Merge branch 'g-andrade/strong-random-numbers/PR-1367/OTP-14317'

* g-andrade/strong-random-numbers/PR-1367/OTP-14317:
  Clean up documentation and test cases
  Attempt faster approach to strong random floats
  Allow for crypto upgrades when using rand plugin
  fixup! Support cryptographically strong rand plugin
  fixup! Support cryptographically strong rand plugin
  fixup! Support cryptographically strong rand plugin
  fixup! Support cryptographically strong rand plugin
  No longer expose strong_rand_(range|float)
  Support cryptographically strong rand plugin
  Restyle crypto strong numeric generators for usage in rand
  Support generation of strong random numbers

1 files changed, 109 insertions, 1 deletions

diff --git a/lib/crypto/test/crypto_SUITE.erl b/lib/crypto/test/crypto_SUITE.erl
index 1d7037d003..1b7456af18 100644
--- a/lib/crypto/test/crypto_SUITE.erl
+++ b/lib/crypto/test/crypto_SUITE.erl
@@ -36,7 +36,9 @@ all() ->
      {group, non_fips},
      mod_pow,
      exor,
-     rand_uniform
+     rand_uniform,
+     rand_plugin,
+     rand_plugin_s
     ].
 
 groups() ->
@@ -486,6 +488,17 @@ rand_uniform(Config) when is_list(Config) ->
     10 = byte_size(crypto:strong_rand_bytes(10)).
 
 %%--------------------------------------------------------------------
+rand_plugin() ->
+    [{doc, "crypto rand plugin testing (implicit state / process dictionary)"}].
+rand_plugin(Config) when is_list(Config) ->
+    rand_plugin_aux(implicit_state).
+
+rand_plugin_s() ->
+    [{doc, "crypto rand plugin testing (explicit state)"}].
+rand_plugin_s(Config) when is_list(Config) ->
+    rand_plugin_aux(explicit_state).
+
+%%--------------------------------------------------------------------
 %% Internal functions ------------------------------------------------
 %%--------------------------------------------------------------------
 hash(_, [], []) ->
@@ -951,6 +964,101 @@ crypto_rand_uniform(L,H) ->
 	    ct:fail({"Not in interval", R1, L, H})
     end.
 
+foldallmap(_Fun, AccN, []) ->
+    {true, AccN};
+foldallmap(Fun, AccN, [H|T]) ->
+    case Fun(H, AccN) of
+        {true, AccM} -> foldallmap(Fun, AccM, T);
+        {{false, Result}, AccM} -> {Result, AccM}
+    end.
+
+allmap(_Fun, []) ->
+    true;
+allmap(Fun, [H|T]) ->
+    case Fun(H) of
+        true -> allmap(Fun, T);
+        {false, Result} -> Result
+    end.
+
+rand_plugin_aux(StateType) ->
+    {Seeder, SeedExporter, FloatGenerator, IntegerGenerator} = rand_plugin_functions(StateType),
+    State0 = Seeder(),
+    {crypto, no_seed} = SeedExporter(State0),
+    {FloatTestResult, State1} = rand_plugin_aux_floats(State0, FloatGenerator),
+    case FloatTestResult of
+        true ->
+            {IntegerTestResult, _State2} = rand_plugin_aux_integers(State1, IntegerGenerator),
+            IntegerTestResult;
+        {false, _} ->
+            FloatTestResult
+    end.
+
+% returns {Seeder, SeedExporter, FloatGenerator, IntegerGenerator} with consistent signatures
+rand_plugin_functions(implicit_state) ->
+    {fun () -> crypto:rand_seed(), implicit_state end,
+     fun (implicit_state) -> rand:export_seed() end,
+     fun (implicit_state) -> {rand:uniform(), implicit_state} end,
+     fun (N, implicit_state) -> {rand:uniform(N), implicit_state} end};
+rand_plugin_functions(explicit_state) ->
+    {fun crypto:rand_seed_s/0,
+     fun rand:export_seed_s/1,
+     fun rand:uniform_s/1,
+     fun rand:uniform_s/2}.
+
+rand_plugin_aux_floats(State0, FloatGenerator) ->
+    {FloatSamples, State1} =
+        lists:mapfoldl(
+          fun (_, StateAcc) ->
+                  FloatGenerator(StateAcc)
+          end,
+          State0,
+          lists:seq(1, 10000)),
+
+    {allmap(
+       fun (V) ->
+               (V >= 0.0 andalso V < 1.0)
+               orelse {false, ct:fail({"Float sample not in interval", V, 0.0, 1.0})}
+       end,
+       FloatSamples),
+     State1}.
+
+rand_plugin_aux_integers(State0, IntegerGenerator) ->
+    MaxIntegerCeiling = 1 bsl 32,
+    {IntegerCeilings, State1} =
+        lists:mapfoldl(
+          fun (_, StateAcc) ->
+                  IntegerGenerator(MaxIntegerCeiling, StateAcc)
+          end,
+          State0,
+          lists:seq(1, 100)),
+
+    foldallmap(
+      fun (Ceiling, StateAcc) ->
+              case Ceiling >= 1 andalso Ceiling =< MaxIntegerCeiling of
+                  false ->
+                      {{false, ct:fail({"Integer ceiling not in interval",
+                                        Ceiling, 1, MaxIntegerCeiling})},
+                       StateAcc};
+                  true ->
+                      foldallmap(
+                        fun (_, SubStateAcc) ->
+                                {Sample, NewSubStateAcc} = IntegerGenerator(Ceiling, SubStateAcc),
+                                case Sample >= 1 andalso Sample =< Ceiling of
+                                    false ->
+                                        {{false, ct:fail({"Integer sample not in interval",
+                                                          Sample, 1, Ceiling})},
+                                         NewSubStateAcc};
+                                    true ->
+                                        {true, NewSubStateAcc}
+                                end
+                        end,
+                        StateAcc,
+                        lists:seq(1, 100))
+              end
+      end,
+      State1,
+      IntegerCeilings).
+
 %%--------------------------------------------------------------------
 %% Test data ------------------------------------------------
 %%--------------------------------------------------------------------