view scpmisc.c @ 1902:4a6725ac957c

Revert "Don't include sk keys at all in KEX list" This reverts git commit f972813ecdc7bb981d25b5a63638bd158f1c8e72. The sk algorithms need to remain in the sigalgs list so that they are included in the server-sig-algs ext-info message sent by the server. RFC8308 for server-sig-algs requires that all algorithms are listed (though OpenSSH client 8.4p1 tested doesn't require that)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 24 Mar 2022 13:42:08 +0800
parents 9579377b5f8b
children
line wrap: on
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/* Dropbear Note: This file is based on OpenSSH 4.3p2. Avoid unnecessary 
   changes to simplify future updates */

/*
 * Copyright (c) 2000 Markus Friedl.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*RCSID("OpenBSD: misc.c,v 1.22 2003/09/18 08:49:45 markus Exp ");*/

/* For xmalloc, xfree etc:
 * Author: Tatu Ylonen <[email protected]>
 * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
 *                    All rights reserved
 * Versions of malloc and friends that check their results, and never return
 * failure (they call fatal if they encounter an error).
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */

/*RCSID("OpenBSD: xmalloc.c,v 1.16 2001/07/23 18:21:46 stevesk Exp ");*/

#define _GNU_SOURCE
#include "includes.h"
#include "scpmisc.h"

void *
xmalloc(size_t size)
{
	void *ptr;

	if (size == 0) {
		fprintf(stderr, "xmalloc: zero size\n");
		exit(EXIT_FAILURE);
	}
	ptr = malloc(size);
	if (ptr == NULL) {
		fprintf(stderr, "xmalloc: out of memory (allocating %lu bytes)\n", (u_long) size);
		exit(EXIT_FAILURE);
	}
	return ptr;
}

void *
xrealloc(void *ptr, size_t new_size)
{
	void *new_ptr;

	if (new_size == 0) {
		fprintf(stderr, "xrealloc: zero size\n");
		exit(EXIT_FAILURE);
	}
	if (ptr == NULL)
		new_ptr = malloc(new_size);
	else
		new_ptr = realloc(ptr, new_size);
	if (new_ptr == NULL) {
		fprintf(stderr, "xrealloc: out of memory (new_size %lu bytes)\n", (u_long) new_size);
		exit(EXIT_FAILURE);
	}
	return new_ptr;
}

void
xfree(void *ptr)
{
	if (ptr == NULL) {
		fprintf(stderr, "xfree: NULL pointer given as argument\n");
		exit(EXIT_FAILURE);
	}
	free(ptr);
}

char *
xstrdup(const char *str)
{
	size_t len;
	char *cp;

	len = strlen(str) + 1;
	cp = xmalloc(len);
	strlcpy(cp, str, len);
	return cp;
}

char *
cleanhostname(char *host)
{
	if (*host == '[' && host[strlen(host) - 1] == ']') {
		host[strlen(host) - 1] = '\0';
		return (host + 1);
	} else
		return host;
}

char *
colon(char *cp)
{
	int flag = 0;

	if (*cp == ':')		/* Leading colon is part of file name. */
		return (0);
	if (*cp == '[')
		flag = 1;

	for (; *cp; ++cp) {
		if (*cp == '@' && *(cp+1) == '[')
			flag = 1;
		if (*cp == ']' && *(cp+1) == ':' && flag)
			return (cp+1);
		if (*cp == ':' && !flag)
			return (cp);
		if (*cp == '/')
			return (0);
	}
	return (0);
}

/* function to assist building execv() arguments */
void
addargs(arglist *args, char *fmt, ...)
{
	va_list ap;
	char *cp;
	u_int nalloc;
	int r;

	va_start(ap, fmt);
	r = vasprintf(&cp, fmt, ap);
	va_end(ap);
	if (r == -1)
		fatal("addargs: argument too long");

	nalloc = args->nalloc;
	if (args->list == NULL) {
		nalloc = 32;
		args->num = 0;
	} else if (args->num+2 >= nalloc)
		nalloc *= 2;

	args->list = xrealloc(args->list, nalloc * sizeof(char *));
	args->nalloc = nalloc;
	args->list[args->num++] = cp;
	args->list[args->num] = NULL;
}

void
replacearg(arglist *args, u_int which, char *fmt, ...)
{
	va_list ap;
	char *cp;
	int r;

	va_start(ap, fmt);
	r = vasprintf(&cp, fmt, ap);
	va_end(ap);
	if (r == -1)
		fatal("replacearg: argument too long");

	if (which >= args->num)
		fatal("replacearg: tried to replace invalid arg %d >= %d",
		    which, args->num);
	xfree(args->list[which]);
	args->list[which] = cp;
}

void
freeargs(arglist *args)
{
	u_int i;

	if (args->list != NULL) {
		for (i = 0; i < args->num; i++)
			xfree(args->list[i]);
		xfree(args->list);
		args->nalloc = args->num = 0;
		args->list = NULL;
	}
}

/*
 * NB. duplicate __progname in case it is an alias for argv[0]
 * Otherwise it may get clobbered by setproctitle()
 */
char *ssh_get_progname(char *argv0)
{
	char *p;

	if (argv0 == NULL)
		return ("unknown");	/* XXX */
	p = strrchr(argv0, '/');
	if (p == NULL)
		p = argv0;
	else
		p++;

	return (xstrdup(p));
}

void fatal(char* fmt,...)
{
	va_list args;
	va_start(args, fmt);
	vfprintf(stderr, fmt, args);
	va_end(args);
	fputc('\n', stderr);
	exit(255);
}

void
sanitise_stdfd(void)
{
	int nullfd, dupfd;

	if ((nullfd = dupfd = open(DROPBEAR_PATH_DEVNULL, O_RDWR)) == -1) {
		fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno));
		exit(1);
	}
	while (++dupfd <= 2) {
		/* Only clobber closed fds */
		if (fcntl(dupfd, F_GETFL, 0) >= 0)
			continue;
		if (dup2(nullfd, dupfd) == -1) {
			fprintf(stderr, "dup2: %s", strerror(errno));
			exit(1);
		}
	}
	if (nullfd > 2)
		close(nullfd);
}