--- /dev/null
+/*
+ * Copyright (C) 2010 IBM Corporation
+ *
+ * Author:
+ * David Safford <safford@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * See Documentation/keys-trusted-encrypted.txt
+ */
+
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/parser.h>
+#include <linux/string.h>
+#include <keys/user-type.h>
+#include <keys/trusted-type.h>
+#include <linux/key-type.h>
+#include <linux/rcupdate.h>
+#include <linux/crypto.h>
+#include <crypto/hash.h>
+#include <crypto/sha.h>
+#include <linux/capability.h>
+#include <linux/tpm.h>
+#include <linux/tpm_command.h>
+
+#include "trusted_defined.h"
+
+static const char hmac_alg[] = "hmac(sha1)";
+static const char hash_alg[] = "sha1";
+
+struct sdesc {
+ struct shash_desc shash;
+ char ctx[];
+};
+
+static struct crypto_shash *hashalg;
+static struct crypto_shash *hmacalg;
+
+static struct sdesc *init_sdesc(struct crypto_shash *alg)
+{
+ struct sdesc *sdesc;
+ int size;
+
+ size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
+ sdesc = kmalloc(size, GFP_KERNEL);
+ if (!sdesc)
+ return ERR_PTR(-ENOMEM);
+ sdesc->shash.tfm = alg;
+ sdesc->shash.flags = 0x0;
+ return sdesc;
+}
+
+static int TSS_sha1(const unsigned char *data, const unsigned int datalen,
+ unsigned char *digest)
+{
+ struct sdesc *sdesc;
+ int ret;
+
+ sdesc = init_sdesc(hashalg);
+ if (IS_ERR(sdesc)) {
+ pr_info("trusted_key: can't alloc %s\n", hash_alg);
+ return PTR_ERR(sdesc);
+ }
+
+ ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
+ kfree(sdesc);
+ return ret;
+}
+
+static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
+ const unsigned int keylen, ...)
+{
+ struct sdesc *sdesc;
+ va_list argp;
+ unsigned int dlen;
+ unsigned char *data;
+ int ret;
+
+ sdesc = init_sdesc(hmacalg);
+ if (IS_ERR(sdesc)) {
+ pr_info("trusted_key: can't alloc %s\n", hmac_alg);
+ return PTR_ERR(sdesc);
+ }
+
+ ret = crypto_shash_setkey(hmacalg, key, keylen);
+ if (ret < 0)
+ goto out;
+ ret = crypto_shash_init(&sdesc->shash);
+ if (ret < 0)
+ goto out;
+
+ va_start(argp, keylen);
+ for (;;) {
+ dlen = va_arg(argp, unsigned int);
+ if (dlen == 0)
+ break;
+ data = va_arg(argp, unsigned char *);
+ if (data == NULL)
+ return -EINVAL;
+ ret = crypto_shash_update(&sdesc->shash, data, dlen);
+ if (ret < 0)
+ goto out;
+ }
+ va_end(argp);
+ ret = crypto_shash_final(&sdesc->shash, digest);
+out:
+ kfree(sdesc);
+ return ret;
+}
+
+/*
+ * calculate authorization info fields to send to TPM
+ */
+static uint32_t TSS_authhmac(unsigned char *digest, const unsigned char *key,
+ const unsigned int keylen, unsigned char *h1,
+ unsigned char *h2, unsigned char h3, ...)
+{
+ unsigned char paramdigest[SHA1_DIGEST_SIZE];
+ struct sdesc *sdesc;
+ unsigned int dlen;
+ unsigned char *data;
+ unsigned char c;
+ int ret;
+ va_list argp;
+
+ sdesc = init_sdesc(hashalg);
+ if (IS_ERR(sdesc)) {
+ pr_info("trusted_key: can't alloc %s\n", hash_alg);
+ return PTR_ERR(sdesc);
+ }
+
+ c = h3;
+ ret = crypto_shash_init(&sdesc->shash);
+ if (ret < 0)
+ goto out;
+ va_start(argp, h3);
+ for (;;) {
+ dlen = va_arg(argp, unsigned int);
+ if (dlen == 0)
+ break;
+ data = va_arg(argp, unsigned char *);
+ ret = crypto_shash_update(&sdesc->shash, data, dlen);
+ if (ret < 0)
+ goto out;
+ }
+ va_end(argp);
+ ret = crypto_shash_final(&sdesc->shash, paramdigest);
+ if (!ret)
+ TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
+ paramdigest, TPM_NONCE_SIZE, h1,
+ TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
+out:
+ kfree(sdesc);
+ return ret;
+}
+
+/*
+ * verify the AUTH1_COMMAND (Seal) result from TPM
+ */
+static uint32_t TSS_checkhmac1(unsigned char *buffer,
+ const uint32_t command,
+ const unsigned char *ononce,
+ const unsigned char *key,
+ const unsigned int keylen, ...)
+{
+ uint32_t bufsize;
+ uint16_t tag;
+ uint32_t ordinal;
+ uint32_t result;
+ unsigned char *enonce;
+ unsigned char *continueflag;
+ unsigned char *authdata;
+ unsigned char testhmac[SHA1_DIGEST_SIZE];
+ unsigned char paramdigest[SHA1_DIGEST_SIZE];
+ struct sdesc *sdesc;
+ unsigned int dlen;
+ unsigned int dpos;
+ va_list argp;
+ int ret;
+
+ bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
+ tag = LOAD16(buffer, 0);
+ ordinal = command;
+ result = LOAD32N(buffer, TPM_RETURN_OFFSET);
+ if (tag == TPM_TAG_RSP_COMMAND)
+ return 0;
+ if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
+ return -EINVAL;
+ authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
+ continueflag = authdata - 1;
+ enonce = continueflag - TPM_NONCE_SIZE;
+
+ sdesc = init_sdesc(hashalg);
+ if (IS_ERR(sdesc)) {
+ pr_info("trusted_key: can't alloc %s\n", hash_alg);
+ return PTR_ERR(sdesc);
+ }
+ ret = crypto_shash_init(&sdesc->shash);
+ if (ret < 0)
+ goto out;
+ ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
+ sizeof result);
+ if (ret < 0)
+ goto out;
+ ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
+ sizeof ordinal);
+ if (ret < 0)
+ goto out;
+ va_start(argp, keylen);
+ for (;;) {
+ dlen = va_arg(argp, unsigned int);
+ if (dlen == 0)
+ break;
+ dpos = va_arg(argp, unsigned int);
+ ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
+ if (ret < 0)
+ goto out;
+ }
+ va_end(argp);
+ ret = crypto_shash_final(&sdesc->shash, paramdigest);
+ if (ret < 0)
+ goto out;
+ ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
+ TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
+ 1, continueflag, 0, 0);
+ if (ret < 0)
+ goto out;
+ if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
+ ret = -EINVAL;
+out:
+ kfree(sdesc);
+ return ret;
+}
+
+/*
+ * verify the AUTH2_COMMAND (unseal) result from TPM
+ */
+static uint32_t TSS_checkhmac2(unsigned char *buffer,
+ const uint32_t command,
+ const unsigned char *ononce,
+ const unsigned char *key1,
+ const unsigned int keylen1,
+ const unsigned char *key2,
+ const unsigned int keylen2, ...)
+{
+ uint32_t bufsize;
+ uint16_t tag;
+ uint32_t ordinal;
+ uint32_t result;
+ unsigned char *enonce1;
+ unsigned char *continueflag1;
+ unsigned char *authdata1;
+ unsigned char *enonce2;
+ unsigned char *continueflag2;
+ unsigned char *authdata2;
+ unsigned char testhmac1[SHA1_DIGEST_SIZE];
+ unsigned char testhmac2[SHA1_DIGEST_SIZE];
+ unsigned char paramdigest[SHA1_DIGEST_SIZE];
+ struct sdesc *sdesc;
+ unsigned int dlen;
+ unsigned int dpos;
+ va_list argp;
+ int ret;
+
+ bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
+ tag = LOAD16(buffer, 0);
+ ordinal = command;
+ result = LOAD32N(buffer, TPM_RETURN_OFFSET);
+
+ if (tag == TPM_TAG_RSP_COMMAND)
+ return 0;
+ if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
+ return -EINVAL;
+ authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
+ + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
+ authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
+ continueflag1 = authdata1 - 1;
+ continueflag2 = authdata2 - 1;
+ enonce1 = continueflag1 - TPM_NONCE_SIZE;
+ enonce2 = continueflag2 - TPM_NONCE_SIZE;
+
+ sdesc = init_sdesc(hashalg);
+ if (IS_ERR(sdesc)) {
+ pr_info("trusted_key: can't alloc %s\n", hash_alg);
+ return PTR_ERR(sdesc);
+ }
+ ret = crypto_shash_init(&sdesc->shash);
+ if (ret < 0)
+ goto out;
+ ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
+ sizeof result);
+ if (ret < 0)
+ goto out;
+ ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
+ sizeof ordinal);
+ if (ret < 0)
+ goto out;
+
+ va_start(argp, keylen2);
+ for (;;) {
+ dlen = va_arg(argp, unsigned int);
+ if (dlen == 0)
+ break;
+ dpos = va_arg(argp, unsigned int);
+ ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
+ if (ret < 0)
+ goto out;
+ }
+ ret = crypto_shash_final(&sdesc->shash, paramdigest);
+ if (ret < 0)
+ goto out;
+
+ ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
+ paramdigest, TPM_NONCE_SIZE, enonce1,
+ TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
+ if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
+ paramdigest, TPM_NONCE_SIZE, enonce2,
+ TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
+ if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
+ ret = -EINVAL;
+out:
+ kfree(sdesc);
+ return ret;
+}
+
+/*
+ * For key specific tpm requests, we will generate and send our
+ * own TPM command packets using the drivers send function.
+ */
+static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
+ size_t buflen)
+{
+ int rc;
+
+ dump_tpm_buf(cmd);
+ rc = tpm_send(chip_num, cmd, buflen);
+ dump_tpm_buf(cmd);
+ if (rc > 0)
+ /* Can't return positive return codes values to keyctl */
+ rc = -EPERM;
+ return rc;
+}
+
+/*
+ * get a random value from TPM
+ */
+static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len)
+{
+ int ret;
+
+ INIT_BUF(tb);
+ store16(tb, TPM_TAG_RQU_COMMAND);
+ store32(tb, TPM_GETRANDOM_SIZE);
+ store32(tb, TPM_ORD_GETRANDOM);
+ store32(tb, len);
+ ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data);
+ memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len);
+
+ return ret;
+}
+
+static int my_get_random(unsigned char *buf, int len)
+{
+ struct tpm_buf *tb;
+ int ret;
+
+ tb = kzalloc(sizeof *tb, GFP_KERNEL);
+ if (!tb)
+ return -ENOMEM;
+ ret = tpm_get_random(tb, buf, len);
+
+ kfree(tb);
+ return ret;
+}
+
+/*
+ * Lock a trusted key, by extending a selected PCR.
+ *
+ * Prevents a trusted key that is sealed to PCRs from being accessed.
+ * This uses the tpm driver's extend function.
+ */
+static int pcrlock(const int pcrnum)
+{
+ unsigned char hash[SHA1_DIGEST_SIZE];
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ my_get_random(hash, SHA1_DIGEST_SIZE);
+ return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
+}
+
+/*
+ * Create an object specific authorisation protocol (OSAP) session
+ */
+static int osap(struct tpm_buf *tb, struct osapsess *s,
+ const unsigned char *key, const uint16_t type,
+ const uint32_t handle)
+{
+ unsigned char enonce[TPM_NONCE_SIZE];
+ unsigned char ononce[TPM_NONCE_SIZE];
+ int ret;
+
+ ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE);
+ if (ret < 0)
+ return ret;
+
+ INIT_BUF(tb);
+ store16(tb, TPM_TAG_RQU_COMMAND);
+ store32(tb, TPM_OSAP_SIZE);
+ store32(tb, TPM_ORD_OSAP);
+ store16(tb, type);
+ store32(tb, handle);
+ storebytes(tb, ononce, TPM_NONCE_SIZE);
+
+ ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
+ if (ret < 0)
+ return ret;
+
+ s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
+ memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
+ TPM_NONCE_SIZE);
+ memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
+ TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
+ ret = TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
+ enonce, TPM_NONCE_SIZE, ononce, 0, 0);
+ return ret;
+}
+
+/*
+ * 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 ret;
+}
+
+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, const uint16_t keytype,
+ const uint32_t keyhandle, const unsigned char *keyauth,
+ const unsigned char *data, const uint32_t datalen,
+ unsigned char *blob, uint32_t *bloblen,
+ const unsigned char *blobauth,
+ const unsigned char *pcrinfo, const 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)
+ return ret;
+ 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)
+ return ret;
+
+ ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE);
+ if (ret < 0)
+ return ret;
+ 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 */
+ 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 */
+ 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);
+ }
+
+ /* 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)
+ return ret;
+
+ /* 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 */
+ memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
+ *bloblen = storedsize;
+ return ret;
+}
+
+/*
+ * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
+ */
+static int tpm_unseal(struct tpm_buf *tb,
+ const uint32_t keyhandle, const unsigned char *keyauth,
+ const unsigned char *blob, const 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(tb, nonceodd, TPM_NONCE_SIZE);
+ if (ret < 0) {
+ pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
+ return ret;
+ }
+ TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
+ enonce1, nonceodd, cont, sizeof(uint32_t),
+ &ordinal, bloblen, blob, 0, 0);
+ TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
+ enonce2, nonceodd, cont, sizeof(uint32_t),
+ &ordinal, bloblen, blob, 0, 0);
+
+ /* 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);
+ memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
+ return ret;
+}
+
+/*
+ * 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);
+ /* pull migratable flag out of sealed key */
+ p->migratable = p->key[--p->key_len];
+
+ if (ret < 0)
+ pr_info("trusted_key: srkunseal failed (%d)\n", ret);
+
+ 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;
+ hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len);
+ break;
+ case Opt_keyhandle:
+ res = strict_strtoul(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;
+ hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE);
+ break;
+ case Opt_blobauth:
+ if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
+ return -EINVAL;
+ hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE);
+ break;
+ case Opt_migratable:
+ if (*args[0].from == '0')
+ pay->migratable = 0;
+ else
+ return -EINVAL;
+ break;
+ case Opt_pcrlock:
+ res = strict_strtoul(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 = strict_strtol(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;
+ hex2bin(p->blob, c, p->blob_len);
+ 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)
+ return 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);
+
+ /* migratable by default */
+ p->migratable = 1;
+ 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, const void *data,
+ const size_t datalen)
+{
+ struct trusted_key_payload *payload = NULL;
+ struct trusted_key_options *options = NULL;
+ char *datablob;
+ int ret = 0;
+ int key_cmd;
+
+ if (datalen <= 0 || datalen > 32767 || !data)
+ return -EINVAL;
+
+ datablob = kmalloc(datalen + 1, GFP_KERNEL);
+ if (!datablob)
+ return -ENOMEM;
+ memcpy(datablob, 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:
+ ret = my_get_random(payload->key, payload->key_len);
+ if (ret < 0) {
+ 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_pointer(key->payload.data, 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, const void *data,
+ const size_t datalen)
+{
+ struct trusted_key_payload *p = key->payload.data;
+ struct trusted_key_payload *new_p;
+ struct trusted_key_options *new_o;
+ char *datablob;
+ int ret = 0;
+
+ if (!p->migratable)
+ return -EPERM;
+ if (datalen <= 0 || datalen > 32767 || !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, data, datalen);
+ datablob[datalen] = '\0';
+ ret = datablob_parse(datablob, new_p, new_o);
+ if (ret != Opt_update) {
+ ret = -EINVAL;
+ 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_pointer(key->payload.data, 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_protected(key->payload.data,
+ rwsem_is_locked(&((struct key *)key)->sem));
+ 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 = pack_hex_byte(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");
projects / platform / kernel / linux-exynos.git / commitdiff