From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2155) id 83DBD3857029; Sat, 10 Sep 2022 19:01:50 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 83DBD3857029 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1662836510; bh=/+EbOEvXHXVbxZ4lie6yqxO1PKRcBQnS8BSkASKfajI=; h=From:To:Subject:Date:From; b=vF4s1Xh95DSPHyg3DeCcL3RpG+LKmai08tE6tGoIPfM/B0Oyh06fpco+Al5cvYNGZ MDAsU89tk56pnXcYfmiB1BS3ssllE7KPBOBSMks917EhW+LPBuHYRkzyugWkx1jXIx DHrMbJQ/kAZo1cB/M4M8AVy8DmjgyrQk39kVGzio= Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable From: Corinna Vinschen To: newlib-cvs@sourceware.org Subject: [newlib-cygwin] upstream OpenBSD: arc4random: Randomise the rekey interval a little. X-Act-Checkin: newlib-cygwin X-Git-Author: djm X-Git-Refname: refs/heads/master X-Git-Oldrev: f5fece283864fcfe7c690d4e7c1032b616e5d570 X-Git-Newrev: 52a410f9bdd504d94f1e5711ecbf096eaaf9af97 Message-Id: <20220910190150.83DBD3857029@sourceware.org> Date: Sat, 10 Sep 2022 19:01:50 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=3Dnewlib-cygwin.git;h=3D52a410f9bdd= 504d94f1e5711ecbf096eaaf9af97 commit 52a410f9bdd504d94f1e5711ecbf096eaaf9af97 Author: djm Date: Sun Jul 31 05:10:36 2022 +0000 upstream OpenBSD: arc4random: Randomise the rekey interval a little. =20 Previously, the chacha20 instance would be rekeyed every 1.6MB. This makes it happen at a random point somewhere in the 1-2MB range. =20 Feedback deraadt@ visa@, ok tb@ visa@ =20 newlib port: Make REKEY_BASE depend on SIZE_MAX Signed-off-by: Corinna Vinschen Diff: --- newlib/libc/stdlib/arc4random.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/newlib/libc/stdlib/arc4random.c b/newlib/libc/stdlib/arc4rando= m.c index c394f984a..7b6ac8a7a 100644 --- a/newlib/libc/stdlib/arc4random.c +++ b/newlib/libc/stdlib/arc4random.c @@ -1,4 +1,4 @@ -/* $OpenBSD: arc4random.c,v 1.56 2022/02/28 21:56:29 dtucker Exp $ */ +/* $OpenBSD: arc4random.c,v 1.57 2022/07/31 05:10:36 djm Exp $ */ =20 /* * Copyright (c) 1996, David Mazieres @@ -49,6 +49,14 @@ #define BLOCKSZ 64 #define RSBUFSZ (16*BLOCKSZ) =20 +#if SIZE_MAX <=3D 65535 +#define REKEY_BASE ( 32*1024) /* NB. should be a power of 2 */ +#elif SIZE_MAX <=3D 1048575 +#define REKEY_BASE ( 512*1024) /* NB. should be a power of 2 */ +#else +#define REKEY_BASE (1024*1024) /* NB. should be a power of 2 */ +#endif + /* Marked MAP_INHERIT_ZERO, so zero'd out in fork children. */ static struct _rs { size_t rs_have; /* valid bytes at end of rs_buf */ @@ -86,6 +94,7 @@ static void _rs_stir(void) { u_char rnd[KEYSZ + IVSZ]; + uint32_t rekey_fuzz =3D 0; =20 memset(rnd, 0, (KEYSZ + IVSZ) * sizeof(u_char)); =20 @@ -102,8 +111,10 @@ _rs_stir(void) rs->rs_have =3D 0; memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf)); =20 - rs->rs_count =3D (SIZE_MAX <=3D 65535) ? 65000 - : (SIZE_MAX <=3D 1048575 ? 1048000 : 1600000); + /* rekey interval should not be predictable */ + chacha_encrypt_bytes(&rsx->rs_chacha, (uint8_t *)&rekey_fuzz, + (uint8_t *)&rekey_fuzz, sizeof(rekey_fuzz)); + rs->rs_count =3D REKEY_BASE + (rekey_fuzz % REKEY_BASE); } =20 static inline void