getandset.js

var WebSocket = require( 'ws' ).WebSocket;
var browserifyCipher = require( 'browserify-cipher' );
var nobleSecp256k1 = require( 'noble-secp256k1' );
var crypto = require( 'crypto' );

var privKey = "64c2a35ea7eb34f49f23ff42f7479e00613e01c3335acaaa5adf63aea41e81fc";
var pubKeyMinus2 = nobleSecp256k1.getPublicKey( privKey, true ).substring( 2 );
var randomid = Buffer.from( nobleSecp256k1.utils.randomPrivateKey() ).toString( "hex" );
var randomid2 = Buffer.from( nobleSecp256k1.utils.randomPrivateKey() ).toString( "hex" );

function normalizeRelayURL(e){let[t,...r]=e.trim().split("?");return"http"===t.slice(0,4)&&(t="ws"+t.slice(4)),"ws"!==t.slice(0,2)&&(t="wss://"+t),t.length&&"/"===t[t.length-1]&&(t=t.slice(0,-1)),[t,...r].join("?")}

function sha256( string ) {
        return crypto.createHash( "sha256" ).update( string ).digest( "hex" );
}

function encrypt( privkey, pubkey, text ) {
        var key = nobleSecp256k1.getSharedSecret( privkey, '02' + pubkey, true ).substring( 2 );

        var iv = Uint8Array.from( crypto.randomBytes( 16 ) )
        var cipher = browserifyCipher.createCipheriv(
                'aes-256-cbc',
                Buffer.from( key, 'hex' ),
                iv
        );
        var encryptedMessage = cipher.update( text, "utf8", "base64" );
        emsg = encryptedMessage + cipher.final( "base64" );

        return emsg + "?iv=" + Buffer.from( iv.buffer ).toString( "base64");
}

function decrypt( privkey, pubkey, ciphertext ) {
        var [ emsg, iv ] = ciphertext.split( "?iv=" );
        var key = nobleSecp256k1.getSharedSecret( privkey, '02' + pubkey, true ).substring( 2 );

        var decipher = browserifyCipher.createDecipheriv(
                'aes-256-cbc',
                Buffer.from( key, "hex" ),
                Buffer.from( iv, "base64" )
        );
        var decryptedMessage = decipher.update( emsg, "base64" );
        dmsg = decryptedMessage + decipher.final( "utf8" );

        return dmsg;
}

async function getNote( id ) {
        var relay = "wss://relay.damus.io";
        relay = normalizeRelayURL( relay );
        var socket = new WebSocket( relay );
        var note = "";
        socket.on( 'message', async function( event ) {
                var event = JSON.parse( event );
                if ( event[ 2 ] && event[ 2 ].kind == 4 && event[ 2 ].pubkey == pubKeyMinus2 ) {
                        var i; for ( i=0; i<event[ 2 ].tags.length; i++ ) {
                                if ( event[ 2 ].tags[ i ] && event[ 2 ].tags[ i ][ 1 ] ) {
                                        var recipient = event[ 2 ].tags[ i ][ 1 ];
                                        if ( recipient == pubKeyMinus2 ) {
                                                var decrypted_message = decrypt( privKey, event[ 2 ].pubkey, event[ 2 ].content );
                                                if ( id != event[ 2 ].id ) {
                                                        return;
                                                } else {
                                                        note = ( decrypted_message );
                                                }
                                        } else if ( event[ 2 ].pubkey == pubKeyMinus2 ) {
                                                note = ( decrypt( privKey, recipient, event[ 2 ].content ) );
                                        }
                                }
                        }
                } else if ( event[ 2 ] && event[ 2 ].kind == 1 ) {
                        note = ( event[ 2 ].content );
                }
        });
        socket.on( 'open', function open() {
                var filter = {
                        "ids": [
                                id
                        ]
                }
                var subscription = [ "REQ", randomid, filter ];
                subscription = JSON.stringify( subscription );
                var chaser = [ "CLOSE", randomid ];
                chaser = JSON.stringify( chaser );
                socket.send( subscription );
                setTimeout( function() {socket.send( chaser );}, 1000 );
                setTimeout( function() {socket.terminate();}, 2000 );
        });
        async function isNoteSetYet( note_i_seek ) {
                return new Promise( function( resolve, reject ) {
                        if ( note_i_seek == "" ) {
                                setTimeout( async function() {
                                        var msg = await isNoteSetYet( note );
                                        resolve( msg );
                                }, 100 );
                        } else {
                                resolve( note_i_seek );
                        }
                });
        }
        async function getTimeoutData() {
                var note_i_seek = await isNoteSetYet( note );
                return note_i_seek;
        }
        var returnable = await getTimeoutData();
        return returnable;
}

async function setNote( note ) {
        var relay = "wss://relay.damus.io";
        relay = normalizeRelayURL( relay );
        var socket = new WebSocket( relay );
        var id = "";
        socket.on( 'open', function open() {
                function makePrivateNote( note, recipientpubkey ) {
                        var now = Math.floor( ( new Date().getTime() ) / 1000 );
                        var privatenote = encrypt( privKey, recipientpubkey, note );
                        var newevent = [
                                0,
                                pubKeyMinus2,
                                now,
                                4,
                                [['p', recipientpubkey]],
                                privatenote
                        ];
                        var message = JSON.stringify( newevent );
                        var msghash = sha256( message );
                        nobleSecp256k1.schnorr.sign( msghash, privKey ).then(
                                value => {
                                        sig = value;
                                        nobleSecp256k1.schnorr.verify(
                                                sig,
                                                msghash,
                                                pubKeyMinus2
                                        ).then(
                                                value => {
                                                        if ( value ) {
                                                                var fullevent = {
                                                                        "id": msghash,
                                                                        "pubkey": pubKeyMinus2,
                                                                        "created_at": now,
                                                                        "kind": 4,
                                                                        "tags": [['p', recipientpubkey]],
                                                                        "content": privatenote,
                                                                        "sig": sig
                                                                }
                                                                var sendable = [ "EVENT", fullevent ];
                                                                sendable = JSON.stringify( sendable );
                                                                socket.send( sendable );
                                                                id = msghash;
                                                                setTimeout( function() {socket.terminate();}, 300 );
                                                         }
                                                }
                                       );
                                }
                        );
                }
                makePrivateNote( note, pubKeyMinus2 );
        });
        async function isNoteSetYet( note_i_seek ) {
            return new Promise( function( resolve, reject ) {
                    if ( note_i_seek == "" ) {
                            setTimeout( async function() {
                                    var msg = await isNoteSetYet( id );
                                    resolve( msg );
                            }, 100 );
                    } else {
                            resolve( note_i_seek );
                    }
            });
        }
        async function getTimeoutData() {
            var note_i_seek = await isNoteSetYet( id );
            return note_i_seek;
        }
        var returnable = await getTimeoutData();
        return returnable;
}

async function logAllPrivateMessages() {
        var relay = "wss://relay.damus.io";
        relay = normalizeRelayURL( relay );
        var socket = new WebSocket( relay );
        socket.on( 'message', async function( event ) {
                var event = JSON.parse( event );
                if ( event[ 2 ] && event[ 2 ].kind == 4 && event[ 2 ].pubkey == pubKeyMinus2 ) {
                        var i; for ( i=0; i<event[ 2 ].tags.length; i++ ) {
                                if ( event[ 2 ].tags[ i ] && event[ 2 ].tags[ i ][ 1 ] ) {
                                        var recipient = event[ 2 ].tags[ i ][ 1 ];
                                        if ( recipient == pubKeyMinus2 ) {
                                                var decrypted_message = decrypt( privKey, event[ 2 ].pubkey, event[ 2 ].content );
                                                var note = ( decrypted_message );
                                                console.log( note );
                                        }
                                }
                        }
                }
        });
        socket.on( 'open', function open() {
                var filter = {
                        "#p": [
                                pubKeyMinus2
                        ]
                }
                var subscription = [ "REQ", randomid2, filter ];
                subscription = JSON.stringify( subscription );
                socket.send( subscription );
        });
}

//console.log( "here is my pubkey:", pubKeyMinus2 );
//logAllPrivateMessages();

module.exports = { sha256, getNote, setNote }