moon-DID Library

DID Specification | ERC-1056
| Getting Started

This library conforms to ERC-1056 and is intended to use Ethereum
addresses as fully self-managed Decentralized Identifiers (DIDs), it
allows you to easily create and manage keys for these identifiers. It also lets you sign standards
compliant JSON Web Tokens (JWT) that can be consumed using
the DID-JWT library.

This library can be used to create a new moon-did identifier. It allows moon-did identifiers to be represented as an
object that can perform actions such as updating its DID document, signing messages, and verifying messages from other
DIDs.

Use this if you are looking for the easiest way to start using moon-did identifiers, and want high-level abstractions to
access its entire range of capabilities. It encapsulates all the functionality
of ethr-did-resolver
and moon-did-registry.

A DID is an Identifier that allows you to lookup a DID document that can be used to authenticate you and messages
created by you.

moon-DID provides a scalable identity method for public keys and Ethereum addresses that gives them the ability to
collect on-chain and off-chain data. Because moon-DID allows any Ethereum key pair to become a DID, it is more scalable
and privacy-preserving than smart contract based identity methods, like our
previous Proxy Contract.

This particular DID method relies on the moon-Did-Registry. The
moon-DID-Registry is a smart contract that facilitates public key resolution for off-chain (and on-chain)
authentication. It also facilitates key rotation, delegate assignment and revocation to allow 3rd party signers on a
key's behalf, as well as setting and revoking off-chain attribute data. These interactions and events are used in
aggregate to form a DID's DID document using
the moon-Did-Resolver
.

An example of a DID document resolved using
the moon-did-resolver:

``json5
{
'@context': ['https://www.w3.org/ns/did/v1', 'https://w3id.org/security/suites/secp256k1recovery-2020/v2'],
id: 'did:moon:0xb9c5714089478a327f09197987f16f9e5d936e8a',
verificationMethod: [
{
id: 'did:moon:0xb9c5714089478a327f09197987f16f9e5d936e8a#controller',
type: 'EcdsaSecp256k1RecoveryMethod2020',
controller: 'did:moon:0xb9c5714089478a327f09197987f16f9e5d936e8a',
blockchainAccountId: 'eip155:1:0xb9c5714089478a327f09197987f16f9e5d936e8a',
},
],
assertionMethod: ['did:moon:0xb9c5714089478a327f09197987f16f9e5d936e8a#controller'],
authentication: ['did:moon:0xb9c5714089478a327f09197987f16f9e5d936e8a#controller'],
}
`

On-chain refers to something that queried or modified with a transaction on a blockchain, while off-chain can refer to
anything from temporary payment channels to IPFS and regular web services.

It supports the proposed Decentralized Identifiers spec from
the W3C Credentials Community Group.

DID Method

A "DID method" is a specific implementation of a DID scheme that is identified by a method name. In this case, the
method name is moon, and the method identifier is an Ethereum address or a secp256k1 publicKey.

To encode a DID for an Ethereum address, simply prepend did:moon:

For example:

- DID based on an ethereum address: did:moon:0xf3beac30c498d9e26865f34fcaa57dbb935b0d74
- DID based on a key: did:moon:0x0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798

Configuration

`typescript
import { EthrDID } from 'moon-did'

const chainNameOrId = 1 // mainnet
const provider = InfuraProvider('', chainNameOrId)
const ethrDid = new EthrDID({ identifier: '0x...', privateKey: '...', provider, chainNameOrId })
`

| key | description | required |
| --------------- | --------------------------------------------------------------------------------- | --------------------------------------- |
| identifier | Ethereum address, public key or a full did:moon representing Identity | yes |
| chainNameOrId | The name or chainId of the ethereum network (defaults to 'mainnet') | no, but recommended |
| registry | registry address (defaults to 0xdca7ef03e98e0dc2b855be647c39abe984fcf21b) | no |
| provider | web3 provider | either provider or web3 or rpcUrl |
| web3 | preconfigured web3 object | either provider or web3 or rpcUrl |
| rpcUrl | JSON-RPC endpoint url | either provider or web3 or rpcUrl |
| signer | JWS Signing function | either signer or privateKey |
| txSigner | Ethers.js Signer | either txSigner or privateKey |
| privateKey | Hex encoded private key | yes\* |

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If privateKey is specified, then signer and txSigner don't need to be used. Otherwise, a txSigner is required to
perform CRUD operations on the DID document, and a signer is required to sign JWTs. To generate valid JWT,
the signer must use one of the keys listed in the DID document. To be able to perform CRUD operations, the txSigner
must be backed by the key that governs the owner property.
See https://github.com/uport-project/moon-did-registry#looking-up-identity-ownership

Notes

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An instance created using only an address or publicKey (without access to a privateKey or to signers) can only be used
to encapsulate an external moon-did . This instance will not have the ability to sign anything, but it can be used for a
subset of actions:

- provide its own address (ethrDid.address)
- provide the full DID string (ethrDid.did)
- lookup its owner await ethrDid.lookupOwner()
- verify a JWT await ethrDid.verifyJwt(jwt)

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EthrDid can be configured to control a DID on any ethereum network. To do this, you mush specify the chainNameOrId
during construction. Example:

`ts
console.log(new EthrDID({ identifier: '0xb9c5714089478a327f09197987f16f9e5d936e8a', chainNameOrId: 'alpha' }).did)
// did:moon:goerli:0xB9C5714089478a327F09197987f16f9E5d936E8a
`

If this property is not specified, then the library will attempt to infer it from the provider configuration or from
the identifier if it is specified as a DID. But, be warned that it may lead to inconsistencies since the inference is
not perfect. It is highly recommended that you use a chainNameOrId property to match the provider.

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See the guide to get a better idea about the capabilities of this lib. And, of course, make
sure to familiarize yourself with
the did:moon` spec