Additions to crypto and public_key needed for full PKCS-8 support

2 files changed, 63 insertions, 43 deletions

diff --git a/lib/public_key/src/pubkey_pbe.erl b/lib/public_key/src/pubkey_pbe.erl
index f471871d35..32be347039 100644
--- a/lib/public_key/src/pubkey_pbe.erl
+++ b/lib/public_key/src/pubkey_pbe.erl
@@ -27,35 +27,43 @@
 
 -define(DEFAULT_SHA_MAC_KEYLEN, 20).
 
--define(OCTET_STR, 4).
--define(IV_LEN,    8).
+-define(ASN1_OCTET_STR_TAG, 4).
+-define(IV_LEN, 8).
 
 %%====================================================================
 %% Internal application API
 %%====================================================================
 
-pbdkdf2(Password, Salt, Count, DerivedKeyLen, PrfLen, Prf)->
-    NumBlocks = ceiling(DerivedKeyLen / PrfLen),
-    NumLastBlockOctets = DerivedKeyLen - (NumBlocks - 1) * PrfLen ,
-    blocks(NumBlocks, NumLastBlockOctets, 1, Password, Salt, Count, Prf, PrfLen, <<>>).
+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, <<>>).
 
 encode(Data, Password, "DES-CBC" = Cipher, KeyDevParams) ->
-    {Key, IV} = password_to_key_and_iv(Password, derived_key_length(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, derived_key_length(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).
+    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).
 
 decode(Data, Password,"DES-CBC"= Cipher, KeyDevParams) ->
-    {Key, IV} = password_to_key_and_iv(Password, derived_key_length(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, derived_key_length(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).
+    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().
@@ -94,13 +102,20 @@ decrypt_parameters(#'EncryptedPrivateKeyInfo_encryptionAlgorithm'{
 %%--------------------------------------------------------------------
 %%% Internal functions
 %%--------------------------------------------------------------------
-password_to_key_and_iv(Password, KeyLen, {salt, Salt}) ->
+password_to_key_and_iv(Password, Cipher, {salt, 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}.
 
+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}.
 pem_encrypt(_, _, _, 0, Acc, _) ->
     Acc;
 pem_encrypt(Prev, Password, Salt, Count, Acc, Hash) ->
@@ -118,8 +133,12 @@ iv(#'PBES2-params_encryptionScheme'{algorithm = Algo,
 							       (Algo == ?'des-EDE3-CBC') ->
     %% This is an so called open ASN1-type that in this
     %% case will be an octet-string of length 8
-    <<?OCTET_STR, ?IV_LEN, IV:?IV_LEN/binary>> = ASNIV,
-    IV.
+    <<?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),
@@ -129,53 +148,55 @@ blocks(NumBlocks, N, Index, Password, Salt, Count, Prf, PrfLen, Acc) ->
     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),
-    Result = Prf(Password, [Salt,<<Index:32/unsigned-big-integer>>]),
+    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),
-    Result = Prf(Password, Prev),
+    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'{algorithm = ?'id-PBKDF2',
-							parameters = 
-							    #'PBKDF2-params'{salt = {specified, OctetSalt},
-									     iterationCount = Count,
-									     keyLength = Length,
-									     prf = Prf}}) ->
-    PseudoRandomFunction = pseudo_random_function(Prf),
-    KeyLen = pseudo_key_length(Length, Prf),
-    {iolist_to_binary(OctetSalt), Count, KeyLen, PseudoRandomFunction}.
-
+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),
+    {iolist_to_binary(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_n/3.
-    fun crypto:sha_mac/2.
+    {fun crypto:sha_mac/3, pseudo_output_length(?'id-hmacWithSHA1')}.
 
-pseudo_key_length(asn1_NOVALUE, #'PBKDF2-params_prf'{algorithm = {_,_, _,'id-hmacWithSHA1'}}) ->
-    ?DEFAULT_SHA_MAC_KEYLEN;
-pseudo_key_length(Len, _) when is_integer(Len) ->
-    Len.    
+pseudo_output_length(?'id-hmacWithSHA1') ->
+    ?DEFAULT_SHA_MAC_KEYLEN.
 
-derived_key_length("DES-CBC") ->
+derived_key_length(_, Len) when is_integer(Len) ->
+    Len;
+derived_key_length(Cipher,_) when (Cipher == ?'desCBC') or (Cipher == "DES-CBC") ->
     8;
-%% derived_key_length("RC2-CBC") ->
-%%     5;
-derived_key_length("DES-EDE3-CBC") ->
+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".
+    "DES-EDE3-CBC";
+cipher(#'PBES2-params_encryptionScheme'{algorithm = ?'rc2CBC'}) ->
+    "RC2-CBC".
 
 ceiling(Float) -> 
     erlang:round(Float + 0.5).
diff --git a/lib/public_key/src/public_key.erl b/lib/public_key/src/public_key.erl
index 68c7b7ad93..19465e7828 100644
--- a/lib/public_key/src/public_key.erl
+++ b/lib/public_key/src/public_key.erl
@@ -154,7 +154,6 @@ der_decode(Asn1Type, Der) when (Asn1Type == 'PrivateKeyInfo') or (Asn1Type ==  '
 			       andalso is_binary(Der) ->
     try
 	{ok, Decoded} = 'PKCS-FRAME':decode(Asn1Type, Der),
-	
 	Decoded
     catch
 	error:{badmatch, {error, _}} = Error ->