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![Greg Kroah-Hartman](/assets/img/avatar_default.png)
The function derive_pub_key() should be calling memzero_explicit() instead of memset() in case the complier decides to optimize away the call to memset() because it "knows" no one is going to touch the memory anymore. Cc: stable <stable@vger.kernel.org> Reported-by: Ilil Blum Shem-Tov <ilil.blum.shem-tov@intel.com> Tested-by: Ilil Blum Shem-Tov <ilil.blum.shem-tov@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/X8ns4AfwjKudpyfe@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
957 lines
22 KiB
C
957 lines
22 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#define pr_fmt(fmt) "ASYM-TPM: "fmt
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/export.h>
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#include <linux/kernel.h>
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#include <linux/seq_file.h>
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#include <linux/scatterlist.h>
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#include <linux/tpm.h>
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#include <linux/tpm_command.h>
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#include <crypto/akcipher.h>
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#include <crypto/hash.h>
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#include <crypto/sha1.h>
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#include <asm/unaligned.h>
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#include <keys/asymmetric-subtype.h>
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#include <keys/trusted_tpm.h>
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#include <crypto/asym_tpm_subtype.h>
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#include <crypto/public_key.h>
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#define TPM_ORD_FLUSHSPECIFIC 186
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#define TPM_ORD_LOADKEY2 65
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#define TPM_ORD_UNBIND 30
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#define TPM_ORD_SIGN 60
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#define TPM_RT_KEY 0x00000001
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/*
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* Load a TPM key from the blob provided by userspace
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*/
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static int tpm_loadkey2(struct tpm_buf *tb,
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uint32_t keyhandle, unsigned char *keyauth,
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const unsigned char *keyblob, int keybloblen,
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uint32_t *newhandle)
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{
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unsigned char nonceodd[TPM_NONCE_SIZE];
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unsigned char enonce[TPM_NONCE_SIZE];
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unsigned char authdata[SHA1_DIGEST_SIZE];
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uint32_t authhandle = 0;
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unsigned char cont = 0;
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uint32_t ordinal;
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int ret;
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ordinal = htonl(TPM_ORD_LOADKEY2);
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/* session for loading the key */
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ret = oiap(tb, &authhandle, enonce);
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if (ret < 0) {
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pr_info("oiap failed (%d)\n", ret);
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return ret;
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}
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/* generate odd nonce */
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ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
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if (ret < 0) {
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pr_info("tpm_get_random failed (%d)\n", ret);
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return ret;
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}
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/* calculate authorization HMAC value */
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ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
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nonceodd, cont, sizeof(uint32_t), &ordinal,
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keybloblen, keyblob, 0, 0);
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if (ret < 0)
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return ret;
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/* build the request buffer */
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tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_LOADKEY2);
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tpm_buf_append_u32(tb, keyhandle);
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tpm_buf_append(tb, keyblob, keybloblen);
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tpm_buf_append_u32(tb, authhandle);
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tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
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tpm_buf_append_u8(tb, cont);
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tpm_buf_append(tb, authdata, SHA1_DIGEST_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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pr_info("authhmac failed (%d)\n", ret);
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return ret;
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}
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ret = TSS_checkhmac1(tb->data, ordinal, nonceodd, keyauth,
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SHA1_DIGEST_SIZE, 0, 0);
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if (ret < 0) {
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pr_info("TSS_checkhmac1 failed (%d)\n", ret);
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return ret;
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}
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*newhandle = LOAD32(tb->data, TPM_DATA_OFFSET);
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return 0;
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}
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/*
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* Execute the FlushSpecific TPM command
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*/
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static int tpm_flushspecific(struct tpm_buf *tb, uint32_t handle)
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{
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tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_FLUSHSPECIFIC);
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tpm_buf_append_u32(tb, handle);
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tpm_buf_append_u32(tb, TPM_RT_KEY);
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return trusted_tpm_send(tb->data, MAX_BUF_SIZE);
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}
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/*
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* Decrypt a blob provided by userspace using a specific key handle.
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* The handle is a well known handle or previously loaded by e.g. LoadKey2
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*/
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static int tpm_unbind(struct tpm_buf *tb,
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uint32_t keyhandle, unsigned char *keyauth,
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const unsigned char *blob, uint32_t bloblen,
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void *out, uint32_t outlen)
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{
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unsigned char nonceodd[TPM_NONCE_SIZE];
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unsigned char enonce[TPM_NONCE_SIZE];
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unsigned char authdata[SHA1_DIGEST_SIZE];
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uint32_t authhandle = 0;
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unsigned char cont = 0;
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uint32_t ordinal;
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uint32_t datalen;
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int ret;
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ordinal = htonl(TPM_ORD_UNBIND);
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datalen = htonl(bloblen);
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/* session for loading the key */
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ret = oiap(tb, &authhandle, enonce);
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if (ret < 0) {
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pr_info("oiap failed (%d)\n", ret);
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return ret;
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}
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/* generate odd nonce */
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ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
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if (ret < 0) {
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pr_info("tpm_get_random failed (%d)\n", ret);
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return ret;
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}
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/* calculate authorization HMAC value */
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ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
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nonceodd, cont, sizeof(uint32_t), &ordinal,
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sizeof(uint32_t), &datalen,
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bloblen, blob, 0, 0);
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if (ret < 0)
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return ret;
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/* build the request buffer */
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tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_UNBIND);
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tpm_buf_append_u32(tb, keyhandle);
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tpm_buf_append_u32(tb, bloblen);
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tpm_buf_append(tb, blob, bloblen);
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tpm_buf_append_u32(tb, authhandle);
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tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
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tpm_buf_append_u8(tb, cont);
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tpm_buf_append(tb, authdata, SHA1_DIGEST_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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pr_info("authhmac failed (%d)\n", ret);
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return ret;
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}
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datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
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ret = TSS_checkhmac1(tb->data, ordinal, nonceodd,
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keyauth, SHA1_DIGEST_SIZE,
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sizeof(uint32_t), TPM_DATA_OFFSET,
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datalen, TPM_DATA_OFFSET + sizeof(uint32_t),
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0, 0);
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if (ret < 0) {
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pr_info("TSS_checkhmac1 failed (%d)\n", ret);
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return ret;
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}
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memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t),
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min(outlen, datalen));
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return datalen;
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}
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/*
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* Sign a blob provided by userspace (that has had the hash function applied)
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* using a specific key handle. The handle is assumed to have been previously
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* loaded by e.g. LoadKey2.
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*
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* Note that the key signature scheme of the used key should be set to
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* TPM_SS_RSASSAPKCS1v15_DER. This allows the hashed input to be of any size
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* up to key_length_in_bytes - 11 and not be limited to size 20 like the
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* TPM_SS_RSASSAPKCS1v15_SHA1 signature scheme.
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*/
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static int tpm_sign(struct tpm_buf *tb,
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uint32_t keyhandle, unsigned char *keyauth,
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const unsigned char *blob, uint32_t bloblen,
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void *out, uint32_t outlen)
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{
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unsigned char nonceodd[TPM_NONCE_SIZE];
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unsigned char enonce[TPM_NONCE_SIZE];
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unsigned char authdata[SHA1_DIGEST_SIZE];
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uint32_t authhandle = 0;
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unsigned char cont = 0;
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uint32_t ordinal;
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uint32_t datalen;
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int ret;
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ordinal = htonl(TPM_ORD_SIGN);
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datalen = htonl(bloblen);
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/* session for loading the key */
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ret = oiap(tb, &authhandle, enonce);
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if (ret < 0) {
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pr_info("oiap failed (%d)\n", ret);
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return ret;
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}
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/* generate odd nonce */
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ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
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if (ret < 0) {
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pr_info("tpm_get_random failed (%d)\n", ret);
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return ret;
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}
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/* calculate authorization HMAC value */
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ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
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nonceodd, cont, sizeof(uint32_t), &ordinal,
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sizeof(uint32_t), &datalen,
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bloblen, blob, 0, 0);
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if (ret < 0)
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return ret;
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/* build the request buffer */
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tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SIGN);
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tpm_buf_append_u32(tb, keyhandle);
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tpm_buf_append_u32(tb, bloblen);
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tpm_buf_append(tb, blob, bloblen);
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tpm_buf_append_u32(tb, authhandle);
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tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
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tpm_buf_append_u8(tb, cont);
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tpm_buf_append(tb, authdata, SHA1_DIGEST_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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pr_info("authhmac failed (%d)\n", ret);
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return ret;
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}
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datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
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ret = TSS_checkhmac1(tb->data, ordinal, nonceodd,
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keyauth, SHA1_DIGEST_SIZE,
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sizeof(uint32_t), TPM_DATA_OFFSET,
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datalen, TPM_DATA_OFFSET + sizeof(uint32_t),
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0, 0);
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if (ret < 0) {
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pr_info("TSS_checkhmac1 failed (%d)\n", ret);
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return ret;
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}
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memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t),
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min(datalen, outlen));
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return datalen;
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}
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/* Room to fit two u32 zeros for algo id and parameters length. */
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#define SETKEY_PARAMS_SIZE (sizeof(u32) * 2)
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/*
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* Maximum buffer size for the BER/DER encoded public key. The public key
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* is of the form SEQUENCE { INTEGER n, INTEGER e } where n is a maximum 2048
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* bit key and e is usually 65537
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* The encoding overhead is:
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* - max 4 bytes for SEQUENCE
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* - max 4 bytes for INTEGER n type/length
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* - 257 bytes of n
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* - max 2 bytes for INTEGER e type/length
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* - 3 bytes of e
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* - 4+4 of zeros for set_pub_key parameters (SETKEY_PARAMS_SIZE)
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*/
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#define PUB_KEY_BUF_SIZE (4 + 4 + 257 + 2 + 3 + SETKEY_PARAMS_SIZE)
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/*
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* Provide a part of a description of the key for /proc/keys.
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*/
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static void asym_tpm_describe(const struct key *asymmetric_key,
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struct seq_file *m)
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{
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struct tpm_key *tk = asymmetric_key->payload.data[asym_crypto];
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if (!tk)
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return;
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seq_printf(m, "TPM1.2/Blob");
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}
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static void asym_tpm_destroy(void *payload0, void *payload3)
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{
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struct tpm_key *tk = payload0;
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if (!tk)
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return;
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kfree(tk->blob);
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tk->blob_len = 0;
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kfree(tk);
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}
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/* How many bytes will it take to encode the length */
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static inline uint32_t definite_length(uint32_t len)
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{
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if (len <= 127)
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return 1;
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if (len <= 255)
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return 2;
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return 3;
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}
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static inline uint8_t *encode_tag_length(uint8_t *buf, uint8_t tag,
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uint32_t len)
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{
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*buf++ = tag;
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if (len <= 127) {
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buf[0] = len;
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return buf + 1;
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}
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if (len <= 255) {
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buf[0] = 0x81;
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buf[1] = len;
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return buf + 2;
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}
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buf[0] = 0x82;
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put_unaligned_be16(len, buf + 1);
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return buf + 3;
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}
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static uint32_t derive_pub_key(const void *pub_key, uint32_t len, uint8_t *buf)
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{
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uint8_t *cur = buf;
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uint32_t n_len = definite_length(len) + 1 + len + 1;
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uint32_t e_len = definite_length(3) + 1 + 3;
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uint8_t e[3] = { 0x01, 0x00, 0x01 };
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/* SEQUENCE */
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cur = encode_tag_length(cur, 0x30, n_len + e_len);
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/* INTEGER n */
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cur = encode_tag_length(cur, 0x02, len + 1);
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cur[0] = 0x00;
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memcpy(cur + 1, pub_key, len);
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cur += len + 1;
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cur = encode_tag_length(cur, 0x02, sizeof(e));
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memcpy(cur, e, sizeof(e));
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cur += sizeof(e);
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/* Zero parameters to satisfy set_pub_key ABI. */
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memzero_explicit(cur, SETKEY_PARAMS_SIZE);
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return cur - buf;
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}
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/*
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* Determine the crypto algorithm name.
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*/
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static int determine_akcipher(const char *encoding, const char *hash_algo,
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char alg_name[CRYPTO_MAX_ALG_NAME])
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{
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if (strcmp(encoding, "pkcs1") == 0) {
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if (!hash_algo) {
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strcpy(alg_name, "pkcs1pad(rsa)");
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return 0;
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}
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if (snprintf(alg_name, CRYPTO_MAX_ALG_NAME, "pkcs1pad(rsa,%s)",
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hash_algo) >= CRYPTO_MAX_ALG_NAME)
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return -EINVAL;
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return 0;
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}
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if (strcmp(encoding, "raw") == 0) {
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strcpy(alg_name, "rsa");
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return 0;
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}
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return -ENOPKG;
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}
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/*
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* Query information about a key.
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*/
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static int tpm_key_query(const struct kernel_pkey_params *params,
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struct kernel_pkey_query *info)
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{
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struct tpm_key *tk = params->key->payload.data[asym_crypto];
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int ret;
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char alg_name[CRYPTO_MAX_ALG_NAME];
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struct crypto_akcipher *tfm;
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uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
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uint32_t der_pub_key_len;
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int len;
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/* TPM only works on private keys, public keys still done in software */
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ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
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if (ret < 0)
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return ret;
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tfm = crypto_alloc_akcipher(alg_name, 0, 0);
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if (IS_ERR(tfm))
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return PTR_ERR(tfm);
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der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
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der_pub_key);
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ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
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if (ret < 0)
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goto error_free_tfm;
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len = crypto_akcipher_maxsize(tfm);
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info->key_size = tk->key_len;
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info->max_data_size = tk->key_len / 8;
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info->max_sig_size = len;
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info->max_enc_size = len;
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info->max_dec_size = tk->key_len / 8;
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info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT |
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KEYCTL_SUPPORTS_DECRYPT |
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KEYCTL_SUPPORTS_VERIFY |
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KEYCTL_SUPPORTS_SIGN;
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ret = 0;
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error_free_tfm:
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crypto_free_akcipher(tfm);
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pr_devel("<==%s() = %d\n", __func__, ret);
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return ret;
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}
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/*
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* Encryption operation is performed with the public key. Hence it is done
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* in software
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*/
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static int tpm_key_encrypt(struct tpm_key *tk,
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struct kernel_pkey_params *params,
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const void *in, void *out)
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{
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char alg_name[CRYPTO_MAX_ALG_NAME];
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struct crypto_akcipher *tfm;
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struct akcipher_request *req;
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struct crypto_wait cwait;
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struct scatterlist in_sg, out_sg;
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uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
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uint32_t der_pub_key_len;
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int ret;
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pr_devel("==>%s()\n", __func__);
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ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
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if (ret < 0)
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return ret;
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tfm = crypto_alloc_akcipher(alg_name, 0, 0);
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if (IS_ERR(tfm))
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return PTR_ERR(tfm);
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der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
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der_pub_key);
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ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
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if (ret < 0)
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goto error_free_tfm;
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ret = -ENOMEM;
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req = akcipher_request_alloc(tfm, GFP_KERNEL);
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if (!req)
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|
goto error_free_tfm;
|
|
|
|
sg_init_one(&in_sg, in, params->in_len);
|
|
sg_init_one(&out_sg, out, params->out_len);
|
|
akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len,
|
|
params->out_len);
|
|
crypto_init_wait(&cwait);
|
|
akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
|
|
CRYPTO_TFM_REQ_MAY_SLEEP,
|
|
crypto_req_done, &cwait);
|
|
|
|
ret = crypto_akcipher_encrypt(req);
|
|
ret = crypto_wait_req(ret, &cwait);
|
|
|
|
if (ret == 0)
|
|
ret = req->dst_len;
|
|
|
|
akcipher_request_free(req);
|
|
error_free_tfm:
|
|
crypto_free_akcipher(tfm);
|
|
pr_devel("<==%s() = %d\n", __func__, ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Decryption operation is performed with the private key in the TPM.
|
|
*/
|
|
static int tpm_key_decrypt(struct tpm_key *tk,
|
|
struct kernel_pkey_params *params,
|
|
const void *in, void *out)
|
|
{
|
|
struct tpm_buf tb;
|
|
uint32_t keyhandle;
|
|
uint8_t srkauth[SHA1_DIGEST_SIZE];
|
|
uint8_t keyauth[SHA1_DIGEST_SIZE];
|
|
int r;
|
|
|
|
pr_devel("==>%s()\n", __func__);
|
|
|
|
if (params->hash_algo)
|
|
return -ENOPKG;
|
|
|
|
if (strcmp(params->encoding, "pkcs1"))
|
|
return -ENOPKG;
|
|
|
|
r = tpm_buf_init(&tb, 0, 0);
|
|
if (r)
|
|
return r;
|
|
|
|
/* TODO: Handle a non-all zero SRK authorization */
|
|
memset(srkauth, 0, sizeof(srkauth));
|
|
|
|
r = tpm_loadkey2(&tb, SRKHANDLE, srkauth,
|
|
tk->blob, tk->blob_len, &keyhandle);
|
|
if (r < 0) {
|
|
pr_devel("loadkey2 failed (%d)\n", r);
|
|
goto error;
|
|
}
|
|
|
|
/* TODO: Handle a non-all zero key authorization */
|
|
memset(keyauth, 0, sizeof(keyauth));
|
|
|
|
r = tpm_unbind(&tb, keyhandle, keyauth,
|
|
in, params->in_len, out, params->out_len);
|
|
if (r < 0)
|
|
pr_devel("tpm_unbind failed (%d)\n", r);
|
|
|
|
if (tpm_flushspecific(&tb, keyhandle) < 0)
|
|
pr_devel("flushspecific failed (%d)\n", r);
|
|
|
|
error:
|
|
tpm_buf_destroy(&tb);
|
|
pr_devel("<==%s() = %d\n", __func__, r);
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
|
|
*/
|
|
static const u8 digest_info_md5[] = {
|
|
0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
|
|
0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
|
|
0x05, 0x00, 0x04, 0x10
|
|
};
|
|
|
|
static const u8 digest_info_sha1[] = {
|
|
0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
|
|
0x2b, 0x0e, 0x03, 0x02, 0x1a,
|
|
0x05, 0x00, 0x04, 0x14
|
|
};
|
|
|
|
static const u8 digest_info_rmd160[] = {
|
|
0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
|
|
0x2b, 0x24, 0x03, 0x02, 0x01,
|
|
0x05, 0x00, 0x04, 0x14
|
|
};
|
|
|
|
static const u8 digest_info_sha224[] = {
|
|
0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
|
|
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
|
|
0x05, 0x00, 0x04, 0x1c
|
|
};
|
|
|
|
static const u8 digest_info_sha256[] = {
|
|
0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
|
|
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
|
|
0x05, 0x00, 0x04, 0x20
|
|
};
|
|
|
|
static const u8 digest_info_sha384[] = {
|
|
0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
|
|
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
|
|
0x05, 0x00, 0x04, 0x30
|
|
};
|
|
|
|
static const u8 digest_info_sha512[] = {
|
|
0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
|
|
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
|
|
0x05, 0x00, 0x04, 0x40
|
|
};
|
|
|
|
static const struct asn1_template {
|
|
const char *name;
|
|
const u8 *data;
|
|
size_t size;
|
|
} asn1_templates[] = {
|
|
#define _(X) { #X, digest_info_##X, sizeof(digest_info_##X) }
|
|
_(md5),
|
|
_(sha1),
|
|
_(rmd160),
|
|
_(sha256),
|
|
_(sha384),
|
|
_(sha512),
|
|
_(sha224),
|
|
{ NULL }
|
|
#undef _
|
|
};
|
|
|
|
static const struct asn1_template *lookup_asn1(const char *name)
|
|
{
|
|
const struct asn1_template *p;
|
|
|
|
for (p = asn1_templates; p->name; p++)
|
|
if (strcmp(name, p->name) == 0)
|
|
return p;
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Sign operation is performed with the private key in the TPM.
|
|
*/
|
|
static int tpm_key_sign(struct tpm_key *tk,
|
|
struct kernel_pkey_params *params,
|
|
const void *in, void *out)
|
|
{
|
|
struct tpm_buf tb;
|
|
uint32_t keyhandle;
|
|
uint8_t srkauth[SHA1_DIGEST_SIZE];
|
|
uint8_t keyauth[SHA1_DIGEST_SIZE];
|
|
void *asn1_wrapped = NULL;
|
|
uint32_t in_len = params->in_len;
|
|
int r;
|
|
|
|
pr_devel("==>%s()\n", __func__);
|
|
|
|
if (strcmp(params->encoding, "pkcs1"))
|
|
return -ENOPKG;
|
|
|
|
if (params->hash_algo) {
|
|
const struct asn1_template *asn1 =
|
|
lookup_asn1(params->hash_algo);
|
|
|
|
if (!asn1)
|
|
return -ENOPKG;
|
|
|
|
/* request enough space for the ASN.1 template + input hash */
|
|
asn1_wrapped = kzalloc(in_len + asn1->size, GFP_KERNEL);
|
|
if (!asn1_wrapped)
|
|
return -ENOMEM;
|
|
|
|
/* Copy ASN.1 template, then the input */
|
|
memcpy(asn1_wrapped, asn1->data, asn1->size);
|
|
memcpy(asn1_wrapped + asn1->size, in, in_len);
|
|
|
|
in = asn1_wrapped;
|
|
in_len += asn1->size;
|
|
}
|
|
|
|
if (in_len > tk->key_len / 8 - 11) {
|
|
r = -EOVERFLOW;
|
|
goto error_free_asn1_wrapped;
|
|
}
|
|
|
|
r = tpm_buf_init(&tb, 0, 0);
|
|
if (r)
|
|
goto error_free_asn1_wrapped;
|
|
|
|
/* TODO: Handle a non-all zero SRK authorization */
|
|
memset(srkauth, 0, sizeof(srkauth));
|
|
|
|
r = tpm_loadkey2(&tb, SRKHANDLE, srkauth,
|
|
tk->blob, tk->blob_len, &keyhandle);
|
|
if (r < 0) {
|
|
pr_devel("loadkey2 failed (%d)\n", r);
|
|
goto error_free_tb;
|
|
}
|
|
|
|
/* TODO: Handle a non-all zero key authorization */
|
|
memset(keyauth, 0, sizeof(keyauth));
|
|
|
|
r = tpm_sign(&tb, keyhandle, keyauth, in, in_len, out, params->out_len);
|
|
if (r < 0)
|
|
pr_devel("tpm_sign failed (%d)\n", r);
|
|
|
|
if (tpm_flushspecific(&tb, keyhandle) < 0)
|
|
pr_devel("flushspecific failed (%d)\n", r);
|
|
|
|
error_free_tb:
|
|
tpm_buf_destroy(&tb);
|
|
error_free_asn1_wrapped:
|
|
kfree(asn1_wrapped);
|
|
pr_devel("<==%s() = %d\n", __func__, r);
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Do encryption, decryption and signing ops.
|
|
*/
|
|
static int tpm_key_eds_op(struct kernel_pkey_params *params,
|
|
const void *in, void *out)
|
|
{
|
|
struct tpm_key *tk = params->key->payload.data[asym_crypto];
|
|
int ret = -EOPNOTSUPP;
|
|
|
|
/* Perform the encryption calculation. */
|
|
switch (params->op) {
|
|
case kernel_pkey_encrypt:
|
|
ret = tpm_key_encrypt(tk, params, in, out);
|
|
break;
|
|
case kernel_pkey_decrypt:
|
|
ret = tpm_key_decrypt(tk, params, in, out);
|
|
break;
|
|
case kernel_pkey_sign:
|
|
ret = tpm_key_sign(tk, params, in, out);
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Verify a signature using a public key.
|
|
*/
|
|
static int tpm_key_verify_signature(const struct key *key,
|
|
const struct public_key_signature *sig)
|
|
{
|
|
const struct tpm_key *tk = key->payload.data[asym_crypto];
|
|
struct crypto_wait cwait;
|
|
struct crypto_akcipher *tfm;
|
|
struct akcipher_request *req;
|
|
struct scatterlist src_sg[2];
|
|
char alg_name[CRYPTO_MAX_ALG_NAME];
|
|
uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
|
|
uint32_t der_pub_key_len;
|
|
int ret;
|
|
|
|
pr_devel("==>%s()\n", __func__);
|
|
|
|
BUG_ON(!tk);
|
|
BUG_ON(!sig);
|
|
BUG_ON(!sig->s);
|
|
|
|
if (!sig->digest)
|
|
return -ENOPKG;
|
|
|
|
ret = determine_akcipher(sig->encoding, sig->hash_algo, alg_name);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
tfm = crypto_alloc_akcipher(alg_name, 0, 0);
|
|
if (IS_ERR(tfm))
|
|
return PTR_ERR(tfm);
|
|
|
|
der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
|
|
der_pub_key);
|
|
|
|
ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
|
|
if (ret < 0)
|
|
goto error_free_tfm;
|
|
|
|
ret = -ENOMEM;
|
|
req = akcipher_request_alloc(tfm, GFP_KERNEL);
|
|
if (!req)
|
|
goto error_free_tfm;
|
|
|
|
sg_init_table(src_sg, 2);
|
|
sg_set_buf(&src_sg[0], sig->s, sig->s_size);
|
|
sg_set_buf(&src_sg[1], sig->digest, sig->digest_size);
|
|
akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size,
|
|
sig->digest_size);
|
|
crypto_init_wait(&cwait);
|
|
akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
|
|
CRYPTO_TFM_REQ_MAY_SLEEP,
|
|
crypto_req_done, &cwait);
|
|
ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait);
|
|
|
|
akcipher_request_free(req);
|
|
error_free_tfm:
|
|
crypto_free_akcipher(tfm);
|
|
pr_devel("<==%s() = %d\n", __func__, ret);
|
|
if (WARN_ON_ONCE(ret > 0))
|
|
ret = -EINVAL;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Parse enough information out of TPM_KEY structure:
|
|
* TPM_STRUCT_VER -> 4 bytes
|
|
* TPM_KEY_USAGE -> 2 bytes
|
|
* TPM_KEY_FLAGS -> 4 bytes
|
|
* TPM_AUTH_DATA_USAGE -> 1 byte
|
|
* TPM_KEY_PARMS -> variable
|
|
* UINT32 PCRInfoSize -> 4 bytes
|
|
* BYTE* -> PCRInfoSize bytes
|
|
* TPM_STORE_PUBKEY
|
|
* UINT32 encDataSize;
|
|
* BYTE* -> encDataSize;
|
|
*
|
|
* TPM_KEY_PARMS:
|
|
* TPM_ALGORITHM_ID -> 4 bytes
|
|
* TPM_ENC_SCHEME -> 2 bytes
|
|
* TPM_SIG_SCHEME -> 2 bytes
|
|
* UINT32 parmSize -> 4 bytes
|
|
* BYTE* -> variable
|
|
*/
|
|
static int extract_key_parameters(struct tpm_key *tk)
|
|
{
|
|
const void *cur = tk->blob;
|
|
uint32_t len = tk->blob_len;
|
|
const void *pub_key;
|
|
uint32_t sz;
|
|
uint32_t key_len;
|
|
|
|
if (len < 11)
|
|
return -EBADMSG;
|
|
|
|
/* Ensure this is a legacy key */
|
|
if (get_unaligned_be16(cur + 4) != 0x0015)
|
|
return -EBADMSG;
|
|
|
|
/* Skip to TPM_KEY_PARMS */
|
|
cur += 11;
|
|
len -= 11;
|
|
|
|
if (len < 12)
|
|
return -EBADMSG;
|
|
|
|
/* Make sure this is an RSA key */
|
|
if (get_unaligned_be32(cur) != 0x00000001)
|
|
return -EBADMSG;
|
|
|
|
/* Make sure this is TPM_ES_RSAESPKCSv15 encoding scheme */
|
|
if (get_unaligned_be16(cur + 4) != 0x0002)
|
|
return -EBADMSG;
|
|
|
|
/* Make sure this is TPM_SS_RSASSAPKCS1v15_DER signature scheme */
|
|
if (get_unaligned_be16(cur + 6) != 0x0003)
|
|
return -EBADMSG;
|
|
|
|
sz = get_unaligned_be32(cur + 8);
|
|
if (len < sz + 12)
|
|
return -EBADMSG;
|
|
|
|
/* Move to TPM_RSA_KEY_PARMS */
|
|
len -= 12;
|
|
cur += 12;
|
|
|
|
/* Grab the RSA key length */
|
|
key_len = get_unaligned_be32(cur);
|
|
|
|
switch (key_len) {
|
|
case 512:
|
|
case 1024:
|
|
case 1536:
|
|
case 2048:
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Move just past TPM_KEY_PARMS */
|
|
cur += sz;
|
|
len -= sz;
|
|
|
|
if (len < 4)
|
|
return -EBADMSG;
|
|
|
|
sz = get_unaligned_be32(cur);
|
|
if (len < 4 + sz)
|
|
return -EBADMSG;
|
|
|
|
/* Move to TPM_STORE_PUBKEY */
|
|
cur += 4 + sz;
|
|
len -= 4 + sz;
|
|
|
|
/* Grab the size of the public key, it should jive with the key size */
|
|
sz = get_unaligned_be32(cur);
|
|
if (sz > 256)
|
|
return -EINVAL;
|
|
|
|
pub_key = cur + 4;
|
|
|
|
tk->key_len = key_len;
|
|
tk->pub_key = pub_key;
|
|
tk->pub_key_len = sz;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Given the blob, parse it and load it into the TPM */
|
|
struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len)
|
|
{
|
|
int r;
|
|
struct tpm_key *tk;
|
|
|
|
r = tpm_is_tpm2(NULL);
|
|
if (r < 0)
|
|
goto error;
|
|
|
|
/* We don't support TPM2 yet */
|
|
if (r > 0) {
|
|
r = -ENODEV;
|
|
goto error;
|
|
}
|
|
|
|
r = -ENOMEM;
|
|
tk = kzalloc(sizeof(struct tpm_key), GFP_KERNEL);
|
|
if (!tk)
|
|
goto error;
|
|
|
|
tk->blob = kmemdup(blob, blob_len, GFP_KERNEL);
|
|
if (!tk->blob)
|
|
goto error_memdup;
|
|
|
|
tk->blob_len = blob_len;
|
|
|
|
r = extract_key_parameters(tk);
|
|
if (r < 0)
|
|
goto error_extract;
|
|
|
|
return tk;
|
|
|
|
error_extract:
|
|
kfree(tk->blob);
|
|
tk->blob_len = 0;
|
|
error_memdup:
|
|
kfree(tk);
|
|
error:
|
|
return ERR_PTR(r);
|
|
}
|
|
EXPORT_SYMBOL_GPL(tpm_key_create);
|
|
|
|
/*
|
|
* TPM-based asymmetric key subtype
|
|
*/
|
|
struct asymmetric_key_subtype asym_tpm_subtype = {
|
|
.owner = THIS_MODULE,
|
|
.name = "asym_tpm",
|
|
.name_len = sizeof("asym_tpm") - 1,
|
|
.describe = asym_tpm_describe,
|
|
.destroy = asym_tpm_destroy,
|
|
.query = tpm_key_query,
|
|
.eds_op = tpm_key_eds_op,
|
|
.verify_signature = tpm_key_verify_signature,
|
|
};
|
|
EXPORT_SYMBOL_GPL(asym_tpm_subtype);
|
|
|
|
MODULE_DESCRIPTION("TPM based asymmetric key subtype");
|
|
MODULE_AUTHOR("Intel Corporation");
|
|
MODULE_LICENSE("GPL v2");
|