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authorJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2015-05-30 08:09:04 +0300
committerPeter Huewe <peterhuewe@gmx.de>2015-10-19 01:01:21 +0200
commit954650efb79f99d5c817c121bb0a7c6c53362048 (patch)
tree12da28fd54da6f329cdfe83b42e65a0479313b0e
parentfe351e8d4eec801beeba1df1f36d76316be6f1a2 (diff)
tpm: seal/unseal for TPM 2.0
Added tpm_trusted_seal() and tpm_trusted_unseal() API for sealing trusted keys. This patch implements basic sealing and unsealing functionality for TPM 2.0: * Seal with a parent key using a 20 byte auth value. * Unseal with a parent key using a 20 byte auth value. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
-rw-r--r--drivers/char/tpm/tpm-interface.c76
-rw-r--r--drivers/char/tpm/tpm.h15
-rw-r--r--drivers/char/tpm/tpm2-cmd.c250
-rw-r--r--include/keys/trusted-type.h2
-rw-r--r--include/linux/tpm.h26
5 files changed, 366 insertions, 3 deletions
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index e85d3416d899..c50637db3a8a 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -666,6 +666,30 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
}
/**
+ * tpm_is_tpm2 - is the chip a TPM2 chip?
+ * @chip_num: tpm idx # or ANY
+ *
+ * Returns < 0 on error, and 1 or 0 on success depending whether the chip
+ * is a TPM2 chip.
+ */
+int tpm_is_tpm2(u32 chip_num)
+{
+ struct tpm_chip *chip;
+ int rc;
+
+ chip = tpm_chip_find_get(chip_num);
+ if (chip == NULL)
+ return -ENODEV;
+
+ rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
+
+ tpm_chip_put(chip);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_is_tpm2);
+
+/**
* tpm_pcr_read - read a pcr value
* @chip_num: tpm idx # or ANY
* @pcr_idx: pcr idx to retrieve
@@ -1021,6 +1045,58 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
}
EXPORT_SYMBOL_GPL(tpm_get_random);
+/**
+ * tpm_seal_trusted() - seal a trusted key
+ * @chip_num: A specific chip number for the request or TPM_ANY_NUM
+ * @options: authentication values and other options
+ * @payload: the key data in clear and encrypted form
+ *
+ * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
+ * are supported.
+ */
+int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
+ struct trusted_key_options *options)
+{
+ struct tpm_chip *chip;
+ int rc;
+
+ chip = tpm_chip_find_get(chip_num);
+ if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
+ return -ENODEV;
+
+ rc = tpm2_seal_trusted(chip, payload, options);
+
+ tpm_chip_put(chip);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_seal_trusted);
+
+/**
+ * tpm_unseal_trusted() - unseal a trusted key
+ * @chip_num: A specific chip number for the request or TPM_ANY_NUM
+ * @options: authentication values and other options
+ * @payload: the key data in clear and encrypted form
+ *
+ * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
+ * are supported.
+ */
+int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
+ struct trusted_key_options *options)
+{
+ struct tpm_chip *chip;
+ int rc;
+
+ chip = tpm_chip_find_get(chip_num);
+ if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
+ return -ENODEV;
+
+ rc = tpm2_unseal_trusted(chip, payload, options);
+
+ tpm_chip_put(chip);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
+
static int __init tpm_init(void)
{
int rc;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index cb46f6267af2..a4257a32964f 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -90,6 +90,9 @@ enum tpm2_return_codes {
enum tpm2_algorithms {
TPM2_ALG_SHA1 = 0x0004,
+ TPM2_ALG_KEYEDHASH = 0x0008,
+ TPM2_ALG_SHA256 = 0x000B,
+ TPM2_ALG_NULL = 0x0010
};
enum tpm2_command_codes {
@@ -97,6 +100,10 @@ enum tpm2_command_codes {
TPM2_CC_SELF_TEST = 0x0143,
TPM2_CC_STARTUP = 0x0144,
TPM2_CC_SHUTDOWN = 0x0145,
+ TPM2_CC_CREATE = 0x0153,
+ TPM2_CC_LOAD = 0x0157,
+ TPM2_CC_UNSEAL = 0x015E,
+ TPM2_CC_FLUSH_CONTEXT = 0x0165,
TPM2_CC_GET_CAPABILITY = 0x017A,
TPM2_CC_GET_RANDOM = 0x017B,
TPM2_CC_PCR_READ = 0x017E,
@@ -407,7 +414,7 @@ struct tpm_buf {
u8 *data;
};
-static inline void tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
+static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
{
struct tpm_input_header *head;
@@ -527,6 +534,12 @@ static inline void tpm_add_ppi(struct tpm_chip *chip)
int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash);
int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max);
+int tpm2_seal_trusted(struct tpm_chip *chip,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options);
+int tpm2_unseal_trusted(struct tpm_chip *chip,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options);
ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,
u32 *value, const char *desc);
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 011909a9be96..bd7039fafa8a 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2014 Intel Corporation
+ * Copyright (C) 2014, 2015 Intel Corporation
*
* Authors:
* Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
@@ -16,6 +16,11 @@
*/
#include "tpm.h"
+#include <keys/trusted-type.h>
+
+enum tpm2_object_attributes {
+ TPM2_ATTR_USER_WITH_AUTH = BIT(6),
+};
struct tpm2_startup_in {
__be16 startup_type;
@@ -381,6 +386,249 @@ static const struct tpm_input_header tpm2_get_tpm_pt_header = {
};
/**
+ * Append TPMS_AUTH_COMMAND to the buffer. The buffer must be allocated with
+ * tpm_buf_alloc().
+ *
+ * @param buf: an allocated tpm_buf instance
+ * @param nonce: the session nonce, may be NULL if not used
+ * @param nonce_len: the session nonce length, may be 0 if not used
+ * @param attributes: the session attributes
+ * @param hmac: the session HMAC or password, may be NULL if not used
+ * @param 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 a trusted key
+ * @chip_num: A specific chip number for the request or TPM_ANY_NUM
+ * @options: authentication values and other options
+ * @payload: the key data in clear and encrypted form
+ *
+ * Returns < 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;
+ int rc;
+
+ 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);
+
+ 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);
+ tpm_buf_append(&buf, payload->key, payload->key_len);
+
+ /* public */
+ tpm_buf_append_u16(&buf, 14);
+
+ tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH);
+ tpm_buf_append_u16(&buf, TPM2_ALG_SHA256);
+ tpm_buf_append_u32(&buf, TPM2_ATTR_USER_WITH_AUTH);
+ tpm_buf_append_u16(&buf, 0); /* policy digest size */
+ tpm_buf_append_u16(&buf, TPM2_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_transmit_cmd(chip, buf.data, PAGE_SIZE, "sealing data");
+ 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;
+ }
+
+ memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
+ payload->blob_len = blob_len;
+
+out:
+ tpm_buf_destroy(&buf);
+
+ if (rc > 0)
+ rc = -EPERM;
+
+ return rc;
+}
+
+static int tpm2_load(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_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob");
+ 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;
+}
+
+static void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
+{
+ struct tpm_buf buf;
+ int rc;
+
+ rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
+ if (rc) {
+ dev_warn(chip->pdev, "0x%08x was not flushed, out of memory\n",
+ handle);
+ return;
+ }
+
+ tpm_buf_append_u32(&buf, handle);
+
+ rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "flushing context");
+ if (rc)
+ dev_warn(chip->pdev, "0x%08x was not flushed, rc=%d\n", handle,
+ rc);
+
+ tpm_buf_destroy(&buf);
+}
+
+static int tpm2_unseal(struct tpm_chip *chip,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options,
+ u32 blob_handle)
+{
+ struct tpm_buf buf;
+ 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, TPM2_RS_PW,
+ NULL /* nonce */, 0,
+ 0 /* session_attributes */,
+ options->blobauth /* hmac */,
+ TPM_DIGEST_SIZE);
+
+ rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "unsealing");
+ if (rc > 0)
+ rc = -EPERM;
+
+ if (!rc) {
+ payload->key_len = be16_to_cpup(
+ (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
+
+ memcpy(payload->key, &buf.data[TPM_HEADER_SIZE + 6],
+ payload->key_len);
+ }
+
+ tpm_buf_destroy(&buf);
+ return rc;
+}
+
+/**
+ * tpm_unseal_trusted() - unseal a trusted key
+ * @chip_num: A specific chip number for the request or TPM_ANY_NUM
+ * @options: authentication values and other options
+ * @payload: the key data in clear and encrypted form
+ *
+ * Returns < 0 on error and 0 on success.
+ */
+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(chip, payload, options, &blob_handle);
+ if (rc)
+ return rc;
+
+ rc = tpm2_unseal(chip, payload, options, blob_handle);
+
+ tpm2_flush_context(chip, blob_handle);
+
+ return rc;
+}
+
+/**
* tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
* @chip: TPM chip to use.
* @property_id: property ID.
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
index c91651f91687..f91ecd9d1bb1 100644
--- a/include/keys/trusted-type.h
+++ b/include/keys/trusted-type.h
@@ -16,7 +16,7 @@
#define MIN_KEY_SIZE 32
#define MAX_KEY_SIZE 128
-#define MAX_BLOB_SIZE 320
+#define MAX_BLOB_SIZE 512
#define MAX_PCRINFO_SIZE 64
struct trusted_key_payload {
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 8350c538b486..706e63eea080 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -30,6 +30,8 @@
#define TPM_ANY_NUM 0xFFFF
struct tpm_chip;
+struct trusted_key_payload;
+struct trusted_key_options;
struct tpm_class_ops {
const u8 req_complete_mask;
@@ -46,11 +48,22 @@ struct tpm_class_ops {
#if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
+extern int tpm_is_tpm2(u32 chip_num);
extern int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf);
extern int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash);
extern int tpm_send(u32 chip_num, void *cmd, size_t buflen);
extern int tpm_get_random(u32 chip_num, u8 *data, size_t max);
+extern int tpm_seal_trusted(u32 chip_num,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options);
+extern int tpm_unseal_trusted(u32 chip_num,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options);
#else
+static inline int tpm_is_tpm2(u32 chip_num)
+{
+ return -ENODEV;
+}
static inline int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf) {
return -ENODEV;
}
@@ -63,5 +76,18 @@ static inline int tpm_send(u32 chip_num, void *cmd, size_t buflen) {
static inline int tpm_get_random(u32 chip_num, u8 *data, size_t max) {
return -ENODEV;
}
+
+static inline int tpm_seal_trusted(u32 chip_num,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options)
+{
+ return -ENODEV;
+}
+static inline int tpm_unseal_trusted(u32 chip_num,
+ struct trusted_key_payload *payload,
+ struct trusted_key_options *options)
+{
+ return -ENODEV;
+}
#endif
#endif

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