From b74ff4f6df28405222752fb2b1089f11e96e5406 Mon Sep 17 00:00:00 2001 From: Travis Jensen Date: Fri, 6 May 2011 12:36:38 -0600 Subject: Add true streaming AES (CTR) encryption and streaming HMAC operations The current crypto module implementations require all of the data being encrypted or authenticated to be in memory at one time. When trying to encrypt or authenticate a large file (on order of GBs), this is problematic. The implementation of AES CTR uses the same underlying implementation as aes_ctr_[en|de]crypt, but hands the state back to the client after every operation. The HMAC implementation differs from the previous implementations of sha_mac and md5_mac. The old implementations did not utilize the OpenSSL HMAC implementation. In order to ensure that I didn't implement something incorrectly, I chose to use the OpenSSL HMAC implementation directly, since it handles streaming as well. This has the added side benefit of allowing other hash functions to be used as desired (for instances, I added support for ripemd160 hashing). While I haven't done this, it seems like the existing md5_mac and sha_mac functions could either be depricated or redefined in terms of the new hmac_ functions. Update AES CTR and HMAC streaming with code review input Ensure that memcpy operations in hmac operations are being size checked properly. Rename aes_ctr_XXX_with_state to aes_ctr_stream_XXX. Remove redundant hmac_init_[sha|md5|ripemd160] functions. Fix documentation for hmac_final_n. Fix possible error using negative value as a marker on an unsigned int Now, use a separate marker and add a unit test to test specifically for a case where HashLen is larger than the underlying resultant hash. Revert "Fix possible error using negative value as a marker on an unsigned int" This reverts commit 59cb177aa96444c0fd3ace6d01f7b8a70dd69cc9. Resolve buffer overflow posibility on an unsigned int. Change handling the marker for HashLen to use the fact that a second parameter that has to be the the HashLen was passed. Also, ensure that HashLen parameter is positive. --- lib/crypto/src/crypto.erl | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) (limited to 'lib/crypto/src') diff --git a/lib/crypto/src/crypto.erl b/lib/crypto/src/crypto.erl index cc7b3acc9c..c35dfcebab 100644 --- a/lib/crypto/src/crypto.erl +++ b/lib/crypto/src/crypto.erl @@ -28,6 +28,7 @@ %-export([sha256/1, sha256_init/0, sha256_update/2, sha256_final/1]). %-export([sha512/1, sha512_init/0, sha512_update/2, sha512_final/1]). -export([md5_mac/2, md5_mac_96/2, sha_mac/2, sha_mac_96/2]). +-export([hmac_init/2, hmac_update/2, hmac_final/1, hmac_final_n/2]). -export([des_cbc_encrypt/3, des_cbc_decrypt/3, des_cbc_ivec/1]). -export([des_ecb_encrypt/2, des_ecb_decrypt/2]). -export([des3_cbc_encrypt/5, des3_cbc_decrypt/5]). @@ -53,6 +54,7 @@ -export([aes_cbc_256_encrypt/3, aes_cbc_256_decrypt/3]). -export([aes_cbc_ivec/1]). -export([aes_ctr_encrypt/3, aes_ctr_decrypt/3]). +-export([aes_ctr_stream_init/2, aes_ctr_stream_encrypt/2, aes_ctr_stream_decrypt/2]). -export([dh_generate_parameters/2, dh_check/1]). %% Testing see below @@ -64,6 +66,7 @@ %% sha512, sha512_init, sha512_update, sha512_final, md5_mac, md5_mac_96, sha_mac, sha_mac_96, + sha_mac_init, sha_mac_update, sha_mac_final, des_cbc_encrypt, des_cbc_decrypt, des_ecb_encrypt, des_ecb_decrypt, des_ede3_cbc_encrypt, des_ede3_cbc_decrypt, @@ -85,6 +88,7 @@ %% idea_cbc_encrypt, idea_cbc_decrypt, aes_cbc_256_encrypt, aes_cbc_256_decrypt, aes_ctr_encrypt, aes_ctr_decrypt, + aes_ctr_stream_init, aes_ctr_stream_encrypt, aes_ctr_stream_decrypt, info_lib]). -type rsa_digest_type() :: 'md5' | 'sha'. @@ -216,6 +220,19 @@ sha_final(_Context) -> ?nif_stub. %% MESSAGE AUTHENTICATION CODES %% +%% +%% HMAC (multiple hash options) +%% +-spec hmac_init(atom(), iodata()) -> binary(). +-spec hmac_update(binary(), iodata()) -> binary(). +-spec hmac_final(binary()) -> binary(). +-spec hmac_final_n(binary(), integer()) -> binary(). + +hmac_init(_Type, _Key) -> ?nif_stub. +hmac_update(_Context, _Data) -> ? nif_stub. +hmac_final(_Context) -> ? nif_stub. +hmac_final_n(_Context, _HashLen) -> ? nif_stub. + %% %% MD5_MAC %% @@ -243,7 +260,7 @@ sha_mac_96(Key, Data) -> sha_mac_n(Key,Data,12). sha_mac_n(_Key,_Data,_MacSz) -> ?nif_stub. - + %% %% CRYPTO FUNCTIONS %% @@ -578,6 +595,22 @@ aes_cbc_ivec(Data) when is_list(Data) -> aes_ctr_encrypt(_Key, _IVec, _Data) -> ?nif_stub. aes_ctr_decrypt(_Key, _IVec, _Cipher) -> ?nif_stub. +%% +%% AES - in counter mode (CTR) with state maintained for multi-call streaming +%% +-type ctr_state() :: { iodata(), binary(), binary(), integer() }. + +-spec aes_ctr_stream_init(iodata(), binary()) -> ctr_state(). +-spec aes_ctr_stream_encrypt(ctr_state(), binary()) -> + { ctr_state(), binary() }. +-spec aes_ctr_stream_decrypt(ctr_state(), binary()) -> + { ctr_state(), binary() }. + +aes_ctr_stream_init(Key, IVec) -> + {Key, IVec, << 0:128 >>, 0}. +aes_ctr_stream_encrypt({_Key, _IVec, _ECount, _Num}=_State, _Data) -> ?nif_stub. +aes_ctr_stream_decrypt({_Key, _IVec, _ECount, _Num}=_State, _Cipher) -> ?nif_stub. + %% %% XOR - xor to iolists and return a binary %% NB doesn't check that they are the same size, just concatenates -- cgit v1.2.3