Backport getentropy changes from deraadt@ on MAIN

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

src/lib/libcrypto/arc4random/getentropy_aix.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: getentropy_aix.c,v 1.5 2016/08/07 03:27:21 tb Exp $	*/
+/*	$OpenBSD: getentropy_aix.c,v 1.5.2.1 2018/12/15 15:10:53 bcook Exp $	*/
 
 /*
  * Copyright (c) 2015 Michael Felt <aixtools@gmail.com>
@@ -60,7 +60,6 @@
 
 int	getentropy(void *buf, size_t len);
 
-static int gotdata(char *buf, size_t len);
 static int getentropy_urandom(void *buf, size_t len, const char *path,
     int devfscheck);
 static int getentropy_fallback(void *buf, size_t len);
@@ -118,22 +117,6 @@ 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);
-}
-
 static int
 getentropy_urandom(void *buf, size_t len, const char *path, int devfscheck)
 {
@@ -179,10 +162,8 @@ 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);
@@ -416,10 +397,6 @@ 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 */
 }

src/lib/libcrypto/arc4random/getentropy_hpux.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: getentropy_hpux.c,v 1.5 2016/08/07 03:27:21 tb Exp $	*/
+/*	$OpenBSD: getentropy_hpux.c,v 1.5.2.1 2018/12/15 15:10:53 bcook Exp $	*/
 
 /*
  * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
@@ -64,7 +64,6 @@
 
 int	getentropy(void *buf, size_t len);
 
-static int gotdata(char *buf, size_t len);
 static int getentropy_urandom(void *buf, size_t len, const char *path,
     int devfscheck);
 static int getentropy_fallback(void *buf, size_t len);
@@ -122,22 +121,6 @@ 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);
-}
-
 static int
 getentropy_urandom(void *buf, size_t len, const char *path, int devfscheck)
 {
@@ -183,10 +166,8 @@ 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);
@@ -410,10 +391,6 @@ 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 */
 }

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 1.45.2.1 2018/12/15 15:10:53 bcook 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 */
 }

src/lib/libcrypto/arc4random/getentropy_osx.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: getentropy_osx.c,v 1.11 2016/09/03 15:24:09 bcook Exp $	*/
+/*	$OpenBSD: getentropy_osx.c,v 1.11.2.1 2018/12/15 15:10:53 bcook Exp $	*/
 
 /*
  * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
@@ -82,7 +82,6 @@
 
 int	getentropy(void *buf, size_t len);
 
-static int gotdata(char *buf, size_t len);
 static int getentropy_urandom(void *buf, size_t len);
 static int getentropy_fallback(void *buf, size_t len);
 
@@ -142,22 +141,6 @@ 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);
-}
-
 static int
 getentropy_urandom(void *buf, size_t len)
 {
@@ -203,10 +186,8 @@ 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);
@@ -431,10 +412,6 @@ 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 */
 }

src/lib/libcrypto/arc4random/getentropy_solaris.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: getentropy_solaris.c,v 1.12 2016/08/07 03:27:21 tb Exp $	*/
+/*	$OpenBSD: getentropy_solaris.c,v 1.12.2.1 2018/12/15 15:10:53 bcook Exp $	*/
 
 /*
  * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
@@ -68,7 +68,6 @@
 
 int	getentropy(void *buf, size_t len);
 
-static int gotdata(char *buf, size_t len);
 static int getentropy_urandom(void *buf, size_t len, const char *path,
     int devfscheck);
 static int getentropy_fallback(void *buf, size_t len);
@@ -148,22 +147,6 @@ 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);
-}
-
 static int
 getentropy_urandom(void *buf, size_t len, const char *path, int devfscheck)
 {
@@ -210,10 +193,8 @@ 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);
@@ -436,10 +417,6 @@ 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 */
 }