// SPDX-License-Identifier: GPL-2.0-or-later

#include <linux/kernel.h>
#include <linux/key.h>
#include <keys/asymmetric-type.h>

int x509_load_certificate_list(const u8 cert_list[],
                               const unsigned long list_size,
                               const struct key *keyring)
{
        key_ref_t key;
        const u8 *p, *end;
        size_t plen;

        p = cert_list;
        end = p + list_size;
        while (p < end) {
                /* Each cert begins with an ASN.1 SEQUENCE tag and must be more
                 * than 256 bytes in size.
                 */
                if (end - p < 4)
                        goto dodgy_cert;
                if (p[0] != 0x30 &&
                    p[1] != 0x82)
                        goto dodgy_cert;
                plen = (p[2] << 8) | p[3];
                plen += 4;
                if (plen > end - p)
                        goto dodgy_cert;

                key = key_create_or_update(make_key_ref(keyring, 1),
                                           "asymmetric",
                                           NULL,
                                           p,
                                           plen,
                                           ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
                                           KEY_USR_VIEW | KEY_USR_READ),
                                           KEY_ALLOC_NOT_IN_QUOTA |
                                           KEY_ALLOC_BUILT_IN |
                                           KEY_ALLOC_BYPASS_RESTRICTION);
                if (IS_ERR(key)) {
                        pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
                               PTR_ERR(key));
                } else {
                        pr_notice("Loaded X.509 cert '%s'\n",
                                  key_ref_to_ptr(key)->description);
                        key_ref_put(key);
                }
                p += plen;
        }

        return 0;

dodgy_cert:
        pr_err("Problem parsing in-kernel X.509 certificate list\n");
        return 0;
}
EXPORT_SYMBOL_GPL(x509_load_certificate_list);