tpm: Add TPM command library

TPM command library implements a subset of TPM commands defined in TCG
Main Specification 1.2 that are useful for implementing secure boot.
More TPM commands could be added out of necessity.

You may exercise these commands through the 'tpm' command.  However, the
raw TPM commands are too primitive for writing secure boot in command
interpreter scripts; so the 'tpm' command also provides helper functions
to make scripting easier.

For example, to define a counter in TPM non-volatile storage and
initialize it to zero:

$ tpm init
$ tpm startup TPM_ST_CLEAR
$ tpm nv_define d 0x1001 0x1
$ tpm nv_write d 0x1001 0

And then increment the counter by one:

$ tpm nv_read d 0x1001 i
$ setexpr.l i $i + 1
$ tpm nv_write d 0x1001 $i

Signed-off-by: Che-Liang Chiou <clchiou@chromium.org>

1 files changed, 165 insertions, 32 deletions

diff --git a/include/tpm.h b/include/tpm.h
index 6b21e9c..7219b73 100644
--- a/include/tpm.h
+++ b/include/tpm.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011 The Chromium OS Authors.
+ * Copyright (c) 2013 The Chromium OS Authors.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
@@ -20,52 +20,185 @@
  * MA 02111-1307 USA
  */
 
-#ifndef _INCLUDE_TPM_H_
-#define _INCLUDE_TPM_H_
+#ifndef __TPM_H
+#define __TPM_H
 
-#include <common.h>
+#include <tis.h>
 
 /*
- * tis_init()
+ * Here is a partial implementation of TPM commands.  Please consult TCG Main
+ * Specification for definitions of TPM commands.
+ */
+
+enum tpm_startup_type {
+	TPM_ST_CLEAR		= 0x0001,
+	TPM_ST_STATE		= 0x0002,
+	TPM_ST_DEACTIVATED	= 0x0003,
+};
+
+enum tpm_physical_presence {
+	TPM_PHYSICAL_PRESENCE_HW_DISABLE	= 0x0200,
+	TPM_PHYSICAL_PRESENCE_CMD_DISABLE	= 0x0100,
+	TPM_PHYSICAL_PRESENCE_LIFETIME_LOCK	= 0x0080,
+	TPM_PHYSICAL_PRESENCE_HW_ENABLE		= 0x0040,
+	TPM_PHYSICAL_PRESENCE_CMD_ENABLE	= 0x0020,
+	TPM_PHYSICAL_PRESENCE_NOTPRESENT	= 0x0010,
+	TPM_PHYSICAL_PRESENCE_PRESENT		= 0x0008,
+	TPM_PHYSICAL_PRESENCE_LOCK		= 0x0004,
+};
+
+enum tpm_nv_index {
+	TPM_NV_INDEX_LOCK	= 0xffffffff,
+	TPM_NV_INDEX_0		= 0x00000000,
+	TPM_NV_INDEX_DIR	= 0x10000001,
+};
+
+/**
+ * Initialize TPM device.  It must be called before any TPM commands.
  *
- * Initialize the TPM device. Returns 0 on success or -1 on
- * failure (in case device probing did not succeed).
+ * @return 0 on success, non-0 on error.
  */
-int tis_init(void);
+uint32_t tpm_init(void);
 
-/*
- * tis_open()
+/**
+ * Issue a TPM_Startup command.
  *
- * Requests access to locality 0 for the caller. After all commands have been
- * completed the caller is supposed to call tis_close().
+ * @param mode		TPM startup mode
+ * @return return code of the operation
+ */
+uint32_t tpm_startup(enum tpm_startup_type mode);
+
+/**
+ * Issue a TPM_SelfTestFull command.
  *
- * Returns 0 on success, -1 on failure.
+ * @return return code of the operation
  */
-int tis_open(void);
+uint32_t tpm_self_test_full(void);
 
-/*
- * tis_close()
+/**
+ * Issue a TPM_ContinueSelfTest command.
  *
- * terminate the currect session with the TPM by releasing the locked
- * locality. Returns 0 on success of -1 on failure (in case lock
- * removal did not succeed).
+ * @return return code of the operation
  */
-int tis_close(void);
+uint32_t tpm_continue_self_test(void);
 
-/*
- * tis_sendrecv()
+/**
+ * Issue a TPM_NV_DefineSpace command.  The implementation is limited
+ * to specify TPM_NV_ATTRIBUTES and size of the area.  The area index
+ * could be one of the special value listed in enum tpm_nv_index.
  *
- * Send the requested data to the TPM and then try to get its response
+ * @param index		index of the area
+ * @param perm		TPM_NV_ATTRIBUTES of the area
+ * @param size		size of the area
+ * @return return code of the operation
+ */
+uint32_t tpm_nv_define_space(uint32_t index, uint32_t perm, uint32_t size);
+
+/**
+ * Issue a TPM_NV_ReadValue command.  This implementation is limited
+ * to read the area from offset 0.  The area index could be one of
+ * the special value listed in enum tpm_nv_index.
+ *
+ * @param index		index of the area
+ * @param data		output buffer of the area contents
+ * @param count		size of output buffer
+ * @return return code of the operation
+ */
+uint32_t tpm_nv_read_value(uint32_t index, void *data, uint32_t count);
+
+/**
+ * Issue a TPM_NV_WriteValue command.  This implementation is limited
+ * to write the area from offset 0.  The area index could be one of
+ * the special value listed in enum tpm_nv_index.
+ *
+ * @param index		index of the area
+ * @param data		input buffer to be wrote to the area
+ * @param length	length of data bytes of input buffer
+ * @return return code of the operation
+ */
+uint32_t tpm_nv_write_value(uint32_t index, const void *data, uint32_t length);
+
+/**
+ * Issue a TPM_Extend command.
+ *
+ * @param index		index of the PCR
+ * @param in_digest	160-bit value representing the event to be
+ *			recorded
+ * @param out_digest	160-bit PCR value after execution of the
+ *			command
+ * @return return code of the operation
+ */
+uint32_t tpm_extend(uint32_t index, const void *in_digest, void *out_digest);
+
+/**
+ * Issue a TPM_PCRRead command.
  *
- * @sendbuf - buffer of the data to send
- * @send_size size of the data to send
- * @recvbuf - memory to save the response to
- * @recv_len - pointer to the size of the response buffer
+ * @param index		index of the PCR
+ * @param data		output buffer for contents of the named PCR
+ * @param count		size of output buffer
+ * @return return code of the operation
+ */
+uint32_t tpm_pcr_read(uint32_t index, void *data, size_t count);
+
+/**
+ * Issue a TSC_PhysicalPresence command.  TPM physical presence flag
+ * is bit-wise OR'ed of flags listed in enum tpm_physical_presence.
+ *
+ * @param presence	TPM physical presence flag
+ * @return return code of the operation
+ */
+uint32_t tpm_tsc_physical_presence(uint16_t presence);
+
+/**
+ * Issue a TPM_ReadPubek command.
+ *
+ * @param data		output buffer for the public endorsement key
+ * @param count		size of ouput buffer
+ * @return return code of the operation
+ */
+uint32_t tpm_read_pubek(void *data, size_t count);
+
+/**
+ * Issue a TPM_ForceClear command.
+ *
+ * @return return code of the operation
+ */
+uint32_t tpm_force_clear(void);
+
+/**
+ * Issue a TPM_PhysicalEnable command.
+ *
+ * @return return code of the operation
+ */
+uint32_t tpm_physical_enable(void);
+
+/**
+ * Issue a TPM_PhysicalDisable command.
+ *
+ * @return return code of the operation
+ */
+uint32_t tpm_physical_disable(void);
+
+/**
+ * Issue a TPM_PhysicalSetDeactivated command.
+ *
+ * @param state		boolean state of the deactivated flag
+ * @return return code of the operation
+ */
+uint32_t tpm_physical_set_deactivated(uint8_t state);
+
+/**
+ * Issue a TPM_GetCapability command.  This implementation is limited
+ * to query sub_cap index that is 4-byte wide.
  *
- * Returns 0 on success (and places the number of response bytes at recv_len)
- * or -1 on failure.
+ * @param cap_area	partition of capabilities
+ * @param sub_cap	further definition of capability, which is
+ *			limited to be 4-byte wide
+ * @param cap		output buffer for capability information
+ * @param count		size of ouput buffer
+ * @return return code of the operation
  */
-int tis_sendrecv(const uint8_t *sendbuf, size_t send_size, uint8_t *recvbuf,
-			size_t *recv_len);
+uint32_t tpm_get_capability(uint32_t cap_area, uint32_t sub_cap,
+		void *cap, size_t count);
 
-#endif /* _INCLUDE_TPM_H_ */
+#endif /* __TPM_H */