Creating broker accounts using script

One way to prepare a set of Neuro-Access accounts for a predefined set of users, is to pre-create them using script and then generate onboarding codes that can be sent to the users. Once they receive their corresponding code, they can download the app, scan the code, and connect directly to the predefined account. This method allows you to create accounts on a predefined Neuron for a known set of users, without having to create API keys, and minimizing the risk of the users creating accounts on other neurons. It also allows you to predefine the account names.

To try the following tutorial, you need access to the script prompt on your neuron. The script prompt is available from the administrative page via this option:

Creating the account

The main module of the XMPP broker, hosting the accounts, is Waher.Service.IoTBroker.XmppServerModule, or XmppServerModule for short. It has a property called PersistenceLayer that acts as an interface to the database for the XMPP server. This interface has a method called CreateAccount that allows us to create accounts. This method performs necessary checks to ensure the name is not occupied elsewhere, to protect integrity. Typing its fully qualified name into the prompt allows us to find its arguments:

Note: Finding the names of the types, properties and methods is a combination of using the Namespaces & Types option from the administrative portal, and/or using the script prompt together with the methods and properties functions. You can also use the Neuron Documentation with its DoxyGen code documentation site where you can search for classes and other relevant names.

We are now ready to create accounts. We will generate account names that are GUIDs, using the NewGuid() script function. Each account will receive a random password with sufficient entropy, generated using the RandomPassword() script function. We will not use an API Key (leaving it empty), making the account behave as a manually created account. We will not assign e-mail adddresses or phone numbers to the accounts either. To ensure the account object has a proper remote endpoint associated with its creation, we will use the Request.RemoteEndPoint value, which will contain the remote endpoint of the person executing the script function via the script prompt. (If executing the script via some other interface, you might have to change this reference to something else.) The result of calling the CreateAccount method, is a KeyValuePair<IAccount,string[]> result, where the Key portion contains the new account, if created (or null if not), and the Value portion any alternative name suggestions in case the account could not be created.

P:=Waher.Service.IoTBroker.XmppServerModule.PersistenceLayer.CreateAccount("",Str(NewGuid()),RandomPassword(),"","",Request.RemoteEndPoint);
Account:=P.Key;
AlternativeNames:=P.Value;

Note: You can call properties(Account) to review the properties of the account. You can also see that access to the generated password is protected to reduce the risk of unauthorized access to the account.

Note 2: If you want, you can create a separate API key, and reference it when you create the account. This way, you can separate the accounts from other manually created accounts. You can also control the amount of accounts that can be created.

Creating an onboarding code

Next step is to create an onboarding code. This is done in cooperation with the onboarding neuron configured for the neuron on which the account was created. The onboarding code is a URI with the obinfo: URI scheme, that references the onboarding neuron, and contains a key and a secret. The onboarding neuron on the other hand receives an encrypted BLOB containg the information necessary to access the account. This information can only be decrypted using the secret key available in the onboarding code. Furthermore, the onboarding code can only be used once. You can also define a point in time when the code expires, if it has not been used.

Note: Since the code can only be used once, it is important to transfer the code in a way where it cannot be previewed by mistake. Previewing it will result in the code automatically expiring.

To create the code, we will call the GetOnboardingUrl method on the Account object. It takes one argument: The point in time when the code will expire if not used before. In the following example, we create a code that will be valid for three days:

Code:=Account.GetOnboardingUrl(Now.AddDays(3));

The Code will contain a string representing the onboarding URI. It will be of the form:

obinfo:id.tagroot.io:14gsjgK56X6.................................:NKxDui0EMoLb1....................................

The Onboarding URI contains four parts, delimited by colons (:):

1. The obinfo URI scheme identifying the URI as an onboarding URI.
2. The onboarding neuron that contains the encrypted BLOB (but not the key).
3. The identifier of the encrypted BLOB.
4. The secret key necessary to decrypt the BLOB.

Creating an onboarding QR Code

The Neuron has a QR Code API that permits you to create QR codes for the onboarding URIs generated. The procedure is simple: A URL is generated pointing to the /QR resource on the neuron. After the resource name you add the contents you want to encode into the URI, prefixed by a /. The contents must be URL encoded. After the contents, you can add query parameters controlling how the QR code should be generated. This includes controlling the quality of the image, resolution and colors. Displaying a QR code on screen, or in an email requires less resolution, that including the image in print, for instance. A QR code for light mode displays (or white paper) should look different from QR codes for dark mode displays, for instance.

In the following example, we use the Waher.IoTGateway.Gateway.GetUrl(LocalResource) method to generate an absolute URL to an image containing a 400x400 pixel QR code encoding the onboarding URI just created. It uses a quality setting of 2, meaning 2x2 points are evaluated for every pixel generated, creating an anti-aliasing effect to create smoother edges.

CodeUrl:=Waher.IoTGateway.Gateway.GetUrl("/QR/"+UrlEncode(Code)+"?w=400&h=400&q=2");

For our example, this would result in a URL similar to the following:

https://lab.tagroot.io/QR/obinfo%3Aid.tagroot.io%3A14gsjgK56X6.................................%3ANKxDui0EMoLb1....................................?w=400&h=400&q=2

As an image, this QR code would look like:

The QR Code API documents parameters that can be used to control the colors used when generating the QR code. By appending &fg=white&bg=black&c=c0ffc0 to the URL, for instance, a QR code for dark-mode can be generated instead, as an example:

If higher resolution images are required, you can increase the w (width), h (height) and q (quality) settings. For example, an 800x800 image with 3x3 points per pixel quality would look like:

Batch creation of accounts

We are now ready to create script for the batch creation of accounts, and generate QR codes that can be distributed separately, for each account created. We will use the preview() function to display current progress in the prompt (and the batch procedure may require some time to execute, depending on the number of accounts and QR codes to create), the Get() function to retrieve the image from the generated QR Code URLs, and the SaveFile() function to save the QR codes generated, and the results of the batch procedure into a single JSON file. We will use the Waher.IoTGateway.Gateway.AppDataFolder property to save files in a location that is easily accessible, and where the Neuron has write-access. We will create a subfolder called Batch for the generated files. Finally, we generate an XML document with the same information, and store it as an XML file also. At the end we have a set of onboarding QR code image files, a JSON file with an index of all accounts created, and a similar XML file with the same information. We create the following batch account-creation function:

CreateAccounts([N]):=
(
	Created:=NowUtc;
	Accounts:=
	{
		"NrAccounts":N,
		"Created":Created
	};
	Records:=[];
	AccountNr:=1;

BatchFolder:=Waher.IoTGateway.Gateway.AppDataFolder+"Batch";
if !System.IO.Directory.Exists(BatchFolder) then
	System.IO.Directory.CreateDirectory(BatchFolder);

while AccountNr<=N do
(
	AccountNrStr:=Str(AccountNr);
	preview("Creating account "+Str(AccountNrStr)+"...");

do
(
	P:=Waher.Service.IoTBroker.XmppServerModule.PersistenceLayer.CreateAccount("",Str(NewGuid()),RandomPassword(),"","",Request.RemoteEndPoint);
	Account:=P.Key;
	AlternativeNames:=P.Value
)
while !exists(Account);

Code:=Account.GetOnboardingUrl(Now.AddDays(3));
CodeUrl:=Waher.IoTGateway.Gateway.GetUrl("/QR/"+UrlEncode(Code)+"?w=400&h=400&q=2");
QrCode:=Get(CodeUrl);

QrCodeFileName:=BatchFolder+"\\"+Left("00000000",9-len(AccountNrStr))+AccountNrStr+".png";
SaveFile(QrCode,QrCodeFileName);

Record:=
{
	"AccountNr":AccountNr,
	"UserName":Account.UserName,
	"OnboardingUrl":Code,
	"QrCodeUrl":CodeUrl,
	"QrCode":QrCodeFileName
};

PushLast(Record,Records);
AccountNr++;
);

Accounts["Records"]:=Records;

SaveFile(Accounts,BatchFolder+"\\Accounts.json");

AccountsXml:=<Accounts nrAccounts=N created=Created>
	<[[foreach Record in Records do 
		<Account accountNr=(Record.AccountNr) userName=(Record.UserName) onboardingUrl=(Record.OnboardingUrl) qrCodeUrl=(Record.QrCodeUrl) qrCode=(Record.QrCode) />
	]]>
</Accounts>;

SaveFile(AccountsXml,BatchFolder+"\\Accounts.xml");
);

You can download the script file from the following link: CreateAccount.script

#tutorial, #script, #account, #neuro-access, #onboarding

Killing a State Machine

If a state-machine associated with a token or set of tokens misbehaves, and needs to be stopped, an operator of Neuro-Features on the Neuron® that hosts the state-machine can kill it. This does not destroy the token or tokens associated with the state-machine, it just stops the state-machine. The event is also appropriately logged, with information about who took the responsibility to kill the machine.

In order to be able to kill a state machine, the operator needs to fullfil the following requirements:

• Be an operator on the Neuron hosting the state-machine (i.e. have an administrative account on the Neuron).
• Have a Digital ID associated with the account.
• Have sufficient access rights to administer Neuro-Features. (This means, having the Admin.Notarius.NeuroFeatures privilege associated with one of its roles.)
• Digitally sign an approval of the killing of the machine, where the user affirms to reviewing the token and taking the responsibility of killing the state-machine.

Accessing the Token

To access available tokens on the Neuron, go to the Neuro-Features section in the administrative portal:

Find the corresponding token, and open it by clicking on its ID. A link of the following type is opened:

https://DOMAIN/NeuroFeature.md?ID=TOKEN_ID

If you know the Token ID, you can open the page directly by replacing TOKEN_ID in the URL above with the correct Token ID. If you don’t know the Token ID, but you know the ID of the smart contract that created the token, you can use the script prompt, to find the Token ID, using the following SELECT statement:

select 
	top 1 TokenId 
from 
	NeuroFeatureTokens 
where 
	CreationContract=CONTRACT_ID

Killing the state machine

Once the Current State part of the Neuro-Feature page has loaded, it will present a Kill Machine button, if the token has an associated state-machine.

Press this button to open a new page where you can kill the machine. The page has the following URL. If you have the Token ID already, and cannot open the Neuro-Feature page associated with the token for some reason, you can enter this URL directly into the broker, replacing TOKEN_ID with the corresponding Token ID:

https://DOMAIN/KillMachine.md?ID=TOKEN_ID

The page that opens is simple and informs the user they need to approve the operation using their Digital ID, and that they will be responsible for the action:

Press the Kill Machine button to initiate the process by sending a petition to the Digital Identity of the currently logged in user:

If a Legal Identity is associated with your account you will receive an acknowledgement that a petition has been sent.

You will see this petition in your Digital ID app, as follows:

Take time to read through the purpose of the signature. If you agree, sign the petition, and the state-machine will be killed:

#tutorial, #new, #features, #neuro-feature, #state-machine

Geo-spatial contract parameters in LegalLab

LegalLab has been updated to support geo-spatial contract parameters. An example contract is also available showing how geo-spatial parameters in contracts can work. Make sure the Neuron® to which you are connected is updated to include support for geo-spatial parameters.

Adding to templates

A new button is available that you can click to add a geo-spatial parameter to a contract template you are designing:

Note: When editing geo-spatial parameter values, use GPS Coordinate syntax.

Geo-spatial Publish/Subscribe

When signing contracts with geo-spatial parameters, one of the parmeters can be used to give the contract a location. The example contract contains one such parameter. This means the contract, when signed, is assigned the geo-spatial coordinate provided in the parameter. The contract position is also published using the Neuron’s geo-spatial publish/subscribe service. If the visibility of the contract is set to Public & Searchable, the publication will be persisted. Otherwise, the publication will be ephemeral, i.e. shown only at the time of signature.

#new, #legallab, #features, #contracts, #tutorial

Processing signed contracts in a state machine: Open Vote example

The LegalLab repository contains a new example that illustrates how Neuro-Feature token state machines can be used to process signed smart contracts. The example implements a simple open voting system that tokenizes each vote, counting ballots within a given time frame, as they are cast. Each ballot is a smart contract signed by a participant. The state-machine of the vote counts accepted ballots, rejects incorrect ballots, and logs events to the Neuro-Ledger for transparency and auditability.

Note: The same architecture as exemplified by the Open Vote set of contracts (Vote + Ballot contracts) can be used in many technically similar (albeit conceptually different) cases. One such example is the tokenization of agriculture, for example, where each cultivation can be tokenized, and it can keep track of its current state transparently (for the end consumer) by processing observations, each observation recorded as a signed smart contract with information about what has occurred. Another example can be the tokenization of medical journals, for interoperability and privacy protection. The journal observes diagnoses and tests being performed, each one recorded as a signed smart contract with the appropriate information.

Vote Contract

The first contract in the Open Voting model (OpenVoteYesNoAbstain.xml), contains the state-machine Neuro-Feature token definition and contract. It defines the basic states of ballot processing. It assumes each ballot contains machine-readable information, as defined by the schema OpenVote.xsd, also downloadable online via its target namespace: https://paiwise.tagroot.io/Schema/OpenVote.xsd.

Note: Each contract containing machine-readable instructions will only be accepted if each Neuron® can validate the XML it contains. This is done by downloading the schema files from the corresponding target namespaces and using these schemas for validation. If the validation does not complete successfully, the contract is automatically rejected.

The states defined in the contract can be illustrated with the following state diagram:

The voting contract allows the creator to pose a question, define if participants are allowed to change their votes, and between what times the vote will be active. Times are defined in UTC. Participants need personal digital IDs with at least a validated country code, personal number and full name. Only one ballot per (Country, Country Code) will be counted. Apart from a Creator, the contract also requires a Certifier, which can be the same as the creator. The Certifier are given rights to cancel (invalidate) an election.

The states a voting procedure passes through are:

• During the Preparing state, the state machine checks if it is paired with a Ballot template that points to it. The Ballot template needs to define a contract reference parameter to the vote, and it needs to enforce the template of the vote to match the template used to create the vote. If one such Ballot template is found, it progresses automatically to the next state. If one is not found, it awaits until such a template is approved on the Neuron®.

• The Pending state, is a state where the vote is prepared, but has not commenced yet. During this state, the present view can be displayed, and links to the vote can be distributed. Any ballots cast during this state will be automatically rejected. Once the time to open the vote has been reached, the state-machine progresses to the next state.

• The Open state is where participants can vote by signing Ballot contracts. If they are signed using the appropriate template, and pointing to the vote, the state-machine will process the ballots. If any errors are encountered, the corresponding ballot is rejected, and error logged. When the finishing time has been reached, the state-machine progresses to the next state.

• The last state is the Closed state. Here, the voting machine is kept alive, to present results, but no ballots are processed, so the tally cannot be changed. Once the expiry time is reached, the state-machine is ended.

During state changes, the creator is notified by XMPP (Instant Chat Message) and e-Mail about the state of the vote. The messages contain links to the vote. These can be distributed to participants of the vote. The vote can also be shown in a browser. If published, voters and other participants can follow the results in real-time.

Ballot Contract

The second contract template is the OpenBallotYesNoAbstain.xml contract. It defines the ballot contract that can be used to participate in any votes generated by the corresponding voting template. The two templates must be paired. So, once the voting template has been proposed and apporved, its ID must be set into the Ballot template contract, before it can be proposed. Once this has been done, it can be proposed and approved accordingly. Then, the pair can be used with as many votes as desired.

The Ballot template defines the Boolean parameters necessary to be able to select Yes, No or Abstain. The Machine-readable part (defined by the https://paiwise.tagroot.io/Schema/OpenVote.xsd namespace) instructs the vote state-machine how the ballot is to be interpreted. The Ballot template has a contract reference parameter of a given name, and it must require a contract reference having a template ID restriction equal to the ID of the voting template. Once the voting state-machine is running, it will provide links to the corresponding Ballot contract template, with these references pre-set, so the user does not need to worry about providing the values for thse references. The user will only scan a QR code to vote.

Approved templates for experimentation

If you want to experiment with the open voting solution described, you can use the following approved contract templates. You can either copy the contract IDs and use in your application, or if you use an App, scan the corresponding QR code to access it.

To create a vote, i.e. define a question partiticpants will vote on, use the following template by scanning the code or entering its ID in the appropriate interface:

The matching Ballot template (which you will not need to scan here directly, as it will be presented pre-filled for you, see below), is:

After scanning the code, a new vote contract will be displayed. Fill in the details (question, if votes can be changed and the time interval the vote will be open; remember the times need to be provided in Universal Time Coordinates, or UTC). Sign the contract, both as Creator and Certifier (unless you want another person to sign as Certifier). Once the vote has been created and been properly signed, a Neuro-Feature token will be created. It will send you an e-mail with a link to the voting results page. The vote only passes slightly the preparation state, as an approved ballot template already exists. The vote page will look something as follows. Note the QR code to the right. It will point to the ballot contract template to use to cast a ballot, and also contain the reference to the current vote pre-filled. All you need to do after scanning the QR-code, is to select how you want to vote.

Note: The vote token is defined to be unique. This means, you can only create one token (one vote) with the same set of parameters. This means, you need to change any of the parameters from previous versions, including the question or time parameters, before you can create additional votes.

Vote Count & real-time presentation

The token that is generated by the vote contract has a present report that displays the current state of the vote. The creator can access the present report from the client used to create the vote contract, and by extension the token. The creator will also get an Instant Chat Message and an e-Mail, containing the present report and current vote count (which would be zero and pending, before the count starts). There will also be a web URL which can be distributed, that will show the vote to any online viewer. The URL will have a format similar to https://sa.id.tagroot.io/NF/a86d6033-b694-7b5e-c8d3-42d5200ec85c@edaler.sa.id.tagroot.io. The ID in the URL corresponds to the ID of the Vote. You can match this ID with the ID displayed for the vote (see below). The present report can be projected and displayed in kiosk mode as well. It will be updated in real-time as votes are counted. The initial view may be something as follows:

Note The QR code in the report can be scanned by participants, and will point to the ballot template, with the vote reference pre-filled in. All the participant needs to do, is vote, and sign the ballot and the vote will be counted. Once the vote closes, the report will be updated accordingly also.

Note: Once the vote closes, the QR code changes. It is no longer pointing to the ballot template, but instead to the token that performed the count. Scanning it will give access to the token, and the reports it publishes.

Presentation Layout

The layout presenting the vote count is generated by the voting token itself, and is part of the vote contract template, and can therefore be reviewed as well. It is an XML Layout format, availble in the OpenVoteResultLayout.xml file. You can edit such XML files and preview the layout using LegalLab as follows:

The variables and script functions used in the layout need to be initialized. This can be done in the Script tab. You can use the initialization script published in the repository: OpenVoteResultLayoutInit.script to generate the view above.

Neuro-Ledger entries recorded

Apart from all entries recorded regarding Digital Identities, Smart Contracts, Tokens and State-Machines, the Open Vote example records several entries by itself. These include:

Entry	Description
BallotCounted	A ballot has been counted.
BallotRejected	A ballot has been rejected.
BallotRevoked	When an older ballot has been revoked because the participant submits a new ballot.
CommentReceived	A comment by a participant has been received.

Note: The vote contract defining the vote, also defines the Neuro-Ledger Collection these entries are recorded in.

The other common Neuro-Ledger collections annotating entries are:

Neuro-Ledger Collections
LegalIdentities	Contains entries related to digital identities, including Neuro-Access digital identities.
Contracts	Contains entries related to smart contracts, including the voting contract and the ballot contracts used during voting.
NeauroFeatureTokens	Contains information regarding Neuro-Feature tokens, including the token definition of the open voting logic.
StateMachines	State-Machine information is recorded in this collection. This includes the open voting process performing the ballot counting and presentation.
StateMachineCurrentStates	Contains current states of different State-Machines.
StateMachineSamples	Contains variable changes as they are persisted by State-Machines. These samples can be used to track the counting process.

#tutorial, #example, #legallab, #contracts, #neuro-feature, #neuro-ledger, #state-machine

Troubleshooting Stack Overflow and Out of Memory Errors

The Neuron® normally runs as a Windows Service using the limited Local Service user account. Any errors in the Neuron® or any of the applications hosted within it, are normally logged to the internal event log, which distributes events to registered event sinks. These may record them in files, internal databases, the Windows Event Log, or forward them to external sources, both for real-time monitoring or storage. Communications can also be monitoried and trouble-shooted using sniffers that can be temporarily attached to different communication channels. Any Exception occurring within the system can also be logged separately together with stack traces, and statistics of such is generated when the Neuron® restarts. But one type of Exception is particularly difficult to troubleshoot, especially for a Windows Service that runs invisibly on a server: Stack Overflow, Out-of-Memory, Access Violation Exceptions and other fatal exceptions can typically shut down the service immediately, without any possibility to record details about the event for troubleshooting. The only notification an operator may receive, is that the Neuron® restarts unexpectedly. After reviewing the backups folder, the operator may also notice the database has been repaired, since the Neuron® was shut down ungracefully (i.e. the process was killed). There are a couple of ways you can find out what causes such an error.

Remote Debugging

One way to find this error, is to attach to the Neuron® process on the server using Visual Studio Remote Debugging tools. Once attached to the process, the debugger can be configured to break when the Exception occurs, giving you a chance to examine the stack trace before the process is killed. There are difficulties with this approach however. One is that the code is probably optimized for Release, and difficult to Debug. You must also open ports, install the remote debugger, etc.

Running as a Console

Another way to troubleshoot the Exception, is to run the console version of the Neuron® in a Terminal Window or Command Prompt. The difficulty here, is to make sure the Terminal Window is using the correct user privileges to mimic the environment the Windows Service has. This can be done by downloading PSTools from Microsoft. It provides tools to access internal features in the Windows operating system. Once installed, you open a Terminal Window (Command Prompt) with administrative privileges. You go to the folder where PSTools is installed, and you type the following command:

psexec -i -s -u "NT AUTHORITY\LocalService" cmd.exe

This will open a new terminal window with the correct user privileges. Before starting the Neuron® in the new terminal window, you need to stop and disable the Windows Service, so it does not interfere. Then, in the new terminal window, go to the installation folder of the Neuron®, and type:

Waher.IoTGateway.Svc.exe -console

It uses the same executable file that is executed by the Windows Service, but the -console switch starts it in console mode. This will enable terminal output of the internal event log, and any system message that will appear. If a Stack Overflow, Out of Memory or Access Violation Exception occurs (or any other fatal type of Exception), this information will be output to the terminal window as the process is killed.

#tutorial, #troubleshooting