AnonCreds: support queries by credential attribute presence and value

[genaris]

AnonCreds spec defines a number of properties that can be set as restrictions in proof requests. Most of them are already supported in @aries-framework/anoncreds-rs module but we are missing two:

• attr::<attribute-name>::marker
• attr::<attribute-name>::<attribute-value>

For that purpose, AnonCredsRsHolderCredentialService must be updated to properly query the wallet according to them, and apply the corresponding tags when storing the credentials.

[Vickysomtee]

I will pick this!

[TimoGlastra]

Example:

// Verifier
const proofRequest = {
    request_attributes: {
        userDetails: {
            names: ['name'],
            restrictions: [{
                cred_def_id: '123',
                // 'attr::name::value': 'Victor',
                // 'attr::age::marker': '1'
            }]
        }
    }
}

// send to holder over DIDComm

// Holder has 100000
const credentials = [{
 attributes: {
    name: 'Timo',
    age: 20
 },
 cred_def_id: '123'
}, {
    attributes: {
        name: 'Victor',
     },
     cred_def_id: '456'
}, {
    attributes: {
        age: '25',
     },
     cred_def_id: '123'
}]


// Filter based on request
const filteredCredentials = [{
    name: 'Timo',
    age: 20
 }, {
    age: '25',
 }]

[TimoGlastra]

When a record is stored, and the getTags method is called on the AnonCredsCredentialRecord we want to calculate the attribute value and marker tags.

This code is currnetly here: https://github.com/hyperledger/aries-framework-javascript/blob/main/packages/anoncreds/src/repository/AnonCredsCredentialRecord.ts#LL73C55-L73C55 and just sets the following tag for attributes:

Curent format:

{
  // ... other tags ...
  attributes: ['name', 'age']
}

Desired format:

{
  // ... other tags ...
  
  // should exist for every attribute in the credential
  'attr::${attributeName}::marker': true,
  'attr::${attributeName}::value': attributeValue
}

Then when querying credentials for a proof request, we need to query by these tags in the AnonCredsCredentialRecord.

This method transforms proof request restrictions into a storage query, which would need to be extended to include the attribute value and marker restrictions: https://github.com/hyperledger/aries-framework-javascript/blob/main/packages/anoncreds-rs/src/services/AnonCredsRsHolderService.ts#L336

In here: https://github.com/hyperledger/aries-framework-javascript/blob/main/packages/anoncreds-rs/src/services/AnonCredsRsHolderService.ts#L369 add checks:

• if this is a attribute value restirction
• if this is a attribute marker restriction

If one is found, we need to add the restriction to the query that algns with the tag structure in the AnonCredsCredentialRecord

How to check if this is a attribute value restriction or a attribute marker restriction you can look here: https://github.com/hyperledger/aries-framework-javascript/blob/main/packages/anoncreds/src/models/AnonCredsRestriction.ts#L135-L143