[newlib-cygwin] Delete Cygwin's arc4random in favor of new Newlib implementation

[Corinna Vinschen <corinna at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=e0fc33322d507c0730b1d1517eb4b85181f0a2d9

commit e0fc33322d507c0730b1d1517eb4b85181f0a2d9
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Fri Mar 18 14:41:33 2016 +0100

    Delete Cygwin's arc4random in favor of new Newlib implementation
    
    	* Makefile.in (DLL_OFILES): Remove arc4random.o.
    	* libc/arc4random.c: Remove file.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/Makefile.in        |   1 -
 winsup/cygwin/libc/arc4random.cc | 363 ---------------------------------------
 2 files changed, 364 deletions(-)

diff --git a/winsup/cygwin/Makefile.in b/winsup/cygwin/Makefile.in
index fac9b3e..c6131d1 100644
--- a/winsup/cygwin/Makefile.in
+++ b/winsup/cygwin/Makefile.in
@@ -155,7 +155,6 @@ MT_SAFE_OBJECTS:=
 #
 DLL_OFILES:= \
 	advapi32.o \
-	arc4random.o \
 	assert.o \
 	autoload.o \
 	base64.o \
diff --git a/winsup/cygwin/libc/arc4random.cc b/winsup/cygwin/libc/arc4random.cc
deleted file mode 100644
index 2a38b13..0000000
--- a/winsup/cygwin/libc/arc4random.cc
+++ /dev/null
@@ -1,363 +0,0 @@
-/*	$OpenBSD: arc4random.c,v 1.22 2010/12/22 08:23:42 otto Exp $	*/
-
-/*
- * Copyright (c) 1996, David Mazieres <dm@uun.org>
- * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-/*
- * Arc4 random number generator for OpenBSD.
- *
- * This code is derived from section 17.1 of Applied Cryptography,
- * second edition, which describes a stream cipher allegedly
- * compatible with RSA Labs "RC4" cipher (the actual description of
- * which is a trade secret).  The same algorithm is used as a stream
- * cipher called "arcfour" in Tatu Ylonen's ssh package.
- *
- * RC4 is a registered trademark of RSA Laboratories.
- */
-
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/lib/libc/gen/arc4random.c,v 1.30 2012/11/17 01:49:23 svnexp Exp $");
-
-#ifdef __CYGWIN__
-#include "winsup.h"
-#include "sync.h"
-#else
-#include "namespace.h"
-#endif
-#include <fcntl.h>
-#include <limits.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/param.h>
-#ifndef __CYGWIN__
-#include <sys/sysctl.h>
-#endif
-#include <sys/time.h>
-#include <pthread.h>
-
-#ifndef __CYGWIN__
-#include "libc_private.h"
-#include "un-namespace.h"
-#endif
-
-#ifdef __CYGWIN__
-#define _open open
-#define _read read
-#define _close close
-#endif
-
-#ifdef __GNUC__
-#define inline __inline
-#else				/* !__GNUC__ */
-#define inline
-#endif				/* !__GNUC__ */
-
-struct arc4_stream {
-	u_int8_t i;
-	u_int8_t j;
-	u_int8_t s[256];
-};
-
-#ifdef __CYGWIN__
-static NO_COPY muto arc4random_mtx;
-#else
-static pthread_mutex_t	arc4random_mtx = PTHREAD_MUTEX_INITIALIZER;
-#endif
-
-#define	RANDOMDEV	"/dev/random"
-#define	KEYSIZE		128
-#ifdef __CYGWIN__
-#define _ARC4_LOCK()						\
-	do {							\
-		if (__isthreaded)				\
-			arc4random_mtx.init ("arc4random_mtx")->acquire (); \
-	} while (0)
-#define _ARC4_UNLOCK()						\
-	do {							\
-		if (__isthreaded)				\
-			arc4random_mtx.release ();		\
-	} while (0)
-#else
-#define	_ARC4_LOCK()						\
-	do {							\
-		if (__isthreaded)				\
-			_pthread_mutex_lock(&arc4random_mtx);	\
-	} while (0)
-
-#define	_ARC4_UNLOCK()						\
-	do {							\
-		if (__isthreaded)				\
-			_pthread_mutex_unlock(&arc4random_mtx);	\
-	} while (0)
-#endif
-
-static int rs_initialized;
-static struct arc4_stream rs;
-static pid_t arc4_stir_pid;
-static int arc4_count;
-
-#ifndef __CYGWIN__
-extern int __sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
-    void *newp, size_t newlen);
-#endif
-
-static inline u_int8_t arc4_getbyte(void);
-static void arc4_stir(void);
-
-static inline void
-arc4_init(void)
-{
-	int     n;
-
-	for (n = 0; n < 256; n++)
-		rs.s[n] = n;
-	rs.i = 0;
-	rs.j = 0;
-}
-
-static inline void
-arc4_addrandom(u_char *dat, int datlen)
-{
-	int     n;
-	u_int8_t si;
-
-	rs.i--;
-	for (n = 0; n < 256; n++) {
-		rs.i = (rs.i + 1);
-		si = rs.s[rs.i];
-		rs.j = (rs.j + si + dat[n % datlen]);
-		rs.s[rs.i] = rs.s[rs.j];
-		rs.s[rs.j] = si;
-	}
-	rs.j = rs.i;
-}
-
-#ifndef __CYGWIN__
-static size_t
-arc4_sysctl(u_char *buf, size_t size)
-{
-	int mib[2];
-	size_t len, done;
-
-	mib[0] = CTL_KERN;
-	mib[1] = KERN_ARND;
-	done = 0;
-
-	do {
-		len = size;
-		if (__sysctl(mib, 2, buf, &len, NULL, 0) == -1)
-			return (done);
-		done += len;
-		buf += len;
-		size -= len;
-	} while (size > 0);
-
-	return (done);
-}
-#endif
-
-static void
-arc4_stir(void)
-{
-	int done, fd, i;
-	struct {
-		struct timeval	tv;
-		pid_t		pid;
-		u_char	 	rnd[KEYSIZE];
-	} rdat;
-
-	if (!rs_initialized) {
-		arc4_init();
-		rs_initialized = 1;
-	}
-	done = 0;
-#ifndef __CYGWIN__
-	if (arc4_sysctl((u_char *)&rdat, KEYSIZE) == KEYSIZE)
-		done = 1;
-#endif
-	if (!done) {
-		fd = _open(RANDOMDEV, O_RDONLY | O_CLOEXEC, 0);
-		if (fd >= 0) {
-			if (_read(fd, &rdat, KEYSIZE) == KEYSIZE)
-				done = 1;
-			(void)_close(fd);
-		}
-	}
-	if (!done) {
-		(void)gettimeofday(&rdat.tv, NULL);
-		rdat.pid = getpid();
-		/* We'll just take whatever was on the stack too... */
-	}
-
-	arc4_addrandom((u_char *)&rdat, KEYSIZE);
-
-	/*
-	 * Discard early keystream, as per recommendations in:
-	 * "(Not So) Random Shuffles of RC4" by Ilya Mironov.
-	 */
-	for (i = 0; i < 1024; i++)
-		(void)arc4_getbyte();
-	arc4_count = 1600000;
-}
-
-static void
-arc4_stir_if_needed(void)
-{
-	pid_t pid = getpid();
-
-	if (arc4_count <= 0 || !rs_initialized || arc4_stir_pid != pid)
-	{
-		arc4_stir_pid = pid;
-		arc4_stir();
-	}
-}
-
-static inline u_int8_t
-arc4_getbyte(void)
-{
-	u_int8_t si, sj;
-
-	rs.i = (rs.i + 1);
-	si = rs.s[rs.i];
-	rs.j = (rs.j + si);
-	sj = rs.s[rs.j];
-	rs.s[rs.i] = sj;
-	rs.s[rs.j] = si;
-	return (rs.s[(si + sj) & 0xff]);
-}
-
-static inline u_int32_t
-arc4_getword(void)
-{
-	u_int32_t val;
-	val = arc4_getbyte() << 24;
-	val |= arc4_getbyte() << 16;
-	val |= arc4_getbyte() << 8;
-	val |= arc4_getbyte();
-	return val;
-}
-
-void
-arc4random_stir(void)
-{
-	_ARC4_LOCK();
-	arc4_stir();
-	_ARC4_UNLOCK();
-}
-
-void
-arc4random_addrandom(u_char *dat, int datlen)
-{
-	_ARC4_LOCK();
-	if (!rs_initialized)
-		arc4_stir();
-	arc4_addrandom(dat, datlen);
-	_ARC4_UNLOCK();
-}
-
-u_int32_t
-arc4random(void)
-{
-	u_int32_t val;
-	_ARC4_LOCK();
-	arc4_count -= 4;
-	arc4_stir_if_needed();
-	val = arc4_getword();
-	_ARC4_UNLOCK();
-	return val;
-}
-
-void
-arc4random_buf(void *_buf, size_t n)
-{
-	u_char *buf = (u_char *)_buf;
-	_ARC4_LOCK();
-	arc4_stir_if_needed();
-	while (n--) {
-		if (--arc4_count <= 0)
-			arc4_stir();
-		buf[n] = arc4_getbyte();
-	}
-	_ARC4_UNLOCK();
-}
-
-/*
- * Calculate a uniformly distributed random number less than upper_bound
- * avoiding "modulo bias".
- *
- * Uniformity is achieved by generating new random numbers until the one
- * returned is outside the range [0, 2**32 % upper_bound).  This
- * guarantees the selected random number will be inside
- * [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
- * after reduction modulo upper_bound.
- */
-u_int32_t
-arc4random_uniform(u_int32_t upper_bound)
-{
-	u_int32_t r, min;
-
-	if (upper_bound < 2)
-		return 0;
-
-#if (ULONG_MAX > 0xffffffffUL)
-	min = 0x100000000UL % upper_bound;
-#else
-	/* Calculate (2**32 % upper_bound) avoiding 64-bit math */
-	if (upper_bound > 0x80000000)
-		min = 1 + ~upper_bound;		/* 2**32 - upper_bound */
-	else {
-		/* (2**32 - (x * 2)) % x == 2**32 % x when x <= 2**31 */
-		min = ((0xffffffff - (upper_bound * 2)) + 1) % upper_bound;
-	}
-#endif
-
-	/*
-	 * This could theoretically loop forever but each retry has
-	 * p > 0.5 (worst case, usually far better) of selecting a
-	 * number inside the range we need, so it should rarely need
-	 * to re-roll.
-	 */
-	for (;;) {
-		r = arc4random();
-		if (r >= min)
-			break;
-	}
-
-	return r % upper_bound;
-}
-
-#if 0
-/*-------- Test code for i386 --------*/
-#include <stdio.h>
-#include <machine/pctr.h>
-int
-main(int argc, char **argv)
-{
-	const int iter = 1000000;
-	int     i;
-	pctrval v;
-
-	v = rdtsc();
-	for (i = 0; i < iter; i++)
-		arc4random();
-	v = rdtsc() - v;
-	v /= iter;
-
-	printf("%qd cycles\n", v);
-}
-#endif