%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2007-2013. 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% %% %% %%---------------------------------------------------------------------- %% 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/3, suite_definition/1, decipher/5, cipher/5, suite/1, suites/1, anonymous_suites/0, psk_suites/1, srp_suites/0, openssl_suite/1, openssl_suite_name/1, filter/2, hash_algorithm/1, sign_algorithm/1]). -compile(inline). %%-------------------------------------------------------------------- -spec security_parameters(tls_version(), 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, Hash, PrfHashAlg} = 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 = hash_algorithm(Hash), prf_algorithm = prf_algorithm(PrfHashAlg, Version), hash_size = hash_size(Hash)}. %%-------------------------------------------------------------------- -spec cipher(cipher_enum(), #cipher_state{}, binary(), binary(), tls_version()) -> {binary(), #cipher_state{}}. %% %% Description: Encrypts the data and the MAC using chipher described %% by cipher_enum() and updating the cipher state %%------------------------------------------------------------------- cipher(?NULL, CipherState, <<>>, Fragment, _Version) -> GenStreamCipherList = [Fragment, <<>>], {GenStreamCipherList, CipherState}; cipher(?RC4, CipherState, Mac, Fragment, _Version) -> State0 = case CipherState#cipher_state.state of undefined -> crypto:rc4_set_key(CipherState#cipher_state.key); S -> S end, GenStreamCipherList = [Fragment, Mac], {State1, T} = crypto:rc4_encrypt_with_state(State0, GenStreamCipherList), {T, CipherState#cipher_state{state = State1}}; cipher(?DES, CipherState, Mac, Fragment, Version) -> block_cipher(fun(Key, IV, T) -> crypto:des_cbc_encrypt(Key, IV, T) end, block_size(des_cbc), CipherState, Mac, Fragment, Version); cipher(?'3DES', CipherState, Mac, Fragment, Version) -> block_cipher(fun(<>, IV, T) -> crypto:des3_cbc_encrypt(K1, K2, K3, IV, T) end, block_size(des_cbc), CipherState, Mac, Fragment, Version); cipher(?AES, CipherState, Mac, Fragment, Version) -> block_cipher(fun(Key, IV, T) when byte_size(Key) =:= 16 -> crypto:aes_cbc_128_encrypt(Key, IV, T); (Key, IV, T) when byte_size(Key) =:= 32 -> crypto:aes_cbc_256_encrypt(Key, IV, T) end, block_size(aes_128_cbc), CipherState, Mac, Fragment, Version). build_cipher_block(BlockSz, Mac, Fragment) -> TotSz = byte_size(Mac) + erlang:iolist_size(Fragment) + 1, {PaddingLength, Padding} = get_padding(TotSz, BlockSz), [Fragment, Mac, PaddingLength, Padding]. 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} = CS0, Mac, Fragment, {3, N}) when N == 2; N == 3 -> NextIV = random_iv(IV), L0 = build_cipher_block(BlockSz, Mac, Fragment), L = [NextIV|L0], T = Fun(Key, IV, L), {T, CS0#cipher_state{iv=NextIV}}. %%-------------------------------------------------------------------- -spec decipher(cipher_enum(), integer(), #cipher_state{}, binary(), tls_version()) -> {binary(), binary(), #cipher_state{}} | #alert{}. %% %% Description: Decrypts the data and the MAC using cipher described %% by cipher_enum() and updating the cipher state. %%------------------------------------------------------------------- decipher(?NULL, _HashSz, CipherState, Fragment, _) -> {Fragment, <<>>, CipherState}; decipher(?RC4, HashSz, CipherState, Fragment, _) -> State0 = case CipherState#cipher_state.state of undefined -> crypto:rc4_set_key(CipherState#cipher_state.key); S -> S end, try crypto:rc4_encrypt_with_state(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) end; decipher(?DES, HashSz, CipherState, Fragment, Version) -> block_decipher(fun(Key, IV, T) -> crypto:des_cbc_decrypt(Key, IV, T) end, CipherState, HashSz, Fragment, Version); decipher(?'3DES', HashSz, CipherState, Fragment, Version) -> block_decipher(fun(<>, IV, T) -> crypto:des3_cbc_decrypt(K1, K2, K3, IV, T) end, CipherState, HashSz, Fragment, Version); decipher(?AES, HashSz, CipherState, Fragment, Version) -> block_decipher(fun(Key, IV, T) when byte_size(Key) =:= 16 -> crypto:aes_cbc_128_decrypt(Key, IV, T); (Key, IV, T) when byte_size(Key) =:= 32 -> crypto:aes_cbc_256_decrypt(Key, IV, T) end, CipherState, HashSz, Fragment, Version). block_decipher(Fun, #cipher_state{key=Key, iv=IV} = CipherState0, HashSz, Fragment, Version) -> 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) 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) end. %%-------------------------------------------------------------------- -spec suites(tls_version()) -> [cipher_suite()]. %% %% Description: Returns a list of supported cipher suites. %%-------------------------------------------------------------------- suites({3, 0}) -> ssl_ssl3:suites(); suites({3, N}) -> ssl_tls1:suites(N). %%-------------------------------------------------------------------- -spec anonymous_suites() -> [cipher_suite()]. %% %% Description: Returns a list of the anonymous cipher suites, only supported %% if explicitly set by user. Intended only for testing. %%-------------------------------------------------------------------- anonymous_suites() -> [?TLS_DH_anon_WITH_RC4_128_MD5, ?TLS_DH_anon_WITH_DES_CBC_SHA, ?TLS_DH_anon_WITH_3DES_EDE_CBC_SHA, ?TLS_DH_anon_WITH_AES_128_CBC_SHA, ?TLS_DH_anon_WITH_AES_256_CBC_SHA, ?TLS_DH_anon_WITH_AES_128_CBC_SHA256, ?TLS_DH_anon_WITH_AES_256_CBC_SHA256]. %%-------------------------------------------------------------------- -spec psk_suites(tls_version()) -> [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 -> psk_suites(0) ++ [?TLS_DHE_PSK_WITH_AES_256_CBC_SHA384, ?TLS_RSA_PSK_WITH_AES_256_CBC_SHA384, ?TLS_PSK_WITH_AES_256_CBC_SHA384, ?TLS_DHE_PSK_WITH_AES_128_CBC_SHA256, ?TLS_RSA_PSK_WITH_AES_128_CBC_SHA256, ?TLS_PSK_WITH_AES_128_CBC_SHA256]; psk_suites(_) -> [?TLS_DHE_PSK_WITH_AES_256_CBC_SHA, ?TLS_RSA_PSK_WITH_AES_256_CBC_SHA, ?TLS_PSK_WITH_AES_256_CBC_SHA, ?TLS_DHE_PSK_WITH_AES_128_CBC_SHA, ?TLS_RSA_PSK_WITH_AES_128_CBC_SHA, ?TLS_PSK_WITH_AES_128_CBC_SHA, ?TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA, ?TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA, ?TLS_PSK_WITH_3DES_EDE_CBC_SHA, ?TLS_DHE_PSK_WITH_RC4_128_SHA, ?TLS_RSA_PSK_WITH_RC4_128_SHA, ?TLS_PSK_WITH_RC4_128_SHA]. %%-------------------------------------------------------------------- -spec srp_suites() -> [cipher_suite()]. %% %% Description: Returns a list of the SRP cipher suites, only supported %% if explicitly set by user. %%-------------------------------------------------------------------- srp_suites() -> [?TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA, ?TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA, ?TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA, ?TLS_SRP_SHA_WITH_AES_128_CBC_SHA, ?TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA, ?TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA, ?TLS_SRP_SHA_WITH_AES_256_CBC_SHA, ?TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA, ?TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA]. %%-------------------------------------------------------------------- -spec suite_definition(cipher_suite()) -> int_cipher_suite(). %% %% Description: Return erlang cipher suite definition. %% Note: Currently not supported suites are commented away. %% They should be supported or removed in the future. %%------------------------------------------------------------------- %% TLS v1.1 suites suite_definition(?TLS_NULL_WITH_NULL_NULL) -> {null, null, null, null}; %% suite_definition(?TLS_RSA_WITH_NULL_MD5) -> %% {rsa, null, md5, default_prf}; %% suite_definition(?TLS_RSA_WITH_NULL_SHA) -> %% {rsa, null, sha, default_prf}; suite_definition(?TLS_RSA_WITH_RC4_128_MD5) -> {rsa, rc4_128, md5, default_prf}; suite_definition(?TLS_RSA_WITH_RC4_128_SHA) -> {rsa, rc4_128, sha, default_prf}; suite_definition(?TLS_RSA_WITH_DES_CBC_SHA) -> {rsa, des_cbc, sha, default_prf}; suite_definition(?TLS_RSA_WITH_3DES_EDE_CBC_SHA) -> {rsa, '3des_ede_cbc', sha, default_prf}; suite_definition(?TLS_DHE_DSS_WITH_DES_CBC_SHA) -> {dhe_dss, des_cbc, sha, default_prf}; suite_definition(?TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA) -> {dhe_dss, '3des_ede_cbc', sha, default_prf}; suite_definition(?TLS_DHE_RSA_WITH_DES_CBC_SHA) -> {dhe_rsa, des_cbc, sha, default_prf}; suite_definition(?TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA) -> {dhe_rsa, '3des_ede_cbc', sha, default_prf}; %%% TSL V1.1 AES suites suite_definition(?TLS_RSA_WITH_AES_128_CBC_SHA) -> {rsa, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_DHE_DSS_WITH_AES_128_CBC_SHA) -> {dhe_dss, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_DHE_RSA_WITH_AES_128_CBC_SHA) -> {dhe_rsa, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_RSA_WITH_AES_256_CBC_SHA) -> {rsa, aes_256_cbc, sha, default_prf}; suite_definition(?TLS_DHE_DSS_WITH_AES_256_CBC_SHA) -> {dhe_dss, aes_256_cbc, sha, default_prf}; suite_definition(?TLS_DHE_RSA_WITH_AES_256_CBC_SHA) -> {dhe_rsa, aes_256_cbc, sha, default_prf}; %% TLS v1.2 suites %% suite_definition(?TLS_RSA_WITH_NULL_SHA) -> %% {rsa, null, sha, default_prf}; suite_definition(?TLS_RSA_WITH_AES_128_CBC_SHA256) -> {rsa, aes_128_cbc, sha256, default_prf}; suite_definition(?TLS_RSA_WITH_AES_256_CBC_SHA256) -> {rsa, aes_256_cbc, sha256, default_prf}; suite_definition(?TLS_DHE_DSS_WITH_AES_128_CBC_SHA256) -> {dhe_dss, aes_128_cbc, sha256, default_prf}; suite_definition(?TLS_DHE_RSA_WITH_AES_128_CBC_SHA256) -> {dhe_rsa, aes_128_cbc, sha256, default_prf}; suite_definition(?TLS_DHE_DSS_WITH_AES_256_CBC_SHA256) -> {dhe_dss, aes_256_cbc, sha256, default_prf}; suite_definition(?TLS_DHE_RSA_WITH_AES_256_CBC_SHA256) -> {dhe_rsa, aes_256_cbc, sha256, default_prf}; %% not defined YET: %% TLS_DH_DSS_WITH_AES_128_CBC_SHA256 DH_DSS AES_128_CBC SHA256 %% TLS_DH_RSA_WITH_AES_128_CBC_SHA256 DH_RSA AES_128_CBC SHA256 %% TLS_DH_DSS_WITH_AES_256_CBC_SHA256 DH_DSS AES_256_CBC SHA256 %% TLS_DH_RSA_WITH_AES_256_CBC_SHA256 DH_RSA AES_256_CBC SHA256 %%% DH-ANON deprecated by TLS spec and not available %%% by default, but good for testing purposes. suite_definition(?TLS_DH_anon_WITH_RC4_128_MD5) -> {dh_anon, rc4_128, md5, default_prf}; suite_definition(?TLS_DH_anon_WITH_DES_CBC_SHA) -> {dh_anon, des_cbc, sha, default_prf}; suite_definition(?TLS_DH_anon_WITH_3DES_EDE_CBC_SHA) -> {dh_anon, '3des_ede_cbc', sha, default_prf}; suite_definition(?TLS_DH_anon_WITH_AES_128_CBC_SHA) -> {dh_anon, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_DH_anon_WITH_AES_256_CBC_SHA) -> {dh_anon, aes_256_cbc, sha, default_prf}; suite_definition(?TLS_DH_anon_WITH_AES_128_CBC_SHA256) -> {dh_anon, aes_128_cbc, sha256, default_prf}; suite_definition(?TLS_DH_anon_WITH_AES_256_CBC_SHA256) -> {dh_anon, aes_256_cbc, sha256, default_prf}; %%% PSK Cipher Suites RFC 4279 suite_definition(?TLS_PSK_WITH_RC4_128_SHA) -> {psk, rc4_128, sha, default_prf}; suite_definition(?TLS_PSK_WITH_3DES_EDE_CBC_SHA) -> {psk, '3des_ede_cbc', sha, default_prf}; suite_definition(?TLS_PSK_WITH_AES_128_CBC_SHA) -> {psk, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_PSK_WITH_AES_256_CBC_SHA) -> {psk, aes_256_cbc, sha, default_prf}; suite_definition(?TLS_DHE_PSK_WITH_RC4_128_SHA) -> {dhe_psk, rc4_128, sha, default_prf}; suite_definition(?TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA) -> {dhe_psk, '3des_ede_cbc', sha, default_prf}; suite_definition(?TLS_DHE_PSK_WITH_AES_128_CBC_SHA) -> {dhe_psk, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_DHE_PSK_WITH_AES_256_CBC_SHA) -> {dhe_psk, aes_256_cbc, sha, default_prf}; suite_definition(?TLS_RSA_PSK_WITH_RC4_128_SHA) -> {rsa_psk, rc4_128, sha, default_prf}; suite_definition(?TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA) -> {rsa_psk, '3des_ede_cbc', sha, default_prf}; suite_definition(?TLS_RSA_PSK_WITH_AES_128_CBC_SHA) -> {rsa_psk, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_RSA_PSK_WITH_AES_256_CBC_SHA) -> {rsa_psk, aes_256_cbc, sha, default_prf}; %%% TLS 1.2 PSK Cipher Suites RFC 5487 suite_definition(?TLS_PSK_WITH_AES_128_CBC_SHA256) -> {psk, aes_128_cbc, sha256, default_prf}; suite_definition(?TLS_PSK_WITH_AES_256_CBC_SHA384) -> {psk, aes_256_cbc, sha384, default_prf}; suite_definition(?TLS_DHE_PSK_WITH_AES_128_CBC_SHA256) -> {dhe_psk, aes_128_cbc, sha256, default_prf}; suite_definition(?TLS_DHE_PSK_WITH_AES_256_CBC_SHA384) -> {dhe_psk, aes_256_cbc, sha384, default_prf}; suite_definition(?TLS_RSA_PSK_WITH_AES_128_CBC_SHA256) -> {rsa_psk, aes_128_cbc, sha256, default_prf}; suite_definition(?TLS_RSA_PSK_WITH_AES_256_CBC_SHA384) -> {rsa_psk, aes_256_cbc, sha384, default_prf}; suite_definition(?TLS_PSK_WITH_NULL_SHA256) -> {psk, null, sha256, default_prf}; suite_definition(?TLS_PSK_WITH_NULL_SHA384) -> {psk, null, sha384, default_prf}; suite_definition(?TLS_DHE_PSK_WITH_NULL_SHA256) -> {dhe_psk, null, sha256, default_prf}; suite_definition(?TLS_DHE_PSK_WITH_NULL_SHA384) -> {dhe_psk, null, sha384, default_prf}; suite_definition(?TLS_RSA_PSK_WITH_NULL_SHA256) -> {rsa_psk, null, sha256, default_prf}; suite_definition(?TLS_RSA_PSK_WITH_NULL_SHA384) -> {rsa_psk, null, sha384, default_prf}; %%% SRP Cipher Suites RFC 5054 suite_definition(?TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA) -> {srp_anon, '3des_ede_cbc', sha, default_prf}; suite_definition(?TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA) -> {srp_rsa, '3des_ede_cbc', sha, default_prf}; suite_definition(?TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA) -> {srp_dss, '3des_ede_cbc', sha, default_prf}; suite_definition(?TLS_SRP_SHA_WITH_AES_128_CBC_SHA) -> {srp_anon, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA) -> {srp_rsa, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA) -> {srp_dss, aes_128_cbc, sha, default_prf}; suite_definition(?TLS_SRP_SHA_WITH_AES_256_CBC_SHA) -> {srp_anon, aes_256_cbc, sha, default_prf}; suite_definition(?TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA) -> {srp_rsa, aes_256_cbc, sha, default_prf}; suite_definition(?TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA) -> {srp_dss, aes_256_cbc, sha, default_prf}. %%-------------------------------------------------------------------- -spec suite(erl_cipher_suite()) -> cipher_suite(). %% %% Description: Return TLS cipher suite definition. %%-------------------------------------------------------------------- %% TLS v1.1 suites %%suite({rsa, null, md5}) -> %% ?TLS_RSA_WITH_NULL_MD5; %%suite({rsa, null, sha}) -> %% ?TLS_RSA_WITH_NULL_SHA; suite({rsa, rc4_128, md5}) -> ?TLS_RSA_WITH_RC4_128_MD5; suite({rsa, rc4_128, sha}) -> ?TLS_RSA_WITH_RC4_128_SHA; suite({rsa, des_cbc, sha}) -> ?TLS_RSA_WITH_DES_CBC_SHA; suite({rsa, '3des_ede_cbc', sha}) -> ?TLS_RSA_WITH_3DES_EDE_CBC_SHA; suite({dhe_dss, des_cbc, sha}) -> ?TLS_DHE_DSS_WITH_DES_CBC_SHA; suite({dhe_dss, '3des_ede_cbc', sha}) -> ?TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA; suite({dhe_rsa, des_cbc, sha}) -> ?TLS_DHE_RSA_WITH_DES_CBC_SHA; suite({dhe_rsa, '3des_ede_cbc', sha}) -> ?TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA; suite({dh_anon, rc4_128, md5}) -> ?TLS_DH_anon_WITH_RC4_128_MD5; suite({dh_anon, des_cbc, sha}) -> ?TLS_DH_anon_WITH_DES_CBC_SHA; suite({dh_anon, '3des_ede_cbc', sha}) -> ?TLS_DH_anon_WITH_3DES_EDE_CBC_SHA; %%% TSL V1.1 AES suites suite({rsa, aes_128_cbc, sha}) -> ?TLS_RSA_WITH_AES_128_CBC_SHA; suite({dhe_dss, aes_128_cbc, sha}) -> ?TLS_DHE_DSS_WITH_AES_128_CBC_SHA; suite({dhe_rsa, aes_128_cbc, sha}) -> ?TLS_DHE_RSA_WITH_AES_128_CBC_SHA; suite({dh_anon, aes_128_cbc, sha}) -> ?TLS_DH_anon_WITH_AES_128_CBC_SHA; suite({rsa, aes_256_cbc, sha}) -> ?TLS_RSA_WITH_AES_256_CBC_SHA; suite({dhe_dss, aes_256_cbc, sha}) -> ?TLS_DHE_DSS_WITH_AES_256_CBC_SHA; suite({dhe_rsa, aes_256_cbc, sha}) -> ?TLS_DHE_RSA_WITH_AES_256_CBC_SHA; suite({dh_anon, aes_256_cbc, sha}) -> ?TLS_DH_anon_WITH_AES_256_CBC_SHA; %% TLS v1.2 suites %% suite_definition(?TLS_RSA_WITH_NULL_SHA) -> %% {rsa, null, sha, sha256}; suite({rsa, aes_128_cbc, sha256}) -> ?TLS_RSA_WITH_AES_128_CBC_SHA256; suite({rsa, aes_256_cbc, sha256}) -> ?TLS_RSA_WITH_AES_256_CBC_SHA256; suite({dhe_dss, aes_128_cbc, sha256}) -> ?TLS_DHE_DSS_WITH_AES_128_CBC_SHA256; suite({dhe_rsa, aes_128_cbc, sha256}) -> ?TLS_DHE_RSA_WITH_AES_128_CBC_SHA256; suite({dhe_dss, aes_256_cbc, sha256}) -> ?TLS_DHE_DSS_WITH_AES_256_CBC_SHA256; suite({dhe_rsa, aes_256_cbc, sha256}) -> ?TLS_DHE_RSA_WITH_AES_256_CBC_SHA256; suite({dh_anon, aes_128_cbc, sha256}) -> ?TLS_DH_anon_WITH_AES_128_CBC_SHA256; suite({dh_anon, aes_256_cbc, sha256}) -> ?TLS_DH_anon_WITH_AES_256_CBC_SHA256; %%% PSK Cipher Suites RFC 4279 suite({psk, rc4_128,sha}) -> ?TLS_PSK_WITH_RC4_128_SHA; suite({psk, '3des_ede_cbc',sha}) -> ?TLS_PSK_WITH_3DES_EDE_CBC_SHA; suite({psk, aes_128_cbc,sha}) -> ?TLS_PSK_WITH_AES_128_CBC_SHA; suite({psk, aes_256_cbc,sha}) -> ?TLS_PSK_WITH_AES_256_CBC_SHA; suite({dhe_psk, rc4_128,sha}) -> ?TLS_DHE_PSK_WITH_RC4_128_SHA; suite({dhe_psk, '3des_ede_cbc',sha}) -> ?TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA; suite({dhe_psk, aes_128_cbc,sha}) -> ?TLS_DHE_PSK_WITH_AES_128_CBC_SHA; suite({dhe_psk, aes_256_cbc,sha}) -> ?TLS_DHE_PSK_WITH_AES_256_CBC_SHA; suite({rsa_psk, rc4_128,sha}) -> ?TLS_RSA_PSK_WITH_RC4_128_SHA; suite({rsa_psk, '3des_ede_cbc',sha}) -> ?TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA; suite({rsa_psk, aes_128_cbc,sha}) -> ?TLS_RSA_PSK_WITH_AES_128_CBC_SHA; suite({rsa_psk, aes_256_cbc,sha}) -> ?TLS_RSA_PSK_WITH_AES_256_CBC_SHA; %%% TLS 1.2 PSK Cipher Suites RFC 5487 suite({psk, aes_128_cbc, sha256}) -> ?TLS_PSK_WITH_AES_128_CBC_SHA256; suite({psk, aes_256_cbc, sha384}) -> ?TLS_PSK_WITH_AES_256_CBC_SHA384; suite({dhe_psk, aes_128_cbc, sha256}) -> ?TLS_DHE_PSK_WITH_AES_128_CBC_SHA256; suite({dhe_psk, aes_256_cbc, sha384}) -> ?TLS_DHE_PSK_WITH_AES_256_CBC_SHA384; suite({rsa_psk, aes_128_cbc, sha256}) -> ?TLS_RSA_PSK_WITH_AES_128_CBC_SHA256; suite({rsa_psk, aes_256_cbc, sha384}) -> ?TLS_RSA_PSK_WITH_AES_256_CBC_SHA384; suite({psk, null, sha256}) -> ?TLS_PSK_WITH_NULL_SHA256; suite({psk, null, sha384}) -> ?TLS_PSK_WITH_NULL_SHA384; suite({dhe_psk, null, sha256}) -> ?TLS_DHE_PSK_WITH_NULL_SHA256; suite({dhe_psk, null, sha384}) -> ?TLS_DHE_PSK_WITH_NULL_SHA384; suite({rsa_psk, null, sha256}) -> ?TLS_RSA_PSK_WITH_NULL_SHA256; suite({rsa_psk, null, sha384}) -> ?TLS_RSA_PSK_WITH_NULL_SHA384; %%% SRP Cipher Suites RFC 5054 suite({srp_anon, '3des_ede_cbc', sha}) -> ?TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA; suite({srp_rsa, '3des_ede_cbc', sha}) -> ?TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA; suite({srp_dss, '3des_ede_cbc', sha}) -> ?TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA; suite({srp_anon, aes_128_cbc, sha}) -> ?TLS_SRP_SHA_WITH_AES_128_CBC_SHA; suite({srp_rsa, aes_128_cbc, sha}) -> ?TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA; suite({srp_dss, aes_128_cbc, sha}) -> ?TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA; suite({srp_anon, aes_256_cbc, sha}) -> ?TLS_SRP_SHA_WITH_AES_256_CBC_SHA; suite({srp_rsa, aes_256_cbc, sha}) -> ?TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA; suite({srp_dss, aes_256_cbc, sha}) -> ?TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA. %%-------------------------------------------------------------------- -spec openssl_suite(openssl_cipher_suite()) -> cipher_suite(). %% %% Description: Return TLS cipher suite definition. %%-------------------------------------------------------------------- %% translate constants <-> openssl-strings openssl_suite("DHE-RSA-AES256-SHA256") -> ?TLS_DHE_RSA_WITH_AES_256_CBC_SHA256; openssl_suite("DHE-DSS-AES256-SHA256") -> ?TLS_DHE_DSS_WITH_AES_256_CBC_SHA256; openssl_suite("AES256-SHA256") -> ?TLS_RSA_WITH_AES_256_CBC_SHA256; openssl_suite("DHE-RSA-AES128-SHA256") -> ?TLS_DHE_RSA_WITH_AES_128_CBC_SHA256; openssl_suite("DHE-DSS-AES128-SHA256") -> ?TLS_DHE_DSS_WITH_AES_128_CBC_SHA256; openssl_suite("AES128-SHA256") -> ?TLS_RSA_WITH_AES_128_CBC_SHA256; openssl_suite("DHE-RSA-AES256-SHA") -> ?TLS_DHE_RSA_WITH_AES_256_CBC_SHA; openssl_suite("DHE-DSS-AES256-SHA") -> ?TLS_DHE_DSS_WITH_AES_256_CBC_SHA; openssl_suite("AES256-SHA") -> ?TLS_RSA_WITH_AES_256_CBC_SHA; openssl_suite("EDH-RSA-DES-CBC3-SHA") -> ?TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA; openssl_suite("EDH-DSS-DES-CBC3-SHA") -> ?TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA; openssl_suite("DES-CBC3-SHA") -> ?TLS_RSA_WITH_3DES_EDE_CBC_SHA; openssl_suite("DHE-RSA-AES128-SHA") -> ?TLS_DHE_RSA_WITH_AES_128_CBC_SHA; openssl_suite("DHE-DSS-AES128-SHA") -> ?TLS_DHE_DSS_WITH_AES_128_CBC_SHA; openssl_suite("AES128-SHA") -> ?TLS_RSA_WITH_AES_128_CBC_SHA; openssl_suite("RC4-SHA") -> ?TLS_RSA_WITH_RC4_128_SHA; openssl_suite("RC4-MD5") -> ?TLS_RSA_WITH_RC4_128_MD5; openssl_suite("EDH-RSA-DES-CBC-SHA") -> ?TLS_DHE_RSA_WITH_DES_CBC_SHA; openssl_suite("DES-CBC-SHA") -> ?TLS_RSA_WITH_DES_CBC_SHA; %%% SRP Cipher Suites RFC 5054 openssl_suite("SRP-DSS-AES-256-CBC-SHA") -> ?TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA; openssl_suite("SRP-RSA-AES-256-CBC-SHA") -> ?TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA; openssl_suite("SRP-DSS-3DES-EDE-CBC-SHA") -> ?TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA; openssl_suite("SRP-RSA-3DES-EDE-CBC-SHA") -> ?TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA; openssl_suite("SRP-DSS-AES-128-CBC-SHA") -> ?TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA; openssl_suite("SRP-RSA-AES-128-CBC-SHA") -> ?TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA. %%-------------------------------------------------------------------- -spec openssl_suite_name(cipher_suite()) -> openssl_cipher_suite(). %% %% Description: Return openssl cipher suite name. %%------------------------------------------------------------------- openssl_suite_name(?TLS_DHE_RSA_WITH_AES_256_CBC_SHA) -> "DHE-RSA-AES256-SHA"; openssl_suite_name(?TLS_DHE_DSS_WITH_AES_256_CBC_SHA) -> "DHE-DSS-AES256-SHA"; openssl_suite_name(?TLS_RSA_WITH_AES_256_CBC_SHA) -> "AES256-SHA"; openssl_suite_name(?TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA) -> "EDH-RSA-DES-CBC3-SHA"; openssl_suite_name(?TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA) -> "EDH-DSS-DES-CBC3-SHA"; openssl_suite_name(?TLS_RSA_WITH_3DES_EDE_CBC_SHA) -> "DES-CBC3-SHA"; openssl_suite_name( ?TLS_DHE_RSA_WITH_AES_128_CBC_SHA) -> "DHE-RSA-AES128-SHA"; openssl_suite_name(?TLS_DHE_DSS_WITH_AES_128_CBC_SHA) -> "DHE-DSS-AES128-SHA"; openssl_suite_name(?TLS_RSA_WITH_AES_128_CBC_SHA) -> "AES128-SHA"; openssl_suite_name(?TLS_RSA_WITH_RC4_128_SHA) -> "RC4-SHA"; openssl_suite_name(?TLS_RSA_WITH_RC4_128_MD5) -> "RC4-MD5"; openssl_suite_name(?TLS_DHE_RSA_WITH_DES_CBC_SHA) -> "EDH-RSA-DES-CBC-SHA"; openssl_suite_name(?TLS_RSA_WITH_DES_CBC_SHA) -> "DES-CBC-SHA"; openssl_suite_name(?TLS_RSA_WITH_NULL_SHA256) -> "NULL-SHA256"; openssl_suite_name(?TLS_RSA_WITH_AES_128_CBC_SHA256) -> "AES128-SHA256"; openssl_suite_name(?TLS_RSA_WITH_AES_256_CBC_SHA256) -> "AES256-SHA256"; openssl_suite_name(?TLS_DH_DSS_WITH_AES_128_CBC_SHA256) -> "DH-DSS-AES128-SHA256"; openssl_suite_name(?TLS_DH_RSA_WITH_AES_128_CBC_SHA256) -> "DH-RSA-AES128-SHA256"; openssl_suite_name(?TLS_DHE_DSS_WITH_AES_128_CBC_SHA256) -> "DHE-DSS-AES128-SHA256"; openssl_suite_name(?TLS_DHE_RSA_WITH_AES_128_CBC_SHA256) -> "DHE-RSA-AES128-SHA256"; openssl_suite_name(?TLS_DH_DSS_WITH_AES_256_CBC_SHA256) -> "DH-DSS-AES256-SHA256"; openssl_suite_name(?TLS_DH_RSA_WITH_AES_256_CBC_SHA256) -> "DH-RSA-AES256-SHA256"; openssl_suite_name(?TLS_DHE_DSS_WITH_AES_256_CBC_SHA256) -> "DHE-DSS-AES256-SHA256"; openssl_suite_name(?TLS_DHE_RSA_WITH_AES_256_CBC_SHA256) -> "DHE-RSA-AES256-SHA256"; %%% PSK Cipher Suites RFC 4279 openssl_suite_name(?TLS_PSK_WITH_AES_256_CBC_SHA) -> "PSK-AES256-CBC-SHA"; openssl_suite_name(?TLS_PSK_WITH_3DES_EDE_CBC_SHA) -> "PSK-3DES-EDE-CBC-SHA"; openssl_suite_name(?TLS_PSK_WITH_AES_128_CBC_SHA) -> "PSK-AES128-CBC-SHA"; openssl_suite_name(?TLS_PSK_WITH_RC4_128_SHA) -> "PSK-RC4-SHA"; %%% SRP Cipher Suites RFC 5054 openssl_suite_name(?TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA) -> "SRP-RSA-3DES-EDE-CBC-SHA"; openssl_suite_name(?TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA) -> "SRP-DSS-3DES-EDE-CBC-SHA"; openssl_suite_name(?TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA) -> "SRP-RSA-AES-128-CBC-SHA"; openssl_suite_name(?TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA) -> "SRP-DSS-AES-128-CBC-SHA"; openssl_suite_name(?TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA) -> "SRP-RSA-AES-256-CBC-SHA"; openssl_suite_name(?TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA) -> "SRP-DSS-AES-256-CBC-SHA"; %% No oppenssl name openssl_suite_name(Cipher) -> suite_definition(Cipher). %%-------------------------------------------------------------------- -spec filter(undefined | binary(), [cipher_suite()]) -> [cipher_suite()]. %% %% Description: . %%------------------------------------------------------------------- filter(undefined, Ciphers) -> Ciphers; filter(DerCert, Ciphers) -> OtpCert = public_key:pkix_decode_cert(DerCert, otp), SigAlg = OtpCert#'OTPCertificate'.signatureAlgorithm, case public_key:pkix_sign_types(SigAlg#'SignatureAlgorithm'.algorithm) of {_, rsa} -> filter_rsa(OtpCert, Ciphers -- dsa_signed_suites()); {_, dsa} -> Ciphers -- rsa_signed_suites() end. %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- 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. 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. 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. 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 -> unknown. effective_key_bits(null) -> 0; effective_key_bits(des_cbc) -> 56; effective_key_bits(Cipher) when Cipher == rc4_128; Cipher == aes_128_cbc -> 128; effective_key_bits('3des_ede_cbc') -> 168; effective_key_bits(aes_256_cbc) -> 256. iv_size(Cipher) when Cipher == null; Cipher == rc4_128 -> 0; 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 -> 16. prf_algorithm(default_prf, {3, N}) when N >= 3 -> ?SHA256; prf_algorithm(default_prf, {3, _}) -> ?MD5SHA; prf_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. 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. hash_size(null) -> 0; hash_size(md5) -> 16; hash_size(sha) -> 20; hash_size(sha256) -> 32. %% Currently no supported cipher suites defaults to sha384 or sha512 %% so these clauses are not needed at the moment. %% hash_size(sha384) -> %% 48; %% 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}. %% For interoperability reasons we do not check the padding content in %% SSL 3.0 and TLS 1.0 as it is not strictly required and breaks %% interopability with for instance Google. is_correct_padding(#generic_block_cipher{padding_length = Len, padding = Padding}, {3, N}) when N == 0; N == 1 -> Len == byte_size(Padding); %% Padding must be check in TLS 1.1 and after is_correct_padding(#generic_block_cipher{padding_length = Len, padding = Padding}, _) -> Len == byte_size(Padding) andalso list_to_binary(lists:duplicate(Len, Len)) == Padding. get_padding(Length, BlockSize) -> get_padding_aux(BlockSize, Length rem BlockSize). get_padding_aux(_, 0) -> {0, <<>>}; get_padding_aux(BlockSize, PadLength) -> N = BlockSize - PadLength, {N, list_to_binary(lists:duplicate(N, N))}. random_iv(IV) -> IVSz = byte_size(IV), ssl:random_bytes(IVSz). next_iv(Bin, IV) -> BinSz = byte_size(Bin), IVSz = byte_size(IV), FirstPart = BinSz - IVSz, <<_:FirstPart/binary, NextIV:IVSz/binary>> = Bin, NextIV. rsa_signed_suites() -> dhe_rsa_suites() ++ rsa_suites() ++ psk_rsa_suites() ++ srp_rsa_suites(). dhe_rsa_suites() -> [?TLS_DHE_RSA_WITH_AES_256_CBC_SHA256, ?TLS_DHE_RSA_WITH_AES_256_CBC_SHA, ?TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA, ?TLS_DHE_RSA_WITH_AES_128_CBC_SHA256, ?TLS_DHE_RSA_WITH_AES_128_CBC_SHA, ?TLS_DHE_RSA_WITH_DES_CBC_SHA]. psk_rsa_suites() -> [?TLS_RSA_PSK_WITH_AES_256_CBC_SHA384, ?TLS_RSA_PSK_WITH_AES_128_CBC_SHA256, ?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]. srp_rsa_suites() -> [?TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA, ?TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA, ?TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA]. rsa_suites() -> [?TLS_RSA_WITH_AES_256_CBC_SHA256, ?TLS_RSA_WITH_AES_256_CBC_SHA, ?TLS_RSA_WITH_3DES_EDE_CBC_SHA, ?TLS_RSA_WITH_AES_128_CBC_SHA256, ?TLS_RSA_WITH_AES_128_CBC_SHA, ?TLS_RSA_WITH_RC4_128_SHA, ?TLS_RSA_WITH_RC4_128_MD5, ?TLS_RSA_WITH_DES_CBC_SHA]. dsa_signed_suites() -> dhe_dss_suites() ++ srp_dss_suites(). dhe_dss_suites() -> [?TLS_DHE_DSS_WITH_AES_256_CBC_SHA256, ?TLS_DHE_DSS_WITH_AES_256_CBC_SHA, ?TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA, ?TLS_DHE_DSS_WITH_AES_128_CBC_SHA256, ?TLS_DHE_DSS_WITH_AES_128_CBC_SHA, ?TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA]. srp_dss_suites() -> [?TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA, ?TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA, ?TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA]. filter_rsa(OtpCert, RsaCiphers) -> 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 -> RsaCiphers; #'Extension'{extnValue = KeyUse} -> Result = filter_rsa_suites(keyEncipherment, KeyUse, RsaCiphers, rsa_suites()), filter_rsa_suites(digitalSignature, KeyUse, Result, dhe_rsa_suites()) end. filter_rsa_suites(Use, KeyUse, CipherSuits, RsaSuites) -> case ssl_certificate:is_valid_key_usage(KeyUse, Use) of true -> CipherSuits; false -> CipherSuits -- RsaSuites end.