DICE specification for AVF guest
Consolidate the usage of different keys in Config Descriptor specified
for various components running in AVF guest environment.
Test: N/A
Bug: 291245237
Change-Id: Ic081636ea7e1b8c4767cd18fc5a9ea83b9cc2e6f
diff --git a/dice_for_avf_guest.cddl b/dice_for_avf_guest.cddl
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+; DICE Specification for guest VM
+
+; See the Open DICE specification
+; https://pigweed.googlesource.com/open-dice/+/HEAD/docs/specification.md,
+; and the Android Profile for DICE
+; https://pigweed.googlesource.com/open-dice/+/HEAD/docs/android.md.
+
+; This CDDL describes the Configuration Descriptor used for components running in AVF Guest environment
+; (VM core components and payload). It extends the `ConfigurationDescriptor` specified at
+; https://cs.android.com/android/platform/superproject/main/+/main:hardware/interfaces/security/rkp/aidl/android/hardware/security/keymint/generateCertificateRequestV2.cddl
+
+; Additionally, we reserve range -71000...-71999 for AVF system specific usage. These are or can be
+; used by frameworks & parsers of DICE chains such as local and remote attestation frameworks.
+; Vendor must not use these key/values for other purposes, that may compromise the integrity of the system.
+; Note that each of the key-value pairs may not be useful for all the boot components and therefore
+; are optional. For e.g., SubcomponentDescriptor is only used in Microdroid payload, it may
+; not have immediate use for pVM firmware.
+
+; Each components of VM must specify the value corresponding to `Component name`(-70002).
+; For provided reference implementations:
+;
+; 1. "vm_entry" - Guest 'OS'. This is the payload booted by pVM firmware. For e.g, Microdroid, Rialto.
+; 2. "Microdroid vendor" - The vendor image, specific to Microdroid.
+; 3. "Microdroid Payload" - Payload run by Microdroid Manager.
+
+
+ConfigDescriptor = {
+ -70002 : tstr, ; Component name
+ (? -71000: tstr // ; Path to the payload config file
+ ? -71001: PayloadConfig),
+ ? -71002: [+ SubcomponentDescriptor], ; The order of these should be kept constant on each boot
+ ; of the VM instance
+ ? -71003: bstr .size 64 ; Instance hash: Unique identifier of the VM instance
+}
+
+PayloadConfig = {
+ 1: tstr ; Path to the binary file where payload execution starts
+}
+
+; Describes a unit of code (e.g. an APK or an APEX) present inside the VM.
+;
+; For an APK, the fields are as follows:
+; - Component name: The string "apk:" followed by the package name.
+; - Security version: The long version code from the APK manifest
+; (https://developer.android.com/reference/android/content/pm/PackageInfo#getLongVersionCode()).
+; - Code hash: This is the root hash of a Merkle tree computed over all bytes of the APK, as used
+; in the APK Signature Scheme v4 (https://source.android.com/docs/security/features/apksigning/v4)
+; with empty salt and using SHA-256 as the hash algorithm.
+; - Authority hash: The SHA-512 hash of the DER representation of the X.509 certificate for the
+; public key used to sign the APK.
+;
+; For an APEX, they are as follows:
+; - Component name: The string "apex:" followed by the APEX name as specified in the APEX Manifest
+; (see https://source.android.com/docs/core/ota/apex).
+; - Security version: The version number from the APEX Manifest.
+; - Code hash: The root hash of the apex_payload.img file within the APEX, taken from the first
+; hashtree descriptor in the VBMeta image
+; (see https://android.googlesource.com/platform/external/avb/+/master/README.md).
+; - Authority hash: The SHA-512 hash of the public key used to sign the file system image in the
+; APEX (as stored in the apex_pubkey file). The format is as described for AvbRSAPublicKeyHeader
+; in https://cs.android.com/android/platform/superproject/main/+/main:external/avb/libavb/avb_crypto.h.
+SubcomponentDescriptor = {
+ 1: tstr, ; Component name
+ 2: uint, ; Security version
+ 3: bstr, ; Code hash
+ 4: bstr, ; Authority hash
+}
+
+TODO: Describe how these descriptors are used by AVF components in Android W.
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