tpm1_get_random() and tpm2_get_random() contain duplicate orchestration code. Consolidate orchestration to tpm_get_random().
Signed-off-by: Jarkko Sakkinen <[email protected]> --- drivers/char/tpm/tpm-interface.c | 175 +++++++++++++++++++++++++++++-- drivers/char/tpm/tpm.h | 2 - drivers/char/tpm/tpm1-cmd.c | 69 ------------ drivers/char/tpm/tpm2-cmd.c | 104 ------------------ 4 files changed, 164 insertions(+), 186 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index f745a098908b..d157be738612 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -26,7 +26,7 @@ #include <linux/suspend.h> #include <linux/freezer.h> #include <linux/tpm_eventlog.h> - +#include <linux/tpm_command.h> #include "tpm.h" /* @@ -486,19 +486,153 @@ int tpm_pm_resume(struct device *dev) } EXPORT_SYMBOL_GPL(tpm_pm_resume); +struct tpm1_get_random_out { + __be32 rng_data_len; + u8 rng_data[TPM_MAX_RNG_DATA]; +} __packed; + +static int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max) +{ + struct tpm1_get_random_out *resp; + struct tpm_buf buf; + u32 recd; + int rc; + + if (!out || !max || max > TPM_MAX_RNG_DATA) + return -EINVAL; + + rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GETRANDOM); + if (rc) + return rc; + + tpm_buf_append_u32(&buf, max); + + rc = tpm_transmit_cmd(chip, &buf, sizeof(resp->rng_data_len), "TPM_GetRandom"); + if (rc) { + if (rc > 0) + rc = -EIO; + goto err; + } + + resp = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE]; + + recd = be32_to_cpu(resp->rng_data_len); + if (recd > max) { + rc = -EIO; + goto err; + } + + if (buf.length < TPM_HEADER_SIZE + sizeof(resp->rng_data_len) + recd) { + rc = -EIO; + goto err; + } + + memcpy(out, resp->rng_data, recd); + tpm_buf_destroy(&buf); + return recd; + +err: + tpm_buf_destroy(&buf); + return rc; +} + +struct tpm2_get_random_out { + __be16 size; + u8 buffer[TPM_MAX_RNG_DATA]; +} __packed; + +static int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max) +{ + struct tpm2_get_random_out *resp; + struct tpm_header *head; + struct tpm_buf buf; + off_t offset; + u32 recd; + int ret; + + if (!out || !max || max > TPM_MAX_RNG_DATA) + return -EINVAL; + + ret = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM); + if (ret) + return ret; + + if (tpm2_chip_auth(chip)) { + tpm_buf_append_hmac_session(chip, &buf, + TPM2_SA_ENCRYPT | TPM2_SA_CONTINUE_SESSION, + NULL, 0); + } else { + head = (struct tpm_header *)buf.data; + head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); + } + tpm_buf_append_u16(&buf, max); + + ret = tpm_buf_fill_hmac_session(chip, &buf); + if (ret) { + tpm_buf_destroy(&buf); + return ret; + } + + ret = tpm_transmit_cmd(chip, &buf, offsetof(struct tpm2_get_random_out, buffer), + "TPM2_GetRandom"); + + ret = tpm_buf_check_hmac_response(chip, &buf, ret); + if (ret) { + if (ret > 0) + ret = -EIO; + + goto out; + } + + head = (struct tpm_header *)buf.data; + offset = TPM_HEADER_SIZE; + + /* Skip the parameter size field: */ + if (be16_to_cpu(head->tag) == TPM2_ST_SESSIONS) + offset += 4; + + resp = (struct tpm2_get_random_out *)&buf.data[offset]; + recd = min_t(u32, be16_to_cpu(resp->size), max); + + if (tpm_buf_length(&buf) < + TPM_HEADER_SIZE + offsetof(struct tpm2_get_random_out, buffer) + recd) { + ret = -EIO; + goto out; + } + + memcpy(out, resp->buffer, recd); + return recd; + +out: + tpm2_end_auth_session(chip); + tpm_buf_destroy(&buf); + return ret; +} + /** - * tpm_get_random() - get random bytes from the TPM's RNG - * @chip: a &struct tpm_chip instance, %NULL for the default chip - * @out: destination buffer for the random bytes - * @max: the max number of bytes to write to @out + * tpm_get_random() - Get random bytes from the TPM's RNG + * @chip: A &tpm_chip instance. Whenset to %NULL, the default chip is used. + * @out: Destination buffer for the acquired random bytes. + * @max: The maximum number of bytes to write to @out. + * + * Iterates pulling more bytes from TPM up until all of the @max bytes have been + * received. * - * Return: number of random bytes read or a negative error value. + * Returns the number of random bytes read on success. + * Returns -EINVAL when @out is NULL, or @max is not between zero and + * %TPM_MAX_RNG_DATA. + * Returns tpm_transmit_cmd() error codes when the TPM command results an + * error. */ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max) { + u32 num_bytes = max; + u8 *out_ptr = out; + int retries = 5; + int total = 0; int rc; - if (!out || max > TPM_MAX_RNG_DATA) + if (!out || !max || max > TPM_MAX_RNG_DATA) return -EINVAL; if (!chip) @@ -508,11 +642,30 @@ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max) if (rc) return rc; - if (chip->flags & TPM_CHIP_FLAG_TPM2) - rc = tpm2_get_random(chip, out, max); - else - rc = tpm1_get_random(chip, out, max); + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + rc = tpm2_start_auth_session(chip); + if (rc) + return rc; + } + + do { + if (chip->flags & TPM_CHIP_FLAG_TPM2) + rc = tpm2_get_random(chip, out_ptr, num_bytes); + else + rc = tpm1_get_random(chip, out_ptr, num_bytes); + + if (rc < 0) + goto err; + + out_ptr += rc; + total += rc; + num_bytes -= rc; + } while (retries-- && total < max); + + tpm_put_ops(chip); + return total ? total : -EIO; +err: tpm_put_ops(chip); return rc; } diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 02c07fef41ba..f698d01401de 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -251,7 +251,6 @@ int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash, int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf); ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap, const char *desc, size_t min_cap_length); -int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max); int tpm1_get_pcr_allocation(struct tpm_chip *chip); unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal); int tpm_pm_suspend(struct device *dev); @@ -291,7 +290,6 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digest, u16 *digest_size_ptr); int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digests); -int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max); ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value, const char *desc); diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index b49a790f1bd5..0604e11c9778 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -511,75 +511,6 @@ ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap, } EXPORT_SYMBOL_GPL(tpm1_getcap); -#define TPM_ORD_GET_RANDOM 70 -struct tpm1_get_random_out { - __be32 rng_data_len; - u8 rng_data[TPM_MAX_RNG_DATA]; -} __packed; - -/** - * tpm1_get_random() - get random bytes from the TPM's RNG - * @chip: a &struct tpm_chip instance - * @dest: destination buffer for the random bytes - * @max: the maximum number of bytes to write to @dest - * - * Return: - * * number of bytes read - * * -errno (positive TPM return codes are masked to -EIO) - */ -int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max) -{ - struct tpm1_get_random_out *out; - u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA); - struct tpm_buf buf; - u32 total = 0; - int retries = 5; - u32 recd; - int rc; - - rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM); - if (rc) - return rc; - - do { - tpm_buf_append_u32(&buf, num_bytes); - - rc = tpm_transmit_cmd(chip, &buf, sizeof(out->rng_data_len), - "attempting get random"); - if (rc) { - if (rc > 0) - rc = -EIO; - goto out; - } - - out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE]; - - recd = be32_to_cpu(out->rng_data_len); - if (recd > num_bytes) { - rc = -EFAULT; - goto out; - } - - if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + - sizeof(out->rng_data_len) + recd) { - rc = -EFAULT; - goto out; - } - memcpy(dest, out->rng_data, recd); - - dest += recd; - total += recd; - num_bytes -= recd; - - tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM); - } while (retries-- && total < max); - - rc = total ? (int)total : -EIO; -out: - tpm_buf_destroy(&buf); - return rc; -} - #define TPM_ORD_PCRREAD 21 int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf) { diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 1f561ad3bdcf..461e85c3abe5 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -239,110 +239,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, return rc; } -struct tpm2_get_random_out { - __be16 size; - u8 buffer[TPM_MAX_RNG_DATA]; -} __packed; - -/** - * tpm2_get_random() - get random bytes from the TPM RNG - * - * @chip: a &tpm_chip instance - * @dest: destination buffer - * @max: the max number of random bytes to pull - * - * Return: - * size of the buffer on success, - * -errno otherwise (positive TPM return codes are masked to -EIO) - */ -int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) -{ - struct tpm2_get_random_out *out; - struct tpm_header *head; - struct tpm_buf buf; - u32 recd; - u32 num_bytes = max; - int err; - int total = 0; - int retries = 5; - u8 *dest_ptr = dest; - off_t offset; - - if (!num_bytes || max > TPM_MAX_RNG_DATA) - return -EINVAL; - - err = tpm2_start_auth_session(chip); - if (err) - return err; - - err = tpm_buf_init(&buf, 0, 0); - if (err) { - tpm2_end_auth_session(chip); - return err; - } - - do { - tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM); - if (tpm2_chip_auth(chip)) { - tpm_buf_append_hmac_session(chip, &buf, - TPM2_SA_ENCRYPT | - TPM2_SA_CONTINUE_SESSION, - NULL, 0); - } else { - offset = buf.handles * 4 + TPM_HEADER_SIZE; - head = (struct tpm_header *)buf.data; - if (tpm_buf_length(&buf) == offset) - head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); - } - tpm_buf_append_u16(&buf, num_bytes); - err = tpm_buf_fill_hmac_session(chip, &buf); - if (err) { - tpm_buf_destroy(&buf); - return err; - } - - err = tpm_transmit_cmd(chip, &buf, - offsetof(struct tpm2_get_random_out, - buffer), - "attempting get random"); - err = tpm_buf_check_hmac_response(chip, &buf, err); - if (err) { - if (err > 0) - err = -EIO; - goto out; - } - - head = (struct tpm_header *)buf.data; - offset = TPM_HEADER_SIZE; - /* Skip the parameter size field: */ - if (be16_to_cpu(head->tag) == TPM2_ST_SESSIONS) - offset += 4; - - out = (struct tpm2_get_random_out *)&buf.data[offset]; - recd = min_t(u32, be16_to_cpu(out->size), num_bytes); - if (tpm_buf_length(&buf) < - TPM_HEADER_SIZE + - offsetof(struct tpm2_get_random_out, buffer) + - recd) { - err = -EFAULT; - goto out; - } - memcpy(dest_ptr, out->buffer, recd); - - dest_ptr += recd; - total += recd; - num_bytes -= recd; - } while (retries-- && total < max); - - tpm_buf_destroy(&buf); - - return total ? total : -EIO; -out: - tpm_buf_destroy(&buf); - tpm2_end_auth_session(chip); - return err; -} - /** * tpm2_flush_context() - execute a TPM2_FlushContext command * @chip: TPM chip to use -- 2.39.5
