This commit is contained in:
2025-05-07 20:20:17 +00:00
parent f6377d1973
commit 630e911589
40 changed files with 8745 additions and 333 deletions

View File

@ -3,6 +3,13 @@ import * as paths from '../paths.js';
import { Email } from './classes.email.js';
import type { MtaService } from './classes.mta.js';
import { logger } from '../logger.js';
import {
SecurityLogger,
SecurityLogLevel,
SecurityEventType,
IPReputationChecker,
ReputationThreshold
} from '../security/index.js';
export interface ISmtpServerOptions {
port: number;
@ -53,8 +60,10 @@ export class SMTPServer {
});
}
private handleNewConnection(socket: plugins.net.Socket): void {
console.log(`New connection from ${socket.remoteAddress}:${socket.remotePort}`);
private async handleNewConnection(socket: plugins.net.Socket): Promise<void> {
const clientIp = socket.remoteAddress;
const clientPort = socket.remotePort;
console.log(`New connection from ${clientIp}:${clientPort}`);
// Initialize a new session
this.sessions.set(socket, {
@ -66,6 +75,68 @@ export class SMTPServer {
useTLS: false,
connectionEnded: false
});
// Check IP reputation
try {
if (this.mtaRef.config.security?.checkIPReputation !== false && clientIp) {
const reputationChecker = IPReputationChecker.getInstance();
const reputation = await reputationChecker.checkReputation(clientIp);
// Log the reputation check
SecurityLogger.getInstance().logEvent({
level: reputation.score < ReputationThreshold.HIGH_RISK
? SecurityLogLevel.WARN
: SecurityLogLevel.INFO,
type: SecurityEventType.IP_REPUTATION,
message: `IP reputation checked for new SMTP connection: score=${reputation.score}`,
ipAddress: clientIp,
details: {
clientPort,
score: reputation.score,
isSpam: reputation.isSpam,
isProxy: reputation.isProxy,
isTor: reputation.isTor,
isVPN: reputation.isVPN,
country: reputation.country,
blacklists: reputation.blacklists,
socketId: socket.remotePort.toString() + socket.remoteFamily
}
});
// Handle high-risk IPs - add delay or reject based on score
if (reputation.score < ReputationThreshold.HIGH_RISK) {
// For high-risk connections, add an artificial delay to slow down potential spam
const delayMs = Math.min(5000, Math.max(1000, (ReputationThreshold.HIGH_RISK - reputation.score) * 100));
await new Promise(resolve => setTimeout(resolve, delayMs));
if (reputation.score < 5) {
// Very high risk - can optionally reject the connection
if (this.mtaRef.config.security?.rejectHighRiskIPs) {
this.sendResponse(socket, `554 Transaction failed - IP is on spam blocklist`);
socket.destroy();
return;
}
}
}
}
} catch (error) {
logger.log('error', `Error checking IP reputation: ${error.message}`, {
ip: clientIp,
error: error.message
});
}
// Log the connection as a security event
SecurityLogger.getInstance().logEvent({
level: SecurityLogLevel.INFO,
type: SecurityEventType.CONNECTION,
message: `New SMTP connection established`,
ipAddress: clientIp,
details: {
clientPort,
socketId: socket.remotePort.toString() + socket.remoteFamily
}
});
// Send greeting
this.sendResponse(socket, `220 ${this.hostname} ESMTP Service Ready`);
@ -75,21 +146,69 @@ export class SMTPServer {
});
socket.on('end', () => {
console.log(`Connection ended from ${socket.remoteAddress}:${socket.remotePort}`);
const clientIp = socket.remoteAddress;
const clientPort = socket.remotePort;
console.log(`Connection ended from ${clientIp}:${clientPort}`);
const session = this.sessions.get(socket);
if (session) {
session.connectionEnded = true;
// Log connection end as security event
SecurityLogger.getInstance().logEvent({
level: SecurityLogLevel.INFO,
type: SecurityEventType.CONNECTION,
message: `SMTP connection ended normally`,
ipAddress: clientIp,
details: {
clientPort,
state: SmtpState[session.state],
from: session.mailFrom || 'not set'
}
});
}
});
socket.on('error', (err) => {
const clientIp = socket.remoteAddress;
const clientPort = socket.remotePort;
console.error(`Socket error: ${err.message}`);
// Log connection error as security event
SecurityLogger.getInstance().logEvent({
level: SecurityLogLevel.WARN,
type: SecurityEventType.CONNECTION,
message: `SMTP connection error`,
ipAddress: clientIp,
details: {
clientPort,
error: err.message,
errorCode: (err as any).code,
from: this.sessions.get(socket)?.mailFrom || 'not set'
}
});
this.sessions.delete(socket);
socket.destroy();
});
socket.on('close', () => {
console.log(`Connection closed from ${socket.remoteAddress}:${socket.remotePort}`);
const clientIp = socket.remoteAddress;
const clientPort = socket.remotePort;
console.log(`Connection closed from ${clientIp}:${clientPort}`);
// Log connection closure as security event
SecurityLogger.getInstance().logEvent({
level: SecurityLogLevel.INFO,
type: SecurityEventType.CONNECTION,
message: `SMTP connection closed`,
ipAddress: clientIp,
details: {
clientPort,
sessionEnded: this.sessions.get(socket)?.connectionEnded || false
}
});
this.sessions.delete(socket);
});
}
@ -358,33 +477,165 @@ export class SMTPServer {
// Prepare headers for DKIM verification results
const customHeaders: Record<string, string> = {};
// Verifying the email with enhanced DKIM verification
try {
const verificationResult = await this.mtaRef.dkimVerifier.verify(session.emailData, {
useCache: true,
returnDetails: false
});
// Authentication results
let dkimResult = { domain: '', result: false };
let spfResult = { domain: '', result: false };
// Check security configuration
const securityConfig = this.mtaRef.config.security || {};
// 1. Verify DKIM signature if enabled
if (securityConfig.verifyDkim !== false) {
try {
const verificationResult = await this.mtaRef.dkimVerifier.verify(session.emailData, {
useCache: true,
returnDetails: false
});
mightBeSpam = !verificationResult.isValid;
if (!verificationResult.isValid) {
logger.log('warn', `DKIM verification failed for incoming email: ${verificationResult.errorMessage || 'Unknown error'}`);
} else {
logger.log('info', `DKIM verification passed for incoming email from domain ${verificationResult.domain}`);
dkimResult.result = verificationResult.isValid;
dkimResult.domain = verificationResult.domain || '';
if (!verificationResult.isValid) {
logger.log('warn', `DKIM verification failed for incoming email: ${verificationResult.errorMessage || 'Unknown error'}`);
// Enhanced security logging
SecurityLogger.getInstance().logEvent({
level: SecurityLogLevel.WARN,
type: SecurityEventType.DKIM,
message: `DKIM verification failed for incoming email`,
domain: verificationResult.domain || session.mailFrom.split('@')[1],
details: {
error: verificationResult.errorMessage || 'Unknown error',
status: verificationResult.status,
selector: verificationResult.selector,
senderIP: socket.remoteAddress
},
ipAddress: socket.remoteAddress,
success: false
});
} else {
logger.log('info', `DKIM verification passed for incoming email from domain ${verificationResult.domain}`);
// Enhanced security logging
SecurityLogger.getInstance().logEvent({
level: SecurityLogLevel.INFO,
type: SecurityEventType.DKIM,
message: `DKIM verification passed for incoming email`,
domain: verificationResult.domain,
details: {
selector: verificationResult.selector,
status: verificationResult.status,
senderIP: socket.remoteAddress
},
ipAddress: socket.remoteAddress,
success: true
});
}
// Store verification results in headers
if (verificationResult.domain) {
customHeaders['X-DKIM-Domain'] = verificationResult.domain;
}
customHeaders['X-DKIM-Status'] = verificationResult.status || 'unknown';
customHeaders['X-DKIM-Result'] = verificationResult.isValid ? 'pass' : 'fail';
} catch (error) {
logger.log('error', `Failed to verify DKIM signature: ${error.message}`);
customHeaders['X-DKIM-Status'] = 'error';
customHeaders['X-DKIM-Result'] = 'error';
}
}
// 2. Verify SPF if enabled
if (securityConfig.verifySpf !== false) {
try {
// Get the client IP and hostname
const clientIp = socket.remoteAddress || '127.0.0.1';
const clientHostname = session.clientHostname || 'localhost';
// Store verification results in headers
if (verificationResult.domain) {
customHeaders['X-DKIM-Domain'] = verificationResult.domain;
// Parse the email to get envelope from
const parsedEmail = await plugins.mailparser.simpleParser(session.emailData);
// Create a temporary Email object for SPF verification
const tempEmail = new Email({
from: parsedEmail.from?.value[0].address || session.mailFrom,
to: session.rcptTo[0],
subject: "Temporary Email for SPF Verification",
text: "This is a temporary email for SPF verification"
});
// Set envelope from for SPF verification
tempEmail.setEnvelopeFrom(session.mailFrom);
// Verify SPF
const spfVerified = await this.mtaRef.spfVerifier.verifyAndApply(
tempEmail,
clientIp,
clientHostname
);
// Update SPF result
spfResult.result = spfVerified;
spfResult.domain = session.mailFrom.split('@')[1] || '';
// Copy SPF headers from the temp email
if (tempEmail.headers['Received-SPF']) {
customHeaders['Received-SPF'] = tempEmail.headers['Received-SPF'];
}
// Set spam flag if SPF fails badly
if (tempEmail.mightBeSpam) {
mightBeSpam = true;
}
} catch (error) {
logger.log('error', `Failed to verify SPF: ${error.message}`);
customHeaders['Received-SPF'] = `error (${error.message})`;
}
}
// 3. Verify DMARC if enabled
if (securityConfig.verifyDmarc !== false) {
try {
// Parse the email again
const parsedEmail = await plugins.mailparser.simpleParser(session.emailData);
customHeaders['X-DKIM-Status'] = verificationResult.status || 'unknown';
customHeaders['X-DKIM-Result'] = verificationResult.isValid ? 'pass' : 'fail';
} catch (error) {
logger.log('error', `Failed to verify DKIM signature: ${error.message}`);
mightBeSpam = true;
customHeaders['X-DKIM-Status'] = 'error';
customHeaders['X-DKIM-Result'] = 'error';
// Create a temporary Email object for DMARC verification
const tempEmail = new Email({
from: parsedEmail.from?.value[0].address || session.mailFrom,
to: session.rcptTo[0],
subject: "Temporary Email for DMARC Verification",
text: "This is a temporary email for DMARC verification"
});
// Verify DMARC
const dmarcResult = await this.mtaRef.dmarcVerifier.verify(
tempEmail,
spfResult,
dkimResult
);
// Apply DMARC policy
const dmarcPassed = this.mtaRef.dmarcVerifier.applyPolicy(tempEmail, dmarcResult);
// Add DMARC result to headers
if (tempEmail.headers['X-DMARC-Result']) {
customHeaders['X-DMARC-Result'] = tempEmail.headers['X-DMARC-Result'];
}
// Add Authentication-Results header combining all authentication results
customHeaders['Authentication-Results'] = `${this.mtaRef.config.smtp.hostname}; ` +
`spf=${spfResult.result ? 'pass' : 'fail'} smtp.mailfrom=${session.mailFrom}; ` +
`dkim=${dkimResult.result ? 'pass' : 'fail'} header.d=${dkimResult.domain || 'unknown'}; ` +
`dmarc=${dmarcPassed ? 'pass' : 'fail'} header.from=${tempEmail.getFromDomain()}`;
// Set spam flag if DMARC fails
if (tempEmail.mightBeSpam) {
mightBeSpam = true;
}
} catch (error) {
logger.log('error', `Failed to verify DMARC: ${error.message}`);
customHeaders['X-DMARC-Result'] = `error (${error.message})`;
}
}
try {
@ -411,15 +662,62 @@ export class SMTPServer {
attachments: email.attachments.length,
mightBeSpam: email.mightBeSpam
});
// Enhanced security logging for received email
SecurityLogger.getInstance().logEvent({
level: mightBeSpam ? SecurityLogLevel.WARN : SecurityLogLevel.INFO,
type: mightBeSpam ? SecurityEventType.SPAM : SecurityEventType.EMAIL_VALIDATION,
message: `Email received and ${mightBeSpam ? 'flagged as potential spam' : 'validated successfully'}`,
domain: email.from.split('@')[1],
ipAddress: socket.remoteAddress,
details: {
from: email.from,
subject: email.subject,
recipientCount: email.getAllRecipients().length,
attachmentCount: email.attachments.length,
hasAttachments: email.hasAttachments(),
dkimStatus: customHeaders['X-DKIM-Result'] || 'unknown'
},
success: !mightBeSpam
});
// Process or forward the email via MTA service
try {
await this.mtaRef.processIncomingEmail(email);
} catch (err) {
console.error('Error in MTA processing of incoming email:', err);
// Log processing errors
SecurityLogger.getInstance().logEvent({
level: SecurityLogLevel.ERROR,
type: SecurityEventType.EMAIL_VALIDATION,
message: `Error processing incoming email`,
domain: email.from.split('@')[1],
ipAddress: socket.remoteAddress,
details: {
error: err.message,
from: email.from,
stack: err.stack
},
success: false
});
}
} catch (error) {
console.error('Error parsing email:', error);
// Log parsing errors
SecurityLogger.getInstance().logEvent({
level: SecurityLogLevel.ERROR,
type: SecurityEventType.EMAIL_VALIDATION,
message: `Error parsing incoming email`,
ipAddress: socket.remoteAddress,
details: {
error: error.message,
sender: session.mailFrom,
stack: error.stack
},
success: false
});
}
}