/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "nm-sd-adapt-core.h"
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include "sd-id128.h"
#include "alloc-util.h"
#include "fd-util.h"
#include "hexdecoct.h"
#include "id128-util.h"
#include "io-util.h"
#include "khash.h"
#include "macro.h"
#include "missing_syscall.h"
#include "random-util.h"
#include "user-util.h"
#include "util.h"
#if 0 /* NM_IGNORED */
_public_ char *sd_id128_to_string(sd_id128_t id, char s[_SD_ARRAY_STATIC SD_ID128_STRING_MAX]) {
unsigned n;
assert_return(s, NULL);
for (n = 0; n < 16; n++) {
s[n*2] = hexchar(id.bytes[n] >> 4);
s[n*2+1] = hexchar(id.bytes[n] & 0xF);
}
s[32] = 0;
return s;
}
#endif /* NM_IGNORED */
_public_ int sd_id128_from_string(const char s[], sd_id128_t *ret) {
unsigned n, i;
sd_id128_t t;
bool is_guid = false;
assert_return(s, -EINVAL);
for (n = 0, i = 0; n < 16;) {
int a, b;
if (s[i] == '-') {
/* Is this a GUID? Then be nice, and skip over
* the dashes */
if (i == 8)
is_guid = true;
else if (IN_SET(i, 13, 18, 23)) {
if (!is_guid)
return -EINVAL;
} else
return -EINVAL;
i++;
continue;
}
a = unhexchar(s[i++]);
if (a < 0)
return -EINVAL;
b = unhexchar(s[i++]);
if (b < 0)
return -EINVAL;
t.bytes[n++] = (a << 4) | b;
}
if (i != (is_guid ? 36 : 32))
return -EINVAL;
if (s[i] != 0)
return -EINVAL;
if (ret)
*ret = t;
return 0;
}
_public_ int sd_id128_get_machine(sd_id128_t *ret) {
static thread_local sd_id128_t saved_machine_id = {};
int r;
assert_return(ret, -EINVAL);
if (sd_id128_is_null(saved_machine_id)) {
r = id128_read("/etc/machine-id", ID128_PLAIN, &saved_machine_id);
if (r < 0)
return r;
if (sd_id128_is_null(saved_machine_id))
return -ENOMEDIUM;
}
*ret = saved_machine_id;
return 0;
}
_public_ int sd_id128_get_boot(sd_id128_t *ret) {
static thread_local sd_id128_t saved_boot_id = {};
int r;
assert_return(ret, -EINVAL);
if (sd_id128_is_null(saved_boot_id)) {
r = id128_read("/proc/sys/kernel/random/boot_id", ID128_UUID, &saved_boot_id);
if (r < 0)
return r;
}
*ret = saved_boot_id;
return 0;
}
#if 0 /* NM_IGNORED */
static int get_invocation_from_keyring(sd_id128_t *ret) {
_cleanup_free_ char *description = NULL;
char *d, *p, *g, *u, *e;
unsigned long perms;
key_serial_t key;
size_t sz = 256;
uid_t uid;
gid_t gid;
int r, c;
#define MAX_PERMS ((unsigned long) (KEY_POS_VIEW|KEY_POS_READ|KEY_POS_SEARCH| \
KEY_USR_VIEW|KEY_USR_READ|KEY_USR_SEARCH))
assert(ret);
key = request_key("user", "invocation_id", NULL, 0);
if (key == -1) {
/* Keyring support not available? No invocation key stored? */
if (IN_SET(errno, ENOSYS, ENOKEY))
return -ENXIO;
return -errno;
}
for (;;) {
description = new(char, sz);
if (!description)
return -ENOMEM;
c = keyctl(KEYCTL_DESCRIBE, key, (unsigned long) description, sz, 0);
if (c < 0)
return -errno;
if ((size_t) c <= sz)
break;
sz = c;
free(description);
}
/* The kernel returns a final NUL in the string, verify that. */
assert(description[c-1] == 0);
/* Chop off the final description string */
d = strrchr(description, ';');
if (!d)
return -EIO;
*d = 0;
/* Look for the permissions */
p = strrchr(description, ';');
if (!p)
return -EIO;
errno = 0;
perms = strtoul(p + 1, &e, 16);
if (errno > 0)
return -errno;
if (e == p + 1) /* Read at least one character */
return -EIO;
if (e != d) /* Must reached the end */
return -EIO;
if ((perms & ~MAX_PERMS) != 0)
return -EPERM;
*p = 0;
/* Look for the group ID */
g = strrchr(description, ';');
if (!g)
return -EIO;
r = parse_gid(g + 1, &gid);
if (r < 0)
return r;
if (gid != 0)
return -EPERM;
*g = 0;
/* Look for the user ID */
u = strrchr(description, ';');
if (!u)
return -EIO;
r = parse_uid(u + 1, &uid);
if (r < 0)
return r;
if (uid != 0)
return -EPERM;
c = keyctl(KEYCTL_READ, key, (unsigned long) ret, sizeof(sd_id128_t), 0);
if (c < 0)
return -errno;
if (c != sizeof(sd_id128_t))
return -EIO;
return 0;
}
static int get_invocation_from_environment(sd_id128_t *ret) {
const char *e;
assert(ret);
e = secure_getenv("INVOCATION_ID");
if (!e)
return -ENXIO;
return sd_id128_from_string(e, ret);
}
_public_ int sd_id128_get_invocation(sd_id128_t *ret) {
static thread_local sd_id128_t saved_invocation_id = {};
int r;
assert_return(ret, -EINVAL);
if (sd_id128_is_null(saved_invocation_id)) {
/* We first check the environment. The environment variable is primarily relevant for user
* services, and sufficiently safe as long as no privilege boundary is involved. */
r = get_invocation_from_environment(&saved_invocation_id);
if (r < 0 && r != -ENXIO)
return r;
/* The kernel keyring is relevant for system services (as for user services we don't store
* the invocation ID in the keyring, as there'd be no trust benefit in that). */
r = get_invocation_from_keyring(&saved_invocation_id);
if (r < 0)
return r;
}
*ret = saved_invocation_id;
return 0;
}
_public_ int sd_id128_randomize(sd_id128_t *ret) {
sd_id128_t t;
int r;
assert_return(ret, -EINVAL);
/* We allow usage if x86-64 RDRAND here. It might not be trusted enough for keeping secrets, but it should be
* fine for UUIDS. */
r = genuine_random_bytes(&t, sizeof t, RANDOM_ALLOW_RDRAND);
if (r < 0)
return r;
/* Turn this into a valid v4 UUID, to be nice. Note that we
* only guarantee this for newly generated UUIDs, not for
* pre-existing ones. */
*ret = id128_make_v4_uuid(t);
return 0;
}
static int get_app_specific(sd_id128_t base, sd_id128_t app_id, sd_id128_t *ret) {
_cleanup_(khash_unrefp) khash *h = NULL;
sd_id128_t result;
const void *p;
int r;
assert(ret);
r = khash_new_with_key(&h, "hmac(sha256)", &base, sizeof(base));
if (r < 0)
return r;
r = khash_put(h, &app_id, sizeof(app_id));
if (r < 0)
return r;
r = khash_digest_data(h, &p);
if (r < 0)
return r;
/* We chop off the trailing 16 bytes */
memcpy(&result, p, MIN(khash_get_size(h), sizeof(result)));
*ret = id128_make_v4_uuid(result);
return 0;
}
_public_ int sd_id128_get_machine_app_specific(sd_id128_t app_id, sd_id128_t *ret) {
sd_id128_t id;
int r;
assert_return(ret, -EINVAL);
r = sd_id128_get_machine(&id);
if (r < 0)
return r;
return get_app_specific(id, app_id, ret);
}
_public_ int sd_id128_get_boot_app_specific(sd_id128_t app_id, sd_id128_t *ret) {
sd_id128_t id;
int r;
assert_return(ret, -EINVAL);
r = sd_id128_get_boot(&id);
if (r < 0)
return r;
return get_app_specific(id, app_id, ret);
}
#endif /* NM_IGNORED */