            'ecdh-sha2-zD/b3hu/71952ArpUG4OjQ==': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS]],  # sect233k1
+            'ecmqv-sha2': [[], [FAIL_UNPROVEN]],
+            'ext-info-c': [[], [], [], [INFO_EXTENSION_NEGOTIATION]],  # Extension negotiation (RFC 8308)
+            'ext-info-s': [[], [], [], [INFO_EXTENSION_NEGOTIATION]],  # Extension negotiation (RFC 8308)
+            'kex-strict-c-v00@openssh.com': [[], [], [], [INFO_STRICT_KEX]],  # Strict KEX marker (countermeasure for CVE-2023-48795).
+            'kex-strict-s-v00@openssh.com': [[], [], [], [INFO_STRICT_KEX]],  # Strict KEX marker (countermeasure for CVE-2023-48795).
+
+            # The GSS kex algorithms get special wildcard handling, since they include variable base64 data after their standard prefixes.
+            'gss-13.3.132.0.10-sha256-*': [[], [FAIL_UNKNOWN]],
+            'gss-curve25519-sha256-*': [[]],
+            'gss-curve448-sha512-*': [[]],
+            'gss-gex-sha1-*': [[], [FAIL_SHA1]],
+            'gss-gex-sha256-*': [[]],
+            'gss-group14-sha1-*': [[], [FAIL_SHA1], [WARN_2048BIT_MODULUS]],
+            'gss-group14-sha256-*': [[], [], [WARN_2048BIT_MODULUS]],
+            'gss-group15-sha512-*': [[]],
+            'gss-group16-sha512-*': [[]],
+            'gss-group17-sha512-*': [[]],
+            'gss-group18-sha512-*': [[]],
+            'gss-group1-sha1-*': [[], [FAIL_1024BIT_MODULUS, FAIL_LOGJAM_ATTACK, FAIL_SHA1]],
+            'gss-nistp256-sha256-*': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'gss-nistp384-sha256-*': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'gss-nistp521-sha512-*': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'kexAlgoCurve25519SHA256': [[]],
+            'kexAlgoDH14SHA1': [[], [FAIL_SHA1], [WARN_2048BIT_MODULUS]],
+            'kexAlgoDH1SHA1': [[], [FAIL_1024BIT_MODULUS, FAIL_LOGJAM_ATTACK, FAIL_SHA1]],
+            'kexAlgoECDH256': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'kexAlgoECDH384': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'kexAlgoECDH521': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'kexguess2@matt.ucc.asn.au': [['d2013.57']],
+            'm383-sha384@libassh.org': [[], [FAIL_UNPROVEN]],
+            'm511-sha512@libassh.org': [[], [FAIL_UNPROVEN]],
+            'rsa1024-sha1': [[], [FAIL_1024BIT_MODULUS, FAIL_SHA1]],
+            'rsa2048-sha256': [[], [], [WARN_2048BIT_MODULUS]],
+            'sm2kep-sha2-nistp256': [[], [FAIL_NSA_BACKDOORED_CURVE, FAIL_UNTRUSTED]],
+            'sntrup4591761x25519-sha512@tinyssh.org': [['8.0', '8.4'], [], [WARN_EXPERIMENTAL], [INFO_WITHDRAWN_PQ_ALG]],
+            'sntrup761x25519-sha512@openssh.com': [['8.5'], [], []],
+            'x25519-kyber-512r3-sha256-d00@amazon.com': [[]],
+            'x25519-kyber512-sha512@aws.amazon.com': [[]],
+        },
+        'key': {
+            'dsa2048-sha224@libassh.org': [[], [FAIL_UNPROVEN], [WARN_2048BIT_MODULUS]],
+            'dsa2048-sha256@libassh.org': [[], [FAIL_UNPROVEN], [WARN_2048BIT_MODULUS]],
+            'dsa3072-sha256@libassh.org': [[], [FAIL_UNPROVEN]],
+            'ecdsa-sha2-1.3.132.0.10-cert-v01@openssh.com': [[], [FAIL_UNKNOWN]],
+            'ecdsa-sha2-1.3.132.0.10': [[], [], [WARN_RNDSIG_KEY]],  # ECDSA over secp256k1 (i.e.: the Bitcoin curve)
+            'ecdsa-sha2-curve25519': [[], [], [WARN_RNDSIG_KEY]],  # ECDSA with Curve25519?  Bizarre...
+            'ecdsa-sha2-nistb233': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistb409': [[], [FAIL_UNPROVEN], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistk163': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistk233': [[], [FAIL_UNPROVEN, FAIL_SMALL_ECC_MODULUS], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistk283': [[], [FAIL_UNPROVEN], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistk409': [[], [FAIL_UNPROVEN], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistp224': [[], [FAIL_NSA_BACKDOORED_CURVE, FAIL_SMALL_ECC_MODULUS], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistp192': [[], [FAIL_NSA_BACKDOORED_CURVE, FAIL_SMALL_ECC_MODULUS], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistp256': [['5.7,d2013.62,l10.6.4'], [FAIL_NSA_BACKDOORED_CURVE], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistp256-cert-v01@openssh.com': [['5.7'], [FAIL_NSA_BACKDOORED_CURVE], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistp384': [['5.7,d2013.62,l10.6.4'], [FAIL_NSA_BACKDOORED_CURVE], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistp384-cert-v01@openssh.com': [['5.7'], [FAIL_NSA_BACKDOORED_CURVE], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistp521': [['5.7,d2013.62,l10.6.4'], [FAIL_NSA_BACKDOORED_CURVE], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistp521-cert-v01@openssh.com': [['5.7'], [FAIL_NSA_BACKDOORED_CURVE], [WARN_RNDSIG_KEY]],
+            'ecdsa-sha2-nistt571': [[], [FAIL_UNPROVEN], [WARN_RNDSIG_KEY]],
+            'eddsa-e382-shake256@libassh.org': [[], [FAIL_UNPROVEN]],
+            'eddsa-e521-shake256@libassh.org': [[], [FAIL_UNPROVEN]],
+            'null': [[], [FAIL_PLAINTEXT]],
+            'pgp-sign-dss': [[], [FAIL_1024BIT_MODULUS]],
+            'pgp-sign-rsa': [[], [FAIL_1024BIT_MODULUS]],
+            'rsa-sha2-256': [['7.2']],
+            'rsa-sha2-256-cert-v01@openssh.com': [['7.8']],
+            'rsa-sha2-512': [['7.2']],
+            'rsa-sha2-512-cert-v01@openssh.com': [['7.8']],
+            'sk-ecdsa-sha2-nistp256-cert-v01@openssh.com': [['8.2'], [FAIL_NSA_BACKDOORED_CURVE], [WARN_RNDSIG_KEY]],
+            'sk-ecdsa-sha2-nistp256@openssh.com': [['8.2'], [FAIL_NSA_BACKDOORED_CURVE], [WARN_RNDSIG_KEY]],
+            'sk-ssh-ed25519-cert-v01@openssh.com': [['8.2']],
+            'sk-ssh-ed25519@openssh.com': [['8.2']],
+            'spi-sign-rsa': [[]],
+            'spki-sign-dss': [[], [FAIL_1024BIT_MODULUS]],
+            'spki-sign-rsa': [[], [FAIL_1024BIT_MODULUS]],
+            'ssh-dsa': [[], [FAIL_1024BIT_MODULUS], [WARN_RNDSIG_KEY]],
+            'ssh-dss': [['2.1.0,d0.28,l10.2', '6.9'], [FAIL_1024BIT_MODULUS], [WARN_RNDSIG_KEY], [INFO_DISABLED_IN_OPENSSH70]],
+            'ssh-dss-cert-v00@openssh.com': [['5.4', '6.9'], [FAIL_1024BIT_MODULUS], [WARN_RNDSIG_KEY], [INFO_DISABLED_IN_OPENSSH70]],
+            'ssh-dss-cert-v01@openssh.com': [['5.6', '6.9'], [FAIL_1024BIT_MODULUS], [WARN_RNDSIG_KEY]],
+            'ssh-dss-sha224@ssh.com': [[], [FAIL_1024BIT_MODULUS]],
+            'ssh-dss-sha256@ssh.com': [[], [FAIL_1024BIT_MODULUS]],
+            'ssh-dss-sha384@ssh.com': [[], [FAIL_1024BIT_MODULUS]],
+            'ssh-dss-sha512@ssh.com': [[], [FAIL_1024BIT_MODULUS]],
+            'ssh-ed25519': [['6.5,l10.7.0']],
+            'ssh-ed25519-cert-v01@openssh.com': [['6.5']],
+            'ssh-ed448': [[]],
+            'ssh-ed448-cert-v01@openssh.com': [[], [], [], [INFO_NEVER_IMPLEMENTED_IN_OPENSSH]],
+            'ssh-gost2001': [[], [FAIL_UNTRUSTED]],
+            'ssh-gost2012-256': [[], [FAIL_UNTRUSTED]],
+            'ssh-gost2012-512': [[], [FAIL_UNTRUSTED]],
+            'ssh-rsa1': [[], [FAIL_SHA1]],
+            'ssh-rsa': [['2.5.0,d0.28,l10.2'], [FAIL_SHA1], [], [INFO_DEPRECATED_IN_OPENSSH88]],
+            'ssh-rsa-cert-v00@openssh.com': [['5.4', '6.9'], [FAIL_SHA1], [], [INFO_REMOVED_IN_OPENSSH70]],
+            'ssh-rsa-cert-v01@openssh.com': [['5.6'], [FAIL_SHA1], [], [INFO_DEPRECATED_IN_OPENSSH88]],
+            'ssh-rsa-sha224@ssh.com': [[]],
+            'ssh-rsa-sha2-256': [[]],
+            'ssh-rsa-sha2-512': [[]],
+            'ssh-rsa-sha256@ssh.com': [[]],
+            'ssh-rsa-sha384@ssh.com': [[]],
+            'ssh-rsa-sha512@ssh.com': [[]],
+            'ssh-xmss-cert-v01@openssh.com': [['7.7'], [WARN_EXPERIMENTAL]],
+            'ssh-xmss@openssh.com': [['7.7'], [WARN_EXPERIMENTAL]],
+            'webauthn-sk-ecdsa-sha2-nistp256@openssh.com': [['8.3'], [FAIL_NSA_BACKDOORED_CURVE]],
+            'x509v3-ecdsa-sha2-1.3.132.0.10': [[], [FAIL_UNKNOWN]],
+            'x509v3-ecdsa-sha2-nistp256': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'x509v3-ecdsa-sha2-nistp384': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'x509v3-ecdsa-sha2-nistp521': [[], [FAIL_NSA_BACKDOORED_CURVE]],
+            'x509v3-rsa2048-sha256': [[]],
+            'x509v3-sign-dss': [[], [FAIL_1024BIT_MODULUS], [WARN_RNDSIG_KEY]],
+            'x509v3-sign-dss-sha1': [[], [FAIL_1024BIT_MODULUS, FAIL_SHA1]],
+            'x509v3-sign-dss-sha224@ssh.com': [[], [FAIL_1024BIT_MODULUS]],
+            'x509v3-sign-dss-sha256@ssh.com': [[], [FAIL_1024BIT_MODULUS]],
+            'x509v3-sign-dss-sha384@ssh.com': [[], [FAIL_1024BIT_MODULUS]],
+            'x509v3-sign-dss-sha512@ssh.com': [[], [FAIL_1024BIT_MODULUS]],
+            'x509v3-sign-rsa': [[], [FAIL_SHA1]],
+            'x509v3-sign-rsa-sha1': [[], [FAIL_SHA1]],
+            'x509v3-sign-rsa-sha224@ssh.com': [[]],
+            'x509v3-sign-rsa-sha256': [[]],
+            'x509v3-sign-rsa-sha256@ssh.com': [[]],
+            'x509v3-sign-rsa-sha384@ssh.com': [[]],
+            'x509v3-sign-rsa-sha512@ssh.com': [[]],
+            'x509v3-ssh-dss': [[], [FAIL_1024BIT_MODULUS], [WARN_RNDSIG_KEY]],
+            'x509v3-ssh-rsa': [[], [FAIL_SHA1], [], [INFO_DEPRECATED_IN_OPENSSH88]],
+        },
+        'enc': {
+            '3des-cbc': [['1.2.2,d0.28,l10.2', '6.6', None], [FAIL_3DES], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            '3des-cfb': [[], [FAIL_3DES], [WARN_CIPHER_MODE]],
+            '3des-ctr': [['d0.52'], [FAIL_3DES]],
+            '3des-ecb': [[], [FAIL_3DES], [WARN_CIPHER_MODE]],
+            '3des': [[], [FAIL_3DES], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            '3des-ofb': [[], [FAIL_3DES], [WARN_CIPHER_MODE]],
+            'AEAD_AES_128_GCM': [[]],
+            'AEAD_AES_256_GCM': [[]],
+            'aes128-cbc': [['2.3.0,d0.28,l10.2', '6.6', None], [], [WARN_CIPHER_MODE]],
+            'aes128-ctr': [['3.7,d0.52,l10.4.1']],
+            'aes128-gcm': [[]],
+            'aes128-gcm@openssh.com': [['6.2']],
+            'aes192-cbc': [['2.3.0,l10.2', '6.6', None], [], [WARN_CIPHER_MODE]],
+            'aes192-ctr': [['3.7,l10.4.1']],
+            'aes192-gcm@openssh.com': [[], [], [], [INFO_NEVER_IMPLEMENTED_IN_OPENSSH]],
+            'aes256-cbc': [['2.3.0,d0.47,l10.2', '6.6', None], [], [WARN_CIPHER_MODE]],
+            'aes256-ctr': [['3.7,d0.52,l10.4.1']],
+            'aes256-gcm': [[]],
+            'aes256-gcm@openssh.com': [['6.2']],
+            'arcfour128': [['4.2', '6.6', '7.1'], [FAIL_RC4]],
+            'arcfour': [['2.1.0', '6.6', '7.1'], [FAIL_RC4]],
+            'arcfour256': [['4.2', '6.6', '7.1'], [FAIL_RC4]],
+            'blowfish-cbc': [['1.2.2,d0.28,l10.2', '6.6,d0.52', '7.1,d0.52'], [FAIL_BLOWFISH], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'blowfish-cfb': [[], [FAIL_BLOWFISH], [WARN_CIPHER_MODE]],
+            'blowfish-ctr': [[], [FAIL_BLOWFISH], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'blowfish-ecb': [[], [FAIL_BLOWFISH], [WARN_CIPHER_MODE]],
+            'blowfish': [[], [FAIL_BLOWFISH], [WARN_BLOCK_SIZE]],
+            'blowfish-ofb': [[], [FAIL_BLOWFISH], [WARN_CIPHER_MODE]],
+            'camellia128-cbc@openssh.org': [[], [], [WARN_CIPHER_MODE]],
+            'camellia128-cbc': [[], [], [WARN_CIPHER_MODE]],
+            'camellia128-ctr': [[]],
+            'camellia128-ctr@openssh.org': [[]],
+            'camellia192-cbc@openssh.org': [[], [], [WARN_CIPHER_MODE]],
+            'camellia192-cbc': [[], [], [WARN_CIPHER_MODE]],
+            'camellia192-ctr': [[]],
+            'camellia192-ctr@openssh.org': [[]],
+            'camellia256-cbc@openssh.org': [[], [], [WARN_CIPHER_MODE]],
+            'camellia256-cbc': [[], [], [WARN_CIPHER_MODE]],
+            'camellia256-ctr': [[]],
+            'camellia256-ctr@openssh.org': [[]],
+            'cast128-12-cbc@ssh.com': [[], [FAIL_CAST], [WARN_CIPHER_MODE]],
+            'cast128-cbc': [['2.1.0', '6.6', '7.1'], [FAIL_CAST], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'cast128-12-cbc': [[], [FAIL_CAST], [WARN_CIPHER_MODE]],
+            'cast128-12-cfb': [[], [FAIL_CAST], [WARN_CIPHER_MODE]],
+            'cast128-12-ecb': [[], [FAIL_CAST], [WARN_CIPHER_MODE]],
+            'cast128-12-ofb': [[], [FAIL_CAST], [WARN_CIPHER_MODE]],
+            'cast128-cfb': [[], [FAIL_CAST], [WARN_CIPHER_MODE]],
+            'cast128-ctr': [[], [FAIL_CAST]],
+            'cast128-ecb': [[], [FAIL_CAST], [WARN_CIPHER_MODE]],
+            'cast128-ofb': [[], [FAIL_CAST], [WARN_CIPHER_MODE]],
+            'chacha20-poly1305': [[], [], [], [INFO_DEFAULT_OPENSSH_CIPHER]],
+            'chacha20-poly1305@openssh.com': [['6.5'], [], [], [INFO_DEFAULT_OPENSSH_CIPHER]],
+            'crypticore128@ssh.com': [[], [FAIL_UNPROVEN]],
+            'des-cbc': [[], [FAIL_DES], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'des-cfb': [[], [FAIL_DES], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'des-ecb': [[], [FAIL_DES], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'des-ofb': [[], [FAIL_DES], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'des-cbc-ssh1': [[], [FAIL_DES], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'des-cbc@ssh.com': [[], [FAIL_DES], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'des': [[], [FAIL_DES], [WARN_CIPHER_MODE, WARN_BLOCK_SIZE]],
+            'idea-cbc': [[], [FAIL_IDEA], [WARN_CIPHER_MODE]],
+            'idea-cfb': [[], [FAIL_IDEA], [WARN_CIPHER_MODE]],
+            'idea-ctr': [[], [FAIL_IDEA]],
+            'idea-ecb': [[], [FAIL_IDEA], [WARN_CIPHER_MODE]],
+            'idea-ofb': [[], [FAIL_IDEA], [WARN_CIPHER_MODE]],
+            'none': [['1.2.2,d2013.56,l10.2'], [FAIL_PLAINTEXT]],
+            'rijndael128-cbc': [['2.3.0', '7.0'], [FAIL_RIJNDAEL], [WARN_CIPHER_MODE], [INFO_DISABLED_IN_OPENSSH70]],
+            'rijndael192-cbc': [['2.3.0', '7.0'], [FAIL_RIJNDAEL], [WARN_CIPHER_MODE], [INFO_DISABLED_IN_OPENSSH70]],
+            'rijndael256-cbc': [['2.3.0', '7.0'], [FAIL_RIJNDAEL], [WARN_CIPHER_MODE], [INFO_DISABLED_IN_OPENSSH70]],
+            'rijndael-cbc@lysator.liu.se': [['2.3.0', '6.6', '7.0'], [FAIL_RIJNDAEL], [WARN_CIPHER_MODE], [INFO_DISABLED_IN_OPENSSH70]],
+            'rijndael-cbc@ssh.com': [[], [FAIL_RIJNDAEL], [WARN_CIPHER_MODE]],
+            'seed-cbc@ssh.com': [[], [FAIL_SEED], [WARN_CIPHER_MODE]],
+            'seed-ctr@ssh.com': [[], [FAIL_SEED]],
+            'serpent128-cbc': [[], [FAIL_SERPENT], [WARN_CIPHER_MODE]],
+            'serpent128-ctr': [[], [FAIL_SERPENT]],
+            'serpent128-gcm@libassh.org': [[], [FAIL_SERPENT]],
+            'serpent192-cbc': [[], [FAIL_SERPENT], [WARN_CIPHER_MODE]],
+            'serpent192-ctr': [[], [FAIL_SERPENT]],
+            'serpent256-cbc': [[], [FAIL_SERPENT], [WARN_CIPHER_MODE]],
+            'serpent256-ctr': [[], [FAIL_SERPENT]],
+            'serpent256-gcm@libassh.org': [[], [FAIL_SERPENT]],
+            'twofish128-cbc': [['d0.47', 'd2014.66'], [], [WARN_CIPHER_MODE], [INFO_DISABLED_IN_DBEAR67]],
+            'twofish128-ctr': [['d2015.68']],
+            'twofish128-gcm@libassh.org': [[]],
+            'twofish192-cbc': [[], [], [WARN_CIPHER_MODE]],
+            'twofish192-ctr': [[]],
+            'twofish256-cbc': [['d0.47', 'd2014.66'], [], [WARN_CIPHER_MODE], [INFO_DISABLED_IN_DBEAR67]],
+            'twofish256-ctr': [['d2015.68']],
+            'twofish256-gcm@libassh.org': [[]],
+            'twofish-cbc': [['d0.28', 'd2014.66'], [], [WARN_CIPHER_MODE], [INFO_DISABLED_IN_DBEAR67]],
+            'twofish-cfb': [[], [], [WARN_CIPHER_MODE]],
+            'twofish-ctr': [[]],
+            'twofish-ecb': [[], [], [WARN_CIPHER_MODE]],
+            'twofish-ofb': [[], [], [WARN_CIPHER_MODE]],
+        },
+        'mac': {
+            'AEAD_AES_128_GCM': [[]],
+            'AEAD_AES_256_GCM': [[]],
+            'aes128-gcm': [[]],
+            'aes256-gcm': [[]],
+            'cbcmac-3des': [[], [FAIL_UNPROVEN, FAIL_3DES]],
+            'cbcmac-aes': [[], [FAIL_UNPROVEN]],
+            'cbcmac-blowfish': [[], [FAIL_UNPROVEN, FAIL_BLOWFISH]],
+            'cbcmac-des': [[], [FAIL_UNPROVEN, FAIL_DES]],
+            'cbcmac-rijndael': [[], [FAIL_UNPROVEN, FAIL_RIJNDAEL]],
+            'cbcmac-twofish': [[], [FAIL_UNPROVEN]],
+            'chacha20-poly1305@openssh.com': [[], [], [], [INFO_NEVER_IMPLEMENTED_IN_OPENSSH]],  # Despite the @openssh.com tag, this was never shipped as a MAC in OpenSSH (only as a cipher); it is only implemented as a MAC in Syncplify.
+            'crypticore-mac@ssh.com': [[], [FAIL_UNPROVEN]],
+            'hmac-md5': [['2.1.0,d0.28', '6.6', '7.1'], [FAIL_MD5], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-md5-96': [['2.5.0', '6.6', '7.1'], [FAIL_MD5], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-md5-96-etm@openssh.com': [['6.2', '6.6', '7.1'], [FAIL_MD5]],
+            'hmac-md5-etm@openssh.com': [['6.2', '6.6', '7.1'], [FAIL_MD5]],
+            'hmac-ripemd160': [['2.5.0', '6.6', '7.1'], [FAIL_RIPEMD], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-ripemd160-96': [[], [FAIL_RIPEMD], [WARN_ENCRYPT_AND_MAC, WARN_TAG_SIZE]],
+            'hmac-ripemd160-etm@openssh.com': [['6.2', '6.6', '7.1'], [FAIL_RIPEMD]],
+            'hmac-ripemd160@openssh.com': [['2.1.0', '6.6', '7.1'], [FAIL_RIPEMD], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-ripemd': [[], [FAIL_RIPEMD], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha1': [['2.1.0,d0.28,l10.2'], [FAIL_SHA1], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha1-96': [['2.5.0,d0.47', '6.6', '7.1'], [FAIL_SHA1], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha1-96-etm@openssh.com': [['6.2', '6.6', None], [FAIL_SHA1]],
+            'hmac-sha1-96@openssh.com': [[], [FAIL_SHA1], [WARN_TAG_SIZE, WARN_ENCRYPT_AND_MAC], [INFO_NEVER_IMPLEMENTED_IN_OPENSSH]],
+            'hmac-sha1-etm@openssh.com': [['6.2'], [FAIL_SHA1]],
+            'hmac-sha2-224': [[], [], [WARN_TAG_SIZE, WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha224@ssh.com': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha2-256': [['5.9,d2013.56,l10.7.0'], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha2-256-96': [['5.9', '6.0'], [], [WARN_ENCRYPT_AND_MAC], [INFO_REMOVED_IN_OPENSSH61]],
+            'hmac-sha2-256-96-etm@openssh.com': [[], [], [WARN_TAG_SIZE_96], [INFO_NEVER_IMPLEMENTED_IN_OPENSSH]],  # Only ever implemented in AsyncSSH (?).
+            'hmac-sha2-256-etm@openssh.com': [['6.2']],
+            'hmac-sha2-384': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha2-512': [['5.9,d2013.56,l10.7.0'], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha2-512-96': [['5.9', '6.0'], [], [WARN_ENCRYPT_AND_MAC], [INFO_REMOVED_IN_OPENSSH61]],
+            'hmac-sha2-512-96-etm@openssh.com': [[], [], [WARN_TAG_SIZE_96], [INFO_NEVER_IMPLEMENTED_IN_OPENSSH]],  # Only ever implemented in AsyncSSH (?).
+            'hmac-sha2-512-etm@openssh.com': [['6.2']],
+            'hmac-sha256-2@ssh.com': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha256-96@ssh.com': [[], [], [WARN_ENCRYPT_AND_MAC, WARN_TAG_SIZE]],
+            'hmac-sha256-96': [[], [], [WARN_ENCRYPT_AND_MAC, WARN_TAG_SIZE]],
+            'hmac-sha256@ssh.com': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha256': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha2-56': [[], [], [WARN_TAG_SIZE, WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha3-224': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha3-256': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha3-384': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha3-512': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha384@ssh.com': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha512@ssh.com': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-sha512': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'hmac-whirlpool': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'md5':  [[], [FAIL_PLAINTEXT]],
+            'md5-8':  [[], [FAIL_PLAINTEXT]],
+            'none': [['d2013.56'], [FAIL_PLAINTEXT]],
+            'ripemd160':  [[], [FAIL_PLAINTEXT]],
+            'ripemd160-8':  [[], [FAIL_PLAINTEXT]],
+            'sha1':  [[], [FAIL_PLAINTEXT]],
+            'sha1-8':  [[], [FAIL_PLAINTEXT]],
+            'umac-128': [[], [], [WARN_ENCRYPT_AND_MAC]],
+            'umac-128-etm@openssh.com': [['6.2']],
+            'umac-128@openssh.com': [['6.2'], [], [WARN_ENCRYPT_AND_MAC]],
+            'umac-32@openssh.com': [[], [], [WARN_ENCRYPT_AND_MAC, WARN_TAG_SIZE], [INFO_NEVER_IMPLEMENTED_IN_OPENSSH]],
+            'umac-64-etm@openssh.com': [['6.2'], [], [WARN_TAG_SIZE]],
+            'umac-64@openssh.com': [['4.7'], [], [WARN_ENCRYPT_AND_MAC, WARN_TAG_SIZE]],
+            'umac-96@openssh.com': [[], [], [WARN_ENCRYPT_AND_MAC], [INFO_NEVER_IMPLEMENTED_IN_OPENSSH]],
+        }
+    }
+
+
+    @staticmethod
+    def get_db() -> Dict[str, Dict[str, List[List[Optional[str]]]]]:
+        '''Returns a copy of the MASTER_DB that is private to the calling thread.  This prevents multiple threads from polluting the results of other threads.'''
+        calling_thread_id = threading.get_ident()
+
+        if calling_thread_id not in SSH2_KexDB.DB_PER_THREAD:
+            SSH2_KexDB.DB_PER_THREAD[calling_thread_id] = copy.deepcopy(SSH2_KexDB.MASTER_DB)
+
+        return SSH2_KexDB.DB_PER_THREAD[calling_thread_id]
+
+
+    @staticmethod
+    def thread_exit() -> None:
+        '''Deletes the calling thread's copy of the MASTER_DB.  This is needed because, in rare circumstances, a terminated thread's ID can be re-used by new threads.'''
+
+        calling_thread_id = threading.get_ident()
+
+        if calling_thread_id in SSH2_KexDB.DB_PER_THREAD:
+            del SSH2_KexDB.DB_PER_THREAD[calling_thread_id]