diff options
Diffstat (limited to 'lib/ssl/src/ssl_record.erl')
-rw-r--r-- | lib/ssl/src/ssl_record.erl | 79 |
1 files changed, 70 insertions, 9 deletions
diff --git a/lib/ssl/src/ssl_record.erl b/lib/ssl/src/ssl_record.erl index 659e1485ac..d31e429283 100644 --- a/lib/ssl/src/ssl_record.erl +++ b/lib/ssl/src/ssl_record.erl @@ -45,7 +45,7 @@ -export([compress/3, uncompress/3, compressions/0]). %% Payload encryption/decryption --export([cipher/4, decipher/4, cipher_aead/4, is_correct_mac/2]). +-export([cipher/4, decipher/4, cipher_aead/4, decipher_aead/5, is_correct_mac/2, nonce_seed/3]). -export_type([ssl_version/0, ssl_atom_version/0, connection_states/0, connection_state/0]). @@ -306,22 +306,20 @@ cipher(Version, Fragment, {CipherFragment, CipherS1} = ssl_cipher:cipher(BulkCipherAlgo, CipherS0, MacHash, Fragment, Version), {CipherFragment, WriteState0#{cipher_state => CipherS1}}. -%% %%-------------------------------------------------------------------- -%% -spec cipher_aead(ssl_version(), iodata(), connection_state(), MacHash::binary()) -> -%% {CipherFragment::binary(), connection_state()}. -%% %% -%% %% Description: Payload encryption +%%-------------------------------------------------------------------- +-spec cipher_aead(ssl_version(), iodata(), connection_state(), AAD::binary()) -> + {CipherFragment::binary(), connection_state()}. + +%% Description: Payload encryption %% %%-------------------------------------------------------------------- cipher_aead(Version, Fragment, #{cipher_state := CipherS0, - sequence_number := SeqNo, security_parameters := #security_parameters{bulk_cipher_algorithm = BulkCipherAlgo} } = WriteState0, AAD) -> - {CipherFragment, CipherS1} = - ssl_cipher:cipher_aead(BulkCipherAlgo, CipherS0, SeqNo, AAD, Fragment, Version), + cipher_aead(BulkCipherAlgo, CipherS0, AAD, Fragment, Version), {CipherFragment, WriteState0#{cipher_state => CipherS1}}. %%-------------------------------------------------------------------- @@ -344,10 +342,39 @@ decipher(Version, CipherFragment, #alert{} = Alert -> Alert end. +%%-------------------------------------------------------------------- +-spec decipher_aead(ssl_cipher:cipher_enum(), #cipher_state{}, + binary(), binary(), ssl_record:ssl_version()) -> + {binary(), #cipher_state{}} | #alert{}. +%% +%% Description: Decrypts the data and checks the associated data (AAD) MAC using +%% cipher described by cipher_enum() and updating the cipher state. +%% Use for suites that use authenticated encryption with associated data (AEAD) +%%------------------------------------------------------------------- +decipher_aead(Type, #cipher_state{key = Key} = CipherState, AAD0, CipherFragment, _) -> + try + Nonce = decrypt_nonce(Type, CipherState, CipherFragment), + {AAD, CipherText, CipherTag} = aead_ciphertext_split(Type, CipherState, CipherFragment, AAD0), + case ssl_cipher:aead_decrypt(Type, Key, Nonce, CipherText, CipherTag, AAD) of + Content when is_binary(Content) -> + {Content, CipherState}; + _ -> + ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC, decryption_failed) + end + catch + _:_ -> + ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC, decryption_failed) + end. + +nonce_seed(?CHACHA20_POLY1305, Seed, CipherState) -> + ssl_cipher:nonce_seed(Seed, CipherState); +nonce_seed(_,_, CipherState) -> + CipherState. %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- + empty_connection_state(ConnectionEnd, BeastMitigation) -> SecParams = empty_security_params(ConnectionEnd), #{security_parameters => SecParams, @@ -400,3 +427,37 @@ initial_security_params(ConnectionEnd) -> compression_algorithm = ?NULL}, ssl_cipher:security_parameters(?TLS_NULL_WITH_NULL_NULL, SecParams). +cipher_aead(?CHACHA20_POLY1305 = Type, #cipher_state{key=Key} = CipherState, AAD0, Fragment, _Version) -> + AAD = end_additional_data(AAD0, erlang:iolist_size(Fragment)), + Nonce = encrypt_nonce(Type, CipherState), + {Content, CipherTag} = ssl_cipher:aead_encrypt(Type, Key, Nonce, Fragment, AAD), + {<<Content/binary, CipherTag/binary>>, CipherState}; +cipher_aead(Type, #cipher_state{key=Key, nonce = ExplicitNonce} = CipherState, AAD0, Fragment, _Version) -> + AAD = end_additional_data(AAD0, erlang:iolist_size(Fragment)), + Nonce = encrypt_nonce(Type, CipherState), + {Content, CipherTag} = ssl_cipher:aead_encrypt(Type, Key, Nonce, Fragment, AAD), + {<<ExplicitNonce:64/integer, Content/binary, CipherTag/binary>>, CipherState#cipher_state{nonce = ExplicitNonce + 1}}. + +encrypt_nonce(?CHACHA20_POLY1305, #cipher_state{nonce = Nonce, iv = IV}) -> + crypto:exor(<<?UINT32(0), Nonce/binary>>, IV); +encrypt_nonce(?AES_GCM, #cipher_state{iv = IV, nonce = ExplicitNonce}) -> + <<Salt:4/bytes, _/binary>> = IV, + <<Salt/binary, ExplicitNonce:64/integer>>. + +decrypt_nonce(?CHACHA20_POLY1305, #cipher_state{nonce = Nonce, iv = IV}, _) -> + crypto:exor(<<Nonce:96/unsigned-big-integer>>, IV); +decrypt_nonce(?AES_GCM, #cipher_state{iv = <<Salt:4/bytes, _/binary>>}, <<ExplicitNonce:8/bytes, _/binary>>) -> + <<Salt/binary, ExplicitNonce/binary>>. + +aead_ciphertext_split(?CHACHA20_POLY1305, #cipher_state{tag_len = Len}, CipherTextFragment, AAD) -> + CipherLen = size(CipherTextFragment) - Len, + <<CipherText:CipherLen/bytes, CipherTag:Len/bytes>> = CipherTextFragment, + {end_additional_data(AAD, Len), CipherText, CipherTag}; +aead_ciphertext_split(?AES_GCM, #cipher_state{tag_len = Len}, CipherTextFragment, AAD) -> + CipherLen = size(CipherTextFragment) - (Len + 8), %% 8 is length of explicit Nonce + << _:8/bytes, CipherText:CipherLen/bytes, CipherTag:Len/bytes>> = CipherTextFragment, + {end_additional_data(AAD, CipherLen), CipherText, CipherTag}. + +end_additional_data(AAD, Len) -> + <<AAD/binary, ?UINT16(Len)>>. + |