diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /crypto/asymmetric_keys/tpm_parser.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'crypto/asymmetric_keys/tpm_parser.c')
-rw-r--r-- | crypto/asymmetric_keys/tpm_parser.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/crypto/asymmetric_keys/tpm_parser.c b/crypto/asymmetric_keys/tpm_parser.c new file mode 100644 index 000000000..96405d8dc --- /dev/null +++ b/crypto/asymmetric_keys/tpm_parser.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0 +#define pr_fmt(fmt) "TPM-PARSER: "fmt +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <keys/asymmetric-subtype.h> +#include <keys/asymmetric-parser.h> +#include <crypto/asym_tpm_subtype.h> +#include "tpm.asn1.h" + +struct tpm_parse_context { + const void *blob; + u32 blob_len; +}; + +/* + * Note the key data of the ASN.1 blob. + */ +int tpm_note_key(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm_parse_context *ctx = context; + + ctx->blob = value; + ctx->blob_len = vlen; + + return 0; +} + +/* + * Parse a TPM-encrypted private key blob. + */ +static struct tpm_key *tpm_parse(const void *data, size_t datalen) +{ + struct tpm_parse_context ctx; + long ret; + + memset(&ctx, 0, sizeof(ctx)); + + /* Attempt to decode the private key */ + ret = asn1_ber_decoder(&tpm_decoder, &ctx, data, datalen); + if (ret < 0) + goto error; + + return tpm_key_create(ctx.blob, ctx.blob_len); + +error: + return ERR_PTR(ret); +} +/* + * Attempt to parse a data blob for a key as a TPM private key blob. + */ +static int tpm_key_preparse(struct key_preparsed_payload *prep) +{ + struct tpm_key *tk; + + /* + * TPM 1.2 keys are max 2048 bits long, so assume the blob is no + * more than 4x that + */ + if (prep->datalen > 256 * 4) + return -EMSGSIZE; + + tk = tpm_parse(prep->data, prep->datalen); + + if (IS_ERR(tk)) + return PTR_ERR(tk); + + /* We're pinning the module by being linked against it */ + __module_get(asym_tpm_subtype.owner); + prep->payload.data[asym_subtype] = &asym_tpm_subtype; + prep->payload.data[asym_key_ids] = NULL; + prep->payload.data[asym_crypto] = tk; + prep->payload.data[asym_auth] = NULL; + prep->quotalen = 100; + return 0; +} + +static struct asymmetric_key_parser tpm_key_parser = { + .owner = THIS_MODULE, + .name = "tpm_parser", + .parse = tpm_key_preparse, +}; + +static int __init tpm_key_init(void) +{ + return register_asymmetric_key_parser(&tpm_key_parser); +} + +static void __exit tpm_key_exit(void) +{ + unregister_asymmetric_key_parser(&tpm_key_parser); +} + +module_init(tpm_key_init); +module_exit(tpm_key_exit); + +MODULE_DESCRIPTION("TPM private key-blob parser"); +MODULE_LICENSE("GPL v2"); |