waku-org/go-waku

package static

import (
    "errors"

    "github.com/waku-org/go-zerokit-rln/rln"
)

func Setup(index rln.MembershipIndex) ([]rln.IDCommitment, rln.IdentityCredential, error) {
    // static group
    groupKeys := rln.STATIC_GROUP_KEYS
    groupSize := rln.STATIC_GROUP_SIZE

    // validate the user-supplied membership index
    if index >= rln.MembershipIndex(groupSize) {
        return nil, rln.IdentityCredential{}, errors.New("wrong membership index")
    }

    // create a sequence of MembershipKeyPairs from the group keys (group keys are in string format)
    credentials, err := rln.ToIdentityCredentials(groupKeys)
    if err != nil {
        return nil, rln.IdentityCredential{}, errors.New("invalid data on group keypairs")
    }

    // extract id commitment keys
    var groupOpt []rln.IDCommitment
    for _, c := range credentials {
        groupOpt = append(groupOpt, c.IDCommitment)
    }

    return groupOpt, credentials[index], nil
}