[PATCH v1 06/12] tpm: TPM2 support for tpm_pcr_extend()

From: Jarkko Sakkinen
Date: Wed Sep 24 2014 - 05:16:29 EST


Implemented TPM2 protocol support for tpm_pcr_extend().

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm-interface.c | 6 ++++++
drivers/char/tpm/tpm.h | 17 +++++++++++++++++
drivers/char/tpm/tpm2-commands.c | 37 +++++++++++++++++++++++++++++++++++++
drivers/char/tpm/tpm2.h | 7 +++++++
4 files changed, 67 insertions(+)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 069be1e..ed23ba3 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -717,6 +717,12 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
if (chip == NULL)
return -ENODEV;

+ if (chip->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);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 3cdbf9c..4637342 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -321,6 +321,22 @@ struct tpm2_pcr_read_out {
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;
@@ -348,6 +364,7 @@ typedef union {
struct tpm_startup_in startup_in;
struct tpm2_pcr_read_in tpm2_pcrread_in;
struct tpm2_pcr_read_out tpm2_pcrread_out;
+ struct tpm2_pcr_extend_in tpm2_pcrextend_in;
struct tpm2_self_test_in tpm2_selftest_in;
struct tpm2_get_tpm_pt_in tpm2_get_tpm_pt_in;
struct tpm2_get_tpm_pt_out tpm2_get_tpm_pt_out;
diff --git a/drivers/char/tpm/tpm2-commands.c b/drivers/char/tpm/tpm2-commands.c
index 11c031b..b69999e 100644
--- a/drivers/char/tpm/tpm2-commands.c
+++ b/drivers/char/tpm/tpm2-commands.c
@@ -231,6 +231,43 @@ int tpm2_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
return rc;
}

+/**
+ * tpm_pcr_extend - extend pcr value with hash
+ * @chip_num: tpm idx # or AN&
+ * @pcr_idx: pcr idx to extend
+ * @hash: hash value used to extend pcr value
+ */
+static 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 tpm_cmd_t cmd;
+ int rc;
+
+ cmd.header.in = tpm2_pcrextend_header;
+ cmd.params.tpm2_pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
+ cmd.params.tpm2_pcrextend_in.auth_area_size =
+ cpu_to_be32(sizeof(struct tpm2_null_auth_area));
+ cmd.params.tpm2_pcrextend_in.auth_area.handle =
+ cpu_to_be32(TPM2_RS_PW);
+ cmd.params.tpm2_pcrextend_in.auth_area.nonce_size = 0;
+ cmd.params.tpm2_pcrextend_in.auth_area.attributes = 0;
+ cmd.params.tpm2_pcrextend_in.auth_area.auth_size = 0;
+ cmd.params.tpm2_pcrextend_in.digest_cnt = cpu_to_be32(1);
+ cmd.params.tpm2_pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
+ memcpy(cmd.params.tpm2_pcrextend_in.digest, hash, TPM_DIGEST_SIZE);
+
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ "attempting extend a PCR value");
+
+ return rc;
+}
+
static struct tpm_input_header tpm2_selftest_header = {
.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
.length = cpu_to_be32(sizeof(struct tpm_input_header) +
diff --git a/drivers/char/tpm/tpm2.h b/drivers/char/tpm/tpm2.h
index 61ab0df..e4ed2e5 100644
--- a/drivers/char/tpm/tpm2.h
+++ b/drivers/char/tpm/tpm2.h
@@ -23,6 +23,7 @@ enum tpm2_const {

enum tpm2_structures {
TPM2_ST_NO_SESSIONS = 0x8001,
+ TPM2_ST_SESSIONS = 0x8002,
};

enum tpm2_return_codes {
@@ -38,6 +39,11 @@ enum tpm2_command_codes {
TPM2_CC_SELF_TEST = 0x0143,
TPM2_CC_GET_CAPABILITY = 0x017A,
TPM2_CC_PCR_READ = 0x017E,
+ TPM2_CC_PCR_EXTEND = 0x0182,
+};
+
+enum tpm2_permanent_handles {
+ TPM2_RS_PW = 0x40000009,
};

enum tpm2_capabilities {
@@ -53,6 +59,7 @@ unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *, u32);
ssize_t tpm2_get_tpm_pt(struct device *dev, u32 property_id, u32* value,
const char *desc);
int tpm2_pcr_read_dev(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_do_selftest(struct tpm_chip *chip);

#endif /* __DRIVERS_CHAR_TPM2_H__ */
--
2.1.0

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