| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2019 IBM Corporation |
| * Author: Nayna Jain |
| * |
| * - loads keys and hashes stored and controlled by the firmware. |
| */ |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/cred.h> |
| #include <linux/err.h> |
| #include <linux/slab.h> |
| #include <asm/secure_boot.h> |
| #include <asm/secvar.h> |
| #include "keyring_handler.h" |
| #include "../integrity.h" |
| |
| /* |
| * Get a certificate list blob from the named secure variable. |
| * |
| * Returns: |
| * - a pointer to a kmalloc'd buffer containing the cert list on success |
| * - NULL if the key does not exist |
| * - an ERR_PTR on error |
| */ |
| static __init void *get_cert_list(u8 *key, unsigned long keylen, u64 *size) |
| { |
| int rc; |
| void *db; |
| |
| rc = secvar_ops->get(key, keylen, NULL, size); |
| if (rc) { |
| if (rc == -ENOENT) |
| return NULL; |
| return ERR_PTR(rc); |
| } |
| |
| db = kmalloc(*size, GFP_KERNEL); |
| if (!db) |
| return ERR_PTR(-ENOMEM); |
| |
| rc = secvar_ops->get(key, keylen, db, size); |
| if (rc) { |
| kfree(db); |
| return ERR_PTR(rc); |
| } |
| |
| return db; |
| } |
| |
| /* |
| * Load the certs contained in the keys databases into the platform trusted |
| * keyring and the blacklisted X.509 cert SHA256 hashes into the blacklist |
| * keyring. |
| */ |
| static int __init load_powerpc_certs(void) |
| { |
| void *db = NULL, *dbx = NULL; |
| u64 dbsize = 0, dbxsize = 0; |
| int rc = 0; |
| ssize_t len; |
| char buf[32]; |
| |
| if (!secvar_ops) |
| return -ENODEV; |
| |
| len = secvar_ops->format(buf, sizeof(buf)); |
| if (len <= 0) |
| return -ENODEV; |
| |
| // Check for known secure boot implementations from OPAL or PLPKS |
| if (strcmp("ibm,edk2-compat-v1", buf) && strcmp("ibm,plpks-sb-v1", buf)) { |
| pr_err("Unsupported secvar implementation \"%s\", not loading certs\n", buf); |
| return -ENODEV; |
| } |
| |
| /* |
| * Get db, and dbx. They might not exist, so it isn't an error if we |
| * can't get them. |
| */ |
| db = get_cert_list("db", 3, &dbsize); |
| if (!db) { |
| pr_info("Couldn't get db list from firmware\n"); |
| } else if (IS_ERR(db)) { |
| rc = PTR_ERR(db); |
| pr_err("Error reading db from firmware: %d\n", rc); |
| return rc; |
| } else { |
| rc = parse_efi_signature_list("powerpc:db", db, dbsize, |
| get_handler_for_db); |
| if (rc) |
| pr_err("Couldn't parse db signatures: %d\n", rc); |
| kfree(db); |
| } |
| |
| dbx = get_cert_list("dbx", 4, &dbxsize); |
| if (!dbx) { |
| pr_info("Couldn't get dbx list from firmware\n"); |
| } else if (IS_ERR(dbx)) { |
| rc = PTR_ERR(dbx); |
| pr_err("Error reading dbx from firmware: %d\n", rc); |
| return rc; |
| } else { |
| rc = parse_efi_signature_list("powerpc:dbx", dbx, dbxsize, |
| get_handler_for_dbx); |
| if (rc) |
| pr_err("Couldn't parse dbx signatures: %d\n", rc); |
| kfree(dbx); |
| } |
| |
| return rc; |
| } |
| late_initcall(load_powerpc_certs); |