Mercurial > dropbear
view libtomcrypt/src/hashes/helper/hash_file.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 | 1ff2a1034c52 |
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" #ifndef LTC_NO_FILE /** @file hash_file.c Hash a file, Tom St Denis */ /** @param hash The index of the hash desired @param fname The name of the file you wish to hash @param out [out] The destination of the digest @param outlen [in/out] The max size and resulting size of the message digest @result CRYPT_OK if successful */ int hash_file(int hash, const char *fname, unsigned char *out, unsigned long *outlen) { FILE *in; int err; LTC_ARGCHK(fname != NULL); LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); if ((err = hash_is_valid(hash)) != CRYPT_OK) { return err; } in = fopen(fname, "rb"); if (in == NULL) { return CRYPT_FILE_NOTFOUND; } err = hash_filehandle(hash, in, out, outlen); if (fclose(in) != 0) { return CRYPT_ERROR; } return err; } #endif /* #ifndef LTC_NO_FILE */ /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */