[PATCH v5 11/17] tpm: export the context save and load commands

James Bottomley
2023-11-27T19:15:33Z

The TPM2 session HMAC and encryption handling code needs to save and
restore a single volatile context for the elliptic curve version of
the NULL seed, so export the APIs which do this for internal use.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>

---

v5: add review
---
drivers/char/tpm/tpm.h | 4 ++++
drivers/char/tpm/tpm2-space.c | 8 ++++----
2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 61445f1dc46d..cbc9d1e2974d 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -312,6 +312,10 @@ int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, void *buf,
size_t *bufsiz);
int tpm_devs_add(struct tpm_chip *chip);
void tpm_devs_remove(struct tpm_chip *chip);
+int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
+ unsigned int buf_size, unsigned int *offset);
+int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
+ unsigned int *offset, u32 *handle);

void tpm_bios_log_setup(struct tpm_chip *chip);
void tpm_bios_log_teardown(struct tpm_chip *chip);
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 363afdd4d1d3..24479a81c23c 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -68,8 +68,8 @@ void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space)
kfree(space->session_buf);
}

-static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
- unsigned int *offset, u32 *handle)
+int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
+ unsigned int *offset, u32 *handle)
{
struct tpm_buf tbuf;
struct tpm2_context *ctx;
@@ -119,8 +119,8 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
return 0;
}

-static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
- unsigned int buf_size, unsigned int *offset)
+int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
+ unsigned int buf_size, unsigned int *offset)
{
struct tpm_buf tbuf;
unsigned int body_size;
--
2.35.3