386 lines
8.3 KiB
C
386 lines
8.3 KiB
C
/*
|
|
chronyd/chronyc - Programs for keeping computer clocks accurate.
|
|
|
|
**********************************************************************
|
|
* Copyright (C) Richard P. Curnow 1997-2003
|
|
* Copyright (C) Miroslav Lichvar 2012-2014
|
|
*
|
|
* 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.
|
|
*
|
|
**********************************************************************
|
|
|
|
=======================================================================
|
|
|
|
Module for managing keys used for authenticating NTP packets and commands
|
|
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include "sysincl.h"
|
|
|
|
#include "keys.h"
|
|
#include "cmdparse.h"
|
|
#include "conf.h"
|
|
#include "memory.h"
|
|
#include "util.h"
|
|
#include "local.h"
|
|
#include "logging.h"
|
|
|
|
|
|
typedef struct {
|
|
unsigned long id;
|
|
char *val;
|
|
int len;
|
|
int hash_id;
|
|
int auth_delay;
|
|
} Key;
|
|
|
|
#define MAX_KEYS 256
|
|
|
|
static int n_keys;
|
|
static Key keys[MAX_KEYS];
|
|
|
|
static int command_key_valid;
|
|
static int command_key_id;
|
|
static int cache_valid;
|
|
static unsigned long cache_key_id;
|
|
static int cache_key_pos;
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
generate_key(unsigned long key_id)
|
|
{
|
|
#ifdef FEAT_SECHASH
|
|
unsigned char key[20];
|
|
const char *hashname = "SHA1";
|
|
#else
|
|
unsigned char key[16];
|
|
const char *hashname = "MD5";
|
|
#endif
|
|
const char *key_file, *rand_dev = "/dev/urandom";
|
|
FILE *f;
|
|
struct stat st;
|
|
int i;
|
|
|
|
key_file = CNF_GetKeysFile();
|
|
|
|
if (!key_file)
|
|
return 0;
|
|
|
|
f = fopen(rand_dev, "r");
|
|
if (!f || fread(key, sizeof (key), 1, f) != 1) {
|
|
if (f)
|
|
fclose(f);
|
|
LOG_FATAL(LOGF_Keys, "Could not read %s", rand_dev);
|
|
return 0;
|
|
}
|
|
fclose(f);
|
|
|
|
f = fopen(key_file, "a");
|
|
if (!f) {
|
|
LOG_FATAL(LOGF_Keys, "Could not open keyfile %s for writing", key_file);
|
|
return 0;
|
|
}
|
|
|
|
/* Make sure the keyfile is not world-readable */
|
|
if (stat(key_file, &st) || chmod(key_file, st.st_mode & 0770)) {
|
|
fclose(f);
|
|
LOG_FATAL(LOGF_Keys, "Could not change permissions of keyfile %s", key_file);
|
|
return 0;
|
|
}
|
|
|
|
fprintf(f, "\n%lu %s HEX:", key_id, hashname);
|
|
for (i = 0; i < sizeof (key); i++)
|
|
fprintf(f, "%02hhX", key[i]);
|
|
fprintf(f, "\n");
|
|
fclose(f);
|
|
|
|
/* Erase the key from stack */
|
|
memset(key, 0, sizeof (key));
|
|
|
|
LOG(LOGS_INFO, LOGF_Keys, "Generated key %lu", key_id);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
KEY_Initialise(void)
|
|
{
|
|
n_keys = 0;
|
|
command_key_valid = 0;
|
|
cache_valid = 0;
|
|
KEY_Reload();
|
|
|
|
if (CNF_GetGenerateCommandKey() && !KEY_KeyKnown(KEY_GetCommandKey())) {
|
|
if (generate_key(KEY_GetCommandKey()))
|
|
KEY_Reload();
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
KEY_Finalise(void)
|
|
{
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
determine_hash_delay(unsigned long key_id)
|
|
{
|
|
NTP_Packet pkt;
|
|
struct timeval before, after;
|
|
unsigned long usecs, min_usecs=0;
|
|
int i;
|
|
|
|
for (i = 0; i < 10; i++) {
|
|
LCL_ReadRawTime(&before);
|
|
KEY_GenerateAuth(key_id, (unsigned char *)&pkt, NTP_NORMAL_PACKET_SIZE,
|
|
(unsigned char *)&pkt.auth_data, sizeof (pkt.auth_data));
|
|
LCL_ReadRawTime(&after);
|
|
|
|
usecs = (after.tv_sec - before.tv_sec) * 1000000 + (after.tv_usec - before.tv_usec);
|
|
|
|
if (i == 0 || usecs < min_usecs) {
|
|
min_usecs = usecs;
|
|
}
|
|
}
|
|
|
|
/* Add on a bit extra to allow for copying, conversions etc */
|
|
min_usecs += min_usecs >> 4;
|
|
|
|
DEBUG_LOG(LOGF_Keys, "authentication delay for key %lu: %ld useconds", key_id, min_usecs);
|
|
|
|
return min_usecs;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
/* Compare two keys */
|
|
|
|
static int
|
|
compare_keys_by_id(const void *a, const void *b)
|
|
{
|
|
const Key *c = (const Key *) a;
|
|
const Key *d = (const Key *) b;
|
|
|
|
if (c->id < d->id) {
|
|
return -1;
|
|
} else if (c->id > d->id) {
|
|
return +1;
|
|
} else {
|
|
return 0;
|
|
}
|
|
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
KEY_Reload(void)
|
|
{
|
|
int i, line_number;
|
|
FILE *in;
|
|
unsigned long key_id;
|
|
char line[2048], *keyval, *key_file;
|
|
const char *hashname;
|
|
|
|
for (i=0; i<n_keys; i++) {
|
|
Free(keys[i].val);
|
|
}
|
|
n_keys = 0;
|
|
command_key_valid = 0;
|
|
cache_valid = 0;
|
|
|
|
key_file = CNF_GetKeysFile();
|
|
line_number = 0;
|
|
|
|
if (!key_file)
|
|
return;
|
|
|
|
in = fopen(key_file, "r");
|
|
if (!in) {
|
|
LOG(LOGS_WARN, LOGF_Keys, "Could not open keyfile %s", key_file);
|
|
return;
|
|
}
|
|
|
|
while (fgets(line, sizeof (line), in)) {
|
|
line_number++;
|
|
|
|
CPS_NormalizeLine(line);
|
|
if (!*line)
|
|
continue;
|
|
|
|
if (!CPS_ParseKey(line, &key_id, &hashname, &keyval)) {
|
|
LOG(LOGS_WARN, LOGF_Keys, "Could not parse key at line %d in file %s", line_number, key_file);
|
|
continue;
|
|
}
|
|
|
|
keys[n_keys].hash_id = HSH_GetHashId(hashname);
|
|
if (keys[n_keys].hash_id < 0) {
|
|
LOG(LOGS_WARN, LOGF_Keys, "Unknown hash function in key %lu", key_id);
|
|
continue;
|
|
}
|
|
|
|
keys[n_keys].len = UTI_DecodePasswordFromText(keyval);
|
|
if (!keys[n_keys].len) {
|
|
LOG(LOGS_WARN, LOGF_Keys, "Could not decode password in key %lu", key_id);
|
|
continue;
|
|
}
|
|
|
|
keys[n_keys].id = key_id;
|
|
keys[n_keys].val = MallocArray(char, keys[n_keys].len);
|
|
memcpy(keys[n_keys].val, keyval, keys[n_keys].len);
|
|
n_keys++;
|
|
}
|
|
|
|
fclose(in);
|
|
|
|
/* Sort keys into order. Note, if there's a duplicate, it is
|
|
arbitrary which one we use later - the user should have been
|
|
more careful! */
|
|
qsort((void *) keys, n_keys, sizeof(Key), compare_keys_by_id);
|
|
|
|
/* Check for duplicates */
|
|
for (i = 1; i < n_keys; i++) {
|
|
if (keys[i - 1].id == keys[i].id) {
|
|
LOG(LOGS_WARN, LOGF_Keys, "Detected duplicate key %lu", keys[i].id);
|
|
}
|
|
}
|
|
|
|
/* Erase any passwords from stack */
|
|
memset(line, 0, sizeof (line));
|
|
|
|
for (i=0; i<n_keys; i++) {
|
|
keys[i].auth_delay = determine_hash_delay(keys[i].id);
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
lookup_key(unsigned long id)
|
|
{
|
|
Key specimen, *where;
|
|
int pos;
|
|
|
|
specimen.id = id;
|
|
where = (Key *) bsearch((void *)&specimen, (void *)keys, n_keys, sizeof(Key), compare_keys_by_id);
|
|
if (!where) {
|
|
return -1;
|
|
} else {
|
|
pos = where - keys;
|
|
return pos;
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
get_key_pos(unsigned long key_id)
|
|
{
|
|
int position;
|
|
|
|
if (cache_valid && key_id == cache_key_id)
|
|
return cache_key_pos;
|
|
|
|
position = lookup_key(key_id);
|
|
|
|
if (position >= 0) {
|
|
cache_valid = 1;
|
|
cache_key_pos = position;
|
|
cache_key_id = key_id;
|
|
}
|
|
|
|
return position;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
unsigned long
|
|
KEY_GetCommandKey(void)
|
|
{
|
|
if (!command_key_valid) {
|
|
command_key_id = CNF_GetCommandKey();
|
|
}
|
|
|
|
return command_key_id;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
KEY_KeyKnown(unsigned long key_id)
|
|
{
|
|
return get_key_pos(key_id) >= 0;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
KEY_GetAuthDelay(unsigned long key_id)
|
|
{
|
|
int key_pos;
|
|
|
|
key_pos = get_key_pos(key_id);
|
|
|
|
if (key_pos < 0) {
|
|
return 0;
|
|
}
|
|
|
|
return keys[key_pos].auth_delay;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
KEY_GenerateAuth(unsigned long key_id, const unsigned char *data, int data_len,
|
|
unsigned char *auth, int auth_len)
|
|
{
|
|
int key_pos;
|
|
|
|
key_pos = get_key_pos(key_id);
|
|
|
|
if (key_pos < 0) {
|
|
return 0;
|
|
}
|
|
|
|
return UTI_GenerateNTPAuth(keys[key_pos].hash_id,
|
|
(unsigned char *)keys[key_pos].val, keys[key_pos].len,
|
|
data, data_len, auth, auth_len);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
KEY_CheckAuth(unsigned long key_id, const unsigned char *data, int data_len,
|
|
const unsigned char *auth, int auth_len)
|
|
{
|
|
int key_pos;
|
|
|
|
key_pos = get_key_pos(key_id);
|
|
|
|
if (key_pos < 0) {
|
|
return 0;
|
|
}
|
|
|
|
return UTI_CheckNTPAuth(keys[key_pos].hash_id,
|
|
(unsigned char *)keys[key_pos].val, keys[key_pos].len,
|
|
data, data_len, auth, auth_len);
|
|
}
|