chrony/hash_tomcrypt.c
Miroslav Lichvar 4a219ecbf1 hash: drop support for RIPEMD hash functions
An analysis by Tim Ruffing [1] shows that a length extension attack
adding valid extension fields to NTPv4 packets is possible with some
specific key lengths and hash functions using little-endian length like
MD5 and RIPEMD160.

chronyd currently doesn't process or generate any extension fields, but
it could be a problem in future when a non-authentication extension
field is supported.

Drop support for all RIPEMD functions as they don't seem to be secure in
the context of the NTPv4 MAC. MD5 is kept only for compatibility.

[1] https://mailarchive.ietf.org/arch/msg/ntp/gvibuB6bTbDRBumfHNdJ84Kq4kA
2019-09-24 11:32:31 +02:00

121 lines
2.9 KiB
C

/*
chronyd/chronyc - Programs for keeping computer clocks accurate.
**********************************************************************
* Copyright (C) Miroslav Lichvar 2012, 2018
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
**********************************************************************
=======================================================================
Routines implementing crypto hashing using tomcrypt library.
*/
#include <tomcrypt.h>
#include "config.h"
#include "hash.h"
#include "util.h"
struct hash {
const char *name;
const char *int_name;
const struct ltc_hash_descriptor *desc;
};
static const struct hash hashes[] = {
{ "MD5", "md5", &md5_desc },
#ifdef LTC_SHA1
{ "SHA1", "sha1", &sha1_desc },
#endif
#ifdef LTC_SHA256
{ "SHA256", "sha256", &sha256_desc },
#endif
#ifdef LTC_SHA384
{ "SHA384", "sha384", &sha384_desc },
#endif
#ifdef LTC_SHA512
{ "SHA512", "sha512", &sha512_desc },
#endif
#ifdef LTC_SHA3
{ "SHA3-224", "sha3-224", &sha3_224_desc },
{ "SHA3-256", "sha3-256", &sha3_256_desc },
{ "SHA3-384", "sha3-384", &sha3_384_desc },
{ "SHA3-512", "sha3-512", &sha3_512_desc },
#endif
#ifdef LTC_TIGER
{ "TIGER", "tiger", &tiger_desc },
#endif
#ifdef LTC_WHIRLPOOL
{ "WHIRLPOOL", "whirlpool", &whirlpool_desc },
#endif
{ NULL, NULL, NULL }
};
int
HSH_GetHashId(const char *name)
{
int i, h;
for (i = 0; hashes[i].name; i++) {
if (!strcmp(name, hashes[i].name))
break;
}
if (!hashes[i].name)
return -1; /* not found */
h = find_hash(hashes[i].int_name);
if (h >= 0)
return h; /* already registered */
/* register and try again */
register_hash(hashes[i].desc);
return find_hash(hashes[i].int_name);
}
unsigned int
HSH_Hash(int id, const unsigned char *in1, unsigned int in1_len,
const unsigned char *in2, unsigned int in2_len,
unsigned char *out, unsigned int out_len)
{
unsigned char buf[MAX_HASH_LENGTH];
unsigned long len;
int r;
len = sizeof (buf);
if (in2)
r = hash_memory_multi(id, buf, &len,
in1, (unsigned long)in1_len,
in2, (unsigned long)in2_len, NULL, 0);
else
r = hash_memory(id, in1, in1_len, buf, &len);
if (r != CRYPT_OK)
return 0;
len = MIN(len, out_len);
memcpy(out, buf, len);
return len;
}
void
HSH_Finalise(void)
{
}