corim-store

This is an implementation of an endorsement and reference value store implemented on top of a relational DBMS, and supporting CoRIM inputs.

Installation

go install github.com/veraison/corim-store/cmd/corim-store@latest

API

import (
    "context"
    "fmt"
    "log"
    "os"

	"github.com/veraison/corim-store/pkg/model"
	"github.com/veraison/corim-store/pkg/store"
)

func main() {
    // create and initialize the store.

    cfg := store.NewConfig("sqlite", "file::memory:?cache=shared")

    store, err := store.Open(context.Background(), cfg)
    if err != nil {
        log.Fatal(err)
    }

    if err := store.Init(); err != nil {
        log.Fatal(err)
    }

    // Read a CoRIM and add it to the store.

    corimBytes, err := os.ReadFile("sample/corim/unsigned-cca-ref-plat.cbor")
    if err != nil {
        log.Fatal(err)
    }

    if err := store.AddBytes(corimBytes, "cca"); err != nil {
        log.Fatal(err)
    }

    // Query the store for a trust anchor associated with an instance ID.

    env = model.Environment {
        InstanceBytes: []byte{
            0x01, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01,
            0x00, 0x0f, 0x0e, 0x0d, 0x0c, 0x0b, 0x0a, 0x09,
            0x08, 0x17, 0x16, 0x15, 0x14, 0x13, 0x12, 0x11,
            0x10, 0x1f, 0x1e, 0x1d, 0x1c, 0x1b, 0x1a, 0x19,
            0x18,
    }

    keyTriples, err := store.GetKeyTriples(&env, "cca", false)
    if err != nil {
        log.Fatal(err)
    }

    fmt.Printf("key: %s\n", string(keyTriples[0].KeyList[0].KeyBytes))
}

CLI

This repo includes a CLI tool, corim-store, for interacting with the store. Use -h/--help option to view available commands and their arguments.

Example flow

./corim-store db init

Initialize the database for use with the store.

./corim-store db status

Show the database connection settings and current migration status. This can be used to make sure that the database is up-to-date with what the store expects. This should be run after updating to the latest version of the store. If new migrations are available, the database can be updated by re-running the migrate (but not init!) command.

./corim-store corim add sample/corim/*.cbor

Add sample CoRIM's to the store.

./corim-store list module-tags

List module tags (CoMID's) inside the store.

./corim-store get --class-id 2QJYWCB/RUxGAgEBAAAAAAAAAAAAAwA+AAEAAABQWAAAAAAAAA

Get endorsements associated with the specified class ID from the store.

./corim-store corim dump cca-ref-plat -o /tmp/cca-platform-ref-vals.cbor

Write the contents associated with the specified manifest ID (here, cca-ref-plat) to file as an unsigned CoRIM.

Configuration

corim-store accepts configuration in YAML format. By default, configuration is read from ~/.config/corim-store.yaml if it exists. An alternative file can be specified with --config command line option.

The following settings are accepted:

• dbms: The DBMS backing the store. Accepted values are sqlite, postgres, and mysql (TODO: currently, only sqlite is supported). The default is sqlite.
• dsn: The Data Source Name. This is the string used to connect to the database. The format depends on the DBMS (search the DBMS documentation for "data source name" or "connection string"). The default is file:store:db?cache=shared.
• require-label: A boolean value indicating whether a label MUST be specified for added endorsements. The default is false. (Note: without this flag, labels may still be specified; it is just that they are not required). Labels allow partitioning contained endorsements under different "namespaces" indicated by the label.
• hash-alg: hashing algorithm used to calculate store-internal digests. (Note: this has no impact on the digests included inside endorsements/reference values). Accepted values are md5, sha256, and sha512. The default is sha256.
• trace-sql: A boolean value indicating whether to log executed SQL statements to STDERR. The default is false.
• insecure: A boolean value indicating whether insecure transactions (e.g. adding a signed CoRIM without verifying its signature) should be allowed. The default is false.
• force: A boolean value indicating whether to overwrite existing values. The default is false.
• no-color: A boolean value indicating whether colored output should be suppressed. The default is false (i.e. output is colored by default).

Each of the settings can also be specified via command-line options (the option name is identical to the setting -- just prefix with --), or via environment variables. To get then environment variable name, change the setting name to be upper case, replace - with _, and prefix it with CORIM_STORE_. E.g. to set no-color via an environment variable, you would set CORIM_STORE_NO_COLOR=1.

Store Design Overview

The store is intended for endorsements, reference values, and trust anchors that will be used for attestation verification. These are stored as value and key triples, which associate an attesting environment description with corresponding measurements and cryptographic keys.

Sets of triples are grouped under "module tags" (corresponding to CoMIDs), which are, in turn, associated with "manifests" (corresponding to CoRIMs). Module tags group claims (contained in triples) relating to a logical system module (hardware, firmware, etc). A manifest acts as an "envelope" containing additional metadata about the module tags it contains (such as the validity period).

The above diagram is a simplified entity-relation diagram for the major entities used by the store. It omits some "meta" fields (e.g. foreign keys), and only shows the main logical entities within the store. For a complete overview of the SQL tables created by the store, please see the schema diagram.

Triple Life Cycle

By default, when triples are added, they are in an inactive state. They must be activated in order to become available for use in verification. This decouples provisioning values into the store from making them available for verification. Triples may also be deactivated (e.g. when the associated attesters have been decommissioned), but remain "archived" in the store.

stateDiagram-v2
    [*] --> Inactive: add
    Inactive --> Active: activate
    Active --> Inactive: deactivate
    Inactive --> [*]: delete
    Active --> [*]: delete