% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2007-2019. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. %% You may obtain a copy of the License at %% %% http://www.apache.org/licenses/LICENSE-2.0 %% %% Unless required by applicable law or agreed to in writing, software %% distributed under the License is distributed on an "AS IS" BASIS, %% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %% See the License for the specific language governing permissions and %% limitations under the License. %% %% %CopyrightEnd% %% %% %%---------------------------------------------------------------------- %% Purpose: Help functions for handling the SSL ciphers %% %%---------------------------------------------------------------------- -module(ssl_cipher). -include("ssl_internal.hrl"). -include("ssl_record.hrl"). -include("ssl_cipher.hrl"). -include("ssl_handshake.hrl"). -include("ssl_alert.hrl"). -include_lib("public_key/include/public_key.hrl"). -export([security_parameters/2, security_parameters/3, cipher_init/3, nonce_seed/2, decipher/6, cipher/5, aead_encrypt/5, aead_decrypt/6, suites/1, all_suites/1, crypto_support_filters/0, chacha_suites/1, anonymous_suites/1, psk_suites/1, psk_suites_anon/1, srp_suites/0, srp_suites_anon/0, rc4_suites/1, des_suites/1, rsa_suites/1, filter/3, filter_suites/1, filter_suites/2, hash_algorithm/1, sign_algorithm/1, is_acceptable_hash/2, is_fallback/1, random_bytes/1, calc_mac_hash/4, calc_mac_hash/6, is_stream_ciphersuite/1]). -compile(inline). -type cipher_enum() :: integer(). -export_type([cipher_enum/0]). %%-------------------------------------------------------------------- -spec security_parameters(ssl_cipher_format:cipher_suite(), #security_parameters{}) -> #security_parameters{}. %% Only security_parameters/2 should call security_parameters/3 with undefined as %% first argument. %%-------------------------------------------------------------------- security_parameters(?TLS_NULL_WITH_NULL_NULL = CipherSuite, SecParams) -> security_parameters(undefined, CipherSuite, SecParams). %%-------------------------------------------------------------------- -spec security_parameters(ssl_record:ssl_version() | undefined, ssl_cipher_format:cipher_suite(), #security_parameters{}) -> #security_parameters{}. %% %% Description: Returns a security parameters record where the %% cipher values has been updated according to %%------------------------------------------------------------------- security_parameters(Version, CipherSuite, SecParams) -> #{cipher := Cipher, mac := Hash, prf := PrfHashAlg} = ssl_cipher_format:suite_definition(CipherSuite), SecParams#security_parameters{ cipher_suite = CipherSuite, bulk_cipher_algorithm = bulk_cipher_algorithm(Cipher), cipher_type = type(Cipher), key_size = effective_key_bits(Cipher), expanded_key_material_length = expanded_key_material(Cipher), key_material_length = key_material(Cipher), iv_size = iv_size(Cipher), mac_algorithm = mac_algorithm(Hash), prf_algorithm = prf_algorithm(PrfHashAlg, Version), hash_size = hash_size(Hash)}. %%-------------------------------------------------------------------- -spec cipher_init(cipher_enum(), binary(), binary()) -> #cipher_state{}. %% %% Description: Initializes the #cipher_state according to BCA %%------------------------------------------------------------------- cipher_init(?RC4, IV, Key) -> State = crypto:stream_init(rc4, Key), #cipher_state{iv = IV, key = Key, state = State}; cipher_init(?AES_GCM, IV, Key) -> <> = random_bytes(8), #cipher_state{iv = IV, key = Key, nonce = Nonce, tag_len = 16}; cipher_init(?CHACHA20_POLY1305, IV, Key) -> #cipher_state{iv = IV, key = Key, tag_len = 16}; cipher_init(_BCA, IV, Key) -> %% Initialize random IV cache, not used for aead ciphers #cipher_state{iv = IV, key = Key, state = <<>>}. nonce_seed(Seed, CipherState) -> CipherState#cipher_state{nonce = Seed}. %%-------------------------------------------------------------------- -spec cipher(cipher_enum(), #cipher_state{}, binary(), iodata(), ssl_record:ssl_version()) -> {binary(), #cipher_state{}}. %% %% Description: Encrypts the data and the MAC using chipher described %% by cipher_enum() and updating the cipher state %% Used for "MAC then Cipher" suites where first an HMAC of the %% data is calculated and the data plus the HMAC is ecncrypted. %%------------------------------------------------------------------- cipher(?NULL, CipherState, <<>>, Fragment, _Version) -> GenStreamCipherList = [Fragment, <<>>], {GenStreamCipherList, CipherState}; cipher(?RC4, CipherState = #cipher_state{state = State0}, Mac, Fragment, _Version) -> GenStreamCipherList = [Fragment, Mac], {State1, T} = crypto:stream_encrypt(State0, GenStreamCipherList), {T, CipherState#cipher_state{state = State1}}; cipher(?DES, CipherState, Mac, Fragment, Version) -> block_cipher(fun(Key, IV, T) -> crypto:block_encrypt(des_cbc, Key, IV, T) end, block_size(des_cbc), CipherState, Mac, Fragment, Version); cipher(?'3DES', CipherState, Mac, Fragment, Version) -> block_cipher(fun(<>, IV, T) -> crypto:block_encrypt(des3_cbc, [K1, K2, K3], IV, T) end, block_size(des_cbc), CipherState, Mac, Fragment, Version); cipher(?AES_CBC, CipherState, Mac, Fragment, Version) -> block_cipher(fun(Key, IV, T) when byte_size(Key) =:= 16 -> crypto:block_encrypt(aes_cbc128, Key, IV, T); (Key, IV, T) when byte_size(Key) =:= 32 -> crypto:block_encrypt(aes_cbc256, Key, IV, T) end, block_size(aes_128_cbc), CipherState, Mac, Fragment, Version). aead_encrypt(Type, Key, Nonce, Fragment, AdditionalData) -> crypto:block_encrypt(aead_type(Type), Key, Nonce, {AdditionalData, Fragment}). aead_decrypt(Type, Key, Nonce, CipherText, CipherTag, AdditionalData) -> crypto:block_decrypt(aead_type(Type), Key, Nonce, {AdditionalData, CipherText, CipherTag}). aead_type(?AES_GCM) -> aes_gcm; aead_type(?CHACHA20_POLY1305) -> chacha20_poly1305. build_cipher_block(BlockSz, Mac, Fragment) -> TotSz = byte_size(Mac) + erlang:iolist_size(Fragment) + 1, [Fragment, Mac, padding_with_len(TotSz, BlockSz)]. block_cipher(Fun, BlockSz, #cipher_state{key=Key, iv=IV} = CS0, Mac, Fragment, {3, N}) when N == 0; N == 1 -> L = build_cipher_block(BlockSz, Mac, Fragment), T = Fun(Key, IV, L), NextIV = next_iv(T, IV), {T, CS0#cipher_state{iv=NextIV}}; block_cipher(Fun, BlockSz, #cipher_state{key=Key, iv=IV, state = IV_Cache0} = CS0, Mac, Fragment, {3, N}) when N == 2; N == 3 -> IV_Size = byte_size(IV), <> = case IV_Cache0 of <<>> -> random_bytes(IV_Size bsl 5); % 32 IVs _ -> IV_Cache0 end, L0 = build_cipher_block(BlockSz, Mac, Fragment), L = [NextIV|L0], T = Fun(Key, IV, L), {T, CS0#cipher_state{iv=NextIV, state = IV_Cache}}. %%-------------------------------------------------------------------- -spec decipher(cipher_enum(), integer(), #cipher_state{}, binary(), ssl_record:ssl_version(), boolean()) -> {binary(), binary(), #cipher_state{}} | #alert{}. %% %% Description: Decrypts the data and the MAC using cipher described %% by cipher_enum() and updating the cipher state. %% Used for "MAC then Cipher" suites where first the data is decrypted %% and the an HMAC of the decrypted data is checked %%------------------------------------------------------------------- decipher(?NULL, _HashSz, CipherState, Fragment, _, _) -> {Fragment, <<>>, CipherState}; decipher(?RC4, HashSz, CipherState = #cipher_state{state = State0}, Fragment, _, _) -> try crypto:stream_decrypt(State0, Fragment) of {State, Text} -> GSC = generic_stream_cipher_from_bin(Text, HashSz), #generic_stream_cipher{content = Content, mac = Mac} = GSC, {Content, Mac, CipherState#cipher_state{state = State}} catch _:_ -> %% This is a DECRYPTION_FAILED but %% "differentiating between bad_record_mac and decryption_failed %% alerts may permit certain attacks against CBC mode as used in %% TLS [CBCATT]. It is preferable to uniformly use the %% bad_record_mac alert to hide the specific type of the error." ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC, decryption_failed) end; decipher(?DES, HashSz, CipherState, Fragment, Version, PaddingCheck) -> block_decipher(fun(Key, IV, T) -> crypto:block_decrypt(des_cbc, Key, IV, T) end, CipherState, HashSz, Fragment, Version, PaddingCheck); decipher(?'3DES', HashSz, CipherState, Fragment, Version, PaddingCheck) -> block_decipher(fun(<>, IV, T) -> crypto:block_decrypt(des3_cbc, [K1, K2, K3], IV, T) end, CipherState, HashSz, Fragment, Version, PaddingCheck); decipher(?AES_CBC, HashSz, CipherState, Fragment, Version, PaddingCheck) -> block_decipher(fun(Key, IV, T) when byte_size(Key) =:= 16 -> crypto:block_decrypt(aes_cbc128, Key, IV, T); (Key, IV, T) when byte_size(Key) =:= 32 -> crypto:block_decrypt(aes_cbc256, Key, IV, T) end, CipherState, HashSz, Fragment, Version, PaddingCheck). block_decipher(Fun, #cipher_state{key=Key, iv=IV} = CipherState0, HashSz, Fragment, Version, PaddingCheck) -> try Text = Fun(Key, IV, Fragment), NextIV = next_iv(Fragment, IV), GBC = generic_block_cipher_from_bin(Version, Text, NextIV, HashSz), Content = GBC#generic_block_cipher.content, Mac = GBC#generic_block_cipher.mac, CipherState1 = CipherState0#cipher_state{iv=GBC#generic_block_cipher.next_iv}, case is_correct_padding(GBC, Version, PaddingCheck) of true -> {Content, Mac, CipherState1}; false -> %% decryption failed or invalid padding, %% intentionally break Content to make %% sure a packet with invalid padding %% but otherwise correct data will fail %% the MAC test later {<<16#F0, Content/binary>>, Mac, CipherState1} end catch _:_ -> %% This is a DECRYPTION_FAILED but %% "differentiating between bad_record_mac and decryption_failed %% alerts may permit certain attacks against CBC mode as used in %% TLS [CBCATT]. It is preferable to uniformly use the %% bad_record_mac alert to hide the specific type of the error." ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC, decryption_failed) end. %%-------------------------------------------------------------------- -spec suites(ssl_record:ssl_version()) -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns a list of supported cipher suites. %%-------------------------------------------------------------------- suites({3, 0}) -> ssl_v3:suites(); suites({3, Minor}) -> tls_v1:suites(Minor); suites({_, Minor}) -> dtls_v1:suites(Minor). all_suites({3, _} = Version) -> suites(Version) ++ chacha_suites(Version) ++ psk_suites(Version) ++ srp_suites() ++ rc4_suites(Version) ++ des_suites(Version) ++ rsa_suites(Version); all_suites(Version) -> dtls_v1:all_suites(Version). %%-------------------------------------------------------------------- -spec chacha_suites(ssl_record:ssl_version() | integer()) -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns list of the chacha cipher suites, only supported %% if explicitly set by user for now due to interop problems, proably need %% to be fixed in crypto. %%-------------------------------------------------------------------- chacha_suites({3, _}) -> [?TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, ?TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, ?TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256]; chacha_suites(_) -> []. %%-------------------------------------------------------------------- -spec anonymous_suites(ssl_record:ssl_version() | integer()) -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns a list of the anonymous cipher suites, only supported %% if explicitly set by user. Intended only for testing. %%-------------------------------------------------------------------- anonymous_suites({3, N}) -> srp_suites_anon() ++ anonymous_suites(N); anonymous_suites({254, _} = Version) -> dtls_v1:anonymous_suites(Version); anonymous_suites(N) when N >= 3 -> psk_suites_anon(N) ++ [?TLS_DH_anon_WITH_AES_128_GCM_SHA256, ?TLS_DH_anon_WITH_AES_256_GCM_SHA384, ?TLS_DH_anon_WITH_AES_128_CBC_SHA256, ?TLS_DH_anon_WITH_AES_256_CBC_SHA256, ?TLS_ECDH_anon_WITH_AES_128_CBC_SHA, ?TLS_ECDH_anon_WITH_AES_256_CBC_SHA, ?TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA, ?TLS_DH_anon_WITH_RC4_128_MD5]; anonymous_suites(2 = N) -> psk_suites_anon(N) ++ [?TLS_ECDH_anon_WITH_AES_128_CBC_SHA, ?TLS_ECDH_anon_WITH_AES_256_CBC_SHA, ?TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA, ?TLS_DH_anon_WITH_DES_CBC_SHA, ?TLS_DH_anon_WITH_RC4_128_MD5]; anonymous_suites(N) when N == 0; N == 1 -> psk_suites_anon(N) ++ [?TLS_DH_anon_WITH_RC4_128_MD5, ?TLS_DH_anon_WITH_3DES_EDE_CBC_SHA, ?TLS_DH_anon_WITH_DES_CBC_SHA ]. %%-------------------------------------------------------------------- -spec psk_suites(ssl_record:ssl_version() | integer()) -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns a list of the PSK cipher suites, only supported %% if explicitly set by user. %%-------------------------------------------------------------------- psk_suites({3, N}) -> psk_suites(N); psk_suites(N) when N >= 3 -> [ ?TLS_RSA_PSK_WITH_AES_256_GCM_SHA384, ?TLS_RSA_PSK_WITH_AES_256_CBC_SHA384, ?TLS_RSA_PSK_WITH_AES_128_GCM_SHA256, ?TLS_RSA_PSK_WITH_AES_128_CBC_SHA256 ] ++ psk_suites(0); psk_suites(_) -> [?TLS_RSA_PSK_WITH_AES_256_CBC_SHA, ?TLS_RSA_PSK_WITH_AES_128_CBC_SHA, ?TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA, ?TLS_RSA_PSK_WITH_RC4_128_SHA]. %%-------------------------------------------------------------------- -spec psk_suites_anon(ssl_record:ssl_version() | integer()) -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns a list of the anonymous PSK cipher suites, only supported %% if explicitly set by user. %%-------------------------------------------------------------------- psk_suites_anon({3, N}) -> psk_suites_anon(N); psk_suites_anon(N) when N >= 3 -> [ ?TLS_DHE_PSK_WITH_AES_256_GCM_SHA384, ?TLS_PSK_WITH_AES_256_GCM_SHA384, ?TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384, ?TLS_DHE_PSK_WITH_AES_256_CBC_SHA384, ?TLS_PSK_WITH_AES_256_CBC_SHA384, ?TLS_ECDHE_PSK_WITH_AES_128_GCM_SHA256, ?TLS_DHE_PSK_WITH_AES_128_GCM_SHA256, ?TLS_PSK_WITH_AES_128_GCM_SHA256, ?TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256, ?TLS_DHE_PSK_WITH_AES_128_CBC_SHA256, ?TLS_PSK_WITH_AES_128_CBC_SHA256 ] ++ psk_suites_anon(0); psk_suites_anon(_) -> [?TLS_DHE_PSK_WITH_AES_256_CBC_SHA, ?TLS_PSK_WITH_AES_256_CBC_SHA, ?TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA, ?TLS_DHE_PSK_WITH_AES_128_CBC_SHA, ?TLS_PSK_WITH_AES_128_CBC_SHA, ?TLS_ECDHE_PSK_WITH_3DES_EDE_CBC_SHA, ?TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA, ?TLS_PSK_WITH_3DES_EDE_CBC_SHA, ?TLS_ECDHE_PSK_WITH_RC4_128_SHA, ?TLS_DHE_PSK_WITH_RC4_128_SHA, ?TLS_PSK_WITH_RC4_128_SHA]. %%-------------------------------------------------------------------- -spec srp_suites() -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns a list of the SRP cipher suites, only supported %% if explicitly set by user. %%-------------------------------------------------------------------- srp_suites() -> [?TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA, ?TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA, ?TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA, ?TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA, ?TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA, ?TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA]. %%-------------------------------------------------------------------- -spec srp_suites_anon() -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns a list of the SRP anonymous cipher suites, only supported %% if explicitly set by user. %%-------------------------------------------------------------------- srp_suites_anon() -> [?TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA, ?TLS_SRP_SHA_WITH_AES_128_CBC_SHA, ?TLS_SRP_SHA_WITH_AES_256_CBC_SHA]. %%-------------------------------------------------------------------- -spec rc4_suites(Version::ssl_record:ssl_version() | integer()) -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns a list of the RSA|(ECDH/RSA)| (ECDH/ECDSA) %% with RC4 cipher suites, only supported if explicitly set by user. %% Are not considered secure any more. Other RC4 suites already %% belonged to the user configured only category. %%-------------------------------------------------------------------- rc4_suites({3, 0}) -> rc4_suites(0); rc4_suites({3, Minor}) -> rc4_suites(Minor) ++ rc4_suites(0); rc4_suites(0) -> [?TLS_RSA_WITH_RC4_128_SHA, ?TLS_RSA_WITH_RC4_128_MD5]; rc4_suites(N) when N =< 3 -> [?TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, ?TLS_ECDHE_RSA_WITH_RC4_128_SHA, ?TLS_ECDH_ECDSA_WITH_RC4_128_SHA, ?TLS_ECDH_RSA_WITH_RC4_128_SHA]. %%-------------------------------------------------------------------- -spec des_suites(Version::ssl_record:ssl_version()) -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns a list of the cipher suites %% with DES cipher, only supported if explicitly set by user. %% Are not considered secure any more. %%-------------------------------------------------------------------- des_suites(_)-> [?TLS_DHE_RSA_WITH_DES_CBC_SHA, ?TLS_RSA_WITH_DES_CBC_SHA, ?TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA, ?TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, ?TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA, ?TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA, ?TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA, ?TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA ]. %%-------------------------------------------------------------------- -spec rsa_suites(Version::ssl_record:ssl_version() | integer()) -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Returns a list of the RSA key exchange %% cipher suites, only supported if explicitly set by user. %% Are not considered secure any more. %%-------------------------------------------------------------------- rsa_suites({3, 0}) -> rsa_suites(0); rsa_suites({3, Minor}) -> rsa_suites(Minor) ++ rsa_suites(0); rsa_suites(0) -> [?TLS_RSA_WITH_AES_256_CBC_SHA, ?TLS_RSA_WITH_AES_128_CBC_SHA, ?TLS_RSA_WITH_3DES_EDE_CBC_SHA ]; rsa_suites(N) when N =< 3 -> [ ?TLS_RSA_WITH_AES_256_GCM_SHA384, ?TLS_RSA_WITH_AES_256_CBC_SHA256, ?TLS_RSA_WITH_AES_128_GCM_SHA256, ?TLS_RSA_WITH_AES_128_CBC_SHA256 ]. %%-------------------------------------------------------------------- -spec filter(undefined | binary(), [ssl_cipher_format:cipher_suite()], ssl_record:ssl_version()) -> [ssl_cipher_format:cipher_suite()]. %% %% Description: Select the cipher suites that can be used together with the %% supplied certificate. (Server side functionality) %%------------------------------------------------------------------- filter(undefined, Ciphers, _) -> Ciphers; filter(DerCert, Ciphers0, Version) -> OtpCert = public_key:pkix_decode_cert(DerCert, otp), SigAlg = OtpCert#'OTPCertificate'.signatureAlgorithm, PubKeyInfo = OtpCert#'OTPCertificate'.tbsCertificate#'OTPTBSCertificate'.subjectPublicKeyInfo, PubKeyAlg = PubKeyInfo#'OTPSubjectPublicKeyInfo'.algorithm, Ciphers = filter_suites_pubkey( ssl_certificate:public_key_type(PubKeyAlg#'PublicKeyAlgorithm'.algorithm), Ciphers0, Version, OtpCert), {_, Sign} = public_key:pkix_sign_types(SigAlg#'SignatureAlgorithm'.algorithm), filter_suites_signature(Sign, Ciphers, Version). %%-------------------------------------------------------------------- -spec filter_suites([ssl:erl_cipher_suite()] | [ssl_cipher_format:cipher_suite()], map()) -> [ssl:erl_cipher_suite()] | [ssl_cipher_format:cipher_suite()]. %% %% Description: Filter suites using supplied filter funs %%------------------------------------------------------------------- filter_suites(Suites, Filters) -> ApplyFilters = fun(Suite) -> filter_suite(Suite, Filters) end, lists:filter(ApplyFilters, Suites). filter_suite(#{key_exchange := KeyExchange, cipher := Cipher, mac := Hash, prf := Prf}, #{key_exchange_filters := KeyFilters, cipher_filters := CipherFilters, mac_filters := HashFilters, prf_filters := PrfFilters}) -> all_filters(KeyExchange, KeyFilters) andalso all_filters(Cipher, CipherFilters) andalso all_filters(Hash, HashFilters) andalso all_filters(Prf, PrfFilters); filter_suite(Suite, Filters) -> filter_suite(ssl_cipher_format:suite_definition(Suite), Filters). %%-------------------------------------------------------------------- -spec filter_suites([ssl:erl_cipher_suite()] | [ssl_cipher_format:cipher_suite()]) -> [ssl:erl_cipher_suite()] | [ssl_cipher_format:cipher_suite()]. %% %% Description: Filter suites for algorithms supported by crypto. %%------------------------------------------------------------------- filter_suites(Suites) -> Filters = crypto_support_filters(), filter_suites(Suites, Filters). all_filters(_, []) -> true; all_filters(Value, [Filter| Rest]) -> case Filter(Value) of true -> all_filters(Value, Rest); false -> false end. crypto_support_filters() -> Algos = crypto:supports(), Hashs = proplists:get_value(hashs, Algos), #{key_exchange_filters => [fun(KeyExchange) -> is_acceptable_keyexchange(KeyExchange, proplists:get_value(public_keys, Algos)) end], cipher_filters => [fun(Cipher) -> is_acceptable_cipher(Cipher, proplists:get_value(ciphers, Algos)) end], mac_filters => [fun(Hash) -> is_acceptable_hash(Hash, Hashs) end], prf_filters => [fun(Prf) -> is_acceptable_prf(Prf, proplists:get_value(hashs, Algos)) end]}. is_acceptable_keyexchange(KeyExchange, _Algos) when KeyExchange == psk; KeyExchange == null -> true; is_acceptable_keyexchange(KeyExchange, Algos) when KeyExchange == dh_anon; KeyExchange == dhe_psk -> proplists:get_bool(dh, Algos); is_acceptable_keyexchange(dhe_dss, Algos) -> proplists:get_bool(dh, Algos) andalso proplists:get_bool(dss, Algos); is_acceptable_keyexchange(dhe_rsa, Algos) -> proplists:get_bool(dh, Algos) andalso proplists:get_bool(rsa, Algos); is_acceptable_keyexchange(KeyExchange, Algos) when KeyExchange == ecdh_anon; KeyExchange == ecdhe_psk -> proplists:get_bool(ecdh, Algos); is_acceptable_keyexchange(KeyExchange, Algos) when KeyExchange == ecdh_ecdsa; KeyExchange == ecdhe_ecdsa -> proplists:get_bool(ecdh, Algos) andalso proplists:get_bool(ecdsa, Algos); is_acceptable_keyexchange(KeyExchange, Algos) when KeyExchange == ecdh_rsa; KeyExchange == ecdhe_rsa -> proplists:get_bool(ecdh, Algos) andalso proplists:get_bool(rsa, Algos); is_acceptable_keyexchange(KeyExchange, Algos) when KeyExchange == rsa; KeyExchange == rsa_psk -> proplists:get_bool(rsa, Algos); is_acceptable_keyexchange(srp_anon, Algos) -> proplists:get_bool(srp, Algos); is_acceptable_keyexchange(srp_dss, Algos) -> proplists:get_bool(srp, Algos) andalso proplists:get_bool(dss, Algos); is_acceptable_keyexchange(srp_rsa, Algos) -> proplists:get_bool(srp, Algos) andalso proplists:get_bool(rsa, Algos); is_acceptable_keyexchange(_KeyExchange, _Algos) -> false. is_acceptable_cipher(null, _Algos) -> true; is_acceptable_cipher(rc4_128, Algos) -> proplists:get_bool(rc4, Algos); is_acceptable_cipher(des_cbc, Algos) -> proplists:get_bool(des_cbc, Algos); is_acceptable_cipher('3des_ede_cbc', Algos) -> proplists:get_bool(des_ede3, Algos); is_acceptable_cipher(aes_128_cbc, Algos) -> proplists:get_bool(aes_cbc128, Algos); is_acceptable_cipher(aes_256_cbc, Algos) -> proplists:get_bool(aes_cbc256, Algos); is_acceptable_cipher(Cipher, Algos) when Cipher == aes_128_gcm; Cipher == aes_256_gcm -> proplists:get_bool(aes_gcm, Algos); is_acceptable_cipher(Cipher, Algos) -> proplists:get_bool(Cipher, Algos). is_acceptable_hash(null, _Algos) -> true; is_acceptable_hash(aead, _Algos) -> true; is_acceptable_hash(Hash, Algos) -> proplists:get_bool(Hash, Algos). is_acceptable_prf(default_prf, _) -> true; is_acceptable_prf(Prf, Algos) -> proplists:get_bool(Prf, Algos). is_fallback(CipherSuites)-> lists:member(?TLS_FALLBACK_SCSV, CipherSuites). %%-------------------------------------------------------------------- -spec random_bytes(integer()) -> binary(). %% %% Description: Generates cryptographically secure random sequence %%-------------------------------------------------------------------- random_bytes(N) -> crypto:strong_rand_bytes(N). calc_mac_hash(Type, Version, PlainFragment, #{sequence_number := SeqNo, mac_secret := MacSecret, security_parameters := #security_parameters{mac_algorithm = MacAlgorithm}}) -> calc_mac_hash(Type, Version, PlainFragment, MacAlgorithm, MacSecret, SeqNo). %% calc_mac_hash(Type, Version, PlainFragment, MacAlgorithm, MacSecret, SeqNo) -> Length = erlang:iolist_size(PlainFragment), mac_hash(Version, MacAlgorithm, MacSecret, SeqNo, Type, Length, PlainFragment). is_stream_ciphersuite(#{cipher := rc4_128}) -> true; is_stream_ciphersuite(_) -> false. %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- mac_hash({_,_}, ?NULL, _MacSecret, _SeqNo, _Type, _Length, _Fragment) -> <<>>; mac_hash({3, 0}, MacAlg, MacSecret, SeqNo, Type, Length, Fragment) -> ssl_v3:mac_hash(MacAlg, MacSecret, SeqNo, Type, Length, Fragment); mac_hash({3, N} = Version, MacAlg, MacSecret, SeqNo, Type, Length, Fragment) when N =:= 1; N =:= 2; N =:= 3 -> tls_v1:mac_hash(MacAlg, MacSecret, SeqNo, Type, Version, Length, Fragment). bulk_cipher_algorithm(null) -> ?NULL; bulk_cipher_algorithm(rc4_128) -> ?RC4; bulk_cipher_algorithm(des_cbc) -> ?DES; bulk_cipher_algorithm('3des_ede_cbc') -> ?'3DES'; bulk_cipher_algorithm(Cipher) when Cipher == aes_128_cbc; Cipher == aes_256_cbc -> ?AES_CBC; bulk_cipher_algorithm(Cipher) when Cipher == aes_128_gcm; Cipher == aes_256_gcm -> ?AES_GCM; bulk_cipher_algorithm(chacha20_poly1305) -> ?CHACHA20_POLY1305. type(Cipher) when Cipher == null; Cipher == rc4_128 -> ?STREAM; type(Cipher) when Cipher == des_cbc; Cipher == '3des_ede_cbc'; Cipher == aes_128_cbc; Cipher == aes_256_cbc -> ?BLOCK; type(Cipher) when Cipher == aes_128_gcm; Cipher == aes_256_gcm; Cipher == chacha20_poly1305 -> ?AEAD. key_material(null) -> 0; key_material(rc4_128) -> 16; key_material(des_cbc) -> 8; key_material('3des_ede_cbc') -> 24; key_material(aes_128_cbc) -> 16; key_material(aes_256_cbc) -> 32; key_material(aes_128_gcm) -> 16; key_material(aes_256_gcm) -> 32; key_material(chacha20_poly1305) -> 32. expanded_key_material(null) -> 0; expanded_key_material(rc4_128) -> 16; expanded_key_material(Cipher) when Cipher == des_cbc -> 8; expanded_key_material('3des_ede_cbc') -> 24; expanded_key_material(Cipher) when Cipher == aes_128_cbc; Cipher == aes_256_cbc; Cipher == aes_128_gcm; Cipher == aes_256_gcm; Cipher == chacha20_poly1305 -> unknown. effective_key_bits(null) -> 0; effective_key_bits(des_cbc) -> 56; effective_key_bits(Cipher) when Cipher == rc4_128; Cipher == aes_128_cbc; Cipher == aes_128_gcm -> 128; effective_key_bits('3des_ede_cbc') -> 168; effective_key_bits(Cipher) when Cipher == aes_256_cbc; Cipher == aes_256_gcm; Cipher == chacha20_poly1305 -> 256. iv_size(Cipher) when Cipher == null; Cipher == rc4_128; Cipher == chacha20_poly1305-> 0; iv_size(Cipher) when Cipher == aes_128_gcm; Cipher == aes_256_gcm -> 4; iv_size(Cipher) -> block_size(Cipher). block_size(Cipher) when Cipher == des_cbc; Cipher == '3des_ede_cbc' -> 8; block_size(Cipher) when Cipher == aes_128_cbc; Cipher == aes_256_cbc; Cipher == aes_128_gcm; Cipher == aes_256_gcm; Cipher == chacha20_poly1305 -> 16. prf_algorithm(default_prf, {3, N}) when N >= 3 -> ?SHA256; prf_algorithm(default_prf, {3, _}) -> ?MD5SHA; prf_algorithm(Algo, _) -> hash_algorithm(Algo). mac_algorithm(aead) -> aead; mac_algorithm(Algo) -> hash_algorithm(Algo). hash_algorithm(null) -> ?NULL; hash_algorithm(md5) -> ?MD5; hash_algorithm(sha) -> ?SHA; %% Only sha always refers to "SHA-1" hash_algorithm(sha224) -> ?SHA224; hash_algorithm(sha256) -> ?SHA256; hash_algorithm(sha384) -> ?SHA384; hash_algorithm(sha512) -> ?SHA512; hash_algorithm(?NULL) -> null; hash_algorithm(?MD5) -> md5; hash_algorithm(?SHA) -> sha; hash_algorithm(?SHA224) -> sha224; hash_algorithm(?SHA256) -> sha256; hash_algorithm(?SHA384) -> sha384; hash_algorithm(?SHA512) -> sha512; hash_algorithm(Other) when is_integer(Other) andalso ((Other >= 7) and (Other =< 223)) -> unassigned; hash_algorithm(Other) when is_integer(Other) andalso ((Other >= 224) and (Other =< 255)) -> Other. sign_algorithm(anon) -> ?ANON; sign_algorithm(rsa) -> ?RSA; sign_algorithm(dsa) -> ?DSA; sign_algorithm(ecdsa) -> ?ECDSA; sign_algorithm(?ANON) -> anon; sign_algorithm(?RSA) -> rsa; sign_algorithm(?DSA) -> dsa; sign_algorithm(?ECDSA) -> ecdsa; sign_algorithm(Other) when is_integer(Other) andalso ((Other >= 4) and (Other =< 223)) -> unassigned; sign_algorithm(Other) when is_integer(Other) andalso ((Other >= 224) and (Other =< 255)) -> Other. hash_size(null) -> 0; %% The AEAD MAC hash size is not used in the context %% of calculating the master secret. See RFC 5246 Section 6.2.3.3. hash_size(aead) -> 0; hash_size(md5) -> 16; hash_size(sha) -> 20; %% Uncomment when adding cipher suite that needs it %hash_size(sha224) -> % 28; hash_size(sha256) -> 32; hash_size(sha384) -> 48. %% Uncomment when adding cipher suite that needs it %hash_size(sha512) -> % 64. %% RFC 5246: 6.2.3.2. CBC Block Cipher %% %% Implementation note: Canvel et al. [CBCTIME] have demonstrated a %% timing attack on CBC padding based on the time required to compute %% the MAC. In order to defend against this attack, implementations %% MUST ensure that record processing time is essentially the same %% whether or not the padding is correct. In general, the best way to %% do this is to compute the MAC even if the padding is incorrect, and %% only then reject the packet. For instance, if the pad appears to be %% incorrect, the implementation might assume a zero-length pad and then %% compute the MAC. This leaves a small timing channel, since MAC %% performance depends to some extent on the size of the data fragment, %% but it is not believed to be large enough to be exploitable, due to %% the large block size of existing MACs and the small size of the %% timing signal. %% %% implementation note: %% We return the original (possibly invalid) PadLength in any case. %% An invalid PadLength will be caught by is_correct_padding/2 %% generic_block_cipher_from_bin({3, N}, T, IV, HashSize) when N == 0; N == 1 -> Sz1 = byte_size(T) - 1, <<_:Sz1/binary, ?BYTE(PadLength0)>> = T, PadLength = if PadLength0 >= Sz1 -> 0; true -> PadLength0 end, CompressedLength = byte_size(T) - PadLength - 1 - HashSize, <> = T, #generic_block_cipher{content=Content, mac=Mac, padding=Padding, padding_length=PadLength0, next_iv = IV}; generic_block_cipher_from_bin({3, N}, T, IV, HashSize) when N == 2; N == 3 -> Sz1 = byte_size(T) - 1, <<_:Sz1/binary, ?BYTE(PadLength)>> = T, IVLength = byte_size(IV), CompressedLength = byte_size(T) - IVLength - PadLength - 1 - HashSize, <> = T, #generic_block_cipher{content=Content, mac=Mac, padding=Padding, padding_length=PadLength, next_iv = NextIV}. generic_stream_cipher_from_bin(T, HashSz) -> Sz = byte_size(T), CompressedLength = Sz - HashSz, <> = T, #generic_stream_cipher{content=Content, mac=Mac}. is_correct_padding(#generic_block_cipher{padding_length = Len, padding = Padding}, {3, 0}, _) -> Len == byte_size(Padding); %% Only length check is done in SSL 3.0 spec %% For interoperability reasons it is possible to disable %% the padding check when using TLS 1.0, as it is not strictly required %% in the spec (only recommended), howerver this makes TLS 1.0 vunrable to the Poodle attack %% so by default this clause will not match is_correct_padding(GenBlockCipher, {3, 1}, false) -> is_correct_padding(GenBlockCipher, {3, 0}, false); %% Padding must be checked in TLS 1.1 and after is_correct_padding(#generic_block_cipher{padding_length = Len, padding = Padding}, _, _) -> (Len == byte_size(Padding)) andalso (padding(Len) == Padding). padding(PadLen) -> case PadLen of 0 -> <<>>; 1 -> <<1>>; 2 -> <<2,2>>; 3 -> <<3,3,3>>; 4 -> <<4,4,4,4>>; 5 -> <<5,5,5,5,5>>; 6 -> <<6,6,6,6,6,6>>; 7 -> <<7,7,7,7,7,7,7>>; 8 -> <<8,8,8,8,8,8,8,8>>; 9 -> <<9,9,9,9,9,9,9,9,9>>; 10 -> <<10,10,10,10,10,10,10,10,10,10>>; 11 -> <<11,11,11,11,11,11,11,11,11,11,11>>; 12 -> <<12,12,12,12,12,12,12,12,12,12,12,12>>; 13 -> <<13,13,13,13,13,13,13,13,13,13,13,13,13>>; 14 -> <<14,14,14,14,14,14,14,14,14,14,14,14,14,14>>; 15 -> <<15,15,15,15,15,15,15,15,15,15,15,15,15,15,15>>; _ -> binary:copy(<>, PadLen) end. padding_with_len(TextLen, BlockSize) -> case BlockSize - (TextLen rem BlockSize) of 0 -> <<0>>; 1 -> <<1,1>>; 2 -> <<2,2,2>>; 3 -> <<3,3,3,3>>; 4 -> <<4,4,4,4,4>>; 5 -> <<5,5,5,5,5,5>>; 6 -> <<6,6,6,6,6,6,6>>; 7 -> <<7,7,7,7,7,7,7,7>>; 8 -> <<8,8,8,8,8,8,8,8,8>>; 9 -> <<9,9,9,9,9,9,9,9,9,9>>; 10 -> <<10,10,10,10,10,10,10,10,10,10,10>>; 11 -> <<11,11,11,11,11,11,11,11,11,11,11,11>>; 12 -> <<12,12,12,12,12,12,12,12,12,12,12,12,12>>; 13 -> <<13,13,13,13,13,13,13,13,13,13,13,13,13,13>>; 14 -> <<14,14,14,14,14,14,14,14,14,14,14,14,14,14,14>>; 15 -> <<15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15>>; PadLen -> binary:copy(<>, PadLen + 1) end. next_iv(Bin, IV) -> BinSz = byte_size(Bin), IVSz = byte_size(IV), FirstPart = BinSz - IVSz, <<_:FirstPart/binary, NextIV:IVSz/binary>> = Bin, NextIV. filter_suites_pubkey(rsa, CiphersSuites0, _Version, OtpCert) -> KeyUses = key_uses(OtpCert), NotECDSAKeyed = (CiphersSuites0 -- ec_keyed_suites(CiphersSuites0)) -- dss_keyed_suites(CiphersSuites0), CiphersSuites = filter_keyuse_suites(keyEncipherment, KeyUses, NotECDSAKeyed, rsa_suites_encipher(CiphersSuites0)), filter_keyuse_suites(digitalSignature, KeyUses, CiphersSuites, rsa_ecdhe_dhe_suites(CiphersSuites)); filter_suites_pubkey(dsa, Ciphers, _, OtpCert) -> KeyUses = key_uses(OtpCert), NotECRSAKeyed = (Ciphers -- rsa_keyed_suites(Ciphers)) -- ec_keyed_suites(Ciphers), filter_keyuse_suites(digitalSignature, KeyUses, NotECRSAKeyed, dss_dhe_suites(Ciphers)); filter_suites_pubkey(ec, Ciphers, _, OtpCert) -> Uses = key_uses(OtpCert), NotRSADSAKeyed = (Ciphers -- rsa_keyed_suites(Ciphers)) -- dss_keyed_suites(Ciphers), CiphersSuites = filter_keyuse_suites(digitalSignature, Uses, NotRSADSAKeyed, ec_ecdhe_suites(Ciphers)), filter_keyuse_suites(keyAgreement, Uses, CiphersSuites, ec_ecdh_suites(Ciphers)). filter_suites_signature(_, Ciphers, {3, N}) when N >= 3 -> Ciphers; filter_suites_signature(rsa, Ciphers, Version) -> (Ciphers -- ecdsa_signed_suites(Ciphers, Version)) -- dsa_signed_suites(Ciphers, Version); filter_suites_signature(dsa, Ciphers, Version) -> (Ciphers -- ecdsa_signed_suites(Ciphers, Version)) -- rsa_signed_suites(Ciphers, Version); filter_suites_signature(ecdsa, Ciphers, Version) -> (Ciphers -- rsa_signed_suites(Ciphers, Version)) -- dsa_signed_suites(Ciphers, Version). %% From RFC 5246 - Section 7.4.2. Server Certificate %% If the client provided a "signature_algorithms" extension, then all %% certificates provided by the server MUST be signed by a %% hash/signature algorithm pair that appears in that extension. Note %% that this implies that a certificate containing a key for one %% signature algorithm MAY be signed using a different signature %% algorithm (for instance, an RSA key signed with a DSA key). This is %% a departure from TLS 1.1, which required that the algorithms be the %% same. %% Note that this also implies that the DH_DSS, DH_RSA, %% ECDH_ECDSA, and ECDH_RSA key exchange algorithms do not restrict the %% algorithm used to sign the certificate. Fixed DH certificates MAY be %% signed with any hash/signature algorithm pair appearing in the %% extension. The names DH_DSS, DH_RSA, ECDH_ECDSA, and ECDH_RSA are %% historical. %% Note: DH_DSS and DH_RSA is not supported rsa_signed({3,N}) when N >= 3 -> fun(rsa) -> true; (dhe_rsa) -> true; (ecdhe_rsa) -> true; (rsa_psk) -> true; (srp_rsa) -> true; (_) -> false end; rsa_signed(_) -> fun(rsa) -> true; (dhe_rsa) -> true; (ecdhe_rsa) -> true; (ecdh_rsa) -> true; (rsa_psk) -> true; (srp_rsa) -> true; (_) -> false end. %% Cert should be signed by RSA rsa_signed_suites(Ciphers, Version) -> filter_suites(Ciphers, #{key_exchange_filters => [rsa_signed(Version)], cipher_filters => [], mac_filters => [], prf_filters => []}). ecdsa_signed({3,N}) when N >= 3 -> fun(ecdhe_ecdsa) -> true; (_) -> false end; ecdsa_signed(_) -> fun(ecdhe_ecdsa) -> true; (ecdh_ecdsa) -> true; (_) -> false end. %% Cert should be signed by ECDSA ecdsa_signed_suites(Ciphers, Version) -> filter_suites(Ciphers, #{key_exchange_filters => [ecdsa_signed(Version)], cipher_filters => [], mac_filters => [], prf_filters => []}). rsa_keyed(dhe_rsa) -> true; rsa_keyed(ecdhe_rsa) -> true; rsa_keyed(rsa) -> true; rsa_keyed(rsa_psk) -> true; rsa_keyed(srp_rsa) -> true; rsa_keyed(_) -> false. %% Certs key is an RSA key rsa_keyed_suites(Ciphers) -> filter_suites(Ciphers, #{key_exchange_filters => [fun(Kex) -> rsa_keyed(Kex) end], cipher_filters => [], mac_filters => [], prf_filters => []}). %% RSA Certs key can be used for encipherment rsa_suites_encipher(Ciphers) -> filter_suites(Ciphers, #{key_exchange_filters => [fun(rsa) -> true; (rsa_psk) -> true; (_) -> false end], cipher_filters => [], mac_filters => [], prf_filters => []}). dss_keyed(dhe_dss) -> true; dss_keyed(spr_dss) -> true; dss_keyed(_) -> false. %% Cert should be have DSS key (DSA) dss_keyed_suites(Ciphers) -> filter_suites(Ciphers, #{key_exchange_filters => [fun(Kex) -> dss_keyed(Kex) end], cipher_filters => [], mac_filters => [], prf_filters => []}). %% Cert should be signed by DSS (DSA) dsa_signed_suites(Ciphers, Version) -> filter_suites(Ciphers, #{key_exchange_filters => [dsa_signed(Version)], cipher_filters => [], mac_filters => [], prf_filters => []}). dsa_signed(_) -> fun(dhe_dss) -> true; (_) -> false end. dss_dhe_suites(Ciphers) -> filter_suites(Ciphers, #{key_exchange_filters => [fun(dhe_dss) -> true; (_) -> false end], cipher_filters => [], mac_filters => [], prf_filters => []}). ec_keyed(ecdh_ecdsa) -> true; ec_keyed(ecdh_rsa) -> true; ec_keyed(ecdhe_ecdsa) -> true; ec_keyed(_) -> false. %% Certs key is an ECC key ec_keyed_suites(Ciphers) -> filter_suites(Ciphers, #{key_exchange_filters => [fun(Kex) -> ec_keyed(Kex) end], cipher_filters => [], mac_filters => [], prf_filters => []}). %% EC Certs key usage keyAgreement ec_ecdh_suites(Ciphers)-> filter_suites(Ciphers, #{key_exchange_filters => [fun(ecdh_ecdsa) -> true; (_) -> false end], cipher_filters => [], mac_filters => [], prf_filters => []}). %% EC Certs key usage digitalSignature ec_ecdhe_suites(Ciphers) -> filter_suites(Ciphers, #{key_exchange_filters => [fun(ecdhe_ecdsa) -> true; (ecdhe_rsa) -> true; (_) -> false end], cipher_filters => [], mac_filters => [], prf_filters => []}). %% RSA Certs key usage digitalSignature rsa_ecdhe_dhe_suites(Ciphers) -> filter_suites(Ciphers, #{key_exchange_filters => [fun(dhe_rsa) -> true; (ecdhe_rsa) -> true; (_) -> false end], cipher_filters => [], mac_filters => [], prf_filters => []}). key_uses(OtpCert) -> TBSCert = OtpCert#'OTPCertificate'.tbsCertificate, TBSExtensions = TBSCert#'OTPTBSCertificate'.extensions, Extensions = ssl_certificate:extensions_list(TBSExtensions), case ssl_certificate:select_extension(?'id-ce-keyUsage', Extensions) of undefined -> []; #'Extension'{extnValue = KeyUses} -> KeyUses end. %% If no key-usage extension is defined all key-usages are allowed filter_keyuse_suites(_, [], CiphersSuites, _) -> CiphersSuites; filter_keyuse_suites(Use, KeyUse, CipherSuits, Suites) -> case ssl_certificate:is_valid_key_usage(KeyUse, Use) of true -> CipherSuits; false -> CipherSuits -- Suites end.