chrony/test/unit/keys.c
Miroslav Lichvar eae4b2abe5 ntp: drop precompensation of TX timestamp
The daemon transmit timestamps are precompensated for the time it takes
to generate a MAC using a symmetric key (as measured on chronyd start)
and also an average round-trip time of the Samba signing of MS-SNTP
responses. This improves accuracy of the transmit timestamp, but it
has some issues.

The correction has a random error which is changing over time due to
variable CPU frequency, system load, migration to a different machine,
etc. If the measured delay is too large, the correction may cause the
transmit timestamp to be later than the actual transmission. Also, the
delay is measured for a packet of a minimal length with no extension
fields, and there is no support for NTS.

Drop the precompensation in favor of the interleaved mode, which now
avoids the authentication delay even when no kernel/hardware timestamps
are available.
2020-07-09 14:46:57 +02:00

173 lines
4.1 KiB
C

/*
**********************************************************************
* Copyright (C) Miroslav Lichvar 2017
*
* 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.
*
**********************************************************************
*/
#include <config.h>
#include "test.h"
#if defined(FEAT_NTP) || defined(FEAT_CMDMON)
#include <keys.c>
#define KEYS 100
#define KEYFILE "keys.test-keys"
static
uint32_t write_random_key(FILE *f)
{
const char *type, *prefix;
char key[128];
uint32_t id;
int i, length;
length = random() % sizeof (key) + 1;
length = MAX(length, 4);
prefix = random() % 2 ? "HEX:" : "";
switch (random() % 8) {
#ifdef FEAT_SECHASH
case 0:
type = "SHA1";
break;
case 1:
type = "SHA256";
break;
case 2:
type = "SHA384";
break;
case 3:
type = "SHA512";
break;
#endif
#ifdef HAVE_CMAC
case 4:
type = "AES128";
length = prefix[0] == '\0' ? 8 : 16;
break;
case 5:
type = "AES256";
length = prefix[0] == '\0' ? 16 : 32;
break;
#endif
case 6:
type = "MD5";
break;
default:
type = "";
}
UTI_GetRandomBytes(&id, sizeof (id));
UTI_GetRandomBytes(key, length);
fprintf(f, "%u %s %s", id, type, prefix);
for (i = 0; i < length; i++)
fprintf(f, "%02hhX", key[i]);
fprintf(f, "\n");
return id;
}
static void
generate_key_file(const char *name, uint32_t *keys)
{
FILE *f;
int i;
f = fopen(name, "w");
TEST_CHECK(f);
for (i = 0; i < KEYS; i++)
keys[i] = write_random_key(f);
fclose(f);
}
void
test_unit(void)
{
int i, j, data_len, auth_len, type, bits;
uint32_t keys[KEYS], key;
unsigned char data[100], auth[MAX_HASH_LENGTH];
char conf[][100] = {
"keyfile "KEYFILE
};
CNF_Initialise(0, 0);
for (i = 0; i < sizeof conf / sizeof conf[0]; i++)
CNF_ParseLine(NULL, i + 1, conf[i]);
generate_key_file(KEYFILE, keys);
KEY_Initialise();
for (i = 0; i < 100; i++) {
DEBUG_LOG("iteration %d", i);
if (i) {
generate_key_file(KEYFILE, keys);
KEY_Reload();
}
UTI_GetRandomBytes(data, sizeof (data));
for (j = 0; j < KEYS; j++) {
TEST_CHECK(KEY_KeyKnown(keys[j]));
TEST_CHECK(KEY_GetAuthLength(keys[j]) >= 16);
data_len = random() % (sizeof (data) + 1);
auth_len = KEY_GenerateAuth(keys[j], data, data_len, auth, sizeof (auth));
TEST_CHECK(auth_len >= 16);
TEST_CHECK(KEY_CheckAuth(keys[j], data, data_len, auth, auth_len, auth_len));
if (j > 0 && keys[j - 1] != keys[j])
TEST_CHECK(!KEY_CheckAuth(keys[j - 1], data, data_len, auth, auth_len, auth_len));
auth_len = random() % auth_len + 1;
if (auth_len < MAX_HASH_LENGTH)
auth[auth_len]++;
TEST_CHECK(KEY_CheckAuth(keys[j], data, data_len, auth, auth_len, auth_len));
auth[auth_len - 1]++;
TEST_CHECK(!KEY_CheckAuth(keys[j], data, data_len, auth, auth_len, auth_len));
TEST_CHECK(KEY_GetKeyInfo(keys[j], &type, &bits));
TEST_CHECK(type > 0 && bits > 0);
}
for (j = 0; j < 1000; j++) {
UTI_GetRandomBytes(&key, sizeof (key));
if (KEY_KeyKnown(key))
continue;
TEST_CHECK(!KEY_GetKeyInfo(key, &type, &bits));
TEST_CHECK(!KEY_GenerateAuth(key, data, data_len, auth, sizeof (auth)));
TEST_CHECK(!KEY_CheckAuth(key, data, data_len, auth, auth_len, auth_len));
}
}
unlink(KEYFILE);
KEY_Finalise();
CNF_Finalise();
HSH_Finalise();
}
#else
void
test_unit(void)
{
TEST_REQUIRE(0);
}
#endif