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![Jingoo Han](/assets/img/avatar_default.png)
The usage of strict_strto*() is not preferred, because strict_strto*() is obsolete. Thus, kstrto*() should be used. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
1163 lines
28 KiB
C
1163 lines
28 KiB
C
/*
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* Copyright (C) 2010 IBM Corporation
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*
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* Author:
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* David Safford <safford@us.ibm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, version 2 of the License.
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*
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* See Documentation/security/keys-trusted-encrypted.txt
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*/
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#include <linux/uaccess.h>
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#include <linux/module.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/user-type.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/rcupdate.h>
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#include <linux/crypto.h>
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#include <crypto/hash.h>
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#include <crypto/sha.h>
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#include <linux/capability.h>
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#include <linux/tpm.h>
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#include <linux/tpm_command.h>
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#include "trusted.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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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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sdesc->shash.flags = 0x0;
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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("trusted_key: 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(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("trusted_key: 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(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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static 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 char 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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sdesc = init_sdesc(hashalg);
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if (IS_ERR(sdesc)) {
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pr_info("trusted_key: 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(sdesc);
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return ret;
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}
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/*
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* verify the AUTH1_COMMAND (Seal) result from TPM
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*/
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static 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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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("trusted_key: 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(sdesc);
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return ret;
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}
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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("trusted_key: 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(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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static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
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size_t buflen)
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{
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int rc;
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dump_tpm_buf(cmd);
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rc = tpm_send(chip_num, 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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|
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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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unsigned char hash[SHA1_DIGEST_SIZE];
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int ret;
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|
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE);
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if (ret != SHA1_DIGEST_SIZE)
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return ret;
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return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
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}
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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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|
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ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE);
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if (ret != TPM_NONCE_SIZE)
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return ret;
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|
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INIT_BUF(tb);
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store16(tb, TPM_TAG_RQU_COMMAND);
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store32(tb, TPM_OSAP_SIZE);
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store32(tb, TPM_ORD_OSAP);
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store16(tb, type);
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store32(tb, handle);
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storebytes(tb, ononce, TPM_NONCE_SIZE);
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|
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ret = trusted_tpm_send(TPM_ANY_NUM, 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,
|
|
enonce, TPM_NONCE_SIZE, ononce, 0, 0);
|
|
}
|
|
|
|
/*
|
|
* Create an object independent authorisation protocol (oiap) session
|
|
*/
|
|
static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
|
|
{
|
|
int ret;
|
|
|
|
INIT_BUF(tb);
|
|
store16(tb, TPM_TAG_RQU_COMMAND);
|
|
store32(tb, TPM_OIAP_SIZE);
|
|
store32(tb, TPM_ORD_OIAP);
|
|
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
*handle = LOAD32(tb->data, TPM_DATA_OFFSET);
|
|
memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
|
|
TPM_NONCE_SIZE);
|
|
return 0;
|
|
}
|
|
|
|
struct tpm_digests {
|
|
unsigned char encauth[SHA1_DIGEST_SIZE];
|
|
unsigned char pubauth[SHA1_DIGEST_SIZE];
|
|
unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
|
|
unsigned char xorhash[SHA1_DIGEST_SIZE];
|
|
unsigned char nonceodd[TPM_NONCE_SIZE];
|
|
};
|
|
|
|
/*
|
|
* Have the TPM seal(encrypt) the trusted key, possibly based on
|
|
* Platform Configuration Registers (PCRs). AUTH1 for sealing key.
|
|
*/
|
|
static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
|
|
uint32_t keyhandle, const unsigned char *keyauth,
|
|
const unsigned char *data, uint32_t datalen,
|
|
unsigned char *blob, uint32_t *bloblen,
|
|
const unsigned char *blobauth,
|
|
const unsigned char *pcrinfo, uint32_t pcrinfosize)
|
|
{
|
|
struct osapsess sess;
|
|
struct tpm_digests *td;
|
|
unsigned char cont;
|
|
uint32_t ordinal;
|
|
uint32_t pcrsize;
|
|
uint32_t datsize;
|
|
int sealinfosize;
|
|
int encdatasize;
|
|
int storedsize;
|
|
int ret;
|
|
int i;
|
|
|
|
/* alloc some work space for all the hashes */
|
|
td = kmalloc(sizeof *td, GFP_KERNEL);
|
|
if (!td)
|
|
return -ENOMEM;
|
|
|
|
/* get session for sealing key */
|
|
ret = osap(tb, &sess, keyauth, keytype, keyhandle);
|
|
if (ret < 0)
|
|
goto out;
|
|
dump_sess(&sess);
|
|
|
|
/* calculate encrypted authorization value */
|
|
memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
|
|
memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
|
|
ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE);
|
|
if (ret != TPM_NONCE_SIZE)
|
|
goto out;
|
|
ordinal = htonl(TPM_ORD_SEAL);
|
|
datsize = htonl(datalen);
|
|
pcrsize = htonl(pcrinfosize);
|
|
cont = 0;
|
|
|
|
/* encrypt data authorization key */
|
|
for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
|
|
td->encauth[i] = td->xorhash[i] ^ blobauth[i];
|
|
|
|
/* calculate authorization HMAC value */
|
|
if (pcrinfosize == 0) {
|
|
/* 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 */
|
|
INIT_BUF(tb);
|
|
store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
|
|
store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
|
|
store32(tb, TPM_ORD_SEAL);
|
|
store32(tb, keyhandle);
|
|
storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
|
|
store32(tb, pcrinfosize);
|
|
storebytes(tb, pcrinfo, pcrinfosize);
|
|
store32(tb, datalen);
|
|
storebytes(tb, data, datalen);
|
|
store32(tb, sess.handle);
|
|
storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
|
|
store8(tb, cont);
|
|
storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
|
|
|
|
ret = trusted_tpm_send(TPM_ANY_NUM, 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(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;
|
|
uint32_t keyhndl;
|
|
int ret;
|
|
|
|
/* sessions for unsealing key and data */
|
|
ret = oiap(tb, &authhandle1, enonce1);
|
|
if (ret < 0) {
|
|
pr_info("trusted_key: oiap failed (%d)\n", ret);
|
|
return ret;
|
|
}
|
|
ret = oiap(tb, &authhandle2, enonce2);
|
|
if (ret < 0) {
|
|
pr_info("trusted_key: oiap failed (%d)\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ordinal = htonl(TPM_ORD_UNSEAL);
|
|
keyhndl = htonl(SRKHANDLE);
|
|
ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE);
|
|
if (ret != TPM_NONCE_SIZE) {
|
|
pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
|
|
return ret;
|
|
}
|
|
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 */
|
|
INIT_BUF(tb);
|
|
store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
|
|
store32(tb, TPM_UNSEAL_SIZE + bloblen);
|
|
store32(tb, TPM_ORD_UNSEAL);
|
|
store32(tb, keyhandle);
|
|
storebytes(tb, blob, bloblen);
|
|
store32(tb, authhandle1);
|
|
storebytes(tb, nonceodd, TPM_NONCE_SIZE);
|
|
store8(tb, cont);
|
|
storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
|
|
store32(tb, authhandle2);
|
|
storebytes(tb, nonceodd, TPM_NONCE_SIZE);
|
|
store8(tb, cont);
|
|
storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
|
|
|
|
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
|
|
if (ret < 0) {
|
|
pr_info("trusted_key: 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("trusted_key: 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;
|
|
|
|
tb = kzalloc(sizeof *tb, GFP_KERNEL);
|
|
if (!tb)
|
|
return -ENOMEM;
|
|
|
|
/* 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("trusted_key: srkseal failed (%d)\n", ret);
|
|
|
|
kfree(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;
|
|
|
|
tb = kzalloc(sizeof *tb, GFP_KERNEL);
|
|
if (!tb)
|
|
return -ENOMEM;
|
|
|
|
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("trusted_key: srkunseal failed (%d)\n", ret);
|
|
else
|
|
/* pull migratable flag out of sealed key */
|
|
p->migratable = p->key[--p->key_len];
|
|
|
|
kfree(tb);
|
|
return ret;
|
|
}
|
|
|
|
enum {
|
|
Opt_err = -1,
|
|
Opt_new, Opt_load, Opt_update,
|
|
Opt_keyhandle, Opt_keyauth, Opt_blobauth,
|
|
Opt_pcrinfo, Opt_pcrlock, Opt_migratable
|
|
};
|
|
|
|
static const match_table_t key_tokens = {
|
|
{Opt_new, "new"},
|
|
{Opt_load, "load"},
|
|
{Opt_update, "update"},
|
|
{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_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;
|
|
|
|
while ((p = strsep(&c, " \t"))) {
|
|
if (*p == '\0' || *p == ' ' || *p == '\t')
|
|
continue;
|
|
token = match_token(p, key_tokens, args);
|
|
|
|
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:
|
|
if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
|
|
return -EINVAL;
|
|
res = hex2bin(opt->blobauth, args[0].from,
|
|
SHA1_DIGEST_SIZE);
|
|
if (res < 0)
|
|
return -EINVAL;
|
|
break;
|
|
case Opt_migratable:
|
|
if (*args[0].from == '0')
|
|
pay->migratable = 0;
|
|
else
|
|
return -EINVAL;
|
|
break;
|
|
case Opt_pcrlock:
|
|
res = kstrtoul(args[0].from, 10, &lock);
|
|
if (res < 0)
|
|
return -EINVAL;
|
|
opt->pcrlock = lock;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* datablob_parse - parse the keyctl data and fill in the
|
|
* payload and options structures
|
|
*
|
|
* On success returns 0, otherwise -EINVAL.
|
|
*/
|
|
static int datablob_parse(char *datablob, struct trusted_key_payload *p,
|
|
struct trusted_key_options *o)
|
|
{
|
|
substring_t args[MAX_OPT_ARGS];
|
|
long keylen;
|
|
int ret = -EINVAL;
|
|
int key_cmd;
|
|
char *c;
|
|
|
|
/* main command */
|
|
c = strsep(&datablob, " \t");
|
|
if (!c)
|
|
return -EINVAL;
|
|
key_cmd = match_token(c, key_tokens, args);
|
|
switch (key_cmd) {
|
|
case Opt_new:
|
|
/* first argument is key size */
|
|
c = strsep(&datablob, " \t");
|
|
if (!c)
|
|
return -EINVAL;
|
|
ret = kstrtol(c, 10, &keylen);
|
|
if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
|
|
return -EINVAL;
|
|
p->key_len = keylen;
|
|
ret = getoptions(datablob, p, o);
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = Opt_new;
|
|
break;
|
|
case Opt_load:
|
|
/* first argument is sealed blob */
|
|
c = strsep(&datablob, " \t");
|
|
if (!c)
|
|
return -EINVAL;
|
|
p->blob_len = strlen(c) / 2;
|
|
if (p->blob_len > MAX_BLOB_SIZE)
|
|
return -EINVAL;
|
|
ret = hex2bin(p->blob, c, p->blob_len);
|
|
if (ret < 0)
|
|
return -EINVAL;
|
|
ret = getoptions(datablob, p, o);
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = Opt_load;
|
|
break;
|
|
case Opt_update:
|
|
/* all arguments are options */
|
|
ret = getoptions(datablob, p, o);
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = Opt_update;
|
|
break;
|
|
case Opt_err:
|
|
return -EINVAL;
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static struct trusted_key_options *trusted_options_alloc(void)
|
|
{
|
|
struct trusted_key_options *options;
|
|
|
|
options = kzalloc(sizeof *options, GFP_KERNEL);
|
|
if (options) {
|
|
/* set any non-zero defaults */
|
|
options->keytype = SRK_keytype;
|
|
options->keyhandle = SRKHANDLE;
|
|
}
|
|
return options;
|
|
}
|
|
|
|
static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
|
|
{
|
|
struct trusted_key_payload *p = NULL;
|
|
int ret;
|
|
|
|
ret = key_payload_reserve(key, sizeof *p);
|
|
if (ret < 0)
|
|
return p;
|
|
p = kzalloc(sizeof *p, GFP_KERNEL);
|
|
if (p)
|
|
p->migratable = 1; /* migratable by default */
|
|
return p;
|
|
}
|
|
|
|
/*
|
|
* trusted_instantiate - create a new trusted key
|
|
*
|
|
* Unseal an existing trusted blob or, for a new key, get a
|
|
* random key, then seal and create a trusted key-type key,
|
|
* adding it to the specified keyring.
|
|
*
|
|
* On success, return 0. Otherwise return errno.
|
|
*/
|
|
static int trusted_instantiate(struct key *key,
|
|
struct key_preparsed_payload *prep)
|
|
{
|
|
struct trusted_key_payload *payload = NULL;
|
|
struct trusted_key_options *options = NULL;
|
|
size_t datalen = prep->datalen;
|
|
char *datablob;
|
|
int ret = 0;
|
|
int key_cmd;
|
|
size_t key_len;
|
|
|
|
if (datalen <= 0 || datalen > 32767 || !prep->data)
|
|
return -EINVAL;
|
|
|
|
datablob = kmalloc(datalen + 1, GFP_KERNEL);
|
|
if (!datablob)
|
|
return -ENOMEM;
|
|
memcpy(datablob, prep->data, datalen);
|
|
datablob[datalen] = '\0';
|
|
|
|
options = trusted_options_alloc();
|
|
if (!options) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
payload = trusted_payload_alloc(key);
|
|
if (!payload) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
key_cmd = datablob_parse(datablob, payload, options);
|
|
if (key_cmd < 0) {
|
|
ret = key_cmd;
|
|
goto out;
|
|
}
|
|
|
|
dump_payload(payload);
|
|
dump_options(options);
|
|
|
|
switch (key_cmd) {
|
|
case Opt_load:
|
|
ret = key_unseal(payload, options);
|
|
dump_payload(payload);
|
|
dump_options(options);
|
|
if (ret < 0)
|
|
pr_info("trusted_key: key_unseal failed (%d)\n", ret);
|
|
break;
|
|
case Opt_new:
|
|
key_len = payload->key_len;
|
|
ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len);
|
|
if (ret != key_len) {
|
|
pr_info("trusted_key: key_create failed (%d)\n", ret);
|
|
goto out;
|
|
}
|
|
ret = key_seal(payload, options);
|
|
if (ret < 0)
|
|
pr_info("trusted_key: key_seal failed (%d)\n", ret);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (!ret && options->pcrlock)
|
|
ret = pcrlock(options->pcrlock);
|
|
out:
|
|
kfree(datablob);
|
|
kfree(options);
|
|
if (!ret)
|
|
rcu_assign_keypointer(key, payload);
|
|
else
|
|
kfree(payload);
|
|
return ret;
|
|
}
|
|
|
|
static void trusted_rcu_free(struct rcu_head *rcu)
|
|
{
|
|
struct trusted_key_payload *p;
|
|
|
|
p = container_of(rcu, struct trusted_key_payload, rcu);
|
|
memset(p->key, 0, p->key_len);
|
|
kfree(p);
|
|
}
|
|
|
|
/*
|
|
* trusted_update - reseal an existing key with new PCR values
|
|
*/
|
|
static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
|
|
{
|
|
struct trusted_key_payload *p = key->payload.data;
|
|
struct trusted_key_payload *new_p;
|
|
struct trusted_key_options *new_o;
|
|
size_t datalen = prep->datalen;
|
|
char *datablob;
|
|
int ret = 0;
|
|
|
|
if (!p->migratable)
|
|
return -EPERM;
|
|
if (datalen <= 0 || datalen > 32767 || !prep->data)
|
|
return -EINVAL;
|
|
|
|
datablob = kmalloc(datalen + 1, GFP_KERNEL);
|
|
if (!datablob)
|
|
return -ENOMEM;
|
|
new_o = trusted_options_alloc();
|
|
if (!new_o) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
new_p = trusted_payload_alloc(key);
|
|
if (!new_p) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
memcpy(datablob, prep->data, datalen);
|
|
datablob[datalen] = '\0';
|
|
ret = datablob_parse(datablob, new_p, new_o);
|
|
if (ret != Opt_update) {
|
|
ret = -EINVAL;
|
|
kfree(new_p);
|
|
goto out;
|
|
}
|
|
/* copy old key values, and reseal with new pcrs */
|
|
new_p->migratable = p->migratable;
|
|
new_p->key_len = p->key_len;
|
|
memcpy(new_p->key, p->key, p->key_len);
|
|
dump_payload(p);
|
|
dump_payload(new_p);
|
|
|
|
ret = key_seal(new_p, new_o);
|
|
if (ret < 0) {
|
|
pr_info("trusted_key: key_seal failed (%d)\n", ret);
|
|
kfree(new_p);
|
|
goto out;
|
|
}
|
|
if (new_o->pcrlock) {
|
|
ret = pcrlock(new_o->pcrlock);
|
|
if (ret < 0) {
|
|
pr_info("trusted_key: pcrlock failed (%d)\n", ret);
|
|
kfree(new_p);
|
|
goto out;
|
|
}
|
|
}
|
|
rcu_assign_keypointer(key, new_p);
|
|
call_rcu(&p->rcu, trusted_rcu_free);
|
|
out:
|
|
kfree(datablob);
|
|
kfree(new_o);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* trusted_read - copy the sealed blob data to userspace in hex.
|
|
* On success, return to userspace the trusted key datablob size.
|
|
*/
|
|
static long trusted_read(const struct key *key, char __user *buffer,
|
|
size_t buflen)
|
|
{
|
|
struct trusted_key_payload *p;
|
|
char *ascii_buf;
|
|
char *bufp;
|
|
int i;
|
|
|
|
p = rcu_dereference_key(key);
|
|
if (!p)
|
|
return -EINVAL;
|
|
if (!buffer || buflen <= 0)
|
|
return 2 * p->blob_len;
|
|
ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
|
|
if (!ascii_buf)
|
|
return -ENOMEM;
|
|
|
|
bufp = ascii_buf;
|
|
for (i = 0; i < p->blob_len; i++)
|
|
bufp = hex_byte_pack(bufp, p->blob[i]);
|
|
if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) {
|
|
kfree(ascii_buf);
|
|
return -EFAULT;
|
|
}
|
|
kfree(ascii_buf);
|
|
return 2 * p->blob_len;
|
|
}
|
|
|
|
/*
|
|
* trusted_destroy - before freeing the key, clear the decrypted data
|
|
*/
|
|
static void trusted_destroy(struct key *key)
|
|
{
|
|
struct trusted_key_payload *p = key->payload.data;
|
|
|
|
if (!p)
|
|
return;
|
|
memset(p->key, 0, p->key_len);
|
|
kfree(key->payload.data);
|
|
}
|
|
|
|
struct key_type key_type_trusted = {
|
|
.name = "trusted",
|
|
.instantiate = trusted_instantiate,
|
|
.update = trusted_update,
|
|
.match = user_match,
|
|
.destroy = trusted_destroy,
|
|
.describe = user_describe,
|
|
.read = trusted_read,
|
|
};
|
|
|
|
EXPORT_SYMBOL_GPL(key_type_trusted);
|
|
|
|
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, CRYPTO_ALG_ASYNC);
|
|
if (IS_ERR(hmacalg)) {
|
|
pr_info("trusted_key: could not allocate crypto %s\n",
|
|
hmac_alg);
|
|
return PTR_ERR(hmacalg);
|
|
}
|
|
|
|
hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
|
|
if (IS_ERR(hashalg)) {
|
|
pr_info("trusted_key: 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_trusted(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = trusted_shash_alloc();
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = register_key_type(&key_type_trusted);
|
|
if (ret < 0)
|
|
trusted_shash_release();
|
|
return ret;
|
|
}
|
|
|
|
static void __exit cleanup_trusted(void)
|
|
{
|
|
trusted_shash_release();
|
|
unregister_key_type(&key_type_trusted);
|
|
}
|
|
|
|
late_initcall(init_trusted);
|
|
module_exit(cleanup_trusted);
|
|
|
|
MODULE_LICENSE("GPL");
|