#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 "random-util.h"
+#include "user-util.h"
#include "util.h"
_public_ char *sd_id128_to_string(sd_id128_t id, char s[SD_ID128_STRING_MAX]) {
return 0;
}
+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 0;
+
+ 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 1;
+}
+
+_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 try to read the invocation ID from the kernel keyring. This has the benefit that it is not
+ * fakeable by unprivileged code. If the information is not available in the keyring, we use
+ * $INVOCATION_ID but ignore the data if our process was called by less privileged code
+ * (i.e. secure_getenv() instead of getenv()).
+ *
+ * The kernel keyring is only 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). The environment variable is
+ * primarily relevant for user services, and sufficiently safe as no privilege boundary is involved. */
+
+ r = get_invocation_from_keyring(&saved_invocation_id);
+ if (r < 0)
+ return r;
+
+ if (r == 0) {
+ const char *e;
+
+ e = secure_getenv("INVOCATION_ID");
+ if (!e)
+ return -ENXIO;
+
+ r = sd_id128_from_string(e, &saved_invocation_id);
+ if (r < 0)
+ return r;
+ }
+ }
+
+ *ret = saved_invocation_id;
+ return 0;
+}
+
static sd_id128_t make_v4_uuid(sd_id128_t id) {
/* Stolen from generate_random_uuid() of drivers/char/random.c
* in the kernel sources */
*ret = make_v4_uuid(t);
return 0;
}
+
+_public_ int sd_id128_get_machine_app_specific(sd_id128_t app_id, sd_id128_t *ret) {
+ _cleanup_(khash_unrefp) khash *h = NULL;
+ sd_id128_t m, result;
+ const void *p;
+ int r;
+
+ assert_return(ret, -EINVAL);
+
+ r = sd_id128_get_machine(&m);
+ if (r < 0)
+ return r;
+
+ r = khash_new_with_key(&h, "hmac(sha256)", &m, sizeof(m));
+ 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 = make_v4_uuid(result);
+ return 0;
+}
~ianmdlvl / elogind.git / blobdiff