Create a DID on ION

This page aims to provide a step-by-step instruction to create a DID on ION.

Contribute

I have gathered this information to gain a better understanding of ION and DIDs in general. These steps are currently not working and I ask you to contact me with any questions and corrections! I will do my best to keep this page up to date and factor in any feedback.

Prerequisites

• ION Client Setup ION client v0.5 as described here: ION Installation Guide
  Verify: curl http://localhost:3000/did:ion:test:EiDk2RpPVuC4wNANUTn_4YXJczjzi10zLG1XE4AjkcGOLA returns a DID Document

  the json/bitcoin-config.json

  {
    "bitcoinPeerUri": "http://localhost:18332",
    "bitcoinRpcUsername": "admin",
    "bitcoinRpcPassword": "xxx",
    "bitcoinWalletImportString": "xxx",
    "bitcoinFee": 4000,
    "sidetreeTransactionPrefix": "ion:test:",
    "genesisBlockNumber": 1500000,
    "databaseName": "sidetree-bitcoin",
    "transactionFetchPageSize": 100,
    "mongoDbConnectionString": "mongodb://localhost:27017/",
    "port": 3002
  }

  Note:

  • the bitcoinRpcPassword is shown when you execute the ION Installation Guide
  • the bitcoinWalletImportString is shown as error message when you execute npm run bitcoin for the first time in the course of the ION Installation Guide

• the example here uses the Bitcoin Testnet3 and I made sure to have a configured wallet with some testnet Bitcoins

  bitcoin-0.18.0/bin$ ./bitcoin-cli getwalletinfo
  {
    "walletname": "",
    "walletversion": 169900,
    "balance": 0.21609710,
    "unconfirmed_balance": 0.00000000,
    "immature_balance": 0.00000000,
    "txcount": 2,
    "keypoololdest": 1585431000,
    "keypoolsize": 999,
    "keypoolsize_hd_internal": 1000,
    "paytxfee": 0.00000000,
    "hdseedid": "430960395e7a90aaf1dda3fa6f91a6743a313061",
    "private_keys_enabled": true
  }

• I use Ruby for creating any dynamic fields and require the gems base64, digest, and multihashes

  $ ruby -v
  ruby 2.5.7p206 (2019-10-01 revision 67816) [x86_64-darwin19]
  $ gem install multihashes

  Verify: create a Multihash

  $ echo "1" | ruby -e 'require "base64"; require "multihashes"; require "digest"; puts Base64.strict_encode64(Multihashes.encode(Digest::SHA256.digest(ARGF.read), "sha2-256")).gsub("=","")'

Creating a DID Document

According to the Sidetree Protocol Specification a DID Document should have the following structure:

{
    "type": "create",
    "suffixData": {
        "patchDataHash": "Hash of the patch data.",
        "recoveryKey": "A SECP256K1 public key expressed in compressed JWK format.",
        "nextRecoveryCommitmentHash": "Commitment hash for the next recovery."
    },
    "patchData": {
        "patches": [
            {
                "action": "replace",
                "document": {
                    "publicKeys": [
                        {
                            "id": "A string no longer than 20 characters.",
                            "type": "Secp256k1VerificationKey2019 | EcdsaSecp256k1VerificationKey2019 | JwsVerificationKey2020",
                            "jwk": "Must be JWK format.",
                            "usage": "must be an array containing one or more of the 3 usage types: ops, general, or auth"
                        }
                    ],
                    "serviceEndpoints": [
                        {
                            "id": "A string no longer than 20 characters.",
                            "type": "A string no longer than 30 characters.",
                            "serviceEndpoint": "URIs beginning with a scheme segment (i.e. http://, git://), and be no longer than 80 characters."
                        }
                    ]
                }
            }
        ],
        "nextUpdateCommitmentHash": "Commitment hash to for the next update.",
    }          
}

Here some auxiliary functions to create the individual attributes in the DID Document using as concrete example did.json:

• patchDataHash: use the following Ruby script to remove any white-space characters and calculate the multihash

  $ cat patchData.json | ruby -e 'require "base64"; require "multihashes"; require "digest"; puts Base64.strict_encode64(Multihashes.encode(Digest::SHA256.digest(ARGF.read.gsub(/\s+/,"")), "sha2-256")).gsub("=","")'

  Output: EiBLwuKP50apvP8s6EAAytlYBMcSGZjhfnOba+efshTiIA
• CommitmentHash: I think you can use basicaly any string and create the multihash

  $ echo "1" | ruby -e 'require "base64"; require "multihashes"; require "digest"; puts Base64.strict_encode64(Multihashes.encode(Digest::SHA256.digest(ARGF.read), "sha2-256")).gsub("=","")'

  Output: EiBDVaRrGdNI3C9XwEb472PUU467k2AA88nulUonRg3YZQ
• Keys: OPEN - I don't know how to create Public/Private Key Pairs and use as placeholder for now the public key from an example
  Public Key: 0268ccc80007f82d49c2f2ee25a9dae856559330611f0a62356e59ec8cdb566e69

Writing the DID Document

Use the following command to write the DID Document:

$ cat did.json | ruby -e 'puts ARGF.read.gsub(/\s+/,"")' | curl -s -o /dev/null -w "%{http_code}" -X POST -d @- -H 'Content-Type: application/json' http://localhost:3000

... leads to response 400 - client-side error