Rename our getentropy to prevent possible loops.

Since arc4random seeds from getentropy, and we use OpenSSL for that
if enabled, there's the possibility that if we build on a system that
does not have getentropy then run on a system that does have it, then
OpenSSL could end up calling our getentropy and getting stuck in a loop.
Pointed out by deraadt@, ok djm@

1 files changed, 9 insertions, 0 deletions

diff --git a/openbsd-compat/arc4random.c b/openbsd-compat/arc4random.c
index f43b5c7c..2f91c2b2 100644
--- a/openbsd-compat/arc4random.c
+++ b/openbsd-compat/arc4random.c
@@ -35,6 +35,15 @@
 
 #ifndef HAVE_ARC4RANDOM
 
+/*
+ * If we're not using a native getentropy, use the one from bsd-getentropy.c
+ * under a different name, so that if in future these binaries are run on
+ * a system that has a native getentropy OpenSSL cannot call the wrong one.
+ */
+#ifndef HAVE_GETENTROPY
+# define getentropy(x, y) (_ssh_compat_getentropy((x), (y)))
+#endif
+
 #define MINIMUM(a, b)    (((a) < (b)) ? (a) : (b))
 
 #include "log.h"