From f505644be64cd4844742b361a8ff411d70f4aa88 Mon Sep 17 00:00:00 2001 From: Niclas Eklund Date: Fri, 15 Apr 2011 15:49:42 +0200 Subject: Adds NIFs for cryptographically strong random number generation. Also adds documentation and unit tests. Thanks to Geoff Cant. --- lib/crypto/src/crypto.erl | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'lib/crypto/src') diff --git a/lib/crypto/src/crypto.erl b/lib/crypto/src/crypto.erl index d6e2e033c0..153c7833a9 100644 --- a/lib/crypto/src/crypto.erl +++ b/lib/crypto/src/crypto.erl @@ -46,6 +46,7 @@ -export([rsa_private_encrypt/3, rsa_public_decrypt/3]). -export([dh_generate_key/1, dh_generate_key/2, dh_compute_key/3]). -export([rand_bytes/1, rand_bytes/3, rand_uniform/2]). +-export([strong_rand_bytes/1, strong_rand_uniform/3]). -export([mod_exp/3, mpint/1, erlint/1]). %% -export([idea_cbc_encrypt/3, idea_cbc_decrypt/3]). -export([aes_cbc_128_encrypt/3, aes_cbc_128_decrypt/3]). @@ -68,6 +69,8 @@ des_ede3_cbc_encrypt, des_ede3_cbc_decrypt, aes_cfb_128_encrypt, aes_cfb_128_decrypt, rand_bytes, + strong_rand_bytes, + strong_rand_uniform, rand_uniform, mod_exp, dss_verify,dss_sign, @@ -361,11 +364,23 @@ aes_cfb_128_crypt(_Key, _IVec, _Data, _IsEncrypt) -> ?nif_stub. %% RAND - pseudo random numbers using RN_ functions in crypto lib %% -spec rand_bytes(non_neg_integer()) -> binary(). +-spec strong_rand_bytes(non_neg_integer()) -> binary(). -spec rand_uniform(crypto_integer(), crypto_integer()) -> crypto_integer(). +-spec strong_rand_uniform(Bits::non_neg_integer(), + Top::-1..1, + Bottom::0..1) -> binary(). rand_bytes(_Bytes) -> ?nif_stub. +strong_rand_bytes(Bytes) -> + case strong_rand_bytes_nif(Bytes) of + false -> erlang:error(low_entropy); + Bin -> Bin + end. +strong_rand_bytes_nif(_Bytes) -> ?nif_stub. + rand_bytes(_Bytes, _Topmask, _Bottommask) -> ?nif_stub. +strong_rand_uniform(_Bytes, _Topmask, _Bottommask) -> ?nif_stub. rand_uniform(From,To) when is_binary(From), is_binary(To) -> case rand_uniform_nif(From,To) of -- cgit v1.2.3