From ce63c05b664e491b4cc79c713c68d8170bd0f581 Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Mon, 26 Mar 2018 15:14:06 +0300 Subject: [PATCH] tpm: migrate tpm2_get_random() to use struct tpm_buf In order to make struct tpm_buf the first class object for constructing TPM commands, migrate tpm2_get_random() to use it. In addition, removed remaining references to struct tpm2_cmd. All of them use it to acquire the length of the response, which can be achieved by using tpm_buf_length(). Signed-off-by: Jarkko Sakkinen Tested-by: Nayna Jain --- drivers/char/tpm/tpm.h | 19 +++---- drivers/char/tpm/tpm2-cmd.c | 102 +++++++++++++++--------------------- 2 files changed, 51 insertions(+), 70 deletions(-) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 4426649e431c..9824cccb2c76 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -424,23 +424,24 @@ struct tpm_buf { u8 *data; }; -static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) +static inline void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal) { struct tpm_input_header *head; + head = (struct tpm_input_header *)buf->data; + head->tag = cpu_to_be16(tag); + head->length = cpu_to_be32(sizeof(*head)); + head->ordinal = cpu_to_be32(ordinal); +} +static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) +{ buf->data_page = alloc_page(GFP_HIGHUSER); if (!buf->data_page) return -ENOMEM; buf->flags = 0; buf->data = kmap(buf->data_page); - - head = (struct tpm_input_header *) buf->data; - - head->tag = cpu_to_be16(tag); - head->length = cpu_to_be32(sizeof(*head)); - head->ordinal = cpu_to_be32(ordinal); - + tpm_buf_reset(buf, tag, ordinal); return 0; } @@ -569,7 +570,7 @@ static inline u32 tpm2_rc_value(u32 rc) 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, u32 count, struct tpm2_digest *digests); -int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max); +int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max); void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle, unsigned int flags); int tpm2_seal_trusted(struct tpm_chip *chip, diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 90e3b36cf0dc..c31b490bd41d 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -27,25 +27,6 @@ enum tpm2_session_attributes { TPM2_SA_CONTINUE_SESSION = BIT(0), }; -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_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; - struct tpm2_hash { unsigned int crypto_id; unsigned int tpm_id; @@ -300,67 +281,70 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count, } -#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) -}; +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: TPM chip to use - * @out: destination buffer for the random bytes - * @max: the max number of bytes to write to @out + * @chip: a &tpm_chip instance + * @dest: destination buffer + * @max: the max number of random bytes to pull * * Return: - * Size of the output buffer, or -EIO on error. + * size of the buffer on success, + * -errno otherwise */ -int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max) +int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) { - struct tpm2_cmd cmd; - u32 recd, rlength; - u32 num_bytes; + struct tpm2_get_random_out *out; + struct tpm_buf buf; + u32 recd; + u32 num_bytes = max; int err; int total = 0; int retries = 5; - u8 *dest = out; - - num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer)); + u8 *dest_ptr = dest; - if (!out || !num_bytes || - max > sizeof(cmd.params.getrandom_out.buffer)) + if (!num_bytes || max > TPM_MAX_RNG_DATA) return -EINVAL; - do { - cmd.header.in = tpm2_getrandom_header; - cmd.params.getrandom_in.size = cpu_to_be16(num_bytes); + err = tpm_buf_init(&buf, 0, 0); + if (err) + return err; - err = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), + do { + tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM); + tpm_buf_append_u16(&buf, num_bytes); + err = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, offsetof(struct tpm2_get_random_out, buffer), 0, "attempting get random"); if (err) - break; + goto out; - recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size), - num_bytes); - rlength = be32_to_cpu(cmd.header.out.length); - if (rlength < offsetof(struct tpm2_get_random_out, buffer) + - recd) - return -EFAULT; - memcpy(dest, cmd.params.getrandom_out.buffer, recd); + out = (struct tpm2_get_random_out *) + &buf.data[TPM_HEADER_SIZE]; + recd = min_t(u32, be16_to_cpu(out->size), num_bytes); + if (tpm_buf_length(&buf) < + offsetof(struct tpm2_get_random_out, buffer) + recd) { + err = -EFAULT; + goto out; + } + memcpy(dest_ptr, out->buffer, recd); - dest += 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); + return err; } /** @@ -437,7 +421,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip, { unsigned int blob_len; struct tpm_buf buf; - u32 hash, rlength; + u32 hash; int i; int rc; @@ -512,8 +496,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip, rc = -E2BIG; goto out; } - rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)->header.out.length); - if (rlength < TPM_HEADER_SIZE + 4 + blob_len) { + if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) { rc = -EFAULT; goto out; } @@ -623,7 +606,6 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, u16 data_len; u8 *data; int rc; - u32 rlength; rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL); if (rc) @@ -651,9 +633,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, goto out; } - rlength = be32_to_cpu(((struct tpm2_cmd *)&buf) - ->header.out.length); - if (rlength < TPM_HEADER_SIZE + 6 + data_len) { + if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) { rc = -EFAULT; goto out; } -- 2.39.5