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Diffstat (limited to 'lib/public_key/src/pubkey_pbe.erl')
| -rw-r--r-- | lib/public_key/src/pubkey_pbe.erl | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/lib/public_key/src/pubkey_pbe.erl b/lib/public_key/src/pubkey_pbe.erl new file mode 100644 index 0000000000..43f6c42f10 --- /dev/null +++ b/lib/public_key/src/pubkey_pbe.erl @@ -0,0 +1,213 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2011-2011. 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% +%% +%% Description: Implements Password Based Encryption PKCS-5, RFC-2898 + +-module(pubkey_pbe). + +-include("public_key.hrl"). + +-export([encode/4, decode/4, decrypt_parameters/1]). +-export([pbdkdf1/4, pbdkdf2/6]). + +-define(DEFAULT_SHA_MAC_KEYLEN, 20). +-define(ASN1_OCTET_STR_TAG, 4). +-define(IV_LEN, 8). + +%%==================================================================== +%% Internal application API +%%==================================================================== + +%%-------------------------------------------------------------------- +-spec encode(binary(), string(), string(), term()) -> binary(). +%% +%% Description: Performs password based encoding +%%-------------------------------------------------------------------- +encode(Data, Password, "DES-CBC" = Cipher, KeyDevParams) -> + {Key, IV} = password_to_key_and_iv(Password, Cipher, KeyDevParams), + crypto:des_cbc_encrypt(Key, IV, Data); + +encode(Data, Password, "DES-EDE3-CBC" = Cipher, KeyDevParams) -> + {Key, IV} = password_to_key_and_iv(Password, Cipher, KeyDevParams), + <<Key1:8/binary, Key2:8/binary, Key3:8/binary>> = Key, + crypto:des_ede3_cbc_encrypt(Key1, Key2, Key3, IV, Data); + +encode(Data, Password, "RC2-CBC" = Cipher, KeyDevParams) -> + {Key, IV} = password_to_key_and_iv(Password, Cipher, KeyDevParams), + crypto:rc2_cbc_encrypt(Key, IV, Data). +%%-------------------------------------------------------------------- +-spec decode(binary(), string(), string(), term()) -> binary(). +%% +%% Description: Performs password based decoding +%%-------------------------------------------------------------------- +decode(Data, Password,"DES-CBC"= Cipher, KeyDevParams) -> + {Key, IV} = password_to_key_and_iv(Password, Cipher, KeyDevParams), + crypto:des_cbc_decrypt(Key, IV, Data); + +decode(Data, Password,"DES-EDE3-CBC" = Cipher, KeyDevParams) -> + {Key, IV} = password_to_key_and_iv(Password, Cipher, KeyDevParams), + <<Key1:8/binary, Key2:8/binary, Key3:8/binary>> = Key, + crypto:des_ede3_cbc_decrypt(Key1, Key2, Key3, IV, Data); + +decode(Data, Password,"RC2-CBC"= Cipher, KeyDevParams) -> + {Key, IV} = password_to_key_and_iv(Password, Cipher, KeyDevParams), + crypto:rc2_cbc_decrypt(Key, IV, Data). + +%%-------------------------------------------------------------------- +-spec pbdkdf1(string(), iodata(), integer(), atom()) -> binary(). +%% +%% Description: Implements password based decryption key derive function 1. +%% Exported mainly for testing purposes. +%%-------------------------------------------------------------------- +pbdkdf1(_, _, 0, Acc) -> + Acc; +pbdkdf1(Password, Salt, Count, Hash) -> + Result = crypto:Hash([Password, Salt]), + do_pbdkdf1(Result, Count-1, Result, Hash). + +%%-------------------------------------------------------------------- +-spec pbdkdf2(string(), iodata(), integer(), integer(), fun(), integer()) + -> binary(). +%% +%% Description: Implements password based decryption key derive function 2. +%% Exported mainly for testing purposes. +%%-------------------------------------------------------------------- +pbdkdf2(Password, Salt, Count, DerivedKeyLen, Prf, PrfOutputLen)-> + NumBlocks = ceiling(DerivedKeyLen / PrfOutputLen), + NumLastBlockOctets = DerivedKeyLen - (NumBlocks - 1) * PrfOutputLen , + blocks(NumBlocks, NumLastBlockOctets, 1, Password, Salt, + Count, Prf, PrfOutputLen, <<>>). +%%-------------------------------------------------------------------- +-spec decrypt_parameters(#'EncryptedPrivateKeyInfo_encryptionAlgorithm'{}) -> + {Cipher::string(), #'PBES2-params'{}}. +%% +%% Description: Performs ANS1-decoding of encryption parameters. +%%-------------------------------------------------------------------- +decrypt_parameters(#'EncryptedPrivateKeyInfo_encryptionAlgorithm'{ + algorithm = Oid, parameters = Param}) -> + decrypt_parameters(Oid, Param). + +%%-------------------------------------------------------------------- +%%% Internal functions +%%-------------------------------------------------------------------- +password_to_key_and_iv(Password, _, #'PBES2-params'{} = Params) -> + {Salt, ItrCount, KeyLen, PseudoRandomFunction, PseudoOtputLen, IV} = + key_derivation_params(Params), + <<Key:KeyLen/binary, _/binary>> = + pbdkdf2(Password, Salt, ItrCount, KeyLen, PseudoRandomFunction, PseudoOtputLen), + {Key, IV}; +password_to_key_and_iv(Password, Cipher, Salt) -> + KeyLen = derived_key_length(Cipher, undefined), + <<Key:KeyLen/binary, _/binary>> = + pem_encrypt(<<>>, Password, Salt, ceiling(KeyLen div 16), <<>>, md5), + %% Old PEM encryption does not use standard encryption method + %% pbdkdf1 and uses then salt as IV + {Key, Salt}. + +pem_encrypt(_, _, _, 0, Acc, _) -> + Acc; +pem_encrypt(Prev, Password, Salt, Count, Acc, Hash) -> + Result = crypto:Hash([Prev, Password, Salt]), + pem_encrypt(Result, Password, Salt, Count-1 , <<Acc/binary, Result/binary>>, Hash). + +do_pbdkdf1(_, 0, Acc, _) -> + Acc; +do_pbdkdf1(Prev, Count, Acc, Hash) -> + Result = crypto:Hash(Prev), + do_pbdkdf1(Result, Count-1 , <<Result/binary, Acc/binary>>, Hash). + +iv(#'PBES2-params_encryptionScheme'{algorithm = Algo, + parameters = ASNIV}) when (Algo == ?'desCBC') or + (Algo == ?'des-EDE3-CBC') -> + %% This is an so called open ASN1-type that in this + %% case will be an octet-string of length 8 + <<?ASN1_OCTET_STR_TAG, ?IV_LEN, IV:?IV_LEN/binary>> = ASNIV, + IV; +iv(#'PBES2-params_encryptionScheme'{algorithm = ?'rc2CBC', + parameters = ASN1IV}) -> + {ok, #'RC2-CBC-Parameter'{iv = IV}} = 'PKCS-FRAME':decode('RC2-CBC-Parameter', ASN1IV), + iolist_to_binary(IV). + +blocks(1, N, Index, Password, Salt, Count, Prf, PrfLen, Acc) -> + <<XorSum:N/binary, _/binary>> = xor_sum(Password, Salt, Count, Index, Prf, PrfLen), + <<Acc/binary, XorSum/binary>>; +blocks(NumBlocks, N, Index, Password, Salt, Count, Prf, PrfLen, Acc) -> + XorSum = xor_sum(Password, Salt, Count, Index, Prf, PrfLen), + blocks(NumBlocks -1, N, Index +1, Password, Salt, Count, Prf, + PrfLen, <<Acc/binary, XorSum/binary>>). + +xor_sum(Password, Salt, Count, Index, Prf, PrfLen) -> + Result = Prf(Password, [Salt,<<Index:32/unsigned-big-integer>>], PrfLen), + do_xor_sum(Prf, PrfLen, Result, Password, Count-1, Result). + +do_xor_sum(_, _, _, _, 0, Acc) -> + Acc; +do_xor_sum(Prf, PrfLen, Prev, Password, Count, Acc)-> + Result = Prf(Password, Prev, PrfLen), + do_xor_sum(Prf, PrfLen, Result, Password, Count-1, crypto:exor(Acc, Result)). + +decrypt_parameters(?'id-PBES2', DekParams) -> + {ok, Params} = 'PKCS-FRAME':decode('PBES2-params', DekParams), + {cipher(Params#'PBES2-params'.encryptionScheme), Params}. + +key_derivation_params(#'PBES2-params'{keyDerivationFunc = KeyDerivationFunc, + encryptionScheme = EncScheme}) -> + #'PBES2-params_keyDerivationFunc'{algorithm = ?'id-PBKDF2', + parameters = + #'PBKDF2-params'{salt = {specified, OctetSalt}, + iterationCount = Count, + keyLength = Length, + prf = Prf}} = KeyDerivationFunc, + #'PBES2-params_encryptionScheme'{algorithm = Algo} = EncScheme, + {PseudoRandomFunction, PseudoOtputLen} = pseudo_random_function(Prf), + KeyLen = derived_key_length(Algo, Length), + {OctetSalt, Count, KeyLen, + PseudoRandomFunction, PseudoOtputLen, iv(EncScheme)}. + +%% This function currently matches a tuple that ougth to be the value +%% ?'id-hmacWithSHA1, but we need some kind of ASN1-fix for this. +pseudo_random_function(#'PBKDF2-params_prf'{algorithm = + {_,_, _,'id-hmacWithSHA1'}}) -> + {fun crypto:sha_mac/3, pseudo_output_length(?'id-hmacWithSHA1')}; +pseudo_random_function(#'PBKDF2-params_prf'{algorithm = ?'id-hmacWithSHA1'}) -> + {fun crypto:sha_mac/3, pseudo_output_length(?'id-hmacWithSHA1')}. + +pseudo_output_length(?'id-hmacWithSHA1') -> + ?DEFAULT_SHA_MAC_KEYLEN. + +derived_key_length(_, Len) when is_integer(Len) -> + Len; +derived_key_length(Cipher,_) when (Cipher == ?'desCBC') or + (Cipher == "DES-CBC") -> + 8; +derived_key_length(Cipher,_) when (Cipher == ?'rc2CBC') or + (Cipher == "RC2-CBC") -> + 16; +derived_key_length(Cipher,_) when (Cipher == ?'des-EDE3-CBC') or + (Cipher == "DES-EDE3-CBC") -> + 24. + +cipher(#'PBES2-params_encryptionScheme'{algorithm = ?'desCBC'}) -> + "DES-CBC"; +cipher(#'PBES2-params_encryptionScheme'{algorithm = ?'des-EDE3-CBC'}) -> + "DES-EDE3-CBC"; +cipher(#'PBES2-params_encryptionScheme'{algorithm = ?'rc2CBC'}) -> + "RC2-CBC". + +ceiling(Float) -> + erlang:round(Float + 0.5). |