Mercurial > dropbear
view scpmisc.h @ 1715:3974f087d9c0
Disallow leading lines before the ident for server (#102)
Per RFC4253 4.2 clients must be able to process other lines of data
before the version string, server behavior is not defined neither
with MUST/SHOULD nor with MAY.
If server process up to 50 lines too - it may cause too long hanging
session with invalid/evil client that consume host resources and
potentially may lead to DDoS on poor embedded boxes.
Let's require first line from client to be version string and fail
early if it's not - matches both RFC and real OpenSSH behavior.
author | Vladislav Grishenko <themiron@users.noreply.github.com> |
---|---|
date | Mon, 15 Jun 2020 18:22:18 +0500 |
parents | 292f79307600 |
children |
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/* $OpenBSD: misc.h,v 1.12 2002/03/19 10:49:35 markus Exp $ */ /* * Author: Tatu Ylonen <[email protected]> * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland * All rights reserved * * 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". */ char *chop(char *); char *strdelim(char **); void set_nonblock(int); void unset_nonblock(int); void set_nodelay(int); int a2port(const char *); char *cleanhostname(char *); char *colon(char *); long convtime(const char *); struct passwd *pwcopy(struct passwd *); typedef struct arglist arglist; struct arglist { char **list; u_int num; u_int nalloc; }; void addargs(arglist *, char *, ...); void replacearg(arglist *, u_int, char *, ...); void freeargs(arglist *); /* from xmalloc.h */ void *xmalloc(size_t); void *xrealloc(void *, size_t); void xfree(void *); char *xstrdup(const char *); char *ssh_get_progname(char *); void fatal(char* fmt,...); void sanitise_stdfd(void); /* Required for non-BSD platforms, from OpenSSH's defines.h */ #ifndef timersub #define timersub(a, b, result) \ do { \ (result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \ (result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \ if ((result)->tv_usec < 0) { \ --(result)->tv_sec; \ (result)->tv_usec += 1000000; \ } \ } while (0) #endif #ifndef TIMEVAL_TO_TIMESPEC #define TIMEVAL_TO_TIMESPEC(tv, ts) { \ (ts)->tv_sec = (tv)->tv_sec; \ (ts)->tv_nsec = (tv)->tv_usec * 1000; \ } #endif