diff options
Diffstat (limited to 'lib/crypto/src/crypto.erl')
| -rw-r--r-- | lib/crypto/src/crypto.erl | 52 |
1 files changed, 22 insertions, 30 deletions
diff --git a/lib/crypto/src/crypto.erl b/lib/crypto/src/crypto.erl index 4b386924cb..2c3208a3d5 100644 --- a/lib/crypto/src/crypto.erl +++ b/lib/crypto/src/crypto.erl @@ -30,8 +30,8 @@ -export([hmac/3, hmac/4, hmac_init/2, hmac_update/2, hmac_final/1, hmac_final_n/2]). -export([cmac/3, cmac/4]). -export([exor/2, strong_rand_bytes/1, mod_pow/3]). --export([strong_rand_uniform/0]). --export([strong_rand_uniform/1]). +-export([strong_rand_range/1]). +-export([strong_rand_float/0]). -export([rand_uniform/2]). -export([block_encrypt/3, block_decrypt/3, block_encrypt/4, block_decrypt/4]). -export([next_iv/2, next_iv/3]). @@ -288,8 +288,8 @@ stream_decrypt(State, Data0) -> %% RAND - pseudo random numbers using RN_ and BN_ functions in crypto lib %% -spec strong_rand_bytes(non_neg_integer()) -> binary(). --spec strong_rand_uniform() -> float(). --spec strong_rand_uniform(pos_integer()) -> pos_integer(). +-spec strong_rand_range(pos_integer() | binary()) -> binary(). +-spec strong_rand_float() -> float(). -spec rand_uniform(crypto_integer(), crypto_integer()) -> crypto_integer(). @@ -301,36 +301,28 @@ strong_rand_bytes(Bytes) -> strong_rand_bytes_nif(_Bytes) -> ?nif_stub. -strong_rand_uniform() -> - Sign = 0, % positive - Exponent = 1023, % on the interval [1.0, 2.0[ - Fraction = strong_rand_uniform(1, 1 bsl 52), % the whole interval above (except 1.0) - <<Value:64/big-float>> = <<Sign:1, Exponent:11, Fraction:52>>, - Value - 1.0. - -strong_rand_uniform(N) when is_integer(N), N >= 1 -> - 1 + strong_rand_uniform(0, N). - -strong_rand_uniform(From, To) when is_binary(From), is_binary(To) -> - case strong_rand_uniform_nif(From,To) of +strong_rand_range(Range) when is_integer(Range), Range > 0 -> + BinRange = int_to_bin(Range), + strong_rand_range(BinRange); +strong_rand_range(BinRange) when is_binary(BinRange) -> + case strong_rand_range_nif(BinRange) of false -> erlang:error(low_entropy); - <<Len:32/integer, MSB, Rest/binary>> when MSB > 127 -> - <<(Len + 1):32/integer, 0, MSB, Rest/binary>>; - Whatever -> - Whatever - end; -strong_rand_uniform(From, To) when is_integer(From), is_integer(To), From < To -> - BinFrom = mpint(From), - BinTo = mpint(To), - case strong_rand_uniform(BinFrom, BinTo) of - Result when is_binary(Result) -> - erlint(Result); - Other -> - Other + <<BinResult/binary>> -> + BinResult end. -strong_rand_uniform_nif(_From, _To) -> ?nif_stub. +strong_rand_range_nif(_BinRange) -> ?nif_stub. + + +strong_rand_float() -> + % This could be optimized by having its own NIF + Sign = 0, % positive + Exponent = 1023, % on the interval [1.0, 2.0[ + BinFraction = strong_rand_range(1 bsl 52), % the whole interval above + Fraction = bin_to_int(BinFraction), + <<Value:64/big-float>> = <<Sign:1, Exponent:11, Fraction:52>>, + Value - 1.0. rand_uniform(From,To) when is_binary(From), is_binary(To) -> |