%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2008-2010. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
%%
-module(pubkey_cert).
-include("public_key.hrl").
-export([init_validation_state/3, prepare_for_next_cert/2,
validate_time/3, validate_signature/6,
validate_issuer/4, validate_names/6,
validate_revoked_status/3, validate_extensions/4,
normalize_general_name/1, digest_type/1, is_self_signed/1,
is_issuer/2, issuer_id/2, is_fixed_dh_cert/1,
verify_data/1]).
-define(NULL, 0).
%%====================================================================
%% Internal application API
%%====================================================================
%%--------------------------------------------------------------------
-spec verify_data(der_encoded()) -> {md5 | sha, binary(), binary()}.
%%
%% Description: Extracts data from DerCert needed to call public_key:verify/4.
%%--------------------------------------------------------------------
verify_data(DerCert) ->
{ok, OtpCert} = pubkey_cert_records:decode_cert(DerCert),
extract_verify_data(OtpCert, DerCert).
%%--------------------------------------------------------------------
-spec init_validation_state(#'OTPCertificate'{}, integer(), list()) ->
#path_validation_state{}.
%%
%% Description: Creates inital version of path_validation_state for
%% basic path validation of x509 certificates.
%%--------------------------------------------------------------------
init_validation_state(#'OTPCertificate'{} = OtpCert, DefaultPathLen,
Options) ->
PolicyTree = #policy_tree_node{valid_policy = ?anyPolicy,
qualifier_set = [],
criticality_indicator = false,
expected_policy_set = [?anyPolicy]},
MaxLen = proplists:get_value(max_path_length, Options, DefaultPathLen),
ExplicitPolicy = policy_indicator(MaxLen,
proplists:get_value(explicit_policy, Options, false)),
InhibitAnyPolicy = policy_indicator(MaxLen,
proplists:get_value(inhibit_any_policy,
Options, false)),
PolicyMapping = policy_indicator(MaxLen,
proplists:get_value(policy_mapping, Options, false)),
{VerifyFun, UserState} = proplists:get_value(verify_fun, Options, ?DEFAULT_VERIFYFUN),
State = #path_validation_state{max_path_length = MaxLen,
valid_policy_tree = PolicyTree,
explicit_policy = ExplicitPolicy,
inhibit_any_policy = InhibitAnyPolicy,
policy_mapping = PolicyMapping,
verify_fun = VerifyFun,
user_state = UserState,
cert_num = 0},
prepare_for_next_cert(OtpCert, State).
%%--------------------------------------------------------------------
-spec prepare_for_next_cert(#'OTPCertificate'{}, #path_validation_state{}) ->
#path_validation_state{}.
%%
%% Description: Update path_validation_state for next iteration.
%%--------------------------------------------------------------------
prepare_for_next_cert(OtpCert, ValidationState = #path_validation_state{
working_public_key_algorithm = PrevAlgo,
working_public_key_parameters =
PrevParams}) ->
TBSCert = OtpCert#'OTPCertificate'.tbsCertificate,
Issuer = TBSCert#'OTPTBSCertificate'.subject,
{Algorithm, PublicKey, PublicKeyParams0} =
public_key_info(TBSCert#'OTPTBSCertificate'.subjectPublicKeyInfo,
ValidationState),
PublicKeyParams =
case PublicKeyParams0 of
'NULL' when Algorithm =:= PrevAlgo ->
PrevParams;
asn1_NOVALUE when Algorithm =:= PrevAlgo ->
PrevParams;
_ -> PublicKeyParams0
end,
ValidationState#path_validation_state{
working_public_key_algorithm = Algorithm,
working_public_key = PublicKey,
working_public_key_parameters = PublicKeyParams,
working_issuer_name = Issuer,
cert_num = ValidationState#path_validation_state.cert_num + 1
}.
%%--------------------------------------------------------------------
-spec validate_time(#'OTPCertificate'{}, term(), fun()) -> term().
%%
%% Description: Check that the certificate validity period includes the
%% current time.
%%--------------------------------------------------------------------
validate_time(OtpCert, UserState, VerifyFun) ->
TBSCert = OtpCert#'OTPCertificate'.tbsCertificate,
{'Validity', NotBeforeStr, NotAfterStr}
= TBSCert#'OTPTBSCertificate'.validity,
Now = calendar:datetime_to_gregorian_seconds(calendar:universal_time()),
NotBefore = time_str_2_gregorian_sec(NotBeforeStr),
NotAfter = time_str_2_gregorian_sec(NotAfterStr),
case ((NotBefore =< Now) and (Now =< NotAfter)) of
true ->
UserState;
false ->
verify_fun(OtpCert, {bad_cert, cert_expired}, UserState, VerifyFun)
end.
%%--------------------------------------------------------------------
-spec validate_issuer(#'OTPCertificate'{}, term(), term(), fun()) -> term().
%%
%% Description: Check that the certificate issuer name is the working_issuer_name
%% in path_validation_state.
%%--------------------------------------------------------------------
validate_issuer(OtpCert, Issuer, UserState, VerifyFun) ->
TBSCert = OtpCert#'OTPCertificate'.tbsCertificate,
case is_issuer(Issuer, TBSCert#'OTPTBSCertificate'.issuer) of
true ->
UserState;
_ ->
verify_fun(OtpCert, {bad_cert, invalid_issuer}, UserState, VerifyFun)
end.
%%--------------------------------------------------------------------
-spec validate_signature(#'OTPCertificate'{}, der_encoded(),
term(),term(), term(), fun()) -> term().
%%
%% Description: Check that the signature on the certificate can be verified using
%% working_public_key_algorithm, the working_public_key, and
%% the working_public_key_parameters in path_validation_state.
%%--------------------------------------------------------------------
validate_signature(OtpCert, DerCert, Key, KeyParams,
UserState, VerifyFun) ->
case verify_signature(OtpCert, DerCert, Key, KeyParams) of
true ->
UserState;
false ->
verify_fun(OtpCert, {bad_cert, invalid_signature}, UserState, VerifyFun)
end.
%%--------------------------------------------------------------------
-spec validate_names(#'OTPCertificate'{}, list(), list(),
term(), term(), fun())-> term().
%%
%% Description: Validate Subject Alternative Name.
%%--------------------------------------------------------------------
validate_names(OtpCert, Permit, Exclude, Last, UserState, VerifyFun) ->
case is_self_signed(OtpCert) andalso (not Last) of
true ->
UserState;
false ->
TBSCert = OtpCert#'OTPCertificate'.tbsCertificate,
Subject = TBSCert#'OTPTBSCertificate'.subject,
Extensions =
extensions_list(TBSCert#'OTPTBSCertificate'.extensions),
AltSubject =
select_extension(?'id-ce-subjectAltName', Extensions),
EmailAddress = extract_email(Subject),
Name = [{directoryName, Subject}|EmailAddress],
AltNames = case AltSubject of
undefined ->
[];
_ ->
AltSubject#'Extension'.extnValue
end,
case (is_permitted(Name, Permit) andalso
is_permitted(AltNames, Permit) andalso
(not is_excluded(Name, Exclude)) andalso
(not is_excluded(AltNames, Exclude))) of
true ->
UserState;
false ->
verify_fun(OtpCert, {bad_cert, name_not_permitted},
UserState, VerifyFun)
end
end.
%%--------------------------------------------------------------------
-spec validate_revoked_status(#'OTPCertificate'{}, term(), fun()) ->
term().
%%
%% Description: Check if certificate has been revoked.
%%--------------------------------------------------------------------
validate_revoked_status(_OtpCert, UserState, _VerifyFun) ->
%% TODO: Implement or leave for application?!
%% valid |
%% throw({bad_cert, cert_revoked})
UserState.
%%--------------------------------------------------------------------
-spec validate_extensions(#'OTPCertificate'{}, #path_validation_state{},
term(), fun())->
{#path_validation_state{}, UserState :: term()}.
%%
%% Description: Check extensions included in basic path validation.
%%--------------------------------------------------------------------
validate_extensions(OtpCert, ValidationState, UserState, VerifyFun) ->
TBSCert = OtpCert#'OTPCertificate'.tbsCertificate,
Extensions = TBSCert#'OTPTBSCertificate'.extensions,
validate_extensions(OtpCert, Extensions, ValidationState, no_basic_constraint,
is_self_signed(OtpCert), UserState, VerifyFun).
%%--------------------------------------------------------------------
-spec normalize_general_name({rdnSequence, term()}) -> {rdnSequence, term()}.
%%
%% Description: Normalizes a general name so that it can be easily
%% compared to another genral name.
%%--------------------------------------------------------------------
normalize_general_name({rdnSequence, Issuer}) ->
NormIssuer = do_normalize_general_name(Issuer),
{rdnSequence, NormIssuer}.
%%--------------------------------------------------------------------
-spec is_self_signed(#'OTPCertificate'{}) -> boolean().
%%
%% Description: Checks if the certificate is self signed.
%%--------------------------------------------------------------------
is_self_signed(#'OTPCertificate'{tbsCertificate=
#'OTPTBSCertificate'{issuer = Issuer,
subject = Subject}}) ->
is_issuer(Issuer, Subject).
%%--------------------------------------------------------------------
-spec is_issuer({rdnSequence, term()}, {rdnSequence, term()}) -> boolean().
%%
%% Description: Checks if <Issuer> issued <Candidate>.
%%--------------------------------------------------------------------
is_issuer({rdnSequence, Issuer}, {rdnSequence, Candidate}) ->
is_dir_name(Issuer, Candidate, true).
%%--------------------------------------------------------------------
-spec issuer_id(#'OTPCertificate'{}, self | other) ->
{ok, {integer(), term()}} | {error, issuer_not_found}.
%%
%% Description: Extracts the issuer id from a certificate if possible.
%%--------------------------------------------------------------------
issuer_id(Otpcert, other) ->
TBSCert = Otpcert#'OTPCertificate'.tbsCertificate,
Extensions = extensions_list(TBSCert#'OTPTBSCertificate'.extensions),
case select_extension(?'id-ce-authorityKeyIdentifier', Extensions) of
undefined ->
{error, issuer_not_found};
AuthKeyExt ->
cert_auth_key_id(AuthKeyExt#'Extension'.extnValue)
end;
issuer_id(Otpcert, self) ->
TBSCert = Otpcert#'OTPCertificate'.tbsCertificate,
Issuer = TBSCert#'OTPTBSCertificate'.issuer,
SerialNr = TBSCert#'OTPTBSCertificate'.serialNumber,
{ok, {SerialNr, normalize_general_name(Issuer)}}.
%%--------------------------------------------------------------------
-spec is_fixed_dh_cert(#'OTPCertificate'{}) -> boolean().
%%
%% Description: Checks if the certificate can be be used
%% for DH key agreement.
%%--------------------------------------------------------------------
is_fixed_dh_cert(#'OTPCertificate'{tbsCertificate =
#'OTPTBSCertificate'{subjectPublicKeyInfo =
SubjectPublicKeyInfo,
extensions =
Extensions}}) ->
is_fixed_dh_cert(SubjectPublicKeyInfo, extensions_list(Extensions)).
%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------
do_normalize_general_name(Issuer) ->
Normalize = fun([{Description, Type, {printableString, Value}}]) ->
NewValue = string:to_lower(strip_spaces(Value)),
[{Description, Type, {printableString, NewValue}}];
(Atter) ->
Atter
end,
lists:sort(lists:map(Normalize, Issuer)).
%% See rfc3280 4.1.2.6 Subject: regarding emails.
extract_email({rdnSequence, List}) ->
extract_email2(List).
extract_email2([[#'AttributeTypeAndValue'{type=?'id-emailAddress',
value=Mail}]|_]) ->
[{rfc822Name, Mail}];
extract_email2([_|Rest]) ->
extract_email2(Rest);
extract_email2([]) -> [].
extensions_list(asn1_NOVALUE) ->
[];
extensions_list(Extensions) ->
Extensions.
verify_fun(Otpcert, Result, UserState0, VerifyFun) ->
case VerifyFun(Otpcert, Result, UserState0) of
{valid,UserState} ->
UserState;
{fail, Reason} ->
case Result of
{bad_cert, _} ->
throw(Result);
_ ->
throw({bad_cert, Reason})
end;
{unknown, UserState} ->
case Result of
{extension, #'Extension'{critical = true}} ->
throw({bad_cert, unknown_critical_extension});
_ ->
UserState
end
end.
extract_verify_data(OtpCert, DerCert) ->
{0, Signature} = OtpCert#'OTPCertificate'.signature,
SigAlgRec = OtpCert#'OTPCertificate'.signatureAlgorithm,
SigAlg = SigAlgRec#'SignatureAlgorithm'.algorithm,
PlainText = encoded_tbs_cert(DerCert),
DigestType = digest_type(SigAlg),
{DigestType, PlainText, Signature}.
verify_signature(OtpCert, DerCert, Key, KeyParams) ->
{DigestType, PlainText, Signature} = extract_verify_data(OtpCert, DerCert),
case Key of
#'RSAPublicKey'{} ->
public_key:verify(PlainText, DigestType, Signature, Key);
_ ->
public_key:verify(PlainText, DigestType, Signature, {Key, KeyParams})
end.
encoded_tbs_cert(Cert) ->
{ok, PKIXCert} =
'OTP-PUB-KEY':decode_TBSCert_exclusive(Cert),
{'Certificate',
{'Certificate_tbsCertificate', EncodedTBSCert}, _, _} = PKIXCert,
EncodedTBSCert.
digest_type(?sha1WithRSAEncryption) ->
sha;
digest_type(?md5WithRSAEncryption) ->
md5;
digest_type(?'id-dsa-with-sha1') ->
sha.
public_key_info(PublicKeyInfo,
#path_validation_state{working_public_key_algorithm =
WorkingAlgorithm,
working_public_key_parameters =
WorkingParams}) ->
PublicKey = PublicKeyInfo#'OTPSubjectPublicKeyInfo'.subjectPublicKey,
AlgInfo = PublicKeyInfo#'OTPSubjectPublicKeyInfo'.algorithm,
PublicKeyParams = AlgInfo#'PublicKeyAlgorithm'.parameters,
Algorithm = AlgInfo#'PublicKeyAlgorithm'.algorithm,
NewPublicKeyParams =
case PublicKeyParams of
'NULL' when WorkingAlgorithm == Algorithm ->
WorkingParams;
_ ->
PublicKeyParams
end,
{Algorithm, PublicKey, NewPublicKeyParams}.
time_str_2_gregorian_sec({utcTime, [Y1,Y2,M1,M2,D1,D2,H1,H2,M3,M4,S1,S2,Z]}) ->
case list_to_integer([Y1,Y2]) of
N when N >= 50 ->
time_str_2_gregorian_sec({generalTime,
[$1,$9,Y1,Y2,M1,M2,D1,D2,
H1,H2,M3,M4,S1,S2,Z]});
_ ->
time_str_2_gregorian_sec({generalTime,
[$2,$0,Y1,Y2,M1,M2,D1,D2,
H1,H2,M3,M4,S1,S2,Z]})
end;
time_str_2_gregorian_sec({_,[Y1,Y2,Y3,Y4,M1,M2,D1,D2,H1,H2,M3,M4,S1,S2,$Z]}) ->
Year = list_to_integer([Y1, Y2, Y3, Y4]),
Month = list_to_integer([M1, M2]),
Day = list_to_integer([D1, D2]),
Hour = list_to_integer([H1, H2]),
Min = list_to_integer([M3, M4]),
Sec = list_to_integer([S1, S2]),
calendar:datetime_to_gregorian_seconds({{Year, Month, Day},
{Hour, Min, Sec}}).
is_dir_name([], [], _Exact) -> true;
is_dir_name([H|R1],[H|R2], Exact) -> is_dir_name(R1,R2, Exact);
is_dir_name([[{'AttributeTypeAndValue', Type, What1}]|Rest1],
[[{'AttributeTypeAndValue', Type, What2}]|Rest2],Exact) ->
case is_dir_name2(What1,What2) of
true -> is_dir_name(Rest1,Rest2,Exact);
false -> false
end;
is_dir_name(_,[],false) ->
true;
is_dir_name(_,_,_) ->
false.
is_dir_name2(Value, Value) -> true;
is_dir_name2({printableString, Value1}, {printableString, Value2}) ->
string:to_lower(strip_spaces(Value1)) =:=
string:to_lower(strip_spaces(Value2));
is_dir_name2({utf8String, Value1}, String) -> %% BUGBUG FIX UTF8 conv
is_dir_name2({printableString, binary_to_list(Value1)}, String);
is_dir_name2(String, {utf8String, Value1}) -> %% BUGBUG FIX UTF8 conv
is_dir_name2(String, {printableString, binary_to_list(Value1)});
is_dir_name2(_, _) ->
false.
cert_auth_key_id(#'AuthorityKeyIdentifier'{authorityCertIssuer
= asn1_NOVALUE}) ->
{error, issuer_not_found};
cert_auth_key_id(#'AuthorityKeyIdentifier'{authorityCertIssuer =
AuthCertIssuer,
authorityCertSerialNumber =
SerialNr}) ->
{ok, {SerialNr, decode_general_name(AuthCertIssuer)}}.
decode_general_name([{directoryName, Issuer}]) ->
normalize_general_name(Issuer).
%% Strip all leading and trailing spaces and make
%% sure there is no double spaces in between.
strip_spaces(String) ->
NewString =
lists:foldl(fun(Char, Acc) -> Acc ++ Char ++ " " end, [],
string:tokens(String, " ")),
string:strip(NewString).
select_extension(_, []) ->
undefined;
select_extension(Id, [#'Extension'{extnID = Id} = Extension | _]) ->
Extension;
select_extension(Id, [_ | Extensions]) ->
select_extension(Id, Extensions).
%% No extensions present
validate_extensions(OtpCert, asn1_NOVALUE, ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun) ->
validate_extensions(OtpCert, [], ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun);
validate_extensions(_,[], ValidationState, basic_constraint, _SelfSigned,
UserState, _) ->
{ValidationState, UserState};
validate_extensions(OtpCert, [], ValidationState =
#path_validation_state{max_path_length = Len,
last_cert = Last},
no_basic_constraint, SelfSigned, UserState0, VerifyFun) ->
case Last of
true when SelfSigned ->
{ValidationState, UserState0};
true ->
{ValidationState#path_validation_state{max_path_length = Len - 1},
UserState0};
%% basic_constraint must appear in certs used for digital sign
%% see 4.2.1.10 in rfc 3280
false ->
UserState = verify_fun(OtpCert, {bad_cert, missing_basic_constraint},
UserState0, VerifyFun),
case SelfSigned of
true ->
{ValidationState, UserState};
false ->
{ValidationState#path_validation_state{max_path_length =
Len - 1},
UserState}
end
end;
validate_extensions(OtpCert,
[#'Extension'{extnID = ?'id-ce-basicConstraints',
extnValue =
#'BasicConstraints'{cA = true,
pathLenConstraint = N}} |
Rest],
ValidationState =
#path_validation_state{max_path_length = Len}, _,
SelfSigned, UserState, VerifyFun) ->
Length = if SelfSigned -> erlang:min(N, Len);
true -> erlang:min(N, Len-1)
end,
validate_extensions(OtpCert, Rest,
ValidationState#path_validation_state{max_path_length =
Length},
basic_constraint, SelfSigned,
UserState, VerifyFun);
%% The pathLenConstraint field is meaningful only if cA is set to
%% TRUE.
validate_extensions(OtpCert, [#'Extension'{extnID = ?'id-ce-basicConstraints',
extnValue =
#'BasicConstraints'{cA = false}} |
Rest], ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun) ->
validate_extensions(OtpCert, Rest, ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun);
validate_extensions(OtpCert, [#'Extension'{extnID = ?'id-ce-keyUsage',
extnValue = KeyUse
} | Rest],
#path_validation_state{last_cert=Last} = ValidationState,
ExistBasicCon, SelfSigned,
UserState0, VerifyFun) ->
case Last orelse is_valid_key_usage(KeyUse, keyCertSign) of
true ->
validate_extensions(OtpCert, Rest, ValidationState, ExistBasicCon,
SelfSigned, UserState0, VerifyFun);
false ->
UserState = verify_fun(OtpCert, {bad_cert, invalid_key_usage},
UserState0, VerifyFun),
validate_extensions(OtpCert, Rest, ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun)
end;
validate_extensions(OtpCert, [#'Extension'{extnID = ?'id-ce-subjectAltName',
extnValue = Names} | Rest],
ValidationState, ExistBasicCon,
SelfSigned, UserState0, VerifyFun) ->
case validate_subject_alt_names(Names) of
true when Names =/= [] ->
validate_extensions(OtpCert, Rest, ValidationState, ExistBasicCon,
SelfSigned, UserState0, VerifyFun);
_ ->
UserState = verify_fun(OtpCert, {bad_cert, invalid_subject_altname},
UserState0, VerifyFun),
validate_extensions(OtpCert, Rest, ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun)
end;
%% This extension SHOULD NOT be marked critical. Its value
%% does not have to be further validated at this point.
validate_extensions(OtpCert, [#'Extension'{extnID = ?'id-ce-issuerAltName',
extnValue = _} | Rest],
ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun) ->
validate_extensions(OtpCert, Rest, ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun);
%% This extension MUST NOT be marked critical.Its value
%% does not have to be further validated at this point.
validate_extensions(OtpCert, [#'Extension'{extnID = Id,
extnValue = _,
critical = false} | Rest],
ValidationState,
ExistBasicCon, SelfSigned,
UserState, VerifyFun)
when Id == ?'id-ce-subjectKeyIdentifier';
Id == ?'id-ce-authorityKeyIdentifier'->
validate_extensions(OtpCert, Rest, ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun);
validate_extensions(OtpCert, [#'Extension'{extnID = ?'id-ce-nameConstraints',
extnValue = NameConst} | Rest],
ValidationState,
ExistBasicCon, SelfSigned, UserState, VerifyFun) ->
Permitted = NameConst#'NameConstraints'.permittedSubtrees,
Excluded = NameConst#'NameConstraints'.excludedSubtrees,
NewValidationState = add_name_constraints(Permitted, Excluded,
ValidationState),
validate_extensions(OtpCert, Rest, NewValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun);
validate_extensions(OtpCert, [#'Extension'{extnID = ?'id-ce-certificatePolicies',
critical = true} = Ext| Rest], ValidationState,
ExistBasicCon, SelfSigned, UserState0, VerifyFun) ->
%% TODO: Remove this clause when policy handling is
%% fully implemented
UserState = verify_fun(OtpCert, {extension, Ext},
UserState0, VerifyFun),
validate_extensions(OtpCert,Rest, ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun);
validate_extensions(OtpCert, [#'Extension'{extnID = ?'id-ce-certificatePolicies',
extnValue = #'PolicyInformation'{
policyIdentifier = Id,
policyQualifiers = Qualifier}}
| Rest], #path_validation_state{valid_policy_tree = Tree}
= ValidationState,
ExistBasicCon, SelfSigned, UserState, VerifyFun) ->
%% TODO: Policy imp incomplete
NewTree = process_policy_tree(Id, Qualifier, Tree),
validate_extensions(OtpCert, Rest,
ValidationState#path_validation_state{
valid_policy_tree = NewTree},
ExistBasicCon, SelfSigned, UserState, VerifyFun);
validate_extensions(OtpCert, [#'Extension'{extnID = ?'id-ce-policyConstraints',
critical = true} = Ext | Rest], ValidationState,
ExistBasicCon, SelfSigned, UserState0, VerifyFun) ->
%% TODO: Remove this clause when policy handling is
%% fully implemented
UserState = verify_fun(OtpCert, {extension, Ext},
UserState0, VerifyFun),
validate_extensions(OtpCert, Rest, ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun);
validate_extensions(OtpCert, [#'Extension'{extnID = ?'id-ce-policyConstraints',
extnValue = #'PolicyConstraints'{
requireExplicitPolicy = ExpPolicy,
inhibitPolicyMapping = MapPolicy}}
| Rest], ValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun) ->
%% TODO: Policy imp incomplete
NewValidationState = add_policy_constraints(ExpPolicy, MapPolicy,
ValidationState),
validate_extensions(OtpCert, Rest, NewValidationState, ExistBasicCon,
SelfSigned, UserState, VerifyFun);
validate_extensions(OtpCert, [#'Extension'{} = Extension | Rest],
ValidationState, ExistBasicCon,
SelfSigned, UserState0, VerifyFun) ->
UserState = verify_fun(OtpCert, {extension, Extension}, UserState0, VerifyFun),
validate_extensions(OtpCert, Rest, ValidationState, ExistBasicCon, SelfSigned,
UserState, VerifyFun).
is_valid_key_usage(KeyUse, Use) ->
lists:member(Use, KeyUse).
validate_subject_alt_names([]) ->
true;
validate_subject_alt_names([AltName | Rest]) ->
case is_valid_subject_alt_name(AltName) of
true ->
validate_subject_alt_names(Rest);
false ->
false
end.
is_valid_subject_alt_name({Name, Value}) when Name == rfc822Name;
Name == dNSName ->
case Value of
"" ->
false;
_ ->
true
end;
is_valid_subject_alt_name({iPAdress, Addr}) ->
case length(Addr) of
4 -> %ipv4
true;
16 -> %ipv6
true;
_ ->
false
end;
is_valid_subject_alt_name({uniformResourceIdentifier, URI}) ->
is_valid_uri(URI);
is_valid_subject_alt_name({directoryName, _}) ->
true;
is_valid_subject_alt_name({_, [_|_]}) ->
true;
is_valid_subject_alt_name({_, _}) ->
false.
is_ip_address(Address) ->
case inet_parse:address(Address) of
{ok, _} ->
true;
_ ->
false
end.
is_fully_qualified_name(_Name) ->
true.
is_valid_uri(AbsURI) ->
case split_uri(AbsURI) of
incomplete ->
false;
{StrScheme, _, Host, _, _} ->
case string:to_lower(StrScheme) of
Scheme when Scheme =:= "http"; Scheme =:= "ftp" ->
is_valid_host(Host);
_ ->
false
end
end.
is_valid_host(Host) ->
case is_ip_address(Host) of
true ->
true;
false ->
is_fully_qualified_name(Host)
end.
%% Could have a more general split URI in stdlib? Maybe when
%% regexs are improved. Needed also in inets!
split_uri(Uri) ->
case split_uri(Uri, ":", {error, no_scheme}, 1, 1) of
{error, no_scheme} ->
incomplete;
{StrScheme, "//" ++ URIPart} ->
{Authority, PathQuery} =
split_auth_path(URIPart),
{UserInfo, HostPort} =
split_uri(Authority, "@", {"", Authority}, 1, 1),
{Host, Port} =
split_uri(HostPort, ":", {HostPort, dummy_port}, 1, 1),
{StrScheme, UserInfo, Host, Port, PathQuery}
end.
split_auth_path(URIPart) ->
case split_uri(URIPart, "/", URIPart, 1, 0) of
Split = {_, _} ->
Split;
URIPart ->
case split_uri(URIPart, "\\?", URIPart, 1, 0) of
Split = {_, _} ->
Split;
URIPart ->
{URIPart,""}
end
end.
split_uri(UriPart, SplitChar, NoMatchResult, SkipLeft, SkipRight) ->
case re:run(UriPart, SplitChar) of
{match,[{Start, _}]} ->
StrPos = Start + 1,
{string:substr(UriPart, 1, StrPos - SkipLeft),
string:substr(UriPart, StrPos + SkipRight, length(UriPart))};
nomatch ->
NoMatchResult
end.
is_rdnSeq({rdnSequence,[]}, {rdnSequence,[none]}) ->
true;
is_rdnSeq({rdnSequence,DirName}, {rdnSequence,Permitted}) ->
is_dir_name(DirName, Permitted, false).
is_permitted(_, no_constraints) ->
true;
is_permitted(Names, Constraints) ->
is_valid_name(Names, Constraints, true).
is_excluded([], _) ->
false;
is_excluded(Names, Constraints) ->
is_valid_name(Names, Constraints, false).
is_valid_name([], _, Default) ->
Default;
is_valid_name([{Type, Name} | Rest], Constraints, Default) ->
case type_subtree_names(Type, Constraints) of
[_|_] = ConstraintNames ->
case match_name(Type, Name, ConstraintNames) of
Default ->
is_valid_name(Rest, Constraints, Default);
Fail ->
Fail
end;
[] ->
is_valid_name(Rest, Constraints,Default)
end.
add_name_constraints(NewPermittedTrees, NewExcludedTrees,
#path_validation_state{
permitted_subtrees = PermittedTrees,
excluded_subtrees = ExcludedTrees} =
ValidationState) ->
NewPermitted = subtree_intersection(NewPermittedTrees, PermittedTrees),
NewExcluded = subtree_union(NewExcludedTrees, ExcludedTrees),
ValidationState#path_validation_state{permitted_subtrees = NewPermitted,
excluded_subtrees = NewExcluded}.
subtree_union(asn1_NOVALUE, Trees) ->
Trees;
subtree_union(Trees1, Trees2) ->
Trees1 ++ Trees2.
subtree_intersection(asn1_NOVALUE, Trees) ->
Trees;
subtree_intersection(List, no_constraints) ->
List;
subtree_intersection([Tree | Trees1], Trees2) ->
Trees = is_in_intersection(Tree, Trees2),
subtree_intersection(Trees1, Trees);
subtree_intersection([], TreesInt) ->
TreesInt.
is_in_intersection(#'GeneralSubtree'{base =
{directoryName, {rdnSequence, Name1}}}
= Name,
[#'GeneralSubtree'{base =
{directoryName, {rdnSequence, Name2}}}
| Trees]) ->
case is_dir_name(Name1, Name2, false) of
true ->
[Name|Trees];
false ->
[Name#'GeneralSubtree'{base =
{directoryName, {rdnSequence,[none]}}}
| Trees]
end;
is_in_intersection(#'GeneralSubtree'{base = {ipAdress, Ip}},
Trees = [#'GeneralSubtree'{base = {ipAdress, Ip}} | _]) ->
%% BUGBUG
Trees;
is_in_intersection(#'GeneralSubtree'{base = {x400Address, OrAddr1}} = Addr,
[#'GeneralSubtree'{base = {x400Address, OrAddr2}}
| Trees]) ->
case is_or_address(OrAddr1, OrAddr2) of
true ->
[Addr|Trees];
false ->
[#'GeneralSubtree'{base = {x400Address, ""}} | Trees]
end;
is_in_intersection(#'GeneralSubtree'{base = {Type, Name1}} = Name,
[#'GeneralSubtree'{base = {Type, Name2}}
| Trees]) ->
case case_insensitive_match(Name1, Name2) of
true ->
[Name|Trees];
false ->
[#'GeneralSubtree'{base = {Type, ""}} | Trees]
end;
is_in_intersection(New, []) ->
[New];
is_in_intersection(Name, [Other | IntCandidates]) ->
[Other|is_in_intersection(Name, IntCandidates)].
type_subtree_names(Type, SubTrees) ->
[Name || #'GeneralSubtree'{base = {TreeType, Name}} <- SubTrees,
TreeType =:= Type].
match_name(rfc822Name, Name, [PermittedName | Rest]) ->
match_name(fun is_valid_host_or_domain/2, Name, PermittedName, Rest);
match_name(directoryName, DirName, [PermittedName | Rest]) ->
match_name(fun is_rdnSeq/2, DirName, PermittedName, Rest);
match_name(uniformResourceIdentifier, URI, [PermittedName | Rest]) ->
case split_uri(URI) of
incomplete ->
false;
{_, _, Host, _, _} ->
match_name(fun is_valid_host_or_domain/2, Host,
PermittedName, Rest)
end;
match_name(emailAddress, Name, [PermittedName | Rest]) ->
Fun = fun(Email, PermittedEmail) ->
is_valid_email_address(Email, PermittedEmail,
string:tokens(PermittedEmail,"@"))
end,
match_name(Fun, Name, PermittedName, Rest);
match_name(dNSName, Name, [PermittedName | Rest]) ->
Fun = fun(Domain, [$.|Domain]) -> true;
(Name1,Name2) ->
lists:suffix(string:to_lower(Name2),
string:to_lower(Name1))
end,
match_name(Fun, Name, [$.|PermittedName], Rest);
match_name(x400Address, OrAddress, [PermittedAddr | Rest]) ->
match_name(fun is_or_address/2, OrAddress, PermittedAddr, Rest);
match_name(ipAdress, IP, [PermittedIP | Rest]) ->
Fun = fun([IP1, IP2, IP3, IP4],
[IP5, IP6, IP7, IP8, M1, M2, M3, M4]) ->
is_permitted_ip([IP1, IP2, IP3, IP4],
[IP5, IP6, IP7, IP8],
[M1, M2, M3, M4]);
([IP1, IP2, IP3, IP4, IP5, IP6, IP7, IP8,
IP9, IP10, IP11, IP12, IP13, IP14, IP15, IP16],
[IP17, IP18, IP19, IP20, IP21, IP22, IP23, IP24,
IP25, IP26, IP27, IP28, IP29, IP30, IP31, IP32,
M1, M2, M3, M4, M5, M6, M7, M8,
M9, M10, M11, M12, M13, M14, M15, M16]) ->
is_permitted_ip([IP1, IP2, IP3, IP4, IP5, IP6, IP7, IP8,
IP9, IP10, IP11, IP12, IP13,
IP14, IP15, IP16],
[IP17, IP18, IP19, IP20, IP21, IP22, IP23,
IP24,IP25, IP26, IP27, IP28, IP29, IP30,
IP31, IP32],
[M1, M2, M3, M4, M5, M6, M7, M8, M9, M10,
M11, M12, M13, M14, M15, M16]);
(_,_) ->
false
end,
match_name(Fun, IP, PermittedIP, Rest).
match_name(Fun, Name, PermittedName, []) ->
Fun(Name, PermittedName);
match_name(Fun, Name, PermittedName, [Head | Tail]) ->
case Fun(Name, PermittedName) of
true ->
true;
false ->
match_name(Fun, Name, Head, Tail)
end.
is_permitted_ip([], [], []) ->
true;
is_permitted_ip([CandidatIp | CandidatIpRest],
[PermittedIp | PermittedIpRest], [Mask | MaskRest] ) ->
case mask_cmp(CandidatIp, PermittedIp, Mask) of
true ->
is_permitted_ip(CandidatIpRest, PermittedIpRest, MaskRest);
false ->
false
end.
mask_cmp(Canditate, Permitted, Mask) ->
(Canditate band Mask) == Permitted.
is_valid_host_or_domain(Canditate, [$.|_] = Permitted) ->
is_suffix(Permitted, Canditate);
is_valid_host_or_domain(Canditate, Permitted) ->
case string:tokens(Canditate,"@") of
[CanditateHost] ->
case_insensitive_match(CanditateHost, Permitted);
[_, CanditateHost] ->
case_insensitive_match(CanditateHost, Permitted)
end.
is_valid_email_address(Canditate, [$.|Permitted], [_]) ->
is_suffix(Permitted, Canditate);
is_valid_email_address(Canditate, PermittedHost, [_]) ->
[_ , CanditateHost] = string:tokens(Canditate,"@"),
case_insensitive_match(CanditateHost, PermittedHost);
is_valid_email_address(Canditate, Permitted, [_, _]) ->
case_insensitive_match(Canditate, Permitted).
is_suffix(Suffix, Str) ->
lists:suffix(string:to_lower(Suffix), string:to_lower(Str)).
case_insensitive_match(Str1, Str2) ->
string:to_lower(Str1) == string:to_lower(Str2).
is_or_address(Address, Canditate) ->
%% TODO: Is case_insensitive_match sufficient?
%% study rfc2156 probably need more a complex check.
is_double_quoted(Address) andalso
is_double_quoted(Canditate) andalso
case_insensitive_match(Address, Canditate).
is_double_quoted(["\"" | Tail]) ->
is_double_quote(lists:last(Tail));
is_double_quoted("%22" ++ Tail) ->
case lists:reverse(Tail) of
[A, B, C | _] ->
is_double_quote([C, B, A]);
_ ->
false
end;
is_double_quoted(_) ->
false.
is_double_quote("%22") ->
true;
is_double_quote("\"") ->
true;
is_double_quote(_) ->
false.
add_policy_constraints(ExpPolicy, MapPolicy,
#path_validation_state{cert_num = CertNum,
explicit_policy = CurExpPolicy,
policy_mapping = CurMapPolicy} =
ValidationState) ->
NewExpPolicy = policy_constraint(CurExpPolicy, ExpPolicy, CertNum),
NewMapPolicy = policy_constraint(CurMapPolicy, MapPolicy, CertNum),
ValidationState#path_validation_state{explicit_policy = NewExpPolicy,
policy_mapping = NewMapPolicy}.
policy_constraint(Current, asn1_NOVALUE, _) ->
Current;
policy_constraint(Current, New, CertNum) ->
erlang:min(Current, New + CertNum).
process_policy_tree(_,_, ?NULL) ->
?NULL;
process_policy_tree(_Id, _Qualifier, Tree) ->
%% TODO real imp.
Tree.
policy_indicator(_, true) ->
0;
policy_indicator(N, false) ->
N + 1.
is_fixed_dh_cert(PublicKeyInfo, Extensions) ->
AlgInfo = PublicKeyInfo#'OTPSubjectPublicKeyInfo'.algorithm,
Algorithm = AlgInfo#'PublicKeyAlgorithm'.algorithm,
case select_extension(?'id-ce-keyUsage', Extensions) of
undefined ->
is_dh(Algorithm);
#'Extension'{extnValue=KeyUse} ->
is_dh(Algorithm) andalso is_valid_key_usage(KeyUse, keyAgreement)
end.
is_dh(?'dhpublicnumber')->
true;
is_dh(_) ->
false.
