App2App Samples

This article contains four sample Node.js programs demonstrating message consumption and emission for both Kaleido-managed destination certificates and externally-managed destination certificates.

Kaleido-Managed Sender

Replace the placeholders for APP2APP MESSAGING SERVICE API ENDPOINT, APP CRED USER, APP CRED PASSWORD, SENDER DESTINATION URI and RECIPIENT DESTINATION URI.

// This sample sends a message every two seconds from a Kaleido managed destination
const socket = require("socket.io-client")
    .connect("APP2APP MESSAGING SERVICE API ENDPOINT", {
        extraHeaders: {
            Authorization:
                "Basic " +
                Buffer.from(
                    "APP CRED USER" + ":" + "APP CRED PASSWORD"
                ).toString("base64"),
        },
    })
    .on("connect", () => {
        console.log("Connected.");
        setInterval(send, 2000);
    })
    .on("delivery-report", (data) => {
        console.log("Delivery report: " + JSON.stringify(data));
    })
    .on("disconnect", () => {
        console.log("Disconnected.");
    })
    .on("exception", (exception) => {
        console.log("Exception: " + exception);
    })
    .on("error", (err) => {
        console.log("Error: " + err);
    })
    .on("connect_error", (err) => {
        console.log("Connection error: " + err);
    });

function send() {
    socket.emit(
        "produce",
        {
            headers: {
                from: "SENDER DESTINATION URI",
                to: "RECEPIENT DESTINATION URI",
            },
            content: "Testing 1-2-3",
        },
        "samplekey",
        (err) => {
            if (err) {
                console.log("Delivery error: " + err);
            }
        }
    );
}

Kaleido-Managed Receiver

Replace the placeholders for APP2APP MESSAGING SERVICE API ENDPOINT, APP CREDENTIAL USER, APP CREDENTIAL PASSWORD and DESTINATION URI.

// This sample consumes messages from a Kaleido managed destination
const socket = require("socket.io-client")
    .connect("APP2APP MESSAGING SERVICE API ENDPOINT", {
        extraHeaders: {
            Authorization:
                "Basic " +
                Buffer.from(
                    "APP CREDENTIAL USER" + ":" + "APP CREDENTIAL PASSWORD"
                ).toString("base64"),
        },
    })
    .on("connect", () => {
        console.log("Connected.");
        socket.emit("subscribe", ["DESTINATION URI OR NAME"], (err, result) => {
            if (err) {
                console.log(err);
            } else {
                console.log(result);
            }
        });
    })
    .on("disconnect", () => {
        console.log("Disconnected.");
    })
    .on("exception", (exception) => {
        console.log("Exception: " + exception);
    })
    .on("error", (err) => {
        console.log("Error: " + err);
    })
    .on("connect_error", (err) => {
        console.log("Connection error: " + err);
    })
    .on("data", (message, key, timestamp) => {
        console.log("Message from: " + message.headers.from);
        console.log("Content: " + message.content);
        console.log("key: " + key);
        console.log("timestamp: " + timestamp);
    });

Externally-Managed Sender

Replace the placeholders for APP2APP MESSAGING SERVICE API ENDPOINT, APP CRED USER, APP CRED PASSWORD, PRIVATE KEY PEM, SENDER DESTINATION URI and RECIPIENT DESTINATION URI

// This sample sends a message every two seconds from an externally managed destination
const socket = require("socket.io-client")
    .connect("APP2APP MESSAGING SERVICE API ENDPOINT", {
        extraHeaders: {
            Authorization:
                "Basic " +
                Buffer.from(
                    "APP CRED USER" + ":" + "APP CRED PASSWORD"
                ).toString("base64"),
        },
    })
    .on("connect", () => {
        console.log("Connected.");
        setInterval(send, 2000);
    })
    .on("delivery-report", (data) => {
        console.log("Delivery report: " + JSON.stringify(data));
    })
    .on("disconnect", () => {
        console.log("Client disconnected.");
    })
    .on("exception", (exception) => {
        console.log("Service reported an exception: " + exception);
    })
    .on("error", (err) => {
        console.log("Error: " + err);
    })
    .on("connect_error", (err) => {
        console.log("Connection error: " + err);
    });

function send() {
    let content = "Testing 1-2-3";
    let signature = require("crypto")
        .createSign("RSA-SHA256")
        .update(content)
        .sign("PRIVATE KEY PEM");
    socket.emit(
        "produce",
        {
            headers: {
                from: "SENDER DESTINATION URI",
                to: "RECEPIENT DESTINATION URI",
                signature,
            },
            content,
        },
        "samplekey",
        (err) => {
            if (err) {
                console.log("Delivery error: " + err);
            }
        }
    );
}

Externally-Managed Receiver

Replace the placeholders for APP2APP MESSAGING SERVICE API ENDPOINT, APP CREDENTIAL USER, APP CREDENTIAL PASSWORD, RECIPIENT DESTINATION URI, RECIPIENT PRIVATE KEY PEM and SENDER CERTIFICATE PEM.

// This sample consumes messages from a Kaleido managed destination
const socket = require("socket.io-client")
    .connect("APP2APP MESSAGING SERVICE API ENDPOINT", {
        extraHeaders: {
            Authorization:
                "Basic " +
                Buffer.from(
                    "APP CREDENTIAL USER" + ":" + "APP CREDENTIAL PASSWORD"
                ).toString("base64"),
        },
    })
    .on("connect", () => {
        console.log("Connected.");
        socket.emit(
            "subscribe",
            ["RECEPIENT DESTINATION URI OR NAME"],
            (err, result) => {
                if (err) {
                    console.log(err);
                } else {
                    console.log(result);
                }
            }
        );
    })
    .on("disconnect", () => {
        console.log("Disconnected.");
    })
    .on("exception", (exception) => {
        console.log("Exception: " + exception);
    })
    .on("error", (err) => {
        console.log("Error: " + err);
    })
    .on("connect_error", (err) => {
        console.log("Connection error: " + err);
    })
    .on("data", (pkcs7Envelope, key, timestamp) => {
        const forge = require("node-forge");
        const pkcs7 = forge.pkcs7.messageFromPem(pkcs7Envelope);
        pkcs7.decrypt(
            pkcs7.recipients[0],
            forge.pki.privateKeyFromPem("RECEPIENT PRIVATE KEY PEM")
        );
        const message = JSON.parse(pkcs7.content.toString());
        console.log("Message: " + message.content);
        console.log("Key: " + key + ", timestamp: " + timestamp);
        console.log(
            "Signature checks out: " +
                require("crypto")
                    .createVerify("RSA-SHA256")
                    .update(message.content)
                    .verify(
                        "SENDER CERTIFICATE PEM OBTAINED FROM ID REGISTRY BASED ON SENDER DESTINATION URI",
                        Buffer.from(message.headers.signature)
                    )
        );
    });