T3354: Backport strip-private script

1 files changed, 149 insertions, 0 deletions

diff --git a/src/helpers/strip-private.py b/src/helpers/strip-private.py
new file mode 100755
index 000000000..e4e1fe11d
--- /dev/null
+++ b/src/helpers/strip-private.py
@@ -0,0 +1,149 @@
+#!/usr/bin/python3
+
+# Copyright 2021 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+import argparse
+import re
+import sys
+
+from netaddr import IPNetwork, AddrFormatError
+
+
+parser = argparse.ArgumentParser(description='strip off private information from VyOS config')
+
+strictness = parser.add_mutually_exclusive_group()
+strictness.add_argument('--loose', action='store_true', help='remove only information specified as arguments')
+strictness.add_argument('--strict', action='store_true', help='remove any private information (implies all arguments below). This is the default behavior.')
+
+parser.add_argument('--mac', action='store_true', help='strip off MAC addresses')
+parser.add_argument('--hostname', action='store_true', help='strip off system host and domain names')
+parser.add_argument('--username', action='store_true', help='strip off user names')
+parser.add_argument('--dhcp', action='store_true', help='strip off DHCP shared network and static mapping names')
+parser.add_argument('--domain', action='store_true', help='strip off domain names')
+parser.add_argument('--asn', action='store_true', help='strip off BGP ASNs')
+parser.add_argument('--snmp', action='store_true', help='strip off SNMP location information')
+parser.add_argument('--lldp', action='store_true', help='strip off LLDP location information')
+
+address_preserval = parser.add_mutually_exclusive_group()
+address_preserval.add_argument('--address', action='store_true', help='strip off all IPv4 and IPv6 addresses')
+address_preserval.add_argument('--public-address', action='store_true', help='only strip off public IPv4 and IPv6 addresses')
+address_preserval.add_argument('--keep-address', action='store_true', help='preserve all IPv4 and IPv6 addresses')
+
+# Censor the first half of the address.
+ipv4_re = re.compile(r'(\d{1,3}\.){2}(\d{1,3}\.\d{1,3})')
+ipv4_subst = r'xxx.xxx.\2'
+
+# Censor all but the first two fields.
+ipv6_re = re.compile(r'([0-9a-fA-F]{1,4}\:){2}([0-9a-fA-F:]+)')
+ipv6_subst = r'xxxx:xxxx:\2'
+
+def ip_match(match: re.Match, subst: str) -> str:
+    """
+    Take a Match and a substitution pattern, check if the match contains a valid IP address, strip
+    information if it is. This routine is intended to be passed to `re.sub' as a replacement pattern.
+    """
+    result = match.group(0)
+    # Is this a valid IP address?
+    try:
+        addr = IPNetwork(result).ip
+    # No? Then we've got nothing to do with it.
+    except AddrFormatError:
+        return result
+    # Should we strip it?
+    if args.address or (args.public_address and not addr.is_private()):
+        return match.expand(subst)
+    # No? Then we'll leave it as is.
+    else:
+        return result
+
+def strip_address(line: str) -> str:
+    """
+    Strip IPv4 and IPv6 addresses from the given string.
+    """
+    return ipv4_re.sub(lambda match: ip_match(match, ipv4_subst), ipv6_re.sub(lambda match: ip_match(match, ipv6_subst), line))
+
+def strip_lines(rules: tuple) -> None:
+    """
+    Read stdin line by line and apply the given stripping rules.
+    """
+    try:
+        for line in sys.stdin:
+            if not args.keep_address:
+                line = strip_address(line)
+            for (condition, regexp, subst) in rules:
+                if condition:
+                    line = regexp.sub(subst, line)
+            print(line, end='')
+    # stdin can be cut for any reason, such as user interrupt or the pager terminating before the text can be read.
+    # All we can do is gracefully exit.
+    except (BrokenPipeError, EOFError, KeyboardInterrupt):
+        sys.exit(1)
+
+if __name__ == "__main__":
+    args = parser.parse_args()
+    # Strict mode is the default and the absence of loose mode implies presence of strict mode.
+    if not args.loose:
+        args.mac = args.domain = args.hostname = args.username = args.dhcp = args.asn = args.snmp = args.lldp = True
+        if not args.public_address and not args.keep_address:
+            args.address = True
+    elif not args.address and not args.public_address:
+        args.keep_address = True
+
+    # (condition, precompiled regexp, substitution string)
+    stripping_rules = [
+        # Strip passwords
+        (True, re.compile(r'password \S+'), 'password xxxxxx'),
+        (True, re.compile(r'cisco-authentication \S+'), 'cisco-authentication xxxxxx'),
+        # Strip public key information
+        (True, re.compile(r'public-keys \S+'), 'public-keys xxxx@xxx.xxx'),
+        (True, re.compile(r'type \'ssh-(rsa|dss)\''), 'type ssh-xxx'),
+        (True, re.compile(r' key \S+'), ' key xxxxxx'),
+        # Strip OpenVPN secrets
+        (True, re.compile(r'(shared-secret-key-file|ca-cert-file|cert-file|dh-file|key-file|client) (\S+)'), r'\1 xxxxxx'),
+        # Strip IPSEC secrets
+        (True, re.compile(r'pre-shared-secret \S+'), 'pre-shared-secret xxxxxx'),
+        # Strip OSPF md5-key
+        (True, re.compile(r'md5-key \S+'), 'md5-key xxxxxx'),
+        # Strip WireGuard private-key
+        (True, re.compile(r'private-key \S+'), 'private-key xxxxxx'),
+
+        # Strip MAC addresses
+        (args.mac, re.compile(r'([0-9a-fA-F]{2}\:){5}([0-9a-fA-F]{2}((\:{0,1})){3})'), r'xx:xx:xx:xx:xx:\2'),
+
+        # Strip host-name, domain-name, and domain-search
+        (args.hostname, re.compile(r'(host-name|domain-name|domain-search) \S+'), r'\1 xxxxxx'),
+
+        # Strip user-names
+        (args.username, re.compile(r'(user|username|user-id) \S+'), r'\1 xxxxxx'),
+        # Strip full-name
+        (args.username, re.compile(r'(full-name) [ -_A-Z a-z]+'), r'\1 xxxxxx'),
+
+        # Strip DHCP static-mapping and shared network names
+        (args.dhcp, re.compile(r'(shared-network-name|static-mapping) \S+'), r'\1 xxxxxx'),
+
+        # Strip host/domain names
+        (args.domain, re.compile(r' (peer|remote-host|local-host|server) ([\w-]+\.)+[\w-]+'), r' \1 xxxxx.tld'),
+
+        # Strip BGP ASNs
+        (args.asn, re.compile(r'(bgp|remote-as) (\d+)'), r'\1 XXXXXX'),
+
+        # Strip LLDP location parameters
+        (args.lldp, re.compile(r'(altitude|datum|latitude|longitude|ca-value|country-code) (\S+)'), r'\1 xxxxxx'),
+
+        # Strip SNMP location
+        (args.snmp, re.compile(r'(location) \S+'), r'\1 xxxxxx'),
+    ]
+    strip_lines(stripping_rules)