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Diffstat (limited to 'bin/python/isc/policy.py.in')
| -rw-r--r-- | bin/python/isc/policy.py.in | 761 |
1 files changed, 761 insertions, 0 deletions
diff --git a/bin/python/isc/policy.py.in b/bin/python/isc/policy.py.in new file mode 100644 index 0000000..0fa231c --- /dev/null +++ b/bin/python/isc/policy.py.in @@ -0,0 +1,761 @@ +# Copyright (C) Internet Systems Consortium, Inc. ("ISC") +# +# SPDX-License-Identifier: MPL-2.0 +# +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, you can obtain one at https://mozilla.org/MPL/2.0/. +# +# See the COPYRIGHT file distributed with this work for additional +# information regarding copyright ownership. + +import re +import ply.lex as lex +import ply.yacc as yacc +from string import * +from copy import copy + + +############################################################################ +# PolicyLex: a lexer for the policy file syntax. +############################################################################ +class PolicyLex: + reserved = ( + "POLICY", + "ALGORITHM_POLICY", + "ZONE", + "ALGORITHM", + "DIRECTORY", + "KEYTTL", + "KEY_SIZE", + "ROLL_PERIOD", + "PRE_PUBLISH", + "POST_PUBLISH", + "COVERAGE", + "STANDBY", + "NONE", + ) + + tokens = reserved + ( + "DATESUFFIX", + "KEYTYPE", + "ALGNAME", + "STR", + "QSTRING", + "NUMBER", + "LBRACE", + "RBRACE", + "SEMI", + ) + reserved_map = {} + + t_ignore = " \t" + t_ignore_olcomment = r"(//|\#).*" + + t_LBRACE = r"\{" + t_RBRACE = r"\}" + t_SEMI = r";" + + def t_newline(self, t): + r"\n+" + t.lexer.lineno += t.value.count("\n") + + def t_comment(self, t): + r"/\*(.|\n)*?\*/" + t.lexer.lineno += t.value.count("\n") + + def t_DATESUFFIX(self, t): + r"(?<=[0-9 \t])(y(?:ears|ear|ea|e)?|mo(?:nths|nth|nt|n)?|w(?:eeks|eek|ee|e)?|d(?:ays|ay|a)?|h(?:ours|our|ou|o)?|mi(?:nutes|nute|nut|nu|n)?|s(?:econds|econd|econ|eco|ec|e)?)\b" + t.value = ( + re.match(r"(y|mo|w|d|h|mi|s)([a-z]*)", t.value, re.IGNORECASE) + .group(1) + .lower() + ) + return t + + def t_KEYTYPE(self, t): + r"\b(KSK|ZSK)\b" + t.value = t.value.upper() + return t + + def t_ALGNAME(self, t): + r"\b(DH|ECC|RSASHA1|NSEC3RSASHA1|RSASHA256|RSASHA512|ECDSAP256SHA256|ECDSAP384SHA384|ED25519|ED448)\b" + t.value = t.value.upper() + return t + + def t_STR(self, t): + r"[A-Za-z._-][\w._-]*" + t.type = self.reserved_map.get(t.value, "STR") + return t + + def t_QSTRING(self, t): + r'"([^"\n]|(\\"))*"' + t.type = self.reserved_map.get(t.value, "QSTRING") + t.value = t.value[1:-1] + return t + + def t_NUMBER(self, t): + r"\d+" + t.value = int(t.value) + return t + + def t_error(self, t): + print("Illegal character '%s'" % t.value[0]) + t.lexer.skip(1) + + def __init__(self, **kwargs): + if "maketrans" in dir(str): + trans = str.maketrans("_", "-") + else: + trans = maketrans("_", "-") + for r in self.reserved: + self.reserved_map[r.lower().translate(trans)] = r + self.lexer = lex.lex(object=self, reflags=re.VERBOSE | re.IGNORECASE, **kwargs) + + def test(self, text): + self.lexer.input(text) + while True: + t = self.lexer.token() + if not t: + break + print(t) + + +############################################################################ +# Policy: this object holds a set of DNSSEC policy settings. +############################################################################ +class Policy: + is_zone = False + is_alg = False + is_constructed = False + ksk_rollperiod = None + zsk_rollperiod = None + ksk_prepublish = None + zsk_prepublish = None + ksk_postpublish = None + zsk_postpublish = None + ksk_keysize = None + zsk_keysize = None + ksk_standby = None + zsk_standby = None + keyttl = None + coverage = None + directory = None + valid_key_sz_per_algo = { + "RSASHA1": [1024, 4096], + "NSEC3RSASHA1": [512, 4096], + "RSASHA256": [1024, 4096], + "RSASHA512": [1024, 4096], + "ECDSAP256SHA256": None, + "ECDSAP384SHA384": None, + "ED25519": None, + "ED448": None, + } + + def __init__(self, name=None, algorithm=None, parent=None): + self.name = name + self.algorithm = algorithm + self.parent = parent + pass + + def __repr__(self): + return ( + "%spolicy %s:\n" + "\tinherits %s\n" + "\tdirectory %s\n" + "\talgorithm %s\n" + "\tcoverage %s\n" + "\tksk_keysize %s\n" + "\tzsk_keysize %s\n" + "\tksk_rollperiod %s\n" + "\tzsk_rollperiod %s\n" + "\tksk_prepublish %s\n" + "\tksk_postpublish %s\n" + "\tzsk_prepublish %s\n" + "\tzsk_postpublish %s\n" + "\tksk_standby %s\n" + "\tzsk_standby %s\n" + "\tkeyttl %s\n" + % ( + ( + self.is_constructed + and "constructed " + or self.is_zone + and "zone " + or self.is_alg + and "algorithm " + or "" + ), + self.name or "UNKNOWN", + self.parent and self.parent.name or "None", + self.directory and ('"' + str(self.directory) + '"') or "None", + self.algorithm or "None", + self.coverage and str(self.coverage) or "None", + self.ksk_keysize and str(self.ksk_keysize) or "None", + self.zsk_keysize and str(self.zsk_keysize) or "None", + self.ksk_rollperiod and str(self.ksk_rollperiod) or "None", + self.zsk_rollperiod and str(self.zsk_rollperiod) or "None", + self.ksk_prepublish and str(self.ksk_prepublish) or "None", + self.ksk_postpublish and str(self.ksk_postpublish) or "None", + self.zsk_prepublish and str(self.zsk_prepublish) or "None", + self.zsk_postpublish and str(self.zsk_postpublish) or "None", + self.ksk_standby and str(self.ksk_standby) or "None", + self.zsk_standby and str(self.zsk_standby) or "None", + self.keyttl and str(self.keyttl) or "None", + ) + ) + + def __verify_size(self, key_size, size_range): + return size_range[0] <= key_size <= size_range[1] + + def get_name(self): + return self.name + + def constructed(self): + return self.is_constructed + + def validate(self): + """Check if the values in the policy make sense + :return: True/False if the policy passes validation + """ + if ( + self.ksk_rollperiod + and self.ksk_prepublish is not None + and self.ksk_prepublish > self.ksk_rollperiod + ): + print(self.ksk_rollperiod) + return ( + False, + ( + "KSK pre-publish period (%d) exceeds rollover period %d" + % (self.ksk_prepublish, self.ksk_rollperiod) + ), + ) + + if ( + self.ksk_rollperiod + and self.ksk_postpublish is not None + and self.ksk_postpublish > self.ksk_rollperiod + ): + return ( + False, + ( + "KSK post-publish period (%d) exceeds rollover period %d" + % (self.ksk_postpublish, self.ksk_rollperiod) + ), + ) + + if ( + self.zsk_rollperiod + and self.zsk_prepublish is not None + and self.zsk_prepublish >= self.zsk_rollperiod + ): + return ( + False, + ( + "ZSK pre-publish period (%d) exceeds rollover period %d" + % (self.zsk_prepublish, self.zsk_rollperiod) + ), + ) + + if ( + self.zsk_rollperiod + and self.zsk_postpublish is not None + and self.zsk_postpublish >= self.zsk_rollperiod + ): + return ( + False, + ( + "ZSK post-publish period (%d) exceeds rollover period %d" + % (self.zsk_postpublish, self.zsk_rollperiod) + ), + ) + + if ( + self.ksk_rollperiod + and self.ksk_prepublish + and self.ksk_postpublish + and self.ksk_prepublish + self.ksk_postpublish >= self.ksk_rollperiod + ): + return ( + False, + ( + ( + "KSK pre/post-publish periods (%d/%d) " + + "combined exceed rollover period %d" + ) + % (self.ksk_prepublish, self.ksk_postpublish, self.ksk_rollperiod) + ), + ) + + if ( + self.zsk_rollperiod + and self.zsk_prepublish + and self.zsk_postpublish + and self.zsk_prepublish + self.zsk_postpublish >= self.zsk_rollperiod + ): + return ( + False, + ( + ( + "ZSK pre/post-publish periods (%d/%d) " + + "combined exceed rollover period %d" + ) + % (self.zsk_prepublish, self.zsk_postpublish, self.zsk_rollperiod) + ), + ) + + if self.algorithm is not None: + # Validate the key size + key_sz_range = self.valid_key_sz_per_algo.get(self.algorithm) + if key_sz_range is not None: + # Verify KSK + if not self.__verify_size(self.ksk_keysize, key_sz_range): + return False, "KSK key size %d outside valid range %s" % ( + self.ksk_keysize, + key_sz_range, + ) + + # Verify ZSK + if not self.__verify_size(self.zsk_keysize, key_sz_range): + return False, "ZSK key size %d outside valid range %s" % ( + self.zsk_keysize, + key_sz_range, + ) + + if self.algorithm in [ + "ECDSAP256SHA256", + "ECDSAP384SHA384", + "ED25519", + "ED448", + ]: + self.ksk_keysize = None + self.zsk_keysize = None + + return True, "" + + +############################################################################ +# dnssec_policy: +# This class reads a dnssec.policy file and creates a dictionary of +# DNSSEC policy rules from which a policy for a specific zone can +# be generated. +############################################################################ +class PolicyException(Exception): + pass + + +class dnssec_policy: + alg_policy = {} + named_policy = {} + zone_policy = {} + current = None + filename = None + initial = True + + def __init__(self, filename=None, **kwargs): + self.plex = PolicyLex() + self.tokens = self.plex.tokens + if "debug" not in kwargs: + kwargs["debug"] = False + if "write_tables" not in kwargs: + kwargs["write_tables"] = False + self.parser = yacc.yacc(module=self, **kwargs) + + # set defaults + self.setup( + """policy global { algorithm rsasha256; + key-size ksk 2048; + key-size zsk 2048; + roll-period ksk 0; + roll-period zsk 1y; + pre-publish ksk 1mo; + pre-publish zsk 1mo; + post-publish ksk 1mo; + post-publish zsk 1mo; + standby ksk 0; + standby zsk 0; + keyttl 1h; + coverage 6mo; }; + policy default { policy global; };""" + ) + + p = Policy() + p.algorithm = None + p.is_alg = True + p.ksk_keysize = 2048 + p.zsk_keysize = 2048 + + # set default algorithm policies + + # these can use default settings + self.alg_policy["RSASHA1"] = copy(p) + self.alg_policy["RSASHA1"].algorithm = "RSASHA1" + self.alg_policy["RSASHA1"].name = "RSASHA1" + + self.alg_policy["NSEC3RSASHA1"] = copy(p) + self.alg_policy["NSEC3RSASHA1"].algorithm = "NSEC3RSASHA1" + self.alg_policy["NSEC3RSASHA1"].name = "NSEC3RSASHA1" + + self.alg_policy["RSASHA256"] = copy(p) + self.alg_policy["RSASHA256"].algorithm = "RSASHA256" + self.alg_policy["RSASHA256"].name = "RSASHA256" + + self.alg_policy["RSASHA512"] = copy(p) + self.alg_policy["RSASHA512"].algorithm = "RSASHA512" + self.alg_policy["RSASHA512"].name = "RSASHA512" + + self.alg_policy["ECDSAP256SHA256"] = copy(p) + self.alg_policy["ECDSAP256SHA256"].algorithm = "ECDSAP256SHA256" + self.alg_policy["ECDSAP256SHA256"].name = "ECDSAP256SHA256" + self.alg_policy["ECDSAP256SHA256"].ksk_keysize = None + self.alg_policy["ECDSAP256SHA256"].zsk_keysize = None + + self.alg_policy["ECDSAP384SHA384"] = copy(p) + self.alg_policy["ECDSAP384SHA384"].algorithm = "ECDSAP384SHA384" + self.alg_policy["ECDSAP384SHA384"].name = "ECDSAP384SHA384" + self.alg_policy["ECDSAP384SHA384"].ksk_keysize = None + self.alg_policy["ECDSAP384SHA384"].zsk_keysize = None + + self.alg_policy["ED25519"] = copy(p) + self.alg_policy["ED25519"].algorithm = "ED25519" + self.alg_policy["ED25519"].name = "ED25519" + self.alg_policy["ED25519"].ksk_keysize = None + self.alg_policy["ED25519"].zsk_keysize = None + + self.alg_policy["ED448"] = copy(p) + self.alg_policy["ED448"].algorithm = "ED448" + self.alg_policy["ED448"].name = "ED448" + self.alg_policy["ED448"].ksk_keysize = None + self.alg_policy["ED448"].zsk_keysize = None + + if filename: + self.load(filename) + + def load(self, filename): + self.filename = filename + self.initial = True + with open(filename) as f: + text = f.read() + self.plex.lexer.lineno = 0 + self.parser.parse(text) + + self.filename = None + + def setup(self, text): + self.initial = True + self.plex.lexer.lineno = 0 + self.parser.parse(text) + + def policy(self, zone, **kwargs): + z = zone.lower() + p = None + + if z in self.zone_policy: + p = self.zone_policy[z] + + if p is None: + p = copy(self.named_policy["default"]) + p.name = zone + p.is_constructed = True + + if p.algorithm is None: + parent = p.parent or self.named_policy["default"] + while parent and not parent.algorithm: + parent = parent.parent + p.algorithm = parent and parent.algorithm or None + + if p.algorithm in self.alg_policy: + ap = self.alg_policy[p.algorithm] + else: + raise PolicyException("algorithm not found") + + if p.directory is None: + parent = p.parent or self.named_policy["default"] + while parent is not None and not parent.directory: + parent = parent.parent + p.directory = parent and parent.directory + + if p.coverage is None: + parent = p.parent or self.named_policy["default"] + while parent and not parent.coverage: + parent = parent.parent + p.coverage = parent and parent.coverage or ap.coverage + + if p.ksk_keysize is None: + parent = p.parent or self.named_policy["default"] + while parent.parent and not parent.ksk_keysize: + parent = parent.parent + p.ksk_keysize = parent and parent.ksk_keysize or ap.ksk_keysize + + if p.zsk_keysize is None: + parent = p.parent or self.named_policy["default"] + while parent.parent and not parent.zsk_keysize: + parent = parent.parent + p.zsk_keysize = parent and parent.zsk_keysize or ap.zsk_keysize + + if p.ksk_rollperiod is None: + parent = p.parent or self.named_policy["default"] + while parent.parent and not parent.ksk_rollperiod: + parent = parent.parent + p.ksk_rollperiod = parent and parent.ksk_rollperiod or ap.ksk_rollperiod + + if p.zsk_rollperiod is None: + parent = p.parent or self.named_policy["default"] + while parent.parent and not parent.zsk_rollperiod: + parent = parent.parent + p.zsk_rollperiod = parent and parent.zsk_rollperiod or ap.zsk_rollperiod + + if p.ksk_prepublish is None: + parent = p.parent or self.named_policy["default"] + while parent.parent and not parent.ksk_prepublish: + parent = parent.parent + p.ksk_prepublish = parent and parent.ksk_prepublish or ap.ksk_prepublish + + if p.zsk_prepublish is None: + parent = p.parent or self.named_policy["default"] + while parent.parent and not parent.zsk_prepublish: + parent = parent.parent + p.zsk_prepublish = parent and parent.zsk_prepublish or ap.zsk_prepublish + + if p.ksk_postpublish is None: + parent = p.parent or self.named_policy["default"] + while parent.parent and not parent.ksk_postpublish: + parent = parent.parent + p.ksk_postpublish = parent and parent.ksk_postpublish or ap.ksk_postpublish + + if p.zsk_postpublish is None: + parent = p.parent or self.named_policy["default"] + while parent.parent and not parent.zsk_postpublish: + parent = parent.parent + p.zsk_postpublish = parent and parent.zsk_postpublish or ap.zsk_postpublish + + if p.keyttl is None: + parent = p.parent or self.named_policy["default"] + while parent is not None and not parent.keyttl: + parent = parent.parent + p.keyttl = parent and parent.keyttl + + if "novalidate" not in kwargs or not kwargs["novalidate"]: + (valid, msg) = p.validate() + if not valid: + raise PolicyException(msg) + return None + + return p + + def p_policylist(self, p): + """policylist : init policy + | policylist policy""" + pass + + def p_init(self, p): + "init :" + self.initial = False + + def p_policy(self, p): + """policy : alg_policy + | zone_policy + | named_policy""" + pass + + def p_name(self, p): + """name : STR + | KEYTYPE + | DATESUFFIX""" + p[0] = p[1] + pass + + def p_domain(self, p): + """domain : STR + | QSTRING + | KEYTYPE + | DATESUFFIX""" + p[0] = p[1].strip() + if not re.match(r"^[\w.-][\w.-]*$", p[0]): + raise PolicyException("invalid domain") + pass + + def p_new_policy(self, p): + "new_policy :" + self.current = Policy() + + def p_alg_policy(self, p): + "alg_policy : ALGORITHM_POLICY ALGNAME new_policy alg_option_group SEMI" + self.current.name = p[2] + self.current.is_alg = True + self.alg_policy[p[2]] = self.current + pass + + def p_zone_policy(self, p): + "zone_policy : ZONE domain new_policy policy_option_group SEMI" + self.current.name = p[2].rstrip(".") + self.current.is_zone = True + self.zone_policy[p[2].rstrip(".").lower()] = self.current + pass + + def p_named_policy(self, p): + "named_policy : POLICY name new_policy policy_option_group SEMI" + self.current.name = p[2] + self.named_policy[p[2].lower()] = self.current + pass + + def p_duration_1(self, p): + "duration : NUMBER" + p[0] = p[1] + pass + + def p_duration_2(self, p): + "duration : NONE" + p[0] = None + pass + + def p_duration_3(self, p): + "duration : NUMBER DATESUFFIX" + if p[2] == "y": + p[0] = p[1] * 31536000 # year + elif p[2] == "mo": + p[0] = p[1] * 2592000 # month + elif p[2] == "w": + p[0] = p[1] * 604800 # week + elif p[2] == "d": + p[0] = p[1] * 86400 # day + elif p[2] == "h": + p[0] = p[1] * 3600 # hour + elif p[2] == "mi": + p[0] = p[1] * 60 # minute + elif p[2] == "s": + p[0] = p[1] # second + else: + raise PolicyException("invalid duration") + + def p_policy_option_group(self, p): + "policy_option_group : LBRACE policy_option_list RBRACE" + pass + + def p_policy_option_list(self, p): + """policy_option_list : policy_option SEMI + | policy_option_list policy_option SEMI""" + pass + + def p_policy_option(self, p): + """policy_option : parent_option + | directory_option + | coverage_option + | rollperiod_option + | prepublish_option + | postpublish_option + | keysize_option + | algorithm_option + | keyttl_option + | standby_option""" + pass + + def p_alg_option_group(self, p): + "alg_option_group : LBRACE alg_option_list RBRACE" + pass + + def p_alg_option_list(self, p): + """alg_option_list : alg_option SEMI + | alg_option_list alg_option SEMI""" + pass + + def p_alg_option(self, p): + """alg_option : coverage_option + | rollperiod_option + | prepublish_option + | postpublish_option + | keyttl_option + | keysize_option + | standby_option""" + pass + + def p_parent_option(self, p): + "parent_option : POLICY name" + self.current.parent = self.named_policy[p[2].lower()] + + def p_directory_option(self, p): + "directory_option : DIRECTORY QSTRING" + self.current.directory = p[2] + + def p_coverage_option(self, p): + "coverage_option : COVERAGE duration" + self.current.coverage = p[2] + + def p_rollperiod_option(self, p): + "rollperiod_option : ROLL_PERIOD KEYTYPE duration" + if p[2] == "KSK": + self.current.ksk_rollperiod = p[3] + else: + self.current.zsk_rollperiod = p[3] + + def p_prepublish_option(self, p): + "prepublish_option : PRE_PUBLISH KEYTYPE duration" + if p[2] == "KSK": + self.current.ksk_prepublish = p[3] + else: + self.current.zsk_prepublish = p[3] + + def p_postpublish_option(self, p): + "postpublish_option : POST_PUBLISH KEYTYPE duration" + if p[2] == "KSK": + self.current.ksk_postpublish = p[3] + else: + self.current.zsk_postpublish = p[3] + + def p_keysize_option(self, p): + "keysize_option : KEY_SIZE KEYTYPE NUMBER" + if p[2] == "KSK": + self.current.ksk_keysize = p[3] + else: + self.current.zsk_keysize = p[3] + + def p_standby_option(self, p): + "standby_option : STANDBY KEYTYPE NUMBER" + if p[2] == "KSK": + self.current.ksk_standby = p[3] + else: + self.current.zsk_standby = p[3] + + def p_keyttl_option(self, p): + "keyttl_option : KEYTTL duration" + self.current.keyttl = p[2] + + def p_algorithm_option(self, p): + "algorithm_option : ALGORITHM ALGNAME" + self.current.algorithm = p[2] + + def p_error(self, p): + if p: + print( + "%s%s%d:syntax error near '%s'" + % (self.filename or "", ":" if self.filename else "", p.lineno, p.value) + ) + else: + if not self.initial: + raise PolicyException( + "%s%s%d:unexpected end of input" + % ( + self.filename or "", + ":" if self.filename else "", + p and p.lineno or 0, + ) + ) + + +if __name__ == "__main__": + import sys + + if sys.argv[1] == "lex": + file = open(sys.argv[2]) + text = file.read() + file.close() + plex = PolicyLex(debug=1) + plex.test(text) + elif sys.argv[1] == "parse": + try: + pp = dnssec_policy(sys.argv[2], write_tables=True, debug=True) + print(pp.named_policy["default"]) + print(pp.policy("nonexistent.zone")) + except Exception as e: + print(e.args[0]) |