sucessful login with central server

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MathewFrancis 2025-08-20 16:48:39 +05:30
parent d41d746512
commit b989d65e39

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new_bridge.js Normal file
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// bridge.js — HTTP→TCP bridge for ABS (ABS_POLL + LOG/LOGBT login) using 512-byte MFC-style frames
// CommonJS (Node 18+)
const express = require("express");
const net = require("net");
// ---- ABS endpoint (no server changes) ----
const ABS_HOST = process.env.ABS_HOST || "192.0.0.14";
const ABS_PORT = Number(process.env.ABS_PORT || 7000);
// ---- transaction/opcode constants (from your grep) ----
const ABS_POLL = 178; // connectivity ping
const LOG = 100; // login transaction code
const LOGBT = 6013; // login opcode
const SUCCESS = 0;
// ---- 512-byte framing ----
const PKT_SIZE = 512;
const PAYLOAD_PER_PKT = PKT_SIZE - 1;
const app = express();
// we intentionally avoid global express.json() — we accept empty bodies safely
function readJsonBody(req) {
return new Promise((resolve) => {
const chunks = [];
req.on("data", (c) => chunks.push(c));
req.on("end", () => {
if (!chunks.length) return resolve({});
const txt = Buffer.concat(chunks).toString("utf8").trim();
if (!txt) return resolve({});
try { resolve(JSON.parse(txt)); } catch { resolve({}); }
});
});
}
// ---------- helpers: fixed-width strings, trimming ----------
function writeFixedAscii(buf, offset, s, len) {
const str = (s ?? "").toString();
for (let i = 0; i < len; i++) {
buf[offset + i] = i < str.length ? (str.charCodeAt(i) & 0xff) : 0x00;
}
return offset + len;
}
function readFixedAscii(buf, offset, len) {
let end = offset;
const max = offset + len;
while (end < max && buf[end] !== 0) end++;
const raw = buf.subarray(offset, end).toString("ascii");
return { value: raw.trimEnd(), next: offset + len };
}
// ---------- struct packers / parsers (little-endian) ----------
// sSndHeader (24 bytes)
function packSndHeader({ nTxnCd, nOpCd = 0, nNumRecsSent = 0, nNumRecsRqrd = 0, nTxnId = 0, cBtMake = 0 }) {
const b = Buffer.alloc(24, 0);
let o = 0;
b.writeInt32LE(nTxnCd, o); o += 4;
b.writeInt32LE(nOpCd, o); o += 4;
b.writeInt32LE(nNumRecsSent, o); o += 4;
b.writeInt32LE(nNumRecsRqrd, o); o += 4;
b.writeInt32LE(nTxnId, o); o += 4;
b.writeUInt8(cBtMake & 0xff, o);
return b;
}
// sRcvHeader (18 or 24 bytes on the wire)
function parseRcvHeaderFlexible(buf) {
if (buf.length < 18) throw new Error(`Reply too short for RcvHeader: ${buf.length} bytes`);
let o = 0;
const nTxnCd = buf.readInt32LE(o); o += 4;
const nRetCd = buf.readInt32LE(o); o += 4;
const nNumRecs = buf.readInt32LE(o); o += 4;
const nTxnId = buf.readInt32LE(o); o += 4;
const cBtMake = buf.readUInt8(o);
return { nTxnCd, nRetCd, nNumRecs, nTxnId, cBtMake, size: buf.length >= 24 ? 24 : 18 };
}
// normalized 18-byte header (for display)
function buildRcvHeader18({ nTxnCd, nRetCd, nNumRecs = 0, nTxnId = 0, cBtMake = 0 }) {
const b = Buffer.alloc(18, 0);
let o = 0;
b.writeInt32LE(nTxnCd, o); o += 4;
b.writeInt32LE(nRetCd, o); o += 4;
b.writeInt32LE(nNumRecs, o); o += 4;
b.writeInt32LE(nTxnId, o); o += 4;
b.writeUInt8(cBtMake & 0xff, o);
return b;
}
// ---------- ABS 512-byte packetization ----------
function absSend(sock, payload) {
return new Promise((resolve, reject) => {
let off = 0;
function sendNext() {
const remaining = payload.length - off;
const toCopy = Math.min(PAYLOAD_PER_PKT, Math.max(remaining, 0));
const pkt = Buffer.alloc(PKT_SIZE, 0);
pkt[0] = (off + toCopy >= payload.length) ? 48 /* '0' */ : 49 /* '1' */;
if (toCopy > 0) payload.copy(pkt, 1, off, off + toCopy);
off += toCopy;
sock.write(pkt, (err) => {
if (err) return reject(err);
if (pkt[0] === 48) return resolve(); // last
sendNext();
});
}
sendNext();
});
}
function absRecv(sock, timeoutMs = 7000) {
return new Promise((resolve, reject) => {
const chunks = [];
let buf = Buffer.alloc(0);
const timer = timeoutMs ? setTimeout(() => done(new Error("TCP timeout")), timeoutMs) : null;
function done(err) {
if (timer) clearTimeout(timer);
sock.off("data", onData);
if (err) reject(err);
else resolve(Buffer.concat(chunks));
}
function onData(data) {
buf = Buffer.concat([buf, data]);
while (buf.length >= PKT_SIZE) {
const pkt = buf.subarray(0, PKT_SIZE);
buf = buf.subarray(PKT_SIZE);
const flag = pkt[0];
chunks.push(pkt.subarray(1));
if (flag === 48) return done(); // '0'
}
}
sock.on("data", onData);
sock.on("error", (e) => done(e));
sock.on("end", () => done(new Error("Socket ended before final '0' packet")));
});
}
async function absRoundtrip(payload, timeoutMs = 7000) {
const sock = new net.Socket();
await new Promise((res, rej) => sock.connect(ABS_PORT, ABS_HOST, res).once("error", rej));
try {
await absSend(sock, payload);
const replyConcat = await absRecv(sock, timeoutMs);
sock.end();
return replyConcat;
} catch (e) {
try { sock.destroy(); } catch {}
throw e;
}
}
// ---------- MFC-style password "encryption" ----------
/*
Mirrors the MFC EncryptPassword():
- key = first digit of current UTC seconds (0..5, or 0..9 if seconds >= 100 ever, but it's 0..5)
- for each input char: interpret as digit (non-digit -> 0), add key, keep ones digit
- append key at the end
Result length = input.length + 1 (cPasswd field in sSndLog is 11 bytes, so 10-digit inputs fit).
*/
function encryptPasswordLikeMFC(plain) {
const sec = new Date().getUTCSeconds(); // GetSystemTime (UTC) seconds
const key = Number(String(sec)[0] || "0"); // first digit
let out = "";
const s = (plain ?? "").toString();
for (let i = 0; i < s.length; i++) {
const ch = s[i];
const d = (ch >= "0" && ch <= "9") ? (ch.charCodeAt(0) - 48) : 0; // atoi on non-digit -> 0
out += String((d + key) % 10);
}
return { enc: out + String(key), key, utcSeconds: sec };
}
// ---------- SND/RCV: LOGIN ----------
// sSndLog (38 bytes): cUsrId[5], cOpCardCd[17], cPasswd[11], cBtId[5]
function packSndLog({ usrId = "", opCard, passwd, btId }) {
const b = Buffer.alloc(38, 0);
let o = 0;
o = writeFixedAscii(b, o, usrId, 5);
o = writeFixedAscii(b, o, opCard, 17);
o = writeFixedAscii(b, o, passwd, 11);
o = writeFixedAscii(b, o, btId, 5);
return b;
}
// sRcvLog parser (follows sRcvHeader if nRetCd == 0)
function parseRcvLog(buf, offset = 0) {
let o = offset;
const t1 = readFixedAscii(buf, o, 20); const cDateTime = t1.value; o = t1.next;
const t2 = readFixedAscii(buf, o, 31); const cUsrNm = t2.value; o = t2.next;
const t3 = readFixedAscii(buf, o, 5 ); const cUsrId = t3.value; o = t3.next;
const t4 = readFixedAscii(buf, o, 31); const cSupNm = t4.value; o = t4.next;
const t5 = readFixedAscii(buf, o, 5 ); const cSupId = t5.value; o = t5.next;
const t6 = readFixedAscii(buf, o, 5 ); const cUsrTyp = t6.value; o = t6.next;
function rf() { const v = buf.readFloatLE(o); o += 4; return v; }
function ri() { const v = buf.readInt32LE(o); o += 4; return v; }
const fOpenBal = rf();
const fTktSalesByVoucher = rf();
const fTktSalesByCash = rf();
const fTktSalesByMemCard = rf();
const nTktSalesByVoucherCount = ri();
const nTktSalesByCashCount = ri();
const nTktSalesByMemCardCount = ri();
const fPayoutByVoucher = rf();
const fPayoutByCash = rf();
const fPayoutByMemCard = rf();
const nPayoutByVoucherCount = ri();
const nPayoutByCashCount = ri();
const nPayoutByMemCardCount = ri();
const fCancelByVoucher = rf();
const fCancelByCash = rf();
const fCancelByMemCard = rf();
const nCancelByVoucherCount = ri();
const nCancelByCashCount = ri();
const nCancelByMemCardCount = ri();
const fDeposit = rf();
const fWithdrawAmt = rf();
const fVoucherSales = rf();
const fVoucherEncash = rf();
const fCloseBal = rf();
const fSaleTarget = rf();
return {
cDateTime, cUsrNm, cUsrId, cSupNm, cSupId, cUsrTyp,
fOpenBal, fTktSalesByVoucher, fTktSalesByCash, fTktSalesByMemCard,
nTktSalesByVoucherCount, nTktSalesByCashCount, nTktSalesByMemCardCount,
fPayoutByVoucher, fPayoutByCash, fPayoutByMemCard,
nPayoutByVoucherCount, nPayoutByCashCount, nPayoutByMemCardCount,
fCancelByVoucher, fCancelByCash, fCancelByMemCard,
nCancelByVoucherCount, nCancelByCashCount, nCancelByMemCardCount,
fDeposit, fWithdrawAmt, fVoucherSales, fVoucherEncash,
fCloseBal, fSaleTarget,
size: o - offset
};
}
// ---------- routes ----------
app.get("/", (_req, res) => res.send("ABS bridge is up"));
app.get("/health", (_req, res) => {
const s = new net.Socket();
s.setTimeout(1500);
s.connect(ABS_PORT, ABS_HOST, () => { s.destroy(); res.json({ ok: true, target: `${ABS_HOST}:${ABS_PORT}` }); });
s.on("timeout", () => { s.destroy(); res.status(504).json({ ok: false, error: "TCP timeout" }); });
s.on("error", (e) => { s.destroy(); res.status(502).json({ ok: false, error: String(e) }); });
});
// ---------- ABS_POLL ----------
app.post("/abs/poll", async (req, res) => {
try {
const body = await readJsonBody(req);
const btMake = (typeof body.btMake === "string")
? body.btMake.charCodeAt(0)
: (Number.isFinite(body.btMake) ? (body.btMake|0) : 0x00);
const header = packSndHeader({
nTxnCd: ABS_POLL, nOpCd: 0, nNumRecsSent: 0, nNumRecsRqrd: 0, nTxnId: 0, cBtMake: btMake
});
const reply = await absRoundtrip(header, 7000);
const headerSlice = reply.subarray(0, Math.min(reply.length, 24));
const parsed = parseRcvHeaderFlexible(headerSlice);
const success = parsed.nRetCd === SUCCESS;
const normalized = {
nTxnCd: parsed.nTxnCd || ABS_POLL,
nRetCd: parsed.nRetCd,
nNumRecs: parsed.nNumRecs,
nTxnId: parsed.nTxnId,
cBtMake: parsed.cBtMake,
size: 18
};
res.json({
ok: true,
target: `${ABS_HOST}:${ABS_PORT}`,
sentHeaderHex: header.toString("hex"),
replyBytes: reply.length,
replyHexFirst64: reply.subarray(0, 64).toString("hex"),
parsedRcvHeaderRaw: parsed,
normalizedRcvHeader: normalized,
normalizedHeaderHex: buildRcvHeader18(normalized).toString("hex"),
success
});
} catch (e) {
res.status(502).json({ ok: false, error: String(e) });
}
});
// ---------- LOGIN ----------
// POST /login
// Body (JSON):
// {
// "opCard": "OPCARD17", // REQUIRED (<=17)
// "password": "1234567890", // plain 09; will be encrypted for you
// // OR: "passwordEnc": "45673" // already-encrypted string (skip client encryption)
// "btId": "0483", // REQUIRED (<=5)
// "usrId": "", // optional (<=5)
// "btMake": 0 // optional: numeric or single-char string
// }
app.post("/login", async (req, res) => {
try {
const body = await readJsonBody(req);
const opCard = (body.opCard ?? "").toString();
const btId = (body.btId ?? "").toString();
const usrId = (body.usrId ?? "").toString();
const plain = (body.password ?? "");
const givenEnc = (body.passwordEnc ?? "");
if (!opCard || !btId || (!plain && !givenEnc)) {
return res.status(400).json({ ok: false, error: "Missing opCard, btId, and either password or passwordEnc" });
}
// Encrypt if only plain is supplied (MFC-compatible)
let encInfo = null;
let passwd = givenEnc ? String(givenEnc) : (encInfo = encryptPasswordLikeMFC(String(plain))).enc;
// C field sizes: cPasswd[11] warn if plain > 10 (enc becomes > 11)
if (!givenEnc && String(plain).length > 10) {
// still send (field will truncate), but tell caller
}
const btMake = (typeof body.btMake === "string")
? body.btMake.charCodeAt(0)
: (Number.isFinite(body.btMake) ? (body.btMake|0) : 0x00);
const sndHeader = packSndHeader({
nTxnCd: LOG, nOpCd: LOGBT, nNumRecsSent: 1, nNumRecsRqrd: 1, nTxnId: 0, cBtMake: btMake
});
const sndLog = packSndLog({ usrId, opCard, passwd, btId });
const sendBuf = Buffer.concat([sndHeader, sndLog]);
const reply = await absRoundtrip(sendBuf, 10000);
const hdrSlice = reply.subarray(0, Math.min(reply.length, 24));
const rcvHeader = parseRcvHeaderFlexible(hdrSlice);
const json = {
ok: true,
target: `${ABS_HOST}:${ABS_PORT}`,
sentHeaderHex: sndHeader.toString("hex"),
sentBodyHex: sndLog.toString("hex"),
replyBytes: reply.length,
replyHexFirst64: reply.subarray(0, 64).toString("hex"),
rcvHeaderRaw: rcvHeader,
success: rcvHeader.nRetCd === SUCCESS
};
// include encryption debug (non-sensitive) if we did it here
if (!givenEnc && encInfo) {
json.encryption = {
used: true,
utcSeconds: encInfo.utcSeconds,
key: encInfo.key,
encPasswd: passwd
};
} else if (givenEnc) {
json.encryption = { used: false, providedPasswordEnc: true };
}
const bodyOffset = rcvHeader.size; // 18 or 24
if (json.success && reply.length >= bodyOffset + 20) {
try {
const log = parseRcvLog(reply, bodyOffset);
json.log = log;
} catch (e) {
json.parseLogError = String(e);
}
}
res.json(json);
} catch (e) {
res.status(502).json({ ok: false, error: String(e) });
}
});
// ---- start HTTP server ----
const HTTP_PORT = Number(process.env.HTTP_BRIDGE_PORT || 8080);
app.listen(HTTP_PORT, () => {
console.log(`ABS HTTP bridge listening on :${HTTP_PORT}`);
console.log(`Target ABS server: ${ABS_HOST}:${ABS_PORT}`);
});