| from ctypes import * |
| import re |
| import os |
| import sys |
| import platform |
| import fc_sort |
| |
| ### |
| # Check whether the regex will match a file path starting with the provided |
| # prefix |
| # |
| # Compares regex entries in file_contexts with a path prefix. Regex entries |
| # are often more specific than this file prefix. For example, the regex could |
| # be /system/bin/foo\.sh and the prefix could be /system. This function |
| # loops over the regex removing characters from the end until |
| # 1) there is a match - return True or 2) run out of characters - return |
| # False. |
| # |
| def MatchPathPrefix(pathregex, prefix): |
| for i in range(len(pathregex), 0, -1): |
| try: |
| pattern = re.compile('^' + pathregex[0:i] + "$") |
| except: |
| continue |
| if pattern.match(prefix): |
| return True |
| return False |
| |
| def MatchPathPrefixes(pathregex, Prefixes): |
| for Prefix in Prefixes: |
| if MatchPathPrefix(pathregex, Prefix): |
| return True |
| return False |
| |
| class TERule: |
| def __init__(self, rule): |
| data = rule.split(',') |
| self.flavor = data[0] |
| self.sctx = data[1] |
| self.tctx = data[2] |
| self.tclass = data[3] |
| self.perms = set((data[4].strip()).split(' ')) |
| self.rule = rule |
| |
| class Policy: |
| __ExpandedRules = set() |
| __Rules = set() |
| __FcDict = None |
| __FcSorted = None |
| __GenfsDict = None |
| __libsepolwrap = None |
| __policydbP = None |
| __BUFSIZE = 2048 |
| |
| def AssertPathTypesDoNotHaveAttr(self, MatchPrefix, DoNotMatchPrefix, Attr, ExcludedTypes = []): |
| # Query policy for the types associated with Attr |
| TypesPol = self.QueryTypeAttribute(Attr, True) - set(ExcludedTypes) |
| # Search file_contexts to find types associated with input paths. |
| TypesFc, Files = self.__GetTypesAndFilesByFilePathPrefix(MatchPrefix, DoNotMatchPrefix) |
| violators = TypesFc.intersection(TypesPol) |
| ret = "" |
| if len(violators) > 0: |
| ret += "The following types on " |
| ret += " ".join(str(x) for x in sorted(MatchPrefix)) |
| ret += " must not be associated with the " |
| ret += "\"" + Attr + "\" attribute: " |
| ret += " ".join(str(x) for x in sorted(violators)) + "\n" |
| ret += " corresponding to files: " |
| ret += " ".join(str(x) for x in sorted(Files)) + "\n" |
| return ret |
| |
| # Check that all types for "filesystem" have "attribute" associated with them |
| # for types labeled in genfs_contexts. |
| def AssertGenfsFilesystemTypesHaveAttr(self, Filesystem, Attr): |
| TypesPol = self.QueryTypeAttribute(Attr, True) |
| TypesGenfs = self.__GenfsDict[Filesystem] |
| violators = TypesGenfs.difference(TypesPol) |
| |
| ret = "" |
| if len(violators) > 0: |
| ret += "The following types in " + Filesystem |
| ret += " must be associated with the " |
| ret += "\"" + Attr + "\" attribute: " |
| ret += " ".join(str(x) for x in sorted(violators)) + "\n" |
| return ret |
| |
| # Check that path prefixes that match MatchPrefix, and do not Match |
| # DoNotMatchPrefix have the attribute Attr. |
| # For example assert that all types in /sys, and not in /sys/kernel/debugfs |
| # have the sysfs_type attribute. |
| def AssertPathTypesHaveAttr(self, MatchPrefix, DoNotMatchPrefix, Attr): |
| # Query policy for the types associated with Attr |
| TypesPol = self.QueryTypeAttribute(Attr, True) |
| # Search file_contexts to find paths/types that should be associated with |
| # Attr. |
| TypesFc, Files = self.__GetTypesAndFilesByFilePathPrefix(MatchPrefix, DoNotMatchPrefix) |
| violators = TypesFc.difference(TypesPol) |
| |
| ret = "" |
| if len(violators) > 0: |
| ret += "The following types on " |
| ret += " ".join(str(x) for x in sorted(MatchPrefix)) |
| ret += " must be associated with the " |
| ret += "\"" + Attr + "\" attribute: " |
| ret += " ".join(str(x) for x in sorted(violators)) + "\n" |
| ret += " corresponding to files: " |
| ret += " ".join(str(x) for x in sorted(Files)) + "\n" |
| return ret |
| |
| def AssertPropertyOwnersAreExclusive(self): |
| systemProps = self.QueryTypeAttribute('system_property_type', True) |
| vendorProps = self.QueryTypeAttribute('vendor_property_type', True) |
| violators = systemProps.intersection(vendorProps) |
| ret = "" |
| if len(violators) > 0: |
| ret += "The following types have both system_property_type " |
| ret += "and vendor_property_type: " |
| ret += " ".join(str(x) for x in sorted(violators)) + "\n" |
| return ret |
| |
| # Return all file_contexts entries that map to the input Type. |
| def QueryFc(self, Type): |
| if Type in self.__FcDict: |
| return self.__FcDict[Type] |
| else: |
| return None |
| |
| # Return all attributes associated with a type if IsAttr=False or |
| # all types associated with an attribute if IsAttr=True |
| def QueryTypeAttribute(self, Type, IsAttr): |
| TypeIterP = self.__libsepolwrap.init_type_iter(self.__policydbP, |
| create_string_buffer(Type), IsAttr) |
| if (TypeIterP == None): |
| sys.exit("Failed to initialize type iterator") |
| buf = create_string_buffer(self.__BUFSIZE) |
| TypeAttr = set() |
| while True: |
| ret = self.__libsepolwrap.get_type(buf, self.__BUFSIZE, |
| self.__policydbP, TypeIterP) |
| if ret == 0: |
| TypeAttr.add(buf.value) |
| continue |
| if ret == 1: |
| break; |
| # We should never get here. |
| sys.exit("Failed to import policy") |
| self.__libsepolwrap.destroy_type_iter(TypeIterP) |
| return TypeAttr |
| |
| def __TERuleMatch(self, Rule, **kwargs): |
| # Match source type |
| if ("scontext" in kwargs and |
| len(kwargs['scontext']) > 0 and |
| Rule.sctx not in kwargs['scontext']): |
| return False |
| # Match target type |
| if ("tcontext" in kwargs and |
| len(kwargs['tcontext']) > 0 and |
| Rule.tctx not in kwargs['tcontext']): |
| return False |
| # Match target class |
| if ("tclass" in kwargs and |
| len(kwargs['tclass']) > 0 and |
| not bool(set([Rule.tclass]) & kwargs['tclass'])): |
| return False |
| # Match any perms |
| if ("perms" in kwargs and |
| len(kwargs['perms']) > 0 and |
| not bool(Rule.perms & kwargs['perms'])): |
| return False |
| return True |
| |
| # resolve a type to its attributes or |
| # resolve an attribute to its types and attributes |
| # For example if scontext is the domain attribute, then we need to |
| # include all types with the domain attribute such as untrusted_app and |
| # priv_app and all the attributes of those types such as appdomain. |
| def ResolveTypeAttribute(self, Type): |
| types = self.GetAllTypes(False) |
| attributes = self.GetAllTypes(True) |
| |
| if Type in types: |
| return self.QueryTypeAttribute(Type, False) |
| elif Type in attributes: |
| TypesAndAttributes = set() |
| Types = self.QueryTypeAttribute(Type, True) |
| TypesAndAttributes |= Types |
| for T in Types: |
| TypesAndAttributes |= self.QueryTypeAttribute(T, False) |
| return TypesAndAttributes |
| else: |
| return set() |
| |
| # Return all TERules that match: |
| # (any scontext) or (any tcontext) or (any tclass) or (any perms), |
| # perms. |
| # Any unspecified paramenter will match all. |
| # |
| # Example: QueryTERule(tcontext=["foo", "bar"], perms=["entrypoint"]) |
| # Will return any rule with: |
| # (tcontext="foo" or tcontext="bar") and ("entrypoint" in perms) |
| def QueryTERule(self, **kwargs): |
| if len(self.__Rules) == 0: |
| self.__InitTERules() |
| |
| # add any matching types and attributes for scontext and tcontext |
| if ("scontext" in kwargs and len(kwargs['scontext']) > 0): |
| scontext = set() |
| for sctx in kwargs['scontext']: |
| scontext |= self.ResolveTypeAttribute(sctx) |
| kwargs['scontext'] = scontext |
| if ("tcontext" in kwargs and len(kwargs['tcontext']) > 0): |
| tcontext = set() |
| for tctx in kwargs['tcontext']: |
| tcontext |= self.ResolveTypeAttribute(tctx) |
| kwargs['tcontext'] = tcontext |
| for Rule in self.__Rules: |
| if self.__TERuleMatch(Rule, **kwargs): |
| yield Rule |
| |
| # Same as QueryTERule but only using the expanded ruleset. |
| # i.e. all attributes have been expanded to their various types. |
| def QueryExpandedTERule(self, **kwargs): |
| if len(self.__ExpandedRules) == 0: |
| self.__InitExpandedTERules() |
| for Rule in self.__ExpandedRules: |
| if self.__TERuleMatch(Rule, **kwargs): |
| yield Rule |
| |
| def GetAllTypes(self, isAttr): |
| TypeIterP = self.__libsepolwrap.init_type_iter(self.__policydbP, None, isAttr) |
| if (TypeIterP == None): |
| sys.exit("Failed to initialize type iterator") |
| buf = create_string_buffer(self.__BUFSIZE) |
| AllTypes = set() |
| while True: |
| ret = self.__libsepolwrap.get_type(buf, self.__BUFSIZE, |
| self.__policydbP, TypeIterP) |
| if ret == 0: |
| AllTypes.add(buf.value) |
| continue |
| if ret == 1: |
| break; |
| # We should never get here. |
| sys.exit("Failed to import policy") |
| self.__libsepolwrap.destroy_type_iter(TypeIterP) |
| return AllTypes |
| |
| def __ExactMatchPathPrefix(self, pathregex, prefix): |
| pattern = re.compile('^' + pathregex + "$") |
| if pattern.match(prefix): |
| return True |
| return False |
| |
| # Return a tuple (prefix, i) where i is the index of the most specific |
| # match of prefix in the sorted file_contexts. This is useful for limiting a |
| # file_contexts search to matches that are more specific and omitting less |
| # specific matches. For example, finding all matches to prefix /data/vendor |
| # should not include /data(/.*)? if /data/vendor(/.*)? is also specified. |
| def __FcSortedIndex(self, prefix): |
| index = 0 |
| for i in range(0, len(self.__FcSorted)): |
| if self.__ExactMatchPathPrefix(self.__FcSorted[i].path, prefix): |
| index = i |
| return prefix, index |
| |
| # Return a tuple of (path, Type) for all matching paths. Use the sorted |
| # file_contexts and index returned from __FcSortedIndex() to limit results |
| # to results that are more specific than the prefix. |
| def __MatchPathPrefixTypes(self, prefix, index): |
| PathType = [] |
| for i in range(index, len(self.__FcSorted)): |
| if MatchPathPrefix(self.__FcSorted[i].path, prefix): |
| PathType.append((self.__FcSorted[i].path, self.__FcSorted[i].type)) |
| return PathType |
| |
| # Return types that match MatchPrefixes but do not match |
| # DoNotMatchPrefixes |
| def __GetTypesAndFilesByFilePathPrefix(self, MatchPrefixes, DoNotMatchPrefixes): |
| Types = set() |
| Files = set() |
| |
| MatchPrefixesWithIndex = [] |
| for MatchPrefix in MatchPrefixes: |
| MatchPrefixesWithIndex.append(self.__FcSortedIndex(MatchPrefix)) |
| |
| for MatchPrefixWithIndex in MatchPrefixesWithIndex: |
| PathTypes = self.__MatchPathPrefixTypes(*MatchPrefixWithIndex) |
| for PathType in PathTypes: |
| if MatchPathPrefixes(PathType[0], DoNotMatchPrefixes): |
| continue |
| Types.add(PathType[1]) |
| Files.add(PathType[0]) |
| return Types, Files |
| |
| def __GetTERules(self, policydbP, avtabIterP, Rules): |
| if Rules is None: |
| Rules = set() |
| buf = create_string_buffer(self.__BUFSIZE) |
| ret = 0 |
| while True: |
| ret = self.__libsepolwrap.get_allow_rule(buf, self.__BUFSIZE, |
| policydbP, avtabIterP) |
| if ret == 0: |
| Rule = TERule(buf.value) |
| Rules.add(Rule) |
| continue |
| if ret == 1: |
| break; |
| # We should never get here. |
| sys.exit("Failed to import policy") |
| |
| def __InitTERules(self): |
| avtabIterP = self.__libsepolwrap.init_avtab(self.__policydbP) |
| if (avtabIterP == None): |
| sys.exit("Failed to initialize avtab") |
| self.__GetTERules(self.__policydbP, avtabIterP, self.__Rules) |
| self.__libsepolwrap.destroy_avtab(avtabIterP) |
| avtabIterP = self.__libsepolwrap.init_cond_avtab(self.__policydbP) |
| if (avtabIterP == None): |
| sys.exit("Failed to initialize conditional avtab") |
| self.__GetTERules(self.__policydbP, avtabIterP, self.__Rules) |
| self.__libsepolwrap.destroy_avtab(avtabIterP) |
| |
| def __InitExpandedTERules(self): |
| avtabIterP = self.__libsepolwrap.init_expanded_avtab(self.__policydbP) |
| if (avtabIterP == None): |
| sys.exit("Failed to initialize avtab") |
| self.__GetTERules(self.__policydbP, avtabIterP, self.__ExpandedRules) |
| self.__libsepolwrap.destroy_expanded_avtab(avtabIterP) |
| avtabIterP = self.__libsepolwrap.init_expanded_cond_avtab(self.__policydbP) |
| if (avtabIterP == None): |
| sys.exit("Failed to initialize conditional avtab") |
| self.__GetTERules(self.__policydbP, avtabIterP, self.__ExpandedRules) |
| self.__libsepolwrap.destroy_expanded_avtab(avtabIterP) |
| |
| # load ctypes-ified libsepol wrapper |
| def __InitLibsepolwrap(self, LibPath): |
| lib = CDLL(LibPath) |
| |
| # int get_allow_rule(char *out, size_t len, void *policydbp, void *avtab_iterp); |
| lib.get_allow_rule.restype = c_int |
| lib.get_allow_rule.argtypes = [c_char_p, c_size_t, c_void_p, c_void_p]; |
| # void *load_policy(const char *policy_path); |
| lib.load_policy.restype = c_void_p |
| lib.load_policy.argtypes = [c_char_p] |
| # void destroy_policy(void *policydbp); |
| lib.destroy_policy.argtypes = [c_void_p] |
| # void *init_expanded_avtab(void *policydbp); |
| lib.init_expanded_avtab.restype = c_void_p |
| lib.init_expanded_avtab.argtypes = [c_void_p] |
| # void *init_expanded_cond_avtab(void *policydbp); |
| lib.init_expanded_cond_avtab.restype = c_void_p |
| lib.init_expanded_cond_avtab.argtypes = [c_void_p] |
| # void destroy_expanded_avtab(void *avtab_iterp); |
| lib.destroy_expanded_avtab.argtypes = [c_void_p] |
| # void *init_avtab(void *policydbp); |
| lib.init_avtab.restype = c_void_p |
| lib.init_avtab.argtypes = [c_void_p] |
| # void *init_cond_avtab(void *policydbp); |
| lib.init_cond_avtab.restype = c_void_p |
| lib.init_cond_avtab.argtypes = [c_void_p] |
| # void destroy_avtab(void *avtab_iterp); |
| lib.destroy_avtab.argtypes = [c_void_p] |
| # int get_type(char *out, size_t max_size, void *policydbp, void *type_iterp); |
| lib.get_type.restype = c_int |
| lib.get_type.argtypes = [c_char_p, c_size_t, c_void_p, c_void_p] |
| # void *init_type_iter(void *policydbp, const char *type, bool is_attr); |
| lib.init_type_iter.restype = c_void_p |
| lib.init_type_iter.argtypes = [c_void_p, c_char_p, c_bool] |
| # void destroy_type_iter(void *type_iterp); |
| lib.destroy_type_iter.argtypes = [c_void_p] |
| # void *init_genfs_iter(void *policydbp) |
| lib.init_genfs_iter.restype = c_void_p |
| lib.init_genfs_iter.argtypes = [c_void_p] |
| # int get_genfs(char *out, size_t max_size, void *genfs_iterp); |
| lib.get_genfs.restype = c_int |
| lib.get_genfs.argtypes = [c_char_p, c_size_t, c_void_p, c_void_p] |
| # void destroy_genfs_iter(void *genfs_iterp) |
| lib.destroy_genfs_iter.argtypes = [c_void_p] |
| |
| self.__libsepolwrap = lib |
| |
| def __GenfsDictAdd(self, Dict, buf): |
| fs, path, context = buf.split(" ") |
| Type = context.split(":")[2] |
| if not fs in Dict: |
| Dict[fs] = {Type} |
| else: |
| Dict[fs].add(Type) |
| |
| def __InitGenfsCon(self): |
| self.__GenfsDict = {} |
| GenfsIterP = self.__libsepolwrap.init_genfs_iter(self.__policydbP) |
| if (GenfsIterP == None): |
| sys.exit("Failed to retreive genfs entries") |
| buf = create_string_buffer(self.__BUFSIZE) |
| while True: |
| ret = self.__libsepolwrap.get_genfs(buf, self.__BUFSIZE, |
| self.__policydbP, GenfsIterP) |
| if ret == 0: |
| self.__GenfsDictAdd(self.__GenfsDict, buf.value) |
| continue |
| if ret == 1: |
| self.__GenfsDictAdd(self.__GenfsDict, buf.value) |
| break; |
| # We should never get here. |
| sys.exit("Failed to get genfs entries") |
| self.__libsepolwrap.destroy_genfs_iter(GenfsIterP) |
| |
| # load file_contexts |
| def __InitFC(self, FcPaths): |
| if FcPaths is None: |
| return |
| fc = [] |
| for path in FcPaths: |
| if not os.path.exists(path): |
| sys.exit("file_contexts file " + path + " does not exist.") |
| fd = open(path, "r") |
| fc += fd.readlines() |
| fd.close() |
| self.__FcDict = {} |
| for i in fc: |
| rec = i.split() |
| try: |
| t = rec[-1].split(":")[2] |
| if t in self.__FcDict: |
| self.__FcDict[t].append(rec[0]) |
| else: |
| self.__FcDict[t] = [rec[0]] |
| except: |
| pass |
| self.__FcSorted = fc_sort.sort(FcPaths) |
| |
| # load policy |
| def __InitPolicy(self, PolicyPath): |
| cPolicyPath = create_string_buffer(PolicyPath) |
| self.__policydbP = self.__libsepolwrap.load_policy(cPolicyPath) |
| if (self.__policydbP is None): |
| sys.exit("Failed to load policy") |
| |
| def __init__(self, PolicyPath, FcPaths, LibPath): |
| self.__InitLibsepolwrap(LibPath) |
| self.__InitFC(FcPaths) |
| self.__InitPolicy(PolicyPath) |
| self.__InitGenfsCon() |
| |
| def __del__(self): |
| if self.__policydbP is not None: |
| self.__libsepolwrap.destroy_policy(self.__policydbP) |