tpm: seal/unseal for TPM 2.0

Added tpm_trusted_seal() and tpm_trusted_unseal() API for sealing
trusted keys.

This patch implements basic sealing and unsealing functionality for
TPM 2.0:

* Seal with a parent key using a 20 byte auth value.
* Unseal with a parent key using a 20 byte auth value.

Signed-off-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Peter Huewe <[email protected]>

drivers/char/tpm/tpm-interface.c

@@ -665,6 +665,30 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 	return rc;
 }
 
+/**
+ * tpm_is_tpm2 - is the chip a TPM2 chip?
+ * @chip_num:	tpm idx # or ANY
+ *
+ * Returns < 0 on error, and 1 or 0 on success depending whether the chip
+ * is a TPM2 chip.
+ */
+int tpm_is_tpm2(u32 chip_num)
+{
+	struct tpm_chip *chip;
+	int rc;
+
+	chip = tpm_chip_find_get(chip_num);
+	if (chip == NULL)
+		return -ENODEV;
+
+	rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
+
+	tpm_chip_put(chip);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_is_tpm2);
+
 /**
  * tpm_pcr_read - read a pcr value
  * @chip_num:	tpm idx # or ANY
@@ -1021,6 +1045,58 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 }
 EXPORT_SYMBOL_GPL(tpm_get_random);
 
+/**
+ * tpm_seal_trusted() - seal a trusted key
+ * @chip_num: A specific chip number for the request or TPM_ANY_NUM
+ * @options: authentication values and other options
+ * @payload: the key data in clear and encrypted form
+ *
+ * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
+ * are supported.
+ */
+int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
+		     struct trusted_key_options *options)
+{
+	struct tpm_chip *chip;
+	int rc;
+
+	chip = tpm_chip_find_get(chip_num);
+	if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
+		return -ENODEV;
+
+	rc = tpm2_seal_trusted(chip, payload, options);
+
+	tpm_chip_put(chip);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_seal_trusted);
+
+/**
+ * tpm_unseal_trusted() - unseal a trusted key
+ * @chip_num: A specific chip number for the request or TPM_ANY_NUM
+ * @options: authentication values and other options
+ * @payload: the key data in clear and encrypted form
+ *
+ * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
+ * are supported.
+ */
+int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
+		       struct trusted_key_options *options)
+{
+	struct tpm_chip *chip;
+	int rc;
+
+	chip = tpm_chip_find_get(chip_num);
+	if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
+		return -ENODEV;
+
+	rc = tpm2_unseal_trusted(chip, payload, options);
+
+	tpm_chip_put(chip);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
+
 static int __init tpm_init(void)
 {
 	int rc;

drivers/char/tpm/tpm.h

@@ -90,13 +90,20 @@ enum tpm2_return_codes {
 
 enum tpm2_algorithms {
 	TPM2_ALG_SHA1		= 0x0004,
+	TPM2_ALG_KEYEDHASH	= 0x0008,
+	TPM2_ALG_SHA256		= 0x000B,
+	TPM2_ALG_NULL		= 0x0010
 };
 
 enum tpm2_command_codes {
 	TPM2_CC_FIRST		= 0x011F,
 	TPM2_CC_SELF_TEST	= 0x0143,
 	TPM2_CC_STARTUP		= 0x0144,
 	TPM2_CC_SHUTDOWN	= 0x0145,
+	TPM2_CC_CREATE		= 0x0153,
+	TPM2_CC_LOAD		= 0x0157,
+	TPM2_CC_UNSEAL		= 0x015E,
+	TPM2_CC_FLUSH_CONTEXT	= 0x0165,
 	TPM2_CC_GET_CAPABILITY	= 0x017A,
 	TPM2_CC_GET_RANDOM	= 0x017B,
 	TPM2_CC_PCR_READ	= 0x017E,
@@ -407,7 +414,7 @@ struct tpm_buf {
 	u8 *data;
 };
 
-static inline void tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
+static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
 {
 	struct tpm_input_header *head;
 
@@ -527,6 +534,12 @@ static inline void tpm_add_ppi(struct tpm_chip *chip)
 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, const u8 *hash);
 int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max);
+int tpm2_seal_trusted(struct tpm_chip *chip,
+		      struct trusted_key_payload *payload,
+		      struct trusted_key_options *options);
+int tpm2_unseal_trusted(struct tpm_chip *chip,
+			struct trusted_key_payload *payload,
+			struct trusted_key_options *options);
 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,
 			u32 *value, const char *desc);