Implement New Credential Issuance Schema in IAM Server

[nutrina]

User Story:

As a developer,
I want to create and deploy a version of the IAM server that is capable of issuing credentials in the new format and adjust the on-chain issuance accordingly,
So that I can test against this production deployment and deploy updates to the Passport application that use the new stamp schema.

Acceptance Criteria

GIVEN I am a user of the IAM service
WHEN I make a request for a challenge credential
THEN I get back a valid challenge credential using the new signature (as required in the new VC format)

AND

GIVEN I am a user of the IAM service
WHEN I make a request for verifying a user's claim
AND if I present a valid challenge signature
THEN I get back a valid credential in the new schema
AND that credential has the new proof / signature type EthereumEip712Signature2021
AND the VCs hash is created with a separate key (that will be in the old format)

Product & Design Links:

Example implementation for issuing credentials

Tech Details:

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://w3id.org/vc/status-list/2021/v1"
  ],
  "type": [
    "VerifiableCredential"
  ],
  "credentialSubject": {
    "id": "did:pkh:eip155:1:0x12FeD9f987bc340c6bE43fD80aD641E8cD740682",
    "provider": "Twitter",
    "metaPointer": "https://github.com/gitcoinco/passport-scorer/blob/main/api/scorer/settings/gitcoin_passport_weights.py",
    "customInfo": {
      "field1": "value"
    },
    "hash": "v0.0.0:AjcRjxx7Hp3PKPSNwPeBJjR21pLyA14CVeQ1XijzxUc=",
    "@context": {
      "customInfo": "https://schema.org/Thing",
      "hash": "https://schema.org/Text",
      "metaPointer": "https://schema.org/URL",
      "provider": "https://schema.org/Text"
    }
  },
  "issuer": "did:ethr:0xd6fc34345bc8c8e5659a35bed9629d5558d48c4e",
  "issuanceDate": "2022-07-19T10:42:24.883Z",
  "proof": {
    "@context": "https://w3id.org/security/suites/eip712sig-2021/v1",
    "type": "EthereumEip712Signature2021",
    "proofPurpose": "assertionMethod",
    "proofValue": "0xe0d7dd8ff59a575df3212ecfbbea04dc3364dd5d0b00d3a09115dd6f814fb85c2ca535560ba14bd4d93ff49d20b7f7a21c887afd1403ef19b386e5f436058c071b",
    "verificationMethod": "did:ethr:0xd6fc34345bc8c8e5659a35bed9629d5558d48c4e#controller",
    "created": "2023-08-03T08:09:18.969Z"
  },
  "expirationDate": "2022-10-17T10:42:24.883Z",
  "credentialStatus": {
    "id": "https://example.edu/credentials/status/3#94567",
    "type": "StatusList2021Entry",
    "statusPurpose": "revocation",
    "statusListIndex": "94567",
    "statusListCredential": "https://example.edu/credentials/status/3"
  }
}

• Create a new endpoint in the IAM server to issue stamps using the new schema (please also consider the challenge credential)
• Update the issuing of stamps on-chain. Create a new endpoint that delivers the new payload required for the on-chain stamps.
• The hash of the stamps should be created with the same key as before

Open Questions:

• What are the specific requirements for the new endpoint in the IAM server?
• What changes are needed for the on-chain stamp issuance?

Notes/Assumptions:

• The functionality for the new stamp schema should co-exist with the old stamp schema but preferably hosted on different paths.
• Worst case: we can easily roll back the Passport deployments without the need to roll-back the IAM (since the IAM offers both functionalities)
• The cleanup should be performed 90 days after the go-live to ensure that there are no issues with the new system.

[nutrina]

It's on blocked just because waiting for review.