Private transaction, contract extension, multi tenancy in Quorum blockchain

1. To support private transaction in Quorum, we have to enable privacy enhancement before starting Quorum network.

a. modify the istanbul-genesis.json (or genesis.json) file

“eip155Block”: 0,
“eip158Block”: 0,
“isQuorum”: true,
+ “privacyEnhancementsBlock”: 0,
“maxCodeSizeConfig” : [
{
“block” : 0,

b. modify tessera-config.json (or tessera-config-9.0.json) file

},
- “alwaysSendTo”: []
+ “alwaysSendTo”: [],
+ “features”: {
+ “enablePrivacyEnhancements”: true
+ }
}

c. add the arguments to send API method

To send private transaction in Quorum blockchain, we add parameters to the send API method.

privateFor: [“…”, “…”] — a list of public key of parties included in the private transaction

PrivacyFlag: 3 -for private state validation

PrivacyFlag: 1 -for counterparty protection

.send({
from: accounts1[0],
gas: 1500000,
gasPrice: ‘0’,
privateFor: [“ROAZBWtSacxXQrOe3FGAqJDyJjFePR5ce4TSIzmJ0Bc=”],
// this is public key from tm7 of 7node Quorum samples
PrivacyFlag: 3
})

Reference:

https://docs.goquorum.consensys.net/en/stable/Concepts/Privacy/PrivacyEnhancements/

2. To support contract extension, pass additional parameter to geth when starting quorum:

--rpcapi quorumExtension

To extend quorum contract in javascript, add the code that extends web3 manually

const methods = [
{
name: ‘approveExtension’,
call: ‘quorumExtension_approveExtension’,
params: 3,
inputFormatter: [web3.extend.formatters.inputAddressFormatter, null, web3.extend.formatters.inputTransactionFormatter]
},
{
name: ‘extendContract’,
call: ‘quorumExtension_extendContract’,
params: 4,
inputFormatter: [web3.extend.formatters.inputAddressFormatter, null, web3.extend.formatters.inputAddressFormatter, web3.extend.formatters.inputTransactionFormatter]
},
{
name: ‘cancelExtension’,
call: ‘quorumExtension_cancelExtension’,
params: 2,
inputFormatter: [web3.extend.formatters.inputAddressFormatter, web3.extend.formatters.inputTransactionFormatter]
},
{
name: ‘getExtensionStatus’,
call: ‘quorumExtension_getExtensionStatus’,
params: 1,
inputFormatter: [web3.extend.formatters.inputAddressFormatter]
},
{
name: ‘activeExtensionContracts’,
call: ‘quorumExtension_activeExtensionContracts’,
params: 0
}
];
web3.extend({
property: ‘quorumExtension’,
methods
});

Then use the normal way to call the quorum contract extension APIs.

For example:

web3.quorumExtension.activeExtensionContracts()

3. Multi-tenancy support

From the release:

https://github.com/ConsenSys/quorum/releases/tag/v21.1.0, it is possible to have multiple tenants in the same node. This feature is in alpha release as of May 2021. OAuth2 server is required when multi-tenancy is used.

This pull request enables multi tenants from a single node.

https://github.com/ConsenSys/quorum/pull/1105

Reference:

https://docs.goquorum.consensys.net/en/latest/HowTo/Use/Multitenancy/

https://docs.goquorum.consensys.net/en/latest/Concepts/Multitenancy/Overview/