Mercurial > dropbear
view libtomcrypt/src/headers/tomcrypt_argchk.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 | 1ff2a1034c52 |
children |
line wrap: on
line source
/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. */ /* Defines the LTC_ARGCHK macro used within the library */ /* ARGTYPE is defined in tomcrypt_cfg.h */ #if ARGTYPE == 0 #include <signal.h> /* portability macros for compiler-specific code attributes */ #ifdef __GNUC__ #define ATTRIB_NORETURN __attribute__((noreturn)) #else #define ATTRIB_NORETURN #endif /* this is the default LibTomCrypt macro */ #if defined(__clang__) || defined(__GNUC_MINOR__) #define NORETURN __attribute__ ((noreturn)) #else #define NORETURN #endif void crypt_argchk(const char *v, const char *s, int d) NORETURN; #define LTC_ARGCHK(x) do { if (!(x)) { crypt_argchk(#x, __FILE__, __LINE__); } }while(0) #define LTC_ARGCHKVD(x) do { if (!(x)) { crypt_argchk(#x, __FILE__, __LINE__); } }while(0) #elif ARGTYPE == 1 /* fatal type of error */ #define LTC_ARGCHK(x) assert((x)) #define LTC_ARGCHKVD(x) LTC_ARGCHK(x) #elif ARGTYPE == 2 #define LTC_ARGCHK(x) if (!(x)) { fprintf(stderr, "\nwarning: ARGCHK failed at %s:%d\n", __FILE__, __LINE__); } #define LTC_ARGCHKVD(x) LTC_ARGCHK(x) #elif ARGTYPE == 3 #define LTC_ARGCHK(x) #define LTC_ARGCHKVD(x) LTC_ARGCHK(x) #elif ARGTYPE == 4 #define LTC_ARGCHK(x) if (!(x)) return CRYPT_INVALID_ARG; #define LTC_ARGCHKVD(x) if (!(x)) return; #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */