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, 24 insertions, 9 deletions

diff --git a/lib/stdlib/test/rand_SUITE.erl b/lib/stdlib/test/rand_SUITE.erl
index fe5eaccda5..098eefeb61 100644
--- a/lib/stdlib/test/rand_SUITE.erl
+++ b/lib/stdlib/test/rand_SUITE.erl
@@ -356,14 +356,23 @@ basic_normal_1(0, {#{type:=Alg}, _}, Sum, SumSq) ->
 
 %% Test that the user can write algorithms.
 plugin(Config) when is_list(Config) ->
-    _ = lists:foldl(fun(_, S0) ->
-			    {V1, S1} = rand:uniform_s(10000, S0),
-			    true = is_integer(V1),
-			    {V2, S2} = rand:uniform_s(S1),
-			    true = is_float(V2),
-			    S2
-		    end, crypto_seed(), lists:seq(1, 200)),
-    ok.
+    try crypto:strong_rand_bytes(1) of
+        <<_>> ->
+            _ = lists:foldl(
+                  fun(_, S0) ->
+                          {V1, S1} = rand:uniform_s(10000, S0),
+                          true = is_integer(V1),
+                          {V2, S2} = rand:uniform_s(S1),
+                          true = is_float(V2),
+                          S2
+                  end, crypto_seed(), lists:seq(1, 200)),
+            ok
+    catch
+        error:low_entropy ->
+            {skip,low_entropy};
+        error:undef ->
+            {skip,no_crypto}
+    end.
 
 %% Test implementation
 crypto_seed() ->
@@ -397,7 +406,13 @@ crypto_uniform_n(N, State0) ->
 measure(Suite) when is_atom(Suite) -> [];
 measure(_Config) ->
     ct:timetrap({minutes,15}), %% valgrind needs a lot of time
-    Algos = [crypto64|algs()],
+    Algos =
+        try crypto:strong_rand_bytes(1) of
+            <<_>> -> [crypto64]
+        catch
+            error:low_entropy -> [];
+            error:undef -> []
+        end ++ algs(),
     io:format("RNG uniform integer performance~n",[]),
     _ = measure_1(random, fun(State) -> {int, random:uniform_s(10000, State)} end),
     _ = [measure_1(Algo, fun(State) -> {int, rand:uniform_s(10000, State)} end) || Algo <- Algos],