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authorSumit Garg <sumit.garg@linaro.org>2019-10-16 10:44:55 +0530
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2019-11-12 21:45:37 +0200
commit2e19e10131a08dc65079c755fb6e8af936bfedbd (patch)
tree2d0b6302ac56d77fc57fab16a150a191fd2f61b2 /security/keys/trusted-keys/trusted_tpm2.c
parent47f9c279689107f306fff506753971a39a8a7ffc (diff)
KEYS: trusted: Move TPM2 trusted keys code
Move TPM2 trusted keys code to trusted keys subsystem. The reason being it's better to consolidate all the trusted keys code to a single location so that it can be maintained sanely. Also, utilize existing tpm_send() exported API which wraps the internal tpm_transmit_cmd() API. Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Diffstat (limited to 'security/keys/trusted-keys/trusted_tpm2.c')
-rw-r--r--security/keys/trusted-keys/trusted_tpm2.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
new file mode 100644
index 000000000000..a9810ac2776f
--- /dev/null
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2004 IBM Corporation
+ * Copyright (C) 2014 Intel Corporation
+ */
+
+#include <linux/string.h>
+#include <linux/err.h>
+#include <linux/tpm.h>
+#include <linux/tpm_command.h>
+
+#include <keys/trusted-type.h>
+#include <keys/trusted_tpm.h>
+
+static struct tpm2_hash tpm2_hash_map[] = {
+ {HASH_ALGO_SHA1, TPM_ALG_SHA1},
+ {HASH_ALGO_SHA256, TPM_ALG_SHA256},
+ {HASH_ALGO_SHA384, TPM_ALG_SHA384},
+ {HASH_ALGO_SHA512, TPM_ALG_SHA512},
+ {HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
+};
+
+/**
+ * tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
+ *
+ * @buf: an allocated tpm_buf instance
+ * @session_handle: session handle
+ * @nonce: the session nonce, may be NULL if not used
+ * @nonce_len: the session nonce length, may be 0 if not used
+ * @attributes: the session attributes
+ * @hmac: the session HMAC or password, may be NULL if not used
+ * @hmac_len: the session HMAC or password length, maybe 0 if not used
+ */
+static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
+ const u8 *nonce, u16 nonce_len,
+ u8 attributes,
+ const u8 *hmac, u16 hmac_len)
+{
+ tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
+ tpm_buf_append_u32(buf, session_handle);
+ tpm_buf_append_u16(buf, nonce_len);
+
+ if (nonce && nonce_len)
+ tpm_buf_append(buf, nonce, nonce_len);
+
+ tpm_buf_append_u8(buf, attributes);
+ tpm_buf_append_u16(buf, hmac_len);
+
+ if (hmac && hmac_len)
+ tpm_buf_append(buf, hmac, hmac_len);
+}
+
+/**
+ * tpm2_seal_trusted() - seal the payload of a trusted key
+ *
+ * @chip: TPM chip to use
+ * @payload: the key data in clear and encrypted form
+ * @options: authentication values and other options
+ *
+ * Return: < 0 on error and 0 on success.
+ */
+int tpm2_seal_trusted(struct tpm_chip *chip,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options)
+{
+ unsigned int blob_len;
+ struct tpm_buf buf;
+ u32 hash;
+ int i;
+ int rc;
+
+ for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
+ if (options->hash == tpm2_hash_map[i].crypto_id) {
+ hash = tpm2_hash_map[i].tpm_id;
+ break;
+ }
+ }
+
+ if (i == ARRAY_SIZE(tpm2_hash_map))
+ return -EINVAL;
+
+ rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
+ if (rc)
+ return rc;
+
+ tpm_buf_append_u32(&buf, options->keyhandle);
+ tpm2_buf_append_auth(&buf, TPM2_RS_PW,
+ NULL /* nonce */, 0,
+ 0 /* session_attributes */,
+ options->keyauth /* hmac */,
+ TPM_DIGEST_SIZE);
+
+ /* sensitive */
+ tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
+
+ tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
+ tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
+ tpm_buf_append_u16(&buf, payload->key_len + 1);
+ tpm_buf_append(&buf, payload->key, payload->key_len);
+ tpm_buf_append_u8(&buf, payload->migratable);
+
+ /* public */
+ tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
+ tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH);
+ tpm_buf_append_u16(&buf, hash);
+
+ /* policy */
+ if (options->policydigest_len) {
+ tpm_buf_append_u32(&buf, 0);
+ tpm_buf_append_u16(&buf, options->policydigest_len);
+ tpm_buf_append(&buf, options->policydigest,
+ options->policydigest_len);
+ } else {
+ tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
+ tpm_buf_append_u16(&buf, 0);
+ }
+
+ /* public parameters */
+ tpm_buf_append_u16(&buf, TPM_ALG_NULL);
+ tpm_buf_append_u16(&buf, 0);
+
+ /* outside info */
+ tpm_buf_append_u16(&buf, 0);
+
+ /* creation PCR */
+ tpm_buf_append_u32(&buf, 0);
+
+ if (buf.flags & TPM_BUF_OVERFLOW) {
+ rc = -E2BIG;
+ goto out;
+ }
+
+ rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
+ if (rc)
+ goto out;
+
+ blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
+ if (blob_len > MAX_BLOB_SIZE) {
+ rc = -E2BIG;
+ goto out;
+ }
+ if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
+ payload->blob_len = blob_len;
+
+out:
+ tpm_buf_destroy(&buf);
+
+ if (rc > 0) {
+ if (tpm2_rc_value(rc) == TPM2_RC_HASH)
+ rc = -EINVAL;
+ else
+ rc = -EPERM;
+ }
+
+ return rc;
+}
+
+/**
+ * tpm2_load_cmd() - execute a TPM2_Load command
+ *
+ * @chip: TPM chip to use
+ * @payload: the key data in clear and encrypted form
+ * @options: authentication values and other options
+ * @blob_handle: returned blob handle
+ *
+ * Return: 0 on success.
+ * -E2BIG on wrong payload size.
+ * -EPERM on tpm error status.
+ * < 0 error from tpm_send.
+ */
+static int tpm2_load_cmd(struct tpm_chip *chip,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options,
+ u32 *blob_handle)
+{
+ struct tpm_buf buf;
+ unsigned int private_len;
+ unsigned int public_len;
+ unsigned int blob_len;
+ int rc;
+
+ private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
+ if (private_len > (payload->blob_len - 2))
+ return -E2BIG;
+
+ public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
+ blob_len = private_len + public_len + 4;
+ if (blob_len > payload->blob_len)
+ return -E2BIG;
+
+ rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
+ if (rc)
+ return rc;
+
+ tpm_buf_append_u32(&buf, options->keyhandle);
+ tpm2_buf_append_auth(&buf, TPM2_RS_PW,
+ NULL /* nonce */, 0,
+ 0 /* session_attributes */,
+ options->keyauth /* hmac */,
+ TPM_DIGEST_SIZE);
+
+ tpm_buf_append(&buf, payload->blob, blob_len);
+
+ if (buf.flags & TPM_BUF_OVERFLOW) {
+ rc = -E2BIG;
+ goto out;
+ }
+
+ rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
+ if (!rc)
+ *blob_handle = be32_to_cpup(
+ (__be32 *) &buf.data[TPM_HEADER_SIZE]);
+
+out:
+ tpm_buf_destroy(&buf);
+
+ if (rc > 0)
+ rc = -EPERM;
+
+ return rc;
+}
+
+/**
+ * tpm2_unseal_cmd() - execute a TPM2_Unload command
+ *
+ * @chip: TPM chip to use
+ * @payload: the key data in clear and encrypted form
+ * @options: authentication values and other options
+ * @blob_handle: blob handle
+ *
+ * Return: 0 on success
+ * -EPERM on tpm error status
+ * < 0 error from tpm_send
+ */
+static int tpm2_unseal_cmd(struct tpm_chip *chip,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options,
+ u32 blob_handle)
+{
+ struct tpm_buf buf;
+ u16 data_len;
+ u8 *data;
+ int rc;
+
+ rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
+ if (rc)
+ return rc;
+
+ tpm_buf_append_u32(&buf, blob_handle);
+ tpm2_buf_append_auth(&buf,
+ options->policyhandle ?
+ options->policyhandle : TPM2_RS_PW,
+ NULL /* nonce */, 0,
+ TPM2_SA_CONTINUE_SESSION,
+ options->blobauth /* hmac */,
+ TPM_DIGEST_SIZE);
+
+ rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
+ if (rc > 0)
+ rc = -EPERM;
+
+ if (!rc) {
+ data_len = be16_to_cpup(
+ (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
+ if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
+ rc = -EFAULT;
+ goto out;
+ }
+ data = &buf.data[TPM_HEADER_SIZE + 6];
+
+ memcpy(payload->key, data, data_len - 1);
+ payload->key_len = data_len - 1;
+ payload->migratable = data[data_len - 1];
+ }
+
+out:
+ tpm_buf_destroy(&buf);
+ return rc;
+}
+
+/**
+ * tpm2_unseal_trusted() - unseal the payload of a trusted key
+ *
+ * @chip: TPM chip to use
+ * @payload: the key data in clear and encrypted form
+ * @options: authentication values and other options
+ *
+ * Return: Same as with tpm_send.
+ */
+int tpm2_unseal_trusted(struct tpm_chip *chip,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options)
+{
+ u32 blob_handle;
+ int rc;
+
+ rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
+ if (rc)
+ return rc;
+
+ rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
+
+ return rc;
+}