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 */


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