aboutsummaryrefslogtreecommitdiffstats
path: root/lib/crypto/src/crypto.erl
diff options
context:
space:
mode:
authorGuilherme Andrade <[email protected]>2017-03-18 12:57:19 +0000
committerGuilherme Andrade <[email protected]>2017-03-18 13:03:41 +0000
commite50f63fbb2c974b4b8ad50095ca0b16a846fc161 (patch)
treeb1bc8bc0c335ab4eff625843c49f1d89479de7cb /lib/crypto/src/crypto.erl
parentd07008a0562d1f83dcab144fdec9fd920deb2b96 (diff)
downloadotp-e50f63fbb2c974b4b8ad50095ca0b16a846fc161.tar.gz
otp-e50f63fbb2c974b4b8ad50095ca0b16a846fc161.tar.bz2
otp-e50f63fbb2c974b4b8ad50095ca0b16a846fc161.zip
Restyle crypto strong numeric generators
for usage in rand
Diffstat (limited to 'lib/crypto/src/crypto.erl')
-rw-r--r--lib/crypto/src/crypto.erl52
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) ->