# HG changeset patch
# User Adam Chlipala <adam@chlipala.net>
# Date 1309726217 14400
# Node ID 7f8ddcf12b2067b4d2b90727d8cd60f507275178
# Parent  4300592e68039f6028dcc7d42ab9415e2be78dc2
Change Basis.rand to use cryptographically secure generation

diff -r 4300592e6803 -r 7f8ddcf12b20 src/c/urweb.c
--- a/src/c/urweb.c	Sun Jul 03 16:21:04 2011 -0400
+++ b/src/c/urweb.c	Sun Jul 03 16:50:17 2011 -0400
@@ -14,6 +14,7 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <openssl/des.h>
+#include <openssl/rand.h>
 #include <time.h>
 
 #include <pthread.h>
@@ -3777,8 +3778,13 @@
 }
 
 uw_Basis_int uw_Basis_rand(uw_context ctx) {
-  uw_Basis_int n = abs(rand());
-  return n;
+  uw_Basis_int ret;
+  int r = RAND_bytes((unsigned char *)&ret, sizeof ret);
+  
+  if (r)
+    return abs(ret);
+  else
+    uw_error(ctx, FATAL, "Random number generation failed");
 }
 
 void uw_noPostBody(uw_context ctx) {