chainpoint-cli

Chainpoint CLI

A Command Line Interface (CLI) for creating and verifying Chainpoint proofs. See https://chainpoint.org

The Chainpoint CLI lets you submit hashes to a Chainpoint Node on the Tierion Network. Nodes periodically aggregate hashes and send data to Tierion Core for anchoring the hash to public blockchains.

The CLI lets you retrieve and verify a Chainpoint proof. Each proof cryptographically proves the integrity and existence of data at a point in time.

The CLI also maintains a simple local database that keeps track of every hash you submit, and stores and manages Chainpoint proofs locally for easy retrieval, export, and verification.

Installation

Prerequisites

The CLI requires Node.js version 7.6.0 or higher.

It is recommended to use a modern version of Node.js and its companion npm tool when installing the CLI.

An excellent way of doing so is to use the Node Version Manager (nvm). Here are the quick install steps to get yourself set up with a current version of Node.js and npm using nvm.

Install NVM (optional)

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.4/install.sh | bash

Once you run this installer its recommended to close your current terminal and open a new one to ensure the install takes effect.

Now you can verify the install with this command, which should return the text nvm:

command -v nvm

Install the current Node.js and npm

nvm install node

Check the versions of Node and npm installed once the installation completes successfully. The version numbers you see might vary.

$ node --version
v8.2.1
$ npm --version
5.3.0

Set this version of Node.js/npm to be your system default.

nvm alias default node

Confirm the version(s) of Node you've installed with nvm. The one that the arrow points to should not be system but one of the versions that nvm manages.

nvm list
        v6.11.2
->       v8.2.1
         system
default -> node (-> v8.2.1)

All set! Move on to installing the CLI.

Installing

Ensure you have Node.js version 7.6.0 or higher. If not, install a modern version, perhaps using the nvm install instructions above.

node --version
v8.2.1

We recommend globally installing the CLI from the npmjs.com package respository.

Installing the CLI assumes you already have the npm command line tool, which is installed alongside Node.js. You can learn how to install npm using the nvm Node Version Manager as shown above, or at the npmjs.com/get-npm page.

npm install -g --production chainpoint-cli

This will install the chainpoint-cli npm package, which installs the chp command line tool. You can check that chp is installed and available with the command:

which chp

Pro Tip: You'll note that many of the curl samples in this document have been 'prettified' with jq for easier readability. It is a powerful tool that lets you work with and explore JSON on the command line in new and interesting ways. Its highly recommended to install this tool following the instructions for your platform.

Usage

You can get an overview of the CLI usage by typing the command (chp). The Node that the CLI will communicate with will be chosen from those advertised as healthy on the network.

On first use, the CLI will create a ~/.chainpoint directory where it will store its chainpoint-proofs.db file. The database file will be managed for you and it is not recommended to modify it yourself. The database stores a record of every hash you submit, which Node it was submitted to, and a copy of the proofs. You can create a chainpoint-cli.config file in this directory with a CHAINPOINT_NODE_API_BASE_URI= value if you'd like to permanently specify a Node of your own choosing.

$ chp
Usage: chp <command> [options] <argument>

Commands:
  submit    submit a hash to be anchored (3x Nodes default)
  update    retrieve an updated proof for your hash(es), if available
  verify    verify a proof's anchor claims
  evaluate  evaluate and display a proof's anchor claims
  export    export a proof
  list      display the status of every hash in the local database
  show      show the proof for a hash_id_node
  delete    delete a hash from the local database
  version   show the CLI version

Options:
  -s, --server  specify server to use[string] [default: "http://0.0.0.0"]
  -q, --quiet   suppress all non-error output                          [boolean]
  -j, --json    format all output as json                              [boolean]
  --help        show help                                              [boolean]

You must specify a command.

Submitting a hash

First you'll need to generate a hash of a local file or data of your choice. We recommended using the SHA256 one-way cryptographic hash function. Other hash types will also be accepted as long as they are hex strings between 40 and 128 hex characters ([0-9a-fA-F]) in length.

The Tierion Network only sees a hash of your data, never the original. It is not possible for us to learn anything about your data from the hash.

To submit a hash, simply call:

chp submit 2e75eaf17b8345c67234dfa92e867541ef41dda08baa6f8d5464fac432950794
52eb62c0-f556-11e7-bcf8-016fed1c55ad | 2e75eaf17b8345c67234dfa92e867541ef41dda08baa6f8d5464fac432950794 | submitted

The output returned consists of three parts:

The node_hash_id is 52eb62c0-f556-11e7-bcf8-016fed1c55ad in this example. This type 1 UUID serves as a handle to retrieve a proof.

The original hash you submitted (2e75eaf17b8345c67234dfa92e867541ef41dda08baa6f8d5464fac432950794) is echoed back.

The action that occurred, submitted in this case, is returned.

You can also submit multiple hashes at once by calling submit with multiple hashes.

chp submit <hash> <hash> <hash>

Updating a Proof

Once a hash has been submitted, it will first be anchored to the Calendar and a proof will be generated. A proof that anchors your hash to the Calendar is generally available within ten seconds or less.

chp update 52eb62c0-f556-11e7-bcf8-016fed1c55ad
52eb62c0-f556-11e7-bcf8-016fed1c55ad | updated | cal

You can see that you call chp update and just pass the node_hash_id as well.

You'll see echoed back to you the status, where the cal at the end indicates that the proof is anchored to the Calendar. Later you will see other blockchain anchors become available, such as btc to indicate that a hash was anchored to the Bitcoin blockchain.

You can also call chp update --all to update all proofs locally stored.

Verifying a Proof

Verifying a proof submits it to the Node for cryptographic verification that the hash captured in the proof is anchored all the way up to either the Calendar or to public blockchains. The Calendar contains all of the information needed to verify a proof.

chp verify 52eb62c0-f556-11e7-bcf8-016fed1c55ad
52eb62c0-f556-11e7-bcf8-016fed1c55ad | verified | cal

You can see here that the proof represented by the node_hash_id provided is anchored to the Calendar (cal) level.

Viewing a Proof

You can of course view a proof in its entirety by asking to see the proof associated with a node_hash_id.

chp show 52eb62c0-f556-11e7-bcf8-016fed1c55ad | jq

{
  "@context": "https://w3id.org/chainpoint/v3",
  "type": "Chainpoint",
  "hash": "2e75eaf17b8345c67234dfa92e867541ef41dda08baa6f8d5464fac432950794",
  "hash_id_node": "52eb62c0-f556-11e7-bcf8-016fed1c55ad",
  "hash_submitted_node_at": "2018-01-09T16:01:16Z",
  "hash_id_core": "534fc9e0-f556-11e7-b0bd-016959c78193",
  "hash_submitted_core_at": "2018-01-09T16:01:17Z",
  "branches": [
    {
      "label": "cal_anchor_branch",
      "ops": [
        {
          "l": "node_id:52eb62c0-f556-11e7-bcf8-016fed1c55ad"
        },
        {
          "op": "sha-256"
        },
        {
          "l": "core_id:534fc9e0-f556-11e7-b0bd-016959c78193"
        },
        {
          "op": "sha-256"
        },
        {
          "l": "nist:1515513660:042c2248a9b3af5f1d33f64bb3f8d6a2d1028409b9a028538cca63521e79aeb684f3a48cdbf2074cbf48e54fcd3375703d1ad56602e326a3805ebf1066f7aaff"
        },
        {
          "op": "sha-256"
        },
        {
          "l": "986719:1515513680:1:https://b.chainpoint.org:cal:986719"
        },
        {
          "r": "4d8c2a7eab273ac9a7aa32e3c35805a4eaac3652be27142f8b459dd61737ab06"
        },
        {
          "op": "sha-256"
        },
        {
          "anchors": [
            {
              "type": "cal",
              "anchor_id": "986719",
              "uris": [
                "https://b.chainpoint.org/calendar/986719/hash"
              ]
            }
          ]
        }
      ]
    }
  ]
}

You can see in this case I piped the output of the show sub-command to the jq program. This is just for viewing convenience so we can see the pretty-printed version of the proof.

Other commands

list will show you a list of all hash IDs and hashes that have been submitted from this CLI client.

export allows you to export a proof in either JSON or binary file formats.

delete <hash_id> allows you to manually delete any hash from your local DB.

evaluate <hash_id> calculates and displays the expected values for each anchor in the proof.

You can also get JSON output by passing in the --json flag. For example:

chp verify --json 52eb62c0-f556-11e7-bcf8-016fed1c55ad

Help

You should note that each of the sub-commands also has its own help screen.

$ chp submit --help
Usage: submit [options] (<hash> <hash>... | <hash>,<hash>,... )

Options:
  -s, --server  specify server to use
                                  [string] [default: "http://SERVER"]
  -q, --quiet   suppress all non-error output                          [boolean]
  -j, --json    format all output as json                              [boolean]
  --help        show help                                              [boolean]