Remove agree_key and add configure to keymaster2.
Key agreement (ECDH) has been punted from the N release, and a
configuration method has been added to support version binding.
Change-Id: Ia4aeee1bd7ab88cda3b9faa653470e608aa55942
diff --git a/include/hardware/keymaster2.h b/include/hardware/keymaster2.h
index dcde30e..565ad2e 100644
--- a/include/hardware/keymaster2.h
+++ b/include/hardware/keymaster2.h
@@ -43,6 +43,22 @@
uint32_t flags;
/**
+ * Configures keymaster. This method must be called once after the device is opened and before
+ * it is used. It's used to provide KM_TAG_OS_VERSION and KM_TAG_OS_PATCHLEVEL to keymaster.
+ * Until this method is called, all other methods will return KM_ERROR_KEYMASTER_NOT_CONFIGURED.
+ * The values provided by this method are only accepted by keymaster once per boot. Subsequent
+ * calls will return KM_ERROR_OK, but do nothing.
+ *
+ * If the keymaster implementation is in secure hardware and the OS version and patch level
+ * values provided do not match the values provided to the secure hardware by the bootloader (or
+ * if the bootloader did not provide values), then this method will return
+ * KM_ERROR_INVALID_ARGUMENT, and all other methods will continue returning
+ * KM_ERROR_KEYMASTER_NOT_CONFIGURED.
+ */
+ keymaster_error_t (*configure)(const struct keymaster2_device* dev,
+ const keymaster_key_param_set_t* params);
+
+ /**
* Adds entropy to the RNG used by keymaster. Entropy added through this method is guaranteed
* not to be the only source of entropy used, and the mixing function is required to be secure,
* in the sense that if the RNG is seeded (from any source) with any data the attacker cannot
@@ -202,42 +218,6 @@
keymaster_blob_t* export_data);
/**
- * Derives a shared secret key from \p key, which must be an EC key, and the public key found in
- * /p other_key_certificate, an X.509 certificate containing a compatible EC public key. The
- * derived key's characteristics are described in \p new_key_params, which must include
- * algorithm (KM_TAG_ALGORITHM), key size (KM_TAG_KEY_SIZE) and KDF (KM_TAG_KDF) as well as
- * other desired key characteristics. The resulting key material is not returned directly, but
- * instead a new keymaster key is created and the associated blob returned in \p key_blob. If
- * \p characteristics is non-NULL, the new key's characteristics are placed there.
- *
- * \param[in] dev The keymaster device structure.
- *
- * \param[in] key The keymaster key to use for key agreement. This must be an EC key with the
- * KM_PURPOSE_DERIVE_KEY purpose.
- *
- * \param[in] other_key_certificate An X.509 certificate or certificate fragment containing a
- * SubjectPublicKey field containing an EC public key on the same curve as \p key.
- *
- * \param[in] new_key_params A set of parameters to define/describe the newly-derived symmetric
- * key. The parameters will define how the key may be used. The set must include KM_TAG_KDF to
- * specify how the raw agreed key bytes will be transformed to produce the key material.
- *
- * \param[out] key_blob The key blob containing the newly-derived key. The caller takes
- * ownership of the returned blob.
- *
- * \param[out] characteristics. If non-null, will be used to return the characteristics of the
- * new key blob, which will have KM_TAG_ORIGIN set to KM_ORIGIN_DERIVED. The caller takes
- * ownership of the returned characteristics and must deallocate with
- * keymaster_free_characteristics().
- */
- keymaster_error_t (*agree_key)(const struct keymaster2_device* dev,
- const keymaster_key_blob_t* key,
- const keymaster_blob_t* other_key_certificate,
- const keymaster_key_param_set_t* new_key_params,
- keymaster_key_blob_t* new_key_blob,
- keymaster_key_characteristics_t* characteristics);
-
- /**
* Generates a signed X.509 certificate chain attesting to the presence of \p key_to_attest in
* keymaster (TODO(swillden): Describe certificate contents in more detail). The certificate
* will contain an extension with OID 1.3.6.1.4.1.11129.2.1.17 and value defined in
diff --git a/include/hardware/keymaster_defs.h b/include/hardware/keymaster_defs.h
index d59f3cb..046db52 100644
--- a/include/hardware/keymaster_defs.h
+++ b/include/hardware/keymaster_defs.h
@@ -322,6 +322,25 @@
size_t entry_count;
} keymaster_cert_chain_t;
+typedef enum {
+ KM_VERIFIED_BOOT_VERIFIED = 0, /* Full chain of trust extending from the bootloader to
+ * verified partitions, including the bootloader, boot
+ * partition, and all verified partitions*/
+ KM_VERIFIED_BOOT_SELF_SIGNED = 1, /* The boot partition has been verified using the embedded
+ * certificate, and the signature is valid. The bootloader
+ * displays a warning and the fingerprint of the public
+ * key before allowing the boot process to continue.*/
+ KM_VERIFIED_BOOT_UNVERIFIED = 2, /* The device may be freely modified. Device integrity is left
+ * to the user to verify out-of-band. The bootloader
+ * displays a warning to the user before allowing the boot
+ * process to continue */
+ KM_VERIFIED_BOOT_FAILED = 3, /* The device failed verification. The bootloader displays a
+ * warning and stops the boot process, so no keymaster
+ * implementation should ever actually return this value,
+ * since it should not run. Included here only for
+ * completeness. */
+} keymaster_verified_boot_t;
+
/**
* Formats for key import and export.
*/
@@ -402,6 +421,7 @@
KM_ERROR_UNSUPPORTED_EC_CURVE = -61,
KM_ERROR_KEY_REQUIRES_UPGRADE = -62,
KM_ERROR_ATTESTATION_CHALLENGE_MISSING = -63,
+ KM_ERROR_KEYMASTER_NOT_CONFIGURED = -64,
KM_ERROR_UNIMPLEMENTED = -100,
KM_ERROR_VERSION_MISMATCH = -101,