Mercurial > dropbear
view libtomcrypt/src/mac/f9/f9_memory_multi.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" #include <stdarg.h> /** @file f9_memory_multi.c f9 support, process multiple blocks of memory, Tom St Denis */ #ifdef LTC_F9_MODE /** f9 multiple blocks of memory @param cipher The index of the desired cipher @param key The secret key @param keylen The length of the secret key (octets) @param out [out] The destination of the authentication tag @param outlen [in/out] The max size and resulting size of the authentication tag (octets) @param in The data to send through f9 @param inlen The length of the data to send through f9 (octets) @param ... tuples of (data,len) pairs to f9, terminated with a (NULL,x) (x=don't care) @return CRYPT_OK if successful */ int f9_memory_multi(int cipher, const unsigned char *key, unsigned long keylen, unsigned char *out, unsigned long *outlen, const unsigned char *in, unsigned long inlen, ...) { int err; f9_state *f9; va_list args; const unsigned char *curptr; unsigned long curlen; LTC_ARGCHK(key != NULL); LTC_ARGCHK(in != NULL); LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); /* allocate ram for f9 state */ f9 = XMALLOC(sizeof(f9_state)); if (f9 == NULL) { return CRYPT_MEM; } /* f9 process the message */ if ((err = f9_init(f9, cipher, key, keylen)) != CRYPT_OK) { goto LBL_ERR; } va_start(args, inlen); curptr = in; curlen = inlen; for (;;) { /* process buf */ if ((err = f9_process(f9, curptr, curlen)) != CRYPT_OK) { goto LBL_ERR; } /* step to next */ curptr = va_arg(args, const unsigned char*); if (curptr == NULL) { break; } curlen = va_arg(args, unsigned long); } if ((err = f9_done(f9, out, outlen)) != CRYPT_OK) { goto LBL_ERR; } LBL_ERR: #ifdef LTC_CLEAN_STACK zeromem(f9, sizeof(f9_state)); #endif XFREE(f9); va_end(args); return err; } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */