1075 lines
25 KiB
C
1075 lines
25 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2010 IBM Corporation
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* Copyright (c) 2019-2021, Linaro Limited
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*
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* See Documentation/security/keys/trusted-encrypted.rst
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*/
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#include <crypto/hash_info.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/parser.h>
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#include <linux/string.h>
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#include <linux/err.h>
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#include <keys/trusted-type.h>
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#include <linux/key-type.h>
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#include <linux/crypto.h>
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#include <crypto/hash.h>
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#include <crypto/sha1.h>
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#include <linux/tpm.h>
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#include <linux/tpm_command.h>
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#include <keys/trusted_tpm.h>
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static const char hmac_alg[] = "hmac(sha1)";
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static const char hash_alg[] = "sha1";
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static struct tpm_chip *chip;
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static struct tpm_digest *digests;
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struct sdesc {
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struct shash_desc shash;
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char ctx[];
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};
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static struct crypto_shash *hashalg;
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static struct crypto_shash *hmacalg;
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static struct sdesc *init_sdesc(struct crypto_shash *alg)
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{
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struct sdesc *sdesc;
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int size;
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size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
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sdesc = kmalloc(size, GFP_KERNEL);
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if (!sdesc)
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return ERR_PTR(-ENOMEM);
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sdesc->shash.tfm = alg;
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return sdesc;
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}
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static int TSS_sha1(const unsigned char *data, unsigned int datalen,
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unsigned char *digest)
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{
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struct sdesc *sdesc;
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int ret;
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sdesc = init_sdesc(hashalg);
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if (IS_ERR(sdesc)) {
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pr_info("can't alloc %s\n", hash_alg);
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return PTR_ERR(sdesc);
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}
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ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
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kfree_sensitive(sdesc);
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return ret;
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}
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static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
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unsigned int keylen, ...)
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{
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struct sdesc *sdesc;
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va_list argp;
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unsigned int dlen;
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unsigned char *data;
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int ret;
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sdesc = init_sdesc(hmacalg);
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if (IS_ERR(sdesc)) {
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pr_info("can't alloc %s\n", hmac_alg);
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return PTR_ERR(sdesc);
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}
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ret = crypto_shash_setkey(hmacalg, key, keylen);
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if (ret < 0)
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goto out;
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ret = crypto_shash_init(&sdesc->shash);
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if (ret < 0)
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goto out;
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va_start(argp, keylen);
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for (;;) {
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dlen = va_arg(argp, unsigned int);
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if (dlen == 0)
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break;
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data = va_arg(argp, unsigned char *);
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if (data == NULL) {
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ret = -EINVAL;
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break;
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}
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ret = crypto_shash_update(&sdesc->shash, data, dlen);
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if (ret < 0)
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break;
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}
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va_end(argp);
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if (!ret)
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ret = crypto_shash_final(&sdesc->shash, digest);
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out:
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kfree_sensitive(sdesc);
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return ret;
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}
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/*
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* calculate authorization info fields to send to TPM
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*/
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int TSS_authhmac(unsigned char *digest, const unsigned char *key,
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unsigned int keylen, unsigned char *h1,
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unsigned char *h2, unsigned int h3, ...)
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{
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unsigned char paramdigest[SHA1_DIGEST_SIZE];
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struct sdesc *sdesc;
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unsigned int dlen;
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unsigned char *data;
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unsigned char c;
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int ret;
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va_list argp;
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if (!chip)
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return -ENODEV;
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sdesc = init_sdesc(hashalg);
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if (IS_ERR(sdesc)) {
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pr_info("can't alloc %s\n", hash_alg);
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return PTR_ERR(sdesc);
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}
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c = !!h3;
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ret = crypto_shash_init(&sdesc->shash);
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if (ret < 0)
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goto out;
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va_start(argp, h3);
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for (;;) {
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dlen = va_arg(argp, unsigned int);
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if (dlen == 0)
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break;
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data = va_arg(argp, unsigned char *);
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if (!data) {
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ret = -EINVAL;
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break;
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}
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ret = crypto_shash_update(&sdesc->shash, data, dlen);
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if (ret < 0)
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break;
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}
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va_end(argp);
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if (!ret)
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ret = crypto_shash_final(&sdesc->shash, paramdigest);
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if (!ret)
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ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
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paramdigest, TPM_NONCE_SIZE, h1,
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TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
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out:
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kfree_sensitive(sdesc);
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return ret;
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}
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EXPORT_SYMBOL_GPL(TSS_authhmac);
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/*
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* verify the AUTH1_COMMAND (Seal) result from TPM
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*/
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int TSS_checkhmac1(unsigned char *buffer,
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const uint32_t command,
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const unsigned char *ononce,
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const unsigned char *key,
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unsigned int keylen, ...)
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{
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uint32_t bufsize;
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uint16_t tag;
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uint32_t ordinal;
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uint32_t result;
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unsigned char *enonce;
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unsigned char *continueflag;
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unsigned char *authdata;
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unsigned char testhmac[SHA1_DIGEST_SIZE];
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unsigned char paramdigest[SHA1_DIGEST_SIZE];
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struct sdesc *sdesc;
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unsigned int dlen;
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unsigned int dpos;
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va_list argp;
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int ret;
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if (!chip)
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return -ENODEV;
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bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
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tag = LOAD16(buffer, 0);
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ordinal = command;
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result = LOAD32N(buffer, TPM_RETURN_OFFSET);
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if (tag == TPM_TAG_RSP_COMMAND)
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return 0;
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if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
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return -EINVAL;
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authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
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continueflag = authdata - 1;
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enonce = continueflag - TPM_NONCE_SIZE;
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sdesc = init_sdesc(hashalg);
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if (IS_ERR(sdesc)) {
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pr_info("can't alloc %s\n", hash_alg);
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return PTR_ERR(sdesc);
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}
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ret = crypto_shash_init(&sdesc->shash);
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if (ret < 0)
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goto out;
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ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
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sizeof result);
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if (ret < 0)
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goto out;
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ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
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sizeof ordinal);
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if (ret < 0)
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goto out;
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va_start(argp, keylen);
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for (;;) {
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dlen = va_arg(argp, unsigned int);
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if (dlen == 0)
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break;
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dpos = va_arg(argp, unsigned int);
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ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
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if (ret < 0)
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break;
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}
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va_end(argp);
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if (!ret)
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ret = crypto_shash_final(&sdesc->shash, paramdigest);
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if (ret < 0)
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goto out;
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ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
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TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
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1, continueflag, 0, 0);
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if (ret < 0)
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goto out;
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if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
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ret = -EINVAL;
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out:
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kfree_sensitive(sdesc);
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return ret;
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}
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EXPORT_SYMBOL_GPL(TSS_checkhmac1);
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/*
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* verify the AUTH2_COMMAND (unseal) result from TPM
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*/
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static int TSS_checkhmac2(unsigned char *buffer,
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const uint32_t command,
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const unsigned char *ononce,
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const unsigned char *key1,
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unsigned int keylen1,
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const unsigned char *key2,
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unsigned int keylen2, ...)
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{
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uint32_t bufsize;
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uint16_t tag;
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uint32_t ordinal;
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uint32_t result;
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unsigned char *enonce1;
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unsigned char *continueflag1;
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unsigned char *authdata1;
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unsigned char *enonce2;
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unsigned char *continueflag2;
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unsigned char *authdata2;
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unsigned char testhmac1[SHA1_DIGEST_SIZE];
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unsigned char testhmac2[SHA1_DIGEST_SIZE];
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unsigned char paramdigest[SHA1_DIGEST_SIZE];
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struct sdesc *sdesc;
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unsigned int dlen;
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unsigned int dpos;
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va_list argp;
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int ret;
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bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
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tag = LOAD16(buffer, 0);
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ordinal = command;
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result = LOAD32N(buffer, TPM_RETURN_OFFSET);
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if (tag == TPM_TAG_RSP_COMMAND)
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return 0;
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if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
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return -EINVAL;
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authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
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+ SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
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authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
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continueflag1 = authdata1 - 1;
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continueflag2 = authdata2 - 1;
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enonce1 = continueflag1 - TPM_NONCE_SIZE;
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enonce2 = continueflag2 - TPM_NONCE_SIZE;
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sdesc = init_sdesc(hashalg);
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if (IS_ERR(sdesc)) {
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pr_info("can't alloc %s\n", hash_alg);
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return PTR_ERR(sdesc);
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}
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ret = crypto_shash_init(&sdesc->shash);
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if (ret < 0)
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goto out;
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ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
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sizeof result);
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if (ret < 0)
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goto out;
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ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
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sizeof ordinal);
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if (ret < 0)
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goto out;
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va_start(argp, keylen2);
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for (;;) {
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dlen = va_arg(argp, unsigned int);
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if (dlen == 0)
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break;
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dpos = va_arg(argp, unsigned int);
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ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
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if (ret < 0)
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break;
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}
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va_end(argp);
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if (!ret)
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ret = crypto_shash_final(&sdesc->shash, paramdigest);
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if (ret < 0)
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goto out;
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ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
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paramdigest, TPM_NONCE_SIZE, enonce1,
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TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
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if (ret < 0)
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goto out;
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if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
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ret = -EINVAL;
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goto out;
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}
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ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
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paramdigest, TPM_NONCE_SIZE, enonce2,
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TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
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if (ret < 0)
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goto out;
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if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
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ret = -EINVAL;
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out:
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kfree_sensitive(sdesc);
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return ret;
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}
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/*
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* For key specific tpm requests, we will generate and send our
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* own TPM command packets using the drivers send function.
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*/
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int trusted_tpm_send(unsigned char *cmd, size_t buflen)
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{
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int rc;
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if (!chip)
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return -ENODEV;
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dump_tpm_buf(cmd);
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rc = tpm_send(chip, cmd, buflen);
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dump_tpm_buf(cmd);
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if (rc > 0)
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/* Can't return positive return codes values to keyctl */
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rc = -EPERM;
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return rc;
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}
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EXPORT_SYMBOL_GPL(trusted_tpm_send);
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/*
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* Lock a trusted key, by extending a selected PCR.
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*
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* Prevents a trusted key that is sealed to PCRs from being accessed.
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* This uses the tpm driver's extend function.
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*/
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static int pcrlock(const int pcrnum)
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{
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
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}
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/*
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* Create an object specific authorisation protocol (OSAP) session
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*/
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static int osap(struct tpm_buf *tb, struct osapsess *s,
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const unsigned char *key, uint16_t type, uint32_t handle)
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{
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unsigned char enonce[TPM_NONCE_SIZE];
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unsigned char ononce[TPM_NONCE_SIZE];
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int ret;
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ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
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if (ret < 0)
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return ret;
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if (ret != TPM_NONCE_SIZE)
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return -EIO;
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tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
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tpm_buf_append_u16(tb, type);
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tpm_buf_append_u32(tb, handle);
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tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);
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ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
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if (ret < 0)
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return ret;
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s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
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memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
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TPM_NONCE_SIZE);
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memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
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TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
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return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
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enonce, TPM_NONCE_SIZE, ononce, 0, 0);
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}
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/*
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* Create an object independent authorisation protocol (oiap) session
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*/
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int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
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{
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int ret;
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if (!chip)
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return -ENODEV;
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tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
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ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
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if (ret < 0)
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return ret;
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*handle = LOAD32(tb->data, TPM_DATA_OFFSET);
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memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
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TPM_NONCE_SIZE);
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return 0;
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}
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EXPORT_SYMBOL_GPL(oiap);
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struct tpm_digests {
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unsigned char encauth[SHA1_DIGEST_SIZE];
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unsigned char pubauth[SHA1_DIGEST_SIZE];
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unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
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unsigned char xorhash[SHA1_DIGEST_SIZE];
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unsigned char nonceodd[TPM_NONCE_SIZE];
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};
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|
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/*
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* Have the TPM seal(encrypt) the trusted key, possibly based on
|
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* Platform Configuration Registers (PCRs). AUTH1 for sealing key.
|
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*/
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static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
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uint32_t keyhandle, const unsigned char *keyauth,
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const unsigned char *data, uint32_t datalen,
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unsigned char *blob, uint32_t *bloblen,
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const unsigned char *blobauth,
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const unsigned char *pcrinfo, uint32_t pcrinfosize)
|
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{
|
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struct osapsess sess;
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struct tpm_digests *td;
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unsigned char cont;
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uint32_t ordinal;
|
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uint32_t pcrsize;
|
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uint32_t datsize;
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int sealinfosize;
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int encdatasize;
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int storedsize;
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int ret;
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int i;
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|
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/* alloc some work space for all the hashes */
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td = kmalloc(sizeof *td, GFP_KERNEL);
|
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if (!td)
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return -ENOMEM;
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|
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/* get session for sealing key */
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ret = osap(tb, &sess, keyauth, keytype, keyhandle);
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if (ret < 0)
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goto out;
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dump_sess(&sess);
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|
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/* calculate encrypted authorization value */
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memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
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memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
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ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
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if (ret < 0)
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goto out;
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ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
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if (ret < 0)
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goto out;
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|
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if (ret != TPM_NONCE_SIZE) {
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ret = -EIO;
|
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goto out;
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}
|
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|
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ordinal = htonl(TPM_ORD_SEAL);
|
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datsize = htonl(datalen);
|
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pcrsize = htonl(pcrinfosize);
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cont = 0;
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|
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/* encrypt data authorization key */
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for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
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|
td->encauth[i] = td->xorhash[i] ^ blobauth[i];
|
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|
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/* calculate authorization HMAC value */
|
|
if (pcrinfosize == 0) {
|
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/* no pcr info specified */
|
|
ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
|
|
sess.enonce, td->nonceodd, cont,
|
|
sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
|
|
td->encauth, sizeof(uint32_t), &pcrsize,
|
|
sizeof(uint32_t), &datsize, datalen, data, 0,
|
|
0);
|
|
} else {
|
|
/* pcr info specified */
|
|
ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
|
|
sess.enonce, td->nonceodd, cont,
|
|
sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
|
|
td->encauth, sizeof(uint32_t), &pcrsize,
|
|
pcrinfosize, pcrinfo, sizeof(uint32_t),
|
|
&datsize, datalen, data, 0, 0);
|
|
}
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/* build and send the TPM request packet */
|
|
tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
|
|
tpm_buf_append_u32(tb, keyhandle);
|
|
tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
|
|
tpm_buf_append_u32(tb, pcrinfosize);
|
|
tpm_buf_append(tb, pcrinfo, pcrinfosize);
|
|
tpm_buf_append_u32(tb, datalen);
|
|
tpm_buf_append(tb, data, datalen);
|
|
tpm_buf_append_u32(tb, sess.handle);
|
|
tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
|
|
tpm_buf_append_u8(tb, cont);
|
|
tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
|
|
|
|
ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/* calculate the size of the returned Blob */
|
|
sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
|
|
encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
|
|
sizeof(uint32_t) + sealinfosize);
|
|
storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
|
|
sizeof(uint32_t) + encdatasize;
|
|
|
|
/* check the HMAC in the response */
|
|
ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
|
|
SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
|
|
0);
|
|
|
|
/* copy the returned blob to caller */
|
|
if (!ret) {
|
|
memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
|
|
*bloblen = storedsize;
|
|
}
|
|
out:
|
|
kfree_sensitive(td);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* use the AUTH2_COMMAND form of unseal, to authorize both key and blob
|
|
*/
|
|
static int tpm_unseal(struct tpm_buf *tb,
|
|
uint32_t keyhandle, const unsigned char *keyauth,
|
|
const unsigned char *blob, int bloblen,
|
|
const unsigned char *blobauth,
|
|
unsigned char *data, unsigned int *datalen)
|
|
{
|
|
unsigned char nonceodd[TPM_NONCE_SIZE];
|
|
unsigned char enonce1[TPM_NONCE_SIZE];
|
|
unsigned char enonce2[TPM_NONCE_SIZE];
|
|
unsigned char authdata1[SHA1_DIGEST_SIZE];
|
|
unsigned char authdata2[SHA1_DIGEST_SIZE];
|
|
uint32_t authhandle1 = 0;
|
|
uint32_t authhandle2 = 0;
|
|
unsigned char cont = 0;
|
|
uint32_t ordinal;
|
|
int ret;
|
|
|
|
/* sessions for unsealing key and data */
|
|
ret = oiap(tb, &authhandle1, enonce1);
|
|
if (ret < 0) {
|
|
pr_info("oiap failed (%d)\n", ret);
|
|
return ret;
|
|
}
|
|
ret = oiap(tb, &authhandle2, enonce2);
|
|
if (ret < 0) {
|
|
pr_info("oiap failed (%d)\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ordinal = htonl(TPM_ORD_UNSEAL);
|
|
ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (ret != TPM_NONCE_SIZE) {
|
|
pr_info("tpm_get_random failed (%d)\n", ret);
|
|
return -EIO;
|
|
}
|
|
ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
|
|
enonce1, nonceodd, cont, sizeof(uint32_t),
|
|
&ordinal, bloblen, blob, 0, 0);
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
|
|
enonce2, nonceodd, cont, sizeof(uint32_t),
|
|
&ordinal, bloblen, blob, 0, 0);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
/* build and send TPM request packet */
|
|
tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
|
|
tpm_buf_append_u32(tb, keyhandle);
|
|
tpm_buf_append(tb, blob, bloblen);
|
|
tpm_buf_append_u32(tb, authhandle1);
|
|
tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
|
|
tpm_buf_append_u8(tb, cont);
|
|
tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
|
|
tpm_buf_append_u32(tb, authhandle2);
|
|
tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
|
|
tpm_buf_append_u8(tb, cont);
|
|
tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
|
|
|
|
ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
|
|
if (ret < 0) {
|
|
pr_info("authhmac failed (%d)\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
*datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
|
|
ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
|
|
keyauth, SHA1_DIGEST_SIZE,
|
|
blobauth, SHA1_DIGEST_SIZE,
|
|
sizeof(uint32_t), TPM_DATA_OFFSET,
|
|
*datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
|
|
0);
|
|
if (ret < 0) {
|
|
pr_info("TSS_checkhmac2 failed (%d)\n", ret);
|
|
return ret;
|
|
}
|
|
memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Have the TPM seal(encrypt) the symmetric key
|
|
*/
|
|
static int key_seal(struct trusted_key_payload *p,
|
|
struct trusted_key_options *o)
|
|
{
|
|
struct tpm_buf tb;
|
|
int ret;
|
|
|
|
ret = tpm_buf_init(&tb, 0, 0);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* include migratable flag at end of sealed key */
|
|
p->key[p->key_len] = p->migratable;
|
|
|
|
ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
|
|
p->key, p->key_len + 1, p->blob, &p->blob_len,
|
|
o->blobauth, o->pcrinfo, o->pcrinfo_len);
|
|
if (ret < 0)
|
|
pr_info("srkseal failed (%d)\n", ret);
|
|
|
|
tpm_buf_destroy(&tb);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Have the TPM unseal(decrypt) the symmetric key
|
|
*/
|
|
static int key_unseal(struct trusted_key_payload *p,
|
|
struct trusted_key_options *o)
|
|
{
|
|
struct tpm_buf tb;
|
|
int ret;
|
|
|
|
ret = tpm_buf_init(&tb, 0, 0);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
|
|
o->blobauth, p->key, &p->key_len);
|
|
if (ret < 0)
|
|
pr_info("srkunseal failed (%d)\n", ret);
|
|
else
|
|
/* pull migratable flag out of sealed key */
|
|
p->migratable = p->key[--p->key_len];
|
|
|
|
tpm_buf_destroy(&tb);
|
|
return ret;
|
|
}
|
|
|
|
enum {
|
|
Opt_err,
|
|
Opt_keyhandle, Opt_keyauth, Opt_blobauth,
|
|
Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
|
|
Opt_hash,
|
|
Opt_policydigest,
|
|
Opt_policyhandle,
|
|
};
|
|
|
|
static const match_table_t key_tokens = {
|
|
{Opt_keyhandle, "keyhandle=%s"},
|
|
{Opt_keyauth, "keyauth=%s"},
|
|
{Opt_blobauth, "blobauth=%s"},
|
|
{Opt_pcrinfo, "pcrinfo=%s"},
|
|
{Opt_pcrlock, "pcrlock=%s"},
|
|
{Opt_migratable, "migratable=%s"},
|
|
{Opt_hash, "hash=%s"},
|
|
{Opt_policydigest, "policydigest=%s"},
|
|
{Opt_policyhandle, "policyhandle=%s"},
|
|
{Opt_err, NULL}
|
|
};
|
|
|
|
/* can have zero or more token= options */
|
|
static int getoptions(char *c, struct trusted_key_payload *pay,
|
|
struct trusted_key_options *opt)
|
|
{
|
|
substring_t args[MAX_OPT_ARGS];
|
|
char *p = c;
|
|
int token;
|
|
int res;
|
|
unsigned long handle;
|
|
unsigned long lock;
|
|
unsigned long token_mask = 0;
|
|
unsigned int digest_len;
|
|
int i;
|
|
int tpm2;
|
|
|
|
tpm2 = tpm_is_tpm2(chip);
|
|
if (tpm2 < 0)
|
|
return tpm2;
|
|
|
|
opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
|
|
|
|
if (!c)
|
|
return 0;
|
|
|
|
while ((p = strsep(&c, " \t"))) {
|
|
if (*p == '\0' || *p == ' ' || *p == '\t')
|
|
continue;
|
|
token = match_token(p, key_tokens, args);
|
|
if (test_and_set_bit(token, &token_mask))
|
|
return -EINVAL;
|
|
|
|
switch (token) {
|
|
case Opt_pcrinfo:
|
|
opt->pcrinfo_len = strlen(args[0].from) / 2;
|
|
if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
|
|
return -EINVAL;
|
|
res = hex2bin(opt->pcrinfo, args[0].from,
|
|
opt->pcrinfo_len);
|
|
if (res < 0)
|
|
return -EINVAL;
|
|
break;
|
|
case Opt_keyhandle:
|
|
res = kstrtoul(args[0].from, 16, &handle);
|
|
if (res < 0)
|
|
return -EINVAL;
|
|
opt->keytype = SEAL_keytype;
|
|
opt->keyhandle = handle;
|
|
break;
|
|
case Opt_keyauth:
|
|
if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
|
|
return -EINVAL;
|
|
res = hex2bin(opt->keyauth, args[0].from,
|
|
SHA1_DIGEST_SIZE);
|
|
if (res < 0)
|
|
return -EINVAL;
|
|
break;
|
|
case Opt_blobauth:
|
|
/*
|
|
* TPM 1.2 authorizations are sha1 hashes passed in as
|
|
* hex strings. TPM 2.0 authorizations are simple
|
|
* passwords (although it can take a hash as well)
|
|
*/
|
|
opt->blobauth_len = strlen(args[0].from);
|
|
|
|
if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
|
|
res = hex2bin(opt->blobauth, args[0].from,
|
|
TPM_DIGEST_SIZE);
|
|
if (res < 0)
|
|
return -EINVAL;
|
|
|
|
opt->blobauth_len = TPM_DIGEST_SIZE;
|
|
break;
|
|
}
|
|
|
|
if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
|
|
memcpy(opt->blobauth, args[0].from,
|
|
opt->blobauth_len);
|
|
break;
|
|
}
|
|
|
|
return -EINVAL;
|
|
|
|
break;
|
|
|
|
case Opt_migratable:
|
|
if (*args[0].from == '0')
|
|
pay->migratable = 0;
|
|
else if (*args[0].from != '1')
|
|
return -EINVAL;
|
|
break;
|
|
case Opt_pcrlock:
|
|
res = kstrtoul(args[0].from, 10, &lock);
|
|
if (res < 0)
|
|
return -EINVAL;
|
|
opt->pcrlock = lock;
|
|
break;
|
|
case Opt_hash:
|
|
if (test_bit(Opt_policydigest, &token_mask))
|
|
return -EINVAL;
|
|
for (i = 0; i < HASH_ALGO__LAST; i++) {
|
|
if (!strcmp(args[0].from, hash_algo_name[i])) {
|
|
opt->hash = i;
|
|
break;
|
|
}
|
|
}
|
|
if (i == HASH_ALGO__LAST)
|
|
return -EINVAL;
|
|
if (!tpm2 && i != HASH_ALGO_SHA1) {
|
|
pr_info("TPM 1.x only supports SHA-1.\n");
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
case Opt_policydigest:
|
|
digest_len = hash_digest_size[opt->hash];
|
|
if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
|
|
return -EINVAL;
|
|
res = hex2bin(opt->policydigest, args[0].from,
|
|
digest_len);
|
|
if (res < 0)
|
|
return -EINVAL;
|
|
opt->policydigest_len = digest_len;
|
|
break;
|
|
case Opt_policyhandle:
|
|
if (!tpm2)
|
|
return -EINVAL;
|
|
res = kstrtoul(args[0].from, 16, &handle);
|
|
if (res < 0)
|
|
return -EINVAL;
|
|
opt->policyhandle = handle;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct trusted_key_options *trusted_options_alloc(void)
|
|
{
|
|
struct trusted_key_options *options;
|
|
int tpm2;
|
|
|
|
tpm2 = tpm_is_tpm2(chip);
|
|
if (tpm2 < 0)
|
|
return NULL;
|
|
|
|
options = kzalloc(sizeof *options, GFP_KERNEL);
|
|
if (options) {
|
|
/* set any non-zero defaults */
|
|
options->keytype = SRK_keytype;
|
|
|
|
if (!tpm2)
|
|
options->keyhandle = SRKHANDLE;
|
|
}
|
|
return options;
|
|
}
|
|
|
|
static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
|
|
{
|
|
struct trusted_key_options *options = NULL;
|
|
int ret = 0;
|
|
int tpm2;
|
|
|
|
tpm2 = tpm_is_tpm2(chip);
|
|
if (tpm2 < 0)
|
|
return tpm2;
|
|
|
|
options = trusted_options_alloc();
|
|
if (!options)
|
|
return -ENOMEM;
|
|
|
|
ret = getoptions(datablob, p, options);
|
|
if (ret < 0)
|
|
goto out;
|
|
dump_options(options);
|
|
|
|
if (!options->keyhandle && !tpm2) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (tpm2)
|
|
ret = tpm2_seal_trusted(chip, p, options);
|
|
else
|
|
ret = key_seal(p, options);
|
|
if (ret < 0) {
|
|
pr_info("key_seal failed (%d)\n", ret);
|
|
goto out;
|
|
}
|
|
|
|
if (options->pcrlock) {
|
|
ret = pcrlock(options->pcrlock);
|
|
if (ret < 0) {
|
|
pr_info("pcrlock failed (%d)\n", ret);
|
|
goto out;
|
|
}
|
|
}
|
|
out:
|
|
kfree_sensitive(options);
|
|
return ret;
|
|
}
|
|
|
|
static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
|
|
{
|
|
struct trusted_key_options *options = NULL;
|
|
int ret = 0;
|
|
int tpm2;
|
|
|
|
tpm2 = tpm_is_tpm2(chip);
|
|
if (tpm2 < 0)
|
|
return tpm2;
|
|
|
|
options = trusted_options_alloc();
|
|
if (!options)
|
|
return -ENOMEM;
|
|
|
|
ret = getoptions(datablob, p, options);
|
|
if (ret < 0)
|
|
goto out;
|
|
dump_options(options);
|
|
|
|
if (!options->keyhandle && !tpm2) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (tpm2)
|
|
ret = tpm2_unseal_trusted(chip, p, options);
|
|
else
|
|
ret = key_unseal(p, options);
|
|
if (ret < 0)
|
|
pr_info("key_unseal failed (%d)\n", ret);
|
|
|
|
if (options->pcrlock) {
|
|
ret = pcrlock(options->pcrlock);
|
|
if (ret < 0) {
|
|
pr_info("pcrlock failed (%d)\n", ret);
|
|
goto out;
|
|
}
|
|
}
|
|
out:
|
|
kfree_sensitive(options);
|
|
return ret;
|
|
}
|
|
|
|
static int trusted_tpm_get_random(unsigned char *key, size_t key_len)
|
|
{
|
|
return tpm_get_random(chip, key, key_len);
|
|
}
|
|
|
|
static void trusted_shash_release(void)
|
|
{
|
|
if (hashalg)
|
|
crypto_free_shash(hashalg);
|
|
if (hmacalg)
|
|
crypto_free_shash(hmacalg);
|
|
}
|
|
|
|
static int __init trusted_shash_alloc(void)
|
|
{
|
|
int ret;
|
|
|
|
hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
|
|
if (IS_ERR(hmacalg)) {
|
|
pr_info("could not allocate crypto %s\n",
|
|
hmac_alg);
|
|
return PTR_ERR(hmacalg);
|
|
}
|
|
|
|
hashalg = crypto_alloc_shash(hash_alg, 0, 0);
|
|
if (IS_ERR(hashalg)) {
|
|
pr_info("could not allocate crypto %s\n",
|
|
hash_alg);
|
|
ret = PTR_ERR(hashalg);
|
|
goto hashalg_fail;
|
|
}
|
|
|
|
return 0;
|
|
|
|
hashalg_fail:
|
|
crypto_free_shash(hmacalg);
|
|
return ret;
|
|
}
|
|
|
|
static int __init init_digests(void)
|
|
{
|
|
int i;
|
|
|
|
digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
|
|
GFP_KERNEL);
|
|
if (!digests)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i < chip->nr_allocated_banks; i++)
|
|
digests[i].alg_id = chip->allocated_banks[i].alg_id;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init trusted_tpm_init(void)
|
|
{
|
|
int ret;
|
|
|
|
chip = tpm_default_chip();
|
|
if (!chip)
|
|
return -ENODEV;
|
|
|
|
ret = init_digests();
|
|
if (ret < 0)
|
|
goto err_put;
|
|
ret = trusted_shash_alloc();
|
|
if (ret < 0)
|
|
goto err_free;
|
|
ret = register_key_type(&key_type_trusted);
|
|
if (ret < 0)
|
|
goto err_release;
|
|
return 0;
|
|
err_release:
|
|
trusted_shash_release();
|
|
err_free:
|
|
kfree(digests);
|
|
err_put:
|
|
put_device(&chip->dev);
|
|
return ret;
|
|
}
|
|
|
|
static void trusted_tpm_exit(void)
|
|
{
|
|
if (chip) {
|
|
put_device(&chip->dev);
|
|
kfree(digests);
|
|
trusted_shash_release();
|
|
unregister_key_type(&key_type_trusted);
|
|
}
|
|
}
|
|
|
|
struct trusted_key_ops trusted_key_tpm_ops = {
|
|
.migratable = 1, /* migratable by default */
|
|
.init = trusted_tpm_init,
|
|
.seal = trusted_tpm_seal,
|
|
.unseal = trusted_tpm_unseal,
|
|
.get_random = trusted_tpm_get_random,
|
|
.exit = trusted_tpm_exit,
|
|
};
|