global-functions: $GetRandomNumber: use $GetRandomSha256

1 files changed, 12 insertions, 6 deletions

diff --git a/global-functions b/global-functions
index e6b40ba..149838b 100644
--- a/global-functions
+++ b/global-functions
@@ -305,16 +305,22 @@
 }
 
 # generate random number
-# Warning: This is a *very* weak algorithm and in *no way*
-# useful for cryptography or similar!
 :set GetRandomNumber do={
   :local Max ([ :tonum $1 ] + 1);
-  :local Sum 0;
 
-  :foreach Interface in=[ /interface find ] do={
-    :set Sum ($Sum + [ /interface get $Interface tx-byte ]);
+  :global GetRandomSha256;
+
+  :local Num;
+  :local Sha256 [ $GetRandomSha256 ];
+
+  :for I from=0 to=63 do={
+    :local Char [ :pick $Sha256 $I ];
+    :if ($Char~"[0-9]") do={
+      :set Num ($Num . $Char);
+    }
   }
-  :return ($Sum % $Max);
+
+  :return ([ :tonum [ :pick $Num 0 18 ] ] % $Max);
 }
 
 # generate random sha256 string