^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) #define pr_fmt(fmt) "TPM-PARSER: "fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <keys/asymmetric-subtype.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <keys/asymmetric-parser.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <crypto/asym_tpm_subtype.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include "tpm.asn1.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) struct tpm_parse_context {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) const void *blob;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) u32 blob_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * Note the key data of the ASN.1 blob.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) int tpm_note_key(void *context, size_t hdrlen,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) unsigned char tag,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) const void *value, size_t vlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) struct tpm_parse_context *ctx = context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) ctx->blob = value;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) ctx->blob_len = vlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * Parse a TPM-encrypted private key blob.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static struct tpm_key *tpm_parse(const void *data, size_t datalen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) struct tpm_parse_context ctx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) long ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) memset(&ctx, 0, sizeof(ctx));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) /* Attempt to decode the private key */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) ret = asn1_ber_decoder(&tpm_decoder, &ctx, data, datalen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) return tpm_key_create(ctx.blob, ctx.blob_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) return ERR_PTR(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) * Attempt to parse a data blob for a key as a TPM private key blob.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) static int tpm_key_preparse(struct key_preparsed_payload *prep)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) struct tpm_key *tk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * TPM 1.2 keys are max 2048 bits long, so assume the blob is no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * more than 4x that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) if (prep->datalen > 256 * 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) return -EMSGSIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) tk = tpm_parse(prep->data, prep->datalen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) if (IS_ERR(tk))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) return PTR_ERR(tk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) /* We're pinning the module by being linked against it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) __module_get(asym_tpm_subtype.owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) prep->payload.data[asym_subtype] = &asym_tpm_subtype;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) prep->payload.data[asym_key_ids] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) prep->payload.data[asym_crypto] = tk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) prep->payload.data[asym_auth] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) prep->quotalen = 100;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) static struct asymmetric_key_parser tpm_key_parser = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) .owner = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) .name = "tpm_parser",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) .parse = tpm_key_preparse,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) static int __init tpm_key_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) return register_asymmetric_key_parser(&tpm_key_parser);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) static void __exit tpm_key_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) unregister_asymmetric_key_parser(&tpm_key_parser);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) module_init(tpm_key_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) module_exit(tpm_key_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) MODULE_DESCRIPTION("TPM private key-blob parser");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) MODULE_LICENSE("GPL v2");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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