diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/md/dm-verity-verify-sig.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/md/dm-verity-verify-sig.c')
-rw-r--r-- | drivers/md/dm-verity-verify-sig.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/drivers/md/dm-verity-verify-sig.c b/drivers/md/dm-verity-verify-sig.c new file mode 100644 index 0000000000..4836508ea5 --- /dev/null +++ b/drivers/md/dm-verity-verify-sig.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2019 Microsoft Corporation. + * + * Author: Jaskaran Singh Khurana <jaskarankhurana@linux.microsoft.com> + * + */ +#include <linux/device-mapper.h> +#include <linux/verification.h> +#include <keys/user-type.h> +#include <linux/module.h> +#include "dm-verity.h" +#include "dm-verity-verify-sig.h" + +#define DM_VERITY_VERIFY_ERR(s) DM_VERITY_ROOT_HASH_VERIFICATION " " s + +static bool require_signatures; +module_param(require_signatures, bool, 0444); +MODULE_PARM_DESC(require_signatures, + "Verify the roothash of dm-verity hash tree"); + +#define DM_VERITY_IS_SIG_FORCE_ENABLED() \ + (require_signatures != false) + +bool verity_verify_is_sig_opt_arg(const char *arg_name) +{ + return (!strcasecmp(arg_name, + DM_VERITY_ROOT_HASH_VERIFICATION_OPT_SIG_KEY)); +} + +static int verity_verify_get_sig_from_key(const char *key_desc, + struct dm_verity_sig_opts *sig_opts) +{ + struct key *key; + const struct user_key_payload *ukp; + int ret = 0; + + key = request_key(&key_type_user, + key_desc, NULL); + if (IS_ERR(key)) + return PTR_ERR(key); + + down_read(&key->sem); + + ukp = user_key_payload_locked(key); + if (!ukp) { + ret = -EKEYREVOKED; + goto end; + } + + sig_opts->sig = kmalloc(ukp->datalen, GFP_KERNEL); + if (!sig_opts->sig) { + ret = -ENOMEM; + goto end; + } + sig_opts->sig_size = ukp->datalen; + + memcpy(sig_opts->sig, ukp->data, sig_opts->sig_size); + +end: + up_read(&key->sem); + key_put(key); + + return ret; +} + +int verity_verify_sig_parse_opt_args(struct dm_arg_set *as, + struct dm_verity *v, + struct dm_verity_sig_opts *sig_opts, + unsigned int *argc, + const char *arg_name) +{ + struct dm_target *ti = v->ti; + int ret = 0; + const char *sig_key = NULL; + + if (!*argc) { + ti->error = DM_VERITY_VERIFY_ERR("Signature key not specified"); + return -EINVAL; + } + + sig_key = dm_shift_arg(as); + (*argc)--; + + ret = verity_verify_get_sig_from_key(sig_key, sig_opts); + if (ret < 0) + ti->error = DM_VERITY_VERIFY_ERR("Invalid key specified"); + + v->signature_key_desc = kstrdup(sig_key, GFP_KERNEL); + if (!v->signature_key_desc) + return -ENOMEM; + + return ret; +} + +/* + * verify_verify_roothash - Verify the root hash of the verity hash device + * using builtin trusted keys. + * + * @root_hash: For verity, the roothash/data to be verified. + * @root_hash_len: Size of the roothash/data to be verified. + * @sig_data: The trusted signature that verifies the roothash/data. + * @sig_len: Size of the signature. + * + */ +int verity_verify_root_hash(const void *root_hash, size_t root_hash_len, + const void *sig_data, size_t sig_len) +{ + int ret; + + if (!root_hash || root_hash_len == 0) + return -EINVAL; + + if (!sig_data || sig_len == 0) { + if (DM_VERITY_IS_SIG_FORCE_ENABLED()) + return -ENOKEY; + else + return 0; + } + + ret = verify_pkcs7_signature(root_hash, root_hash_len, sig_data, + sig_len, +#ifdef CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING + VERIFY_USE_SECONDARY_KEYRING, +#else + NULL, +#endif + VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL); + + return ret; +} + +void verity_verify_sig_opts_cleanup(struct dm_verity_sig_opts *sig_opts) +{ + kfree(sig_opts->sig); + sig_opts->sig = NULL; + sig_opts->sig_size = 0; +} |