Saw a mention somewhere a while back that the gotdata() function in

here could creates non-uniformity since very short fetches of 0 would
be excluded.  blocks of 0 are just as random as any other data, including
blocks of 4 4 4..  This is a misguided attempt to identify errors from the
entropy churn/gather code doesn't make sense, errors don't happen.
ok bcook

1 files changed, 7 insertions, 32 deletions

diff --git a/src/lib/libcrypto/arc4random/getentropy_linux.c b/src/lib/libcrypto/arc4random/getentropy_linux.c
index 408d7fda34..6b220be311 100644
--- a/src/lib/libcrypto/arc4random/getentropy_linux.c
+++ b/src/lib/libcrypto/arc4random/getentropy_linux.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: getentropy_linux.c,v 1.45 2018/03/13 22:53:28 bcook Exp $     */
+/*      $OpenBSD: getentropy_linux.c,v 1.46 2018/11/20 08:04:28 deraadt Exp $   */
 
 /*
  * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
@@ -73,7 +73,6 @@
 
 int     getentropy(void *buf, size_t len);
 
-static int gotdata(char *buf, size_t len);
 #if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
 static int getentropy_getrandom(void *buf, size_t len);
 #endif
@@ -177,22 +176,6 @@ getentropy(void *buf, size_t len)
         return (ret);
 }
 
-/*
- * Basic sanity checking; wish we could do better.
- */
-static int
-gotdata(char *buf, size_t len)
-{
-        char    any_set = 0;
-        size_t  i;
-
-        for (i = 0; i < len; ++i)
-                any_set |= buf[i];
-        if (any_set == 0)
-                return (-1);
-        return (0);
-}
-
 #if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
 static int
 getentropy_getrandom(void *buf, size_t len)
@@ -261,10 +244,8 @@ start:
                 i += ret;
         }
         close(fd);
-        if (gotdata(buf, len) == 0) {
-                errno = save_errno;
-                return (0);             /* satisfied */
-        }
+        errno = save_errno;
+        return (0);             /* satisfied */
 nodevrandom:
         errno = EIO;
         return (-1);
@@ -292,10 +273,8 @@ getentropy_sysctl(void *buf, size_t len)
                         goto sysctlfailed;
                 i += chunk;
         }
-        if (gotdata(buf, len) == 0) {
-                errno = save_errno;
-                return (0);                     /* satisfied */
-        }
+        errno = save_errno;
+        return (0);                     /* satisfied */
 sysctlfailed:
         errno = EIO;
         return (-1);
@@ -541,10 +520,6 @@ getentropy_fallback(void *buf, size_t len)
         }
         explicit_bzero(&ctx, sizeof ctx);
         explicit_bzero(results, sizeof results);
-        if (gotdata(buf, len) == 0) {
-                errno = save_errno;
-                return (0);             /* satisfied */
-        }
-        errno = EIO;
-        return (-1);
+        errno = save_errno;
+        return (0);             /* satisfied */
 }