On 11/11/2014 08:45 AM, Jarkko Sakkinen wrote:
TPM 2.0 devices are separated by adding a field 'flags' to struct
tpm_chip and defining a flag TPM_CHIP_FLAG_TPM2 for tagging them.
This patch adds the following internal functions:
- tpm2_get_random()
- tpm2_get_tpm_pt()
- tpm2_pcr_extend()
- tpm2_pcr_read()
- tpm2_startup()
Additionally, the following exported functions are implemented for
implementing TPM 2.0 device drivers:
- tpm2_do_selftest()
- tpm2_calc_ordinal_durations()
- tpm2_gen_interrupt()
The existing functions that are exported for the use for existing
subsystems have been changed to check the flags field in struct
tpm_chip and use appropriate TPM 2.0 counterpart if
TPM_CHIP_FLAG_TPM2 is est.
The code for tpm2_calc_ordinal_duration() and tpm2_startup() were
originally written by Will Arthur.
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Will Arthur <will.c.arthur@xxxxxxxxx>
---
drivers/char/tpm/Makefile | 2 +-
drivers/char/tpm/tpm-chip.c | 21 +-
drivers/char/tpm/tpm-interface.c | 24 +-
drivers/char/tpm/tpm.h | 67 +++++
drivers/char/tpm/tpm2-cmd.c | 566 +++++++++++++++++++++++++++++++++++++++
5 files changed, 668 insertions(+), 12 deletions(-)
create mode 100644 drivers/char/tpm/tpm2-cmd.c
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 837da04..ae56af9 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -2,7 +2,7 @@
# Makefile for the kernel tpm device drivers.
#
obj-$(CONFIG_TCG_TPM) += tpm.o
-tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o
+tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o
tpm-$(CONFIG_ACPI) += tpm_ppi.o
ifdef CONFIG_ACPI
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 5d268ac..4d25b24 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -213,11 +213,14 @@ int tpm_chip_register(struct tpm_chip *chip)
if (rc)
return rc;
- rc = tpm_add_ppi(chip);
- if (rc)
- goto out_err;
+ /* Populate sysfs for TPM1 devices. */
+ if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
+ rc = tpm_add_ppi(chip);
+ if (rc)
+ goto out_err;
- chip->bios_dir = tpm_bios_log_setup(chip->devname);
+ chip->bios_dir = tpm_bios_log_setup(chip->devname);
+ }
/* Make the chip available. */
spin_lock(&driver_lock);
@@ -248,10 +251,12 @@ void tpm_chip_unregister(struct tpm_chip *chip)
spin_unlock(&driver_lock);
synchronize_rcu();
- tpm_remove_ppi(chip);
-
- if (chip->bios_dir)
- tpm_bios_log_teardown(chip->bios_dir);
+ /* Clean up sysfs for TPM1 devices. */
+ if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
+ if (chip->bios_dir)
+ tpm_bios_log_teardown(chip->bios_dir);
+ tpm_remove_ppi(chip);
+ }
tpm_dev_del_device(chip);
}
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 9e4ce4d..e62b835 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -360,7 +360,10 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
if (chip->vendor.irq)
goto out_recv;
- stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
+ else
+ stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
do {
u8 status = chip->ops->status(chip);
if ((status & chip->ops->req_complete_mask) ==
@@ -483,7 +486,7 @@ static const struct tpm_input_header tpm_startup_header = {
static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
{
struct tpm_cmd_t start_cmd;
- start_cmd.header.in = tpm_startup_header;
+
start_cmd.params.startup_in.startup_type = startup_type;
return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
"attempting to start the TPM");
@@ -680,7 +683,10 @@ int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
chip = tpm_chip_find_get(chip_num);
if (chip == NULL)
return -ENODEV;
- rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
+ else
+ rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
tpm_chip_put(chip);
return rc;
}
@@ -714,6 +720,12 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
if (chip == NULL)
return -ENODEV;
+ if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+ rc = tpm2_pcr_extend(chip, pcr_idx, hash);
+ tpm_chip_put(chip);
+ return rc;
+ }
+
cmd.header.in = pcrextend_header;
cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
@@ -974,6 +986,12 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
if (chip == NULL)
return -ENODEV;
+ if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+ err = tpm2_get_random(chip, out, max);
+ tpm_chip_put(chip);
+ return err;
+ }
+
do {
tpm_cmd.header.in = tpm_getrandom_header;
tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 9d062e6..8a434d2 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -62,6 +62,57 @@ enum tpm_duration {
#define TPM_ERR_INVALID_POSTINIT 38
#define TPM_HEADER_SIZE 10
+
+enum tpm2_const {
+ TPM2_PLATFORM_PCR = 24,
+ TPM2_PCR_SELECT_MIN = ((TPM2_PLATFORM_PCR + 7) / 8),
+ TPM2_TIMEOUT_A = 750 * 1000,
+ TPM2_TIMEOUT_B = 2000 * 1000,
+ TPM2_TIMEOUT_C = 200 * 1000,
+ TPM2_TIMEOUT_D = 30 * 1000,
+ TPM2_DURATION_SHORT = 20 * 1000,
+ TPM2_DURATION_MEDIUM = 750 * 1000,
+ TPM2_DURATION_LONG = 2000 * 1000,
+};
+
+enum tpm2_structures {
+ TPM2_ST_NO_SESSIONS = 0x8001,
+ TPM2_ST_SESSIONS = 0x8002,
+};
+
+enum tpm2_return_codes {
+ TPM2_RC_TESTING = 0x090A,
+ TPM2_RC_DISABLED = 0x0120,
+};
+
+enum tpm2_algorithms {
+ TPM2_ALG_SHA1 = 0x0004,
+};
+
+enum tpm2_command_codes {
+ TPM2_CC_FIRST = 0x011F,
+ TPM2_CC_SELF_TEST = 0x0143,
+ TPM2_CC_STARTUP = 0x0144,
+ TPM2_CC_GET_CAPABILITY = 0x017A,
+ TPM2_CC_GET_RANDOM = 0x017B,
+ TPM2_CC_PCR_READ = 0x017E,
+ TPM2_CC_PCR_EXTEND = 0x0182,
+ TPM2_CC_LAST = 0x018F,
+};
+
+enum tpm2_permanent_handles {
+ TPM2_RS_PW = 0x40000009,
+};
+
+enum tpm2_capabilities {
+ TPM2_CAP_TPM_PROPERTIES = 6,
+};
+
+enum tpm2_startup_types {
+ TPM2_SU_CLEAR = 0x0000,
+ TPM2_SU_STATE = 0x0001,
+};
+
struct tpm_chip;
struct tpm_vendor_specific {
@@ -96,12 +147,17 @@ struct tpm_vendor_specific {
#define TPM_PPI_VERSION_LEN 3
+enum tpm_chip_flags {
+ TPM_CHIP_FLAG_TPM2 = BIT(0),
+};
+
struct tpm_chip {
struct device *pdev; /* Device stuff */
struct device dev;
struct cdev cdev;
const struct tpm_class_ops *ops;
+ unsigned int flags;
int dev_num; /* /dev/tpm# */
char devname[7];
@@ -362,3 +418,14 @@ static inline void tpm_remove_ppi(struct tpm_chip *chip)
{
}
#endif
+
+int tpm2_startup(struct tpm_chip *chip, __be16 startup_type);
+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);
+
+extern ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,
+ u32 *value, const char *desc);
+extern unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *, u32);
+extern int tpm2_do_selftest(struct tpm_chip *chip);
+extern int tpm2_gen_interrupt(struct tpm_chip *chip);
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
new file mode 100644
index 0000000..458a17d
--- /dev/null
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -0,0 +1,566 @@
+/*
+ * Copyright (C) 2014 Intel Corporation
+ *
+ * Authors:
+ * Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
+ *
+ * Maintained by: <tpmdd-devel@xxxxxxxxxxxxxxxxxxxxx>
+ *
+ * This file contains TPM2 protocol implementations of the commands
+ * used by the kernel internally.
+ *
+ * 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.
+ */
+
+#include "tpm.h"
+
+struct tpm2_startup_in {
+ __be16 startup_type;
+} __packed;
+
+struct tpm2_self_test_in {
+ u8 full_test;
+} __packed;
+
+struct tpm2_pcr_read_in {
+ __be32 pcr_selects_cnt;
+ __be16 hash_alg;
+ u8 pcr_select_size;
+ u8 pcr_select[TPM2_PCR_SELECT_MIN];
+} __packed;
+
+struct tpm2_pcr_read_out {
+ __be32 update_cnt;
+ __be32 pcr_selects_cnt;
+ __be16 hash_alg;
+ u8 pcr_select_size;
+ u8 pcr_select[TPM2_PCR_SELECT_MIN];
+ __be32 digests_cnt;
+ __be16 digest_size;
+ u8 digest[TPM_DIGEST_SIZE];
+} __packed;
+
+struct tpm2_null_auth_area {
+ __be32 handle;
+ __be16 nonce_size;
+ u8 attributes;
+ __be16 auth_size;
+} __packed;
+
+struct tpm2_pcr_extend_in {
+ __be32 pcr_idx;
+ __be32 auth_area_size;
+ struct tpm2_null_auth_area auth_area;
+ __be32 digest_cnt;
+ __be16 hash_alg;
+ u8 digest[TPM_DIGEST_SIZE];
+} __packed;
+
+struct tpm2_get_tpm_pt_in {
+ __be32 cap_id;
+ __be32 property_id;
+ __be32 property_cnt;
+} __packed;
+
+struct tpm2_get_tpm_pt_out {
+ u8 more_data;
+ __be32 subcap_id;
+ __be32 property_cnt;
+ __be32 property_id;
+ __be32 value;
+} __packed;
+
+struct tpm2_get_random_in {
+ __be16 size;
+} __packed;
+
+struct tpm2_get_random_out {
+ __be16 size;
+ u8 buffer[TPM_MAX_RNG_DATA];
+} __packed;
+
+union tpm2_cmd_params {
+ struct tpm2_startup_in startup_in;
+ struct tpm2_self_test_in selftest_in;
+ struct tpm2_pcr_read_in pcrread_in;
+ struct tpm2_pcr_read_out pcrread_out;
+ struct tpm2_pcr_extend_in pcrextend_in;
+ struct tpm2_get_tpm_pt_in get_tpm_pt_in;
+ struct tpm2_get_tpm_pt_out get_tpm_pt_out;
+ struct tpm2_get_random_in getrandom_in;
+ struct tpm2_get_random_out getrandom_out;
+};
+
+struct tpm2_cmd {
+ tpm_cmd_header header;
+ union tpm2_cmd_params params;
+} __packed;
+
+/*
+ * Array with one entry per ordinal defining the maximum amount
+ * of time the chip could take to return the result. The values
+ * of the SHORT, MEDIUM, and LONG durations are taken from the
+ * PC Client Profile (PTP) specification.
+ */
+static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
+ TPM_UNDEFINED, /* 11F */
+ TPM_UNDEFINED, /* 120 */
+ TPM_LONG, /* 121 */
+ TPM_UNDEFINED, /* 122 */
+ TPM_UNDEFINED, /* 123 */
+ TPM_UNDEFINED, /* 124 */
+ TPM_UNDEFINED, /* 125 */
+ TPM_UNDEFINED, /* 126 */
+ TPM_UNDEFINED, /* 127 */
+ TPM_UNDEFINED, /* 128 */
+ TPM_LONG, /* 129 */
+ TPM_UNDEFINED, /* 12a */
+ TPM_UNDEFINED, /* 12b */
+ TPM_UNDEFINED, /* 12c */
+ TPM_UNDEFINED, /* 12d */
+ TPM_UNDEFINED, /* 12e */
+ TPM_UNDEFINED, /* 12f */
+ TPM_UNDEFINED, /* 130 */
+ TPM_UNDEFINED, /* 131 */
+ TPM_UNDEFINED, /* 132 */
+ TPM_UNDEFINED, /* 133 */
+ TPM_UNDEFINED, /* 134 */
+ TPM_UNDEFINED, /* 135 */
+ TPM_UNDEFINED, /* 136 */
+ TPM_UNDEFINED, /* 137 */
+ TPM_UNDEFINED, /* 138 */
+ TPM_UNDEFINED, /* 139 */
+ TPM_UNDEFINED, /* 13a */
+ TPM_UNDEFINED, /* 13b */
+ TPM_UNDEFINED, /* 13c */
+ TPM_UNDEFINED, /* 13d */
+ TPM_MEDIUM, /* 13e */
+ TPM_UNDEFINED, /* 13f */
+ TPM_UNDEFINED, /* 140 */
+ TPM_UNDEFINED, /* 141 */
+ TPM_UNDEFINED, /* 142 */
+ TPM_LONG, /* 143 */
+ TPM_MEDIUM, /* 144 */
+ TPM_UNDEFINED, /* 145 */
+ TPM_UNDEFINED, /* 146 */
+ TPM_UNDEFINED, /* 147 */
+ TPM_UNDEFINED, /* 148 */
+ TPM_UNDEFINED, /* 149 */
+ TPM_UNDEFINED, /* 14a */
+ TPM_UNDEFINED, /* 14b */
+ TPM_UNDEFINED, /* 14c */
+ TPM_UNDEFINED, /* 14d */
+ TPM_LONG, /* 14e */
+ TPM_UNDEFINED, /* 14f */
+ TPM_UNDEFINED, /* 150 */
+ TPM_UNDEFINED, /* 151 */
+ TPM_UNDEFINED, /* 152 */
+ TPM_UNDEFINED, /* 153 */
+ TPM_UNDEFINED, /* 154 */
+ TPM_UNDEFINED, /* 155 */
+ TPM_UNDEFINED, /* 156 */
+ TPM_UNDEFINED, /* 157 */
+ TPM_UNDEFINED, /* 158 */
+ TPM_UNDEFINED, /* 159 */
+ TPM_UNDEFINED, /* 15a */
+ TPM_UNDEFINED, /* 15b */
+ TPM_MEDIUM, /* 15c */
+ TPM_UNDEFINED, /* 15d */
+ TPM_UNDEFINED, /* 15e */
+ TPM_UNDEFINED, /* 15f */
+ TPM_UNDEFINED, /* 160 */
+ TPM_UNDEFINED, /* 161 */
+ TPM_UNDEFINED, /* 162 */
+ TPM_UNDEFINED, /* 163 */
+ TPM_UNDEFINED, /* 164 */
+ TPM_UNDEFINED, /* 165 */
+ TPM_UNDEFINED, /* 166 */
+ TPM_UNDEFINED, /* 167 */
+ TPM_UNDEFINED, /* 168 */
+ TPM_UNDEFINED, /* 169 */
+ TPM_UNDEFINED, /* 16a */
+ TPM_UNDEFINED, /* 16b */
+ TPM_UNDEFINED, /* 16c */
+ TPM_UNDEFINED, /* 16d */
+ TPM_UNDEFINED, /* 16e */
+ TPM_UNDEFINED, /* 16f */
+ TPM_UNDEFINED, /* 170 */
+ TPM_UNDEFINED, /* 171 */
+ TPM_UNDEFINED, /* 172 */
+ TPM_UNDEFINED, /* 173 */
+ TPM_UNDEFINED, /* 174 */
+ TPM_UNDEFINED, /* 175 */
+ TPM_UNDEFINED, /* 176 */
+ TPM_LONG, /* 177 */
+ TPM_UNDEFINED, /* 178 */
+ TPM_UNDEFINED, /* 179 */
+ TPM_MEDIUM, /* 17a */
+ TPM_LONG, /* 17b */
+ TPM_UNDEFINED, /* 17c */
+ TPM_UNDEFINED, /* 17d */
+ TPM_UNDEFINED, /* 17e */
+ TPM_UNDEFINED, /* 17f */
+ TPM_UNDEFINED, /* 180 */
+ TPM_UNDEFINED, /* 181 */
+ TPM_MEDIUM, /* 182 */
+ TPM_UNDEFINED, /* 183 */
+ TPM_UNDEFINED, /* 184 */
+ TPM_MEDIUM, /* 185 */
+ TPM_MEDIUM, /* 186 */
+ TPM_UNDEFINED, /* 187 */
+ TPM_UNDEFINED, /* 188 */
+ TPM_UNDEFINED, /* 189 */
+ TPM_UNDEFINED, /* 18a */
+ TPM_UNDEFINED, /* 18b */
+ TPM_UNDEFINED, /* 18c */
+ TPM_UNDEFINED, /* 18d */
+ TPM_UNDEFINED, /* 18e */
+ TPM_UNDEFINED /* 18f */
+};
+
+static const struct tpm_input_header tpm2_startup_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(12),
12 -> sizeof(struct tpm_input_header) + sizeof(struct pm2_startup_in)
+ .ordinal = cpu_to_be32(TPM2_CC_STARTUP)
+};
+
+/**
+ * tpm2_startup() - send startup command to the TPM chip
+ * @chip: TPM chip to use.
+ * @startup_type startup type. The value is either
+ * TPM_SU_CLEAR or TPM_SU_STATE.
+ *
+ * 0 is returned when the operation is successful. When a negative number is
+ * returned it remarks a POSIX error code. When a positive number is returned
+ * it remarks a TPM error.
Replace 'When's with 'If's. (when being 'temporal')
+ */
+int tpm2_startup(struct tpm_chip *chip, __be16 startup_type)
+{
+ struct tpm2_cmd cmd;
+
+ cmd.header.in = tpm2_startup_header;
+
+ cmd.params.startup_in.startup_type = startup_type;
+ return tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ "attempting to start the TPM");
+}
+
+#define TPM2_PCR_READ_IN_SIZE \
+ (sizeof(struct tpm_input_header) + \
+ sizeof(struct tpm2_pcr_read_in))
+
Ah! You could also use a #define above!
+static const struct tpm_input_header tpm2_pcrread_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(TPM2_PCR_READ_IN_SIZE),
+ .ordinal = cpu_to_be32(TPM2_CC_PCR_READ)
+};
+
+/**
+ * tpm2_pcr_read() - read a PCR value
+ * @chip: TPM chip to use.
+ * @pcr_idx: index of the PCR to read.
+ * @ref_buf: buffer to store the resulting hash,
+ *
+ * 0 is returned when the operation is successful. When a negative number is
+ * returned it remarks a POSIX error code. When a positive number is returned
+ * it remarks a TPM error.
+ */
Replace 'When's with 'If's. Also further below.
+int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
+{
+ int rc;
+ struct tpm2_cmd cmd;
+ u8 *buf;
+ int i, j;
+
+ if (pcr_idx >= TPM2_PLATFORM_PCR)
+ return -EINVAL;
+
+ cmd.header.in = tpm2_pcrread_header;
+ cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
+ cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
+ cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
+
+ for (i = 0; i < TPM2_PCR_SELECT_MIN; i++) {
+ j = pcr_idx - i * 8;
+
+ cmd.params.pcrread_in.pcr_select[i] =
+ (j >= 0 && j < 8) ? 1 << j : 0;
+ }
Umpf - what's this? You need to set the PCR index as an index in the
bitfield?
pcr_idx >> 3 gives you the index into the array, assuming that [0]
holds bits for PCR0 to 7.
1 << (pcr_idx & 0x7) gives you the bit to set, assuming bit 0 is to be
set for PCR 0
1 << (7- (pcr_idx & 0x7)) gives you the bit to set, assuming bit 7 is to
be set for PCR 0.
memset(cmd.params.pcrread_in.pcr_select, 0,
sizeof(cmd.params.pcrread_in.pcr_select));
cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
+
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ "attempting to read a pcr value");
+
+ if (rc == 0) {
+ buf = cmd.params.pcrread_out.digest;
+ memcpy(res_buf, buf, TPM_DIGEST_SIZE);
+ }
+
+ return rc;
+}
+
+/**
+ * tpm2_pcr_extend() - extend a PCR value
+ * @chip: TPM chip to use.
+ * @pcr_idx: index of the PCR.
+ * @hash: hash value to use for the extend operation.
+ *
+ * 0 is returned when the operation is successful. When a negative number is
+ * returned it remarks a POSIX error code. When a positive number is returned
+ * it remarks a TPM error.
+ */
+static const struct tpm_input_header tpm2_pcrextend_header = {
+ .tag = cpu_to_be16(TPM2_ST_SESSIONS),
+ .length = cpu_to_be32(sizeof(struct tpm_input_header) +
+ sizeof(struct tpm2_pcr_extend_in)),
+ .ordinal = cpu_to_be32(TPM2_CC_PCR_EXTEND)
+};
+
+int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
+{
+ struct tpm2_cmd cmd;
+ int rc;
+
+ cmd.header.in = tpm2_pcrextend_header;
+ cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
+ cmd.params.pcrextend_in.auth_area_size =
+ cpu_to_be32(sizeof(struct tpm2_null_auth_area));
+ cmd.params.pcrextend_in.auth_area.handle =
+ cpu_to_be32(TPM2_RS_PW);
+ cmd.params.pcrextend_in.auth_area.nonce_size = 0;
+ cmd.params.pcrextend_in.auth_area.attributes = 0;
+ cmd.params.pcrextend_in.auth_area.auth_size = 0;
+ cmd.params.pcrextend_in.digest_cnt = cpu_to_be32(1);
+ cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
+ memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE);
+
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ "attempting extend a PCR value");
+
+ return rc;
+}
+
+static const struct tpm_input_header tpm2_getrandom_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(sizeof(struct tpm_input_header) +
+ sizeof(struct tpm2_get_random_in)),
+ .ordinal = cpu_to_be32(TPM2_CC_GET_RANDOM)
+};
+
+/**
+ * tpm2_get_random() - get random bytes from the TPM RNG
+ * @chip: TPM chip to use
+ * @out: destination buffer for the random bytes
+ * @max: the max number of bytes to write to @out
+ *
+ * 0 is returned when the operation is successful. When a negative number is
+ * returned it remarks a POSIX error code. When a positive number is returned
+ * it remarks a TPM error.
+ */
+int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
+{
+ struct tpm2_cmd cmd;
+ u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
num_bytes = min_t(u32, max, sizeof(tpm2_cmd.params.getrandom_out.buffer);
This way you tie it to the actual buffer size of the buffer the TPM can fill
+ int err, total = 0, retries = 5;
+ u8 *dest = out;
+
+ if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
... || max > sizeof((tpm2_cmd.params.getrandom_out.buffer)
+ return -EINVAL;
+
+ do {
+ cmd.header.in = tpm2_getrandom_header;
+ cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
+
+ err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ "attempting get random");
+ if (err)
+ break;
+
+ recd = be16_to_cpu(cmd.params.getrandom_out.size);
+ memcpy(dest, cmd.params.getrandom_out.buffer, recd);
to be on the safe side, I would do
/* never accept more bytes than we asked for */
recd = min(recd, num_bytes);
memcpy(dest, cmd.params.getrandom_out.buffer, recd);
so that the destination buffer can never be overwritten beyond its
boundaries by a TPM that just ends up sending you more bytes than you
asked for (firmware bug).
+
+ dest += recd;
+ total += recd;
+ num_bytes -= recd;
+ } while (retries-- && total < max);
+
+ return total ? total : -EIO;
+}
+
+#define TPM2_GET_TPM_PT_IN_SIZE \
+ (sizeof(struct tpm_input_header) + \
+ sizeof(struct tpm2_get_tpm_pt_in))
+
+static const struct tpm_input_header tpm2_get_tpm_pt_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
+ .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
+};
+
+/**
+ * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
+ * @chip: TPM chip to use.
+ * @property_id: property ID.
+ * @value: output variable.
+ * @desc: passed to tpm_transmit_cmd()
+ *
+ * 0 is returned when the operation is successful. When a negative number is
+ * returned it remarks a POSIX error code. When a positive number is returned
+ * it remarks a TPM error.
+ */
+ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
+ const char *desc)
+{
+ struct tpm2_cmd cmd;
+ int rc;
+
+ cmd.header.in = tpm2_get_tpm_pt_header;
+ cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
+ cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
+ cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
+
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), desc);
+ if (!rc)
+ *value = cmd.params.get_tpm_pt_out.value;
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
+
+/*
+ * tpm2_calc_ordinal_duration() - maximum duration for a command
+ * @chip: TPM chip to use.
+ * @ordinal: command code number.
+ *
+ * 0 is returned when the operation is successful. When a negative number is
+ * returned it remarks a POSIX error code. When a positive number is returned
+ * it remarks a TPM error.
+ */
+unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
+{
+ int index = TPM_UNDEFINED;
+ int duration = 0;
+
+ if (ordinal >= TPM2_CC_FIRST && ordinal <= TPM2_CC_LAST)
+ index = tpm2_ordinal_duration[ordinal - TPM2_CC_FIRST];
+
+ if (index != TPM_UNDEFINED)
+ duration = chip->vendor.duration[index];
+ if (duration <= 0)
+ return 2 * 60 * HZ;
+ else
+ return duration;
+}
+EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration);
+
+static const struct tpm_input_header tpm2_selftest_header = {
+ .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+ .length = cpu_to_be32(sizeof(struct tpm_input_header) +
+ sizeof(struct tpm2_self_test_in)),
+ .ordinal = cpu_to_be32(TPM2_CC_SELF_TEST)
+};
+
+#define TPM2_SELF_TEST_IN_SIZE \
+ (sizeof(struct tpm_input_header) + sizeof(struct tpm2_self_test_in))
+
+/**
+ * tpm2_continue_selftest() - start a self test
+ * @chip: TPM chip to use
+ * @full: test all commands instead of testing only those that were not
+ * previously tested.
+ *
+ * 0 is returned when the operation is successful. When a negative number is
+ * returned it remarks a POSIX error code. When a positive number is returned
+ * it remarks a TPM error.
+ */
+static int tpm2_start_selftest(struct tpm_chip *chip, bool full)
+{
+ int rc;
+ struct tpm2_cmd cmd;
+
+ cmd.header.in = tpm2_selftest_header;
+ cmd.params.selftest_in.full_test = full;
+
+ rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE,
+ "continue selftest");
+
+ return rc;
+}
+
+/**
+ * tpm2_do_selftest() - run a full self test
+ * @chip: TPM chip to use
+ *
+ * During the self test TPM2 commands return with the error code RC_TESTING.
+ * Waiting is done by issuing PCR read until it executes successfully.
+ *
+ * 0 is returned when the operation is successful. When a negative number is
+ * returned it remarks a POSIX error code. When a positive number is returned
+ * it remarks a TPM error.
+ */
+int tpm2_do_selftest(struct tpm_chip *chip)
+{
+ int rc;
+ unsigned int loops;
+ unsigned int delay_msec = 100;
+ unsigned long duration;
+ struct tpm2_cmd cmd;
+ int i;
+
+ duration = tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST);
+
+ loops = jiffies_to_msecs(duration) / delay_msec;
+
+ rc = tpm2_start_selftest(chip, true);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < loops; i++) {
+ /* Attempt to read a PCR value */
+ cmd.header.in = tpm2_pcrread_header;
+ cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
+ cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
+ cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
+ cmd.params.pcrread_in.pcr_select[0] = 0x01;
+ cmd.params.pcrread_in.pcr_select[1] = 0x00;
+ cmd.params.pcrread_in.pcr_select[2] = 0x00;
+
+ rc = tpm_transmit_cmd(chip, (u8 *) &cmd, sizeof(cmd), NULL);
+ if (rc < 0)
+ break;
+
+ rc = be32_to_cpu(cmd.header.out.return_code);
+ if (rc != TPM2_RC_TESTING)
+ break;
+
+ msleep(delay_msec);
+ }
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm2_do_selftest);
+
+/**
+ * tpm2_gen_interrupt() - generate an interrupt
+ * @chip: TPM chip to use
+ *
+ * 0 is returned when the operation is successful. When a negative number is
+ * returned it remarks a POSIX error code. When a positive number is returned
+ * it remarks a TPM error.
+ */
+
+int tpm2_gen_interrupt(struct tpm_chip *chip)
+{
+ u32 dummy;
+ int rc;
+
+ rc = tpm2_get_tpm_pt(chip,
+ TPM2_CAP_TPM_PROPERTIES,
+ &dummy,
+ "attempting to generate an interrupt");
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm2_gen_interrupt);
Stefan
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