diff options
Diffstat (limited to 'drivers/char/tpm/tpm2-cmd.c')
| -rw-r--r-- | drivers/char/tpm/tpm2-cmd.c | 646 |
1 files changed, 646 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c new file mode 100644 index 00000000000..011909a9be9 --- /dev/null +++ b/drivers/char/tpm/tpm2-cmd.c @@ -0,0 +1,646 @@ +/* + * Copyright (C) 2014 Intel Corporation + * + * Authors: + * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> + * + * Maintained by: <tpmdd-devel@lists.sourceforge.net> + * + * 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 */ +}; + +#define TPM2_PCR_READ_IN_SIZE \ + (sizeof(struct tpm_input_header) + \ + sizeof(struct tpm2_pcr_read_in)) + +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. If a negative number is + * returned it remarks a POSIX error code. If a positive number is returned + * it remarks a TPM error. + */ +int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) +{ + int rc; + struct tpm2_cmd cmd; + u8 *buf; + + 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; + + 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; +} + +#define TPM2_GET_PCREXTEND_IN_SIZE \ + (sizeof(struct tpm_input_header) + \ + sizeof(struct tpm2_pcr_extend_in)) + +static const struct tpm_input_header tpm2_pcrextend_header = { + .tag = cpu_to_be16(TPM2_ST_SESSIONS), + .length = cpu_to_be32(TPM2_GET_PCREXTEND_IN_SIZE), + .ordinal = cpu_to_be32(TPM2_CC_PCR_EXTEND) +}; + +/** + * 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. If a negative number is + * returned it remarks a POSIX error code. If a positive number is returned + * it remarks a TPM error. + */ +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; +} + +#define TPM2_GETRANDOM_IN_SIZE \ + (sizeof(struct tpm_input_header) + \ + sizeof(struct tpm2_get_random_in)) + +static const struct tpm_input_header tpm2_getrandom_header = { + .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS), + .length = cpu_to_be32(TPM2_GETRANDOM_IN_SIZE), + .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. If a negative number is + * returned it remarks a POSIX error code. If 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; + u32 num_bytes; + int err; + int total = 0; + int retries = 5; + u8 *dest = out; + + num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer)); + + if (!out || !num_bytes || + max > sizeof(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 = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size), + num_bytes); + memcpy(dest, cmd.params.getrandom_out.buffer, recd); + + 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. If a negative number is + * returned it remarks a POSIX error code. If 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; +} + +#define TPM2_STARTUP_IN_SIZE \ + (sizeof(struct tpm_input_header) + \ + sizeof(struct tpm2_startup_in)) + +static const struct tpm_input_header tpm2_startup_header = { + .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS), + .length = cpu_to_be32(TPM2_STARTUP_IN_SIZE), + .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. If a negative number is + * returned it remarks a POSIX error code. If a positive number is returned + * it remarks a TPM error. + */ +int tpm2_startup(struct tpm_chip *chip, u16 startup_type) +{ + struct tpm2_cmd cmd; + + cmd.header.in = tpm2_startup_header; + + cmd.params.startup_in.startup_type = cpu_to_be16(startup_type); + return tpm_transmit_cmd(chip, &cmd, sizeof(cmd), + "attempting to start the TPM"); +} +EXPORT_SYMBOL_GPL(tpm2_startup); + +#define TPM2_SHUTDOWN_IN_SIZE \ + (sizeof(struct tpm_input_header) + \ + sizeof(struct tpm2_startup_in)) + +static const struct tpm_input_header tpm2_shutdown_header = { + .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS), + .length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE), + .ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN) +}; + +/** + * tpm2_shutdown() - send shutdown command to the TPM chip + * @chip: TPM chip to use. + * @shutdown_type shutdown type. The value is either + * TPM_SU_CLEAR or TPM_SU_STATE. + */ +void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type) +{ + struct tpm2_cmd cmd; + int rc; + + cmd.header.in = tpm2_shutdown_header; + cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type); + + rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), "stopping the TPM"); + + /* In places where shutdown command is sent there's no much we can do + * except print the error code on a system failure. + */ + if (rc < 0) + dev_warn(chip->pdev, "transmit returned %d while stopping the TPM", + rc); +} +EXPORT_SYMBOL_GPL(tpm2_shutdown); + +/* + * 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. If a negative number is + * returned it remarks a POSIX error code. If 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) + duration = 2 * 60 * HZ; + + return duration; +} +EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration); + +#define TPM2_SELF_TEST_IN_SIZE \ + (sizeof(struct tpm_input_header) + \ + sizeof(struct tpm2_self_test_in)) + +static const struct tpm_input_header tpm2_selftest_header = { + .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS), + .length = cpu_to_be32(TPM2_SELF_TEST_IN_SIZE), + .ordinal = cpu_to_be32(TPM2_CC_SELF_TEST) +}; + +/** + * 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. If a negative number is + * returned it remarks a POSIX error code. If 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"); + + /* At least some prototype chips seem to give RC_TESTING error + * immediately. This is a workaround for that. + */ + if (rc == TPM2_RC_TESTING) { + dev_warn(chip->pdev, "Got RC_TESTING, ignoring\n"); + rc = 0; + } + + 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. If a negative number is + * returned it remarks a POSIX error code. If 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. If a negative number is + * returned it remarks a POSIX error code. If a positive number is returned + * it remarks a TPM error. + */ +int tpm2_gen_interrupt(struct tpm_chip *chip) +{ + u32 dummy; + + return tpm2_get_tpm_pt(chip, 0x100, &dummy, + "attempting to generate an interrupt"); +} +EXPORT_SYMBOL_GPL(tpm2_gen_interrupt); + +/** + * tpm2_probe() - probe TPM 2.0 + * @chip: TPM chip to use + * + * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on + * the reply tag. + */ +int tpm2_probe(struct tpm_chip *chip) +{ + 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(0x100); + cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1); + + rc = tpm_transmit(chip, (const char *) &cmd, sizeof(cmd)); + if (rc < 0) + return rc; + else if (rc < TPM_HEADER_SIZE) + return -EFAULT; + + if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS) + chip->flags |= TPM_CHIP_FLAG_TPM2; + + return 0; +} +EXPORT_SYMBOL_GPL(tpm2_probe); |