Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 340 insertions, 0 deletions

diff --git a/src/libsystemd/sd-id128/sd-id128.c b/src/libsystemd/sd-id128/sd-id128.c
new file mode 100644
index 0000000..e72af15
--- /dev/null
+++ b/src/libsystemd/sd-id128/sd-id128.c
@@ -0,0 +1,340 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#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.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_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;
+}
+
+_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;
+}
+
+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 */
+
+        /* Set UUID version to 4 --- truly random generation */
+        id.bytes[6] = (id.bytes[6] & 0x0F) | 0x40;
+
+        /* Set the UUID variant to DCE */
+        id.bytes[8] = (id.bytes[8] & 0x3F) | 0x80;
+
+        return id;
+}
+
+_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 = 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 = 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);
+}