Mercurial > dropbear
view libtomcrypt/src/misc/compare_testvector.c @ 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 | 6dba84798cd5 |
children |
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/* 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. */ #include "tomcrypt.h" /** @file compare_testvector.c Function to compare two testvectors and print a (detailed) error-message if required, Steffen Jaeckel */ #if defined(LTC_TEST) && defined(LTC_TEST_DBG) static void _print_hex(const char* what, const void* v, const unsigned long l) { const unsigned char* p = v; unsigned long x, y = 0, z; fprintf(stderr, "%s contents: \n", what); for (x = 0; x < l; ) { fprintf(stderr, "%02X ", p[x]); if (!(++x % 16) || x == l) { if((x % 16) != 0) { z = 16 - (x % 16); if(z >= 8) fprintf(stderr, " "); for (; z != 0; --z) { fprintf(stderr, " "); } } fprintf(stderr, " | "); for(; y < x; y++) { if((y % 8) == 0) fprintf(stderr, " "); if(isgraph(p[y])) fprintf(stderr, "%c", p[y]); else fprintf(stderr, "."); } fprintf(stderr, "\n"); } else if((x % 8) == 0) { fprintf(stderr, " "); } } } #endif /** Compare two test-vectors @param is The data as it is @param is_len The length of is @param should The data as it should @param should_len The length of should @param what The type of the data @param which The iteration count @return 0 on equality, -1 or 1 on difference */ int compare_testvector(const void* is, const unsigned long is_len, const void* should, const unsigned long should_len, const char* what, int which) { int res = 0; if(is_len != should_len) res = is_len > should_len ? -1 : 1; else res = XMEMCMP(is, should, is_len); #if defined(LTC_TEST) && defined(LTC_TEST_DBG) if (res != 0) { fprintf(stderr, "Testvector #%i of %s failed:\n", which, what); _print_hex("SHOULD", should, should_len); _print_hex("IS ", is, is_len); } #else LTC_UNUSED_PARAM(which); LTC_UNUSED_PARAM(what); #endif return res; } /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */