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| author | Raimo Niskanen <[email protected]> | 2019-01-23 11:13:52 +0100 |
|---|---|---|
| committer | Raimo Niskanen <[email protected]> | 2019-02-13 14:03:17 +0100 |
| commit | 0cc1e1c31ce6bec1bb679628ee1e4e7a095dfba6 (patch) | |
| tree | b8e67a111c0688be42df447e83cd2501a70724dd /lib | |
| parent | adb26a65ff5b1f40c3efb96b23c18b2f14839a5a (diff) | |
| download | otp-0cc1e1c31ce6bec1bb679628ee1e4e7a095dfba6.tar.gz otp-0cc1e1c31ce6bec1bb679628ee1e4e7a095dfba6.tar.bz2 otp-0cc1e1c31ce6bec1bb679628ee1e4e7a095dfba6.zip | |
Optimize padding
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/ssl/src/ssl_cipher.erl | 61 |
1 files changed, 45 insertions, 16 deletions
diff --git a/lib/ssl/src/ssl_cipher.erl b/lib/ssl/src/ssl_cipher.erl index 2c341635a3..ab82b487b9 100644 --- a/lib/ssl/src/ssl_cipher.erl +++ b/lib/ssl/src/ssl_cipher.erl @@ -146,8 +146,7 @@ aead_type(?CHACHA20_POLY1305) -> 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]. + [Fragment, Mac, padding_with_len(TotSz, BlockSz)]. block_cipher(Fun, BlockSz, #cipher_state{key=Key, iv=IV} = CS0, Mac, Fragment, {3, N}) @@ -723,7 +722,6 @@ expanded_key_material(Cipher) when Cipher == aes_128_cbc; Cipher == chacha20_poly1305 -> unknown. - effective_key_bits(null) -> 0; effective_key_bits(des_cbc) -> @@ -743,18 +741,15 @@ 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; @@ -889,17 +884,51 @@ is_correct_padding(GenBlockCipher, {3, 1}, 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 - binary:copy(?byte(Len), Len) == Padding. - -get_padding(Length, BlockSize) -> - get_padding_aux(BlockSize, Length rem BlockSize). + (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>>, PadLen) + end. -get_padding_aux(_, 0) -> - {0, <<>>}; -get_padding_aux(BlockSize, PadLength) -> - N = BlockSize - PadLength, - {N, binary:copy(?byte(N), N)}. +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>>, PadLen + 1) + end. random_iv(IV) -> IVSz = byte_size(IV), |