From: beware <beware@bircd.org>
Date: Fri, 21 Jun 2024 10:12:58 +0000 (+0000)
Subject: add linux syscall sys_getrandom to lcorernd
X-Git-Url: http://www.lcore.org/git/lcore.git/commitdiff_plain

add linux syscall sys_getrandom to lcorernd
---

diff --git a/lcorernd.pas b/lcorernd.pas
index b435305..b7a3bf2 100644
--- a/lcorernd.pas
+++ b/lcorernd.pas
@@ -144,6 +144,9 @@ uses
       baseunix,unix,unixutil,sockets,
     {$endif}
   {$endif}
+  {$ifdef linux}
+  syscall,
+  {$endif}
   fastmd5,sysutils;
 {$endif}
 
@@ -282,6 +285,17 @@ begin
 end;
 
 
+{$ifdef linux}
+ {$ifdef i386}
+  const sys_getrandom = 355;
+ {$endif}
+
+ {$ifdef cpux64}
+  const sys_getrandom = 318;
+ {$endif}
+{$endif}
+
+
 function collect_seeding(var output;const bufsize:integer):integer;
 var
   f:file;
@@ -298,24 +312,30 @@ begin
   if (bufsize < sizeof(l)) then exit;
   result := sizeof(l);
 
-  {/DEV/URANDOM}
-  a := 1;
-  assignfile(f,'/dev/urandom');
-  filemode := 0;
-  {$i-}reset(f,1);{$i+}
-  a := ioresult;
-  if (a <> 0) then begin
-    assignfile(f,'/dev/random');
+  a := -1;
+  {$ifdef linux}
+  a := do_syscall(sys_getrandom,tsysparam(@l.devrnd),sizeof(l.devrnd),0);
+  {$endif}
+
+  if (a < sizeof(l.devrnd)) then begin
+    {if syscall misses or fails, fall back to /dev/urandom}
+    assignfile(f,'/dev/urandom');
+    filemode := 0;
     {$i-}reset(f,1);{$i+}
     a := ioresult;
-  end;
-  if (a = 0) then begin
-    blockread(f,l.devrnd,sizeof(l.devrnd));
-    closefile(f);
-  end else begin
-    {the OS we are on has no /dev/random or /dev/urandom, get a hash from /var/log/wtmp}
-    wtmphash;
-    move(wtmpcached,l.devrnd,sizeof(l.devrnd));
+    if (a <> 0) then begin
+      assignfile(f,'/dev/random');
+      {$i-}reset(f,1);{$i+}
+      a := ioresult;
+    end;
+    if (a = 0) then begin
+      blockread(f,l.devrnd,sizeof(l.devrnd));
+      closefile(f);
+    end else begin
+      {the OS we are on has no /dev/random or /dev/urandom, get a hash from /var/log/wtmp}
+      wtmphash;
+      move(wtmpcached,l.devrnd,sizeof(l.devrnd));
+    end;
   end;
   {get more randomness in case there's no /dev/random}
   rdtsc(@l.rdtscbuf);