Files
openstapps/src/smtp.ts
2021-12-14 12:26:04 +01:00

378 lines
11 KiB
TypeScript

/*
* Copyright (C) 2019 StApps
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation, version 3.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <https://www.gnu.org/licenses/>.
*/
import * as nodemailer from 'nodemailer';
import {MailOptions} from 'nodemailer/lib/sendmail-transport';
import {deleteUndefinedProperties, isProductiveEnvironment, RecursivePartial} from './common';
import {VerifiableTransport} from './transport';
/**
* A configuration of the transport used to send mails via SMTP
*/
export interface SMTPConfig {
/**
* Auth configuration
*/
auth: {
/**
* Password for login
*/
password: string;
/**
* User for login
*/
user: string;
};
/**
* List of "carbon copy" recipients
*/
cc?: string[];
/**
* SMTP host server
*/
host: string;
/**
* SMTP port
*/
port: number;
/**
* List of recipients
*/
recipients: string[];
/**
* Whether or not to establish a secure connection
*/
secure?: boolean;
/**
* Sender configuration
*/
sender: {
/**
* Mail of sender
*/
mail: string;
/**
* Name of sender
*/
name?: string;
};
}
/**
* An implementation of mail transport via SMTP
*/
export class SMTP extends VerifiableTransport {
/**
* Singleton instance
*/
private static _instance: SMTP;
/**
* List of all mail addresses to send in cc
*/
private readonly cc: string[];
/**
* Who is using this service
*/
private readonly from: {
/**
* Mail of sender
*/
mail: string;
/**
* Name of sender
*/
name?: string;
};
/**
* List of all mail addresses to send to
*/
private readonly recipients: string[];
/**
* Connection to SMTP server
*/
private readonly transportAgent: nodemailer.Transporter;
/**
* Set to true if the transport was verified
*/
private verified: boolean;
/**
* Get Singleton Instance of the SMTP Transport
*
* If no config is given it is assumed it will be given via environment variables
* SMTP_AUTH_USER: SMTP username
* SMTP_AUTH_PASSWORD: SMTP password
* SMTP_HOST: SMTP host
* SMTP_PORT: SMTP port
* SMTP_RECIPIENTS: comma seperated list of recipients
* SMTP_CC: comma seperated list of recipients for the carbon copy (CC)
* SMTP_SENDER_MAIL: sender of the mail
* SMTP_SENDER_NAME: name of the sender
* SMTP_SECURE: `true` to enable tls
*
* @param config SMTP config for instance
*/
public static getInstance(config?: SMTPConfig): SMTP | undefined {
// if an instance of SMTP already exists
if (typeof SMTP._instance !== 'undefined') {
return SMTP._instance;
}
// monitoring is not required -> SMTP init can fail
if (!isProductiveEnvironment() || process.env.ALLOW_NO_TRANSPORT === 'true') {
try {
SMTP._instance = new SMTP(config);
} catch (err) {
/* tslint:disable-next-line:no-console */
console.warn('SMTP config failed.');
return;
}
} else {
// monitoring is required -> SMTP will throw error if config is invalid
SMTP._instance = new SMTP(config);
}
return SMTP._instance;
}
/**
* This checks email addresses to be compatible with new standards. RFC 3490 introduced some features that are not
* implemented by every mail transfer agent (MTA).
*
* For more information please consider reading
* https://stackoverflow.com/a/2071250
*
* @param address Address to validate
*/
public static isValidEmailAddress(address: string): boolean {
// tslint:disable-next-line:max-line-length
return /^(([^<>()\[\].,;:\s@"]+(\.[^<>()\[\].,;:\s@"]+)*)|(".+"))@(([^<>()[\].,;:\s@"]+\.)+[^<>()[\].,;:\s@"]{2,})$/i.test(address);
}
/**
* Checks a list of mail addresses for validity
*
* @param recipients List of recipients to check
*/
public static isValidRecipientsList(recipients: string[] | undefined): boolean {
return Array.isArray(recipients) && recipients.length > 0 && recipients.every(SMTP.isValidEmailAddress);
}
/**
* Creates an SMTP connection.
*
* WARNING: This class is supposed to be used as a singleton. You should never call `new SMTP()`
*
* @param smtpConfig SMTP config
*/
private constructor(smtpConfig?: SMTPConfig) {
// create a partial config from environment variables that can overwrite the given config
const envConfig: RecursivePartial<SMTPConfig> = {
auth: {
password: process.env.SMTP_AUTH_PASSWORD,
user: process.env.SMTP_AUTH_USER,
},
cc: ((typeof process.env.SMTP_CC !== 'undefined') ? (process.env.SMTP_CC as string).split(',') : []),
host: process.env.SMTP_HOST,
port: (typeof process.env.SMTP_PORT !== 'undefined') ? parseInt(process.env.SMTP_PORT, 10) : undefined,
recipients: (typeof process.env.SMTP_RECIPIENTS !== 'undefined') ?
(process.env.SMTP_RECIPIENTS).split(',') :
[],
secure: (typeof process.env.SMTP_SECURE !== 'undefined') ? (process.env.SMTP_SECURE === 'true') : false,
sender: {
mail: process.env.SMTP_SENDER_MAIL,
name: process.env.SMTP_SENDER_NAME,
},
};
const config = {
...smtpConfig,
// deleting undefined properties so the actual config doesn't get overwritten by undefined values
...(deleteUndefinedProperties(envConfig) as object),
} as SMTPConfig;
if (typeof config.host === 'undefined') {
throw new Error(
'SMTP configuration needs a host. Add it to the config or use environment variables (SMTP_HOST).',
);
}
if (typeof config.port === 'undefined' || isNaN(config.port)) {
throw new Error(
'SMTP configuration needs a port. Add it to the config or use environment variables (SMTP_PORT).',
);
}
if (typeof config.auth !== 'object') {
throw new Error(
'SMTP configuration needs an auth object.' +
'Add it to the config or use environment variables (SMTP_AUTH_USER, SMTP_AUTH_PASSWORD).',
);
}
if (typeof config.auth.user === 'undefined') {
throw new Error(
'SMTP auth configuration needs a user. Add it to the config or use environment variables (SMTP_AUTH_USER).',
);
}
if (typeof config.auth.password === 'undefined') {
throw new Error(
'SMTP auth configuration needs a password.' +
'Add it to the config or use environment variables (SMTP_AUTH_PASSWORD).',
);
}
if (Array.isArray(config.recipients) && config.recipients.length < 1) {
throw new Error(
'SMTP configuration needs recipients. Add it to the config or use environment variables (SMTP_RECIPIENTS).',
);
}
if (typeof config.sender.mail === 'undefined') {
throw new Error(
'SMTP configuration needs a sender. Add it to the config or use environment variables (SMTP_SENDER_MAIL).',
);
}
super();
if (SMTP.isValidRecipientsList(config.recipients)) {
this.recipients = config.recipients;
} else {
throw new Error('Invalid recipients found');
}
if (typeof config.cc !== 'undefined') {
if (SMTP.isValidRecipientsList(config.cc)) {
this.cc = config.cc;
} else {
throw new Error('Invalid cc recipients found');
}
} else {
this.cc = [];
}
this.from = config.sender;
this.verified = false;
// creating transport with configuration
this.transportAgent = nodemailer.createTransport({
auth: {
pass: config.auth.password,
user: config.auth.user,
},
host: config.host,
port: config.port,
secure: typeof config.secure !== 'undefined' ? config.secure : false,
});
}
/**
* Check if instance was verified at least once
*/
public isVerified(): boolean {
return this.verified;
}
/**
* Sends a preconfigured mail with recipients and sender configured on
* creation of the class (set by environment or on creation of this class)
*
* @param subject Subject of the mail
* @param message message of the mail
*/
public async send(subject: string, message: string): Promise<string> {
return this.sendMail({
cc: this.cc,
// use an address block if name is available, mail otherwise
from: (typeof this.from.name !== 'string') ? `${this.from.name} <${this.from.mail}>` : this.from.mail,
subject: subject,
text: message,
to: this.recipients,
});
}
/**
* Sends a mail object
*
* @param mail Mail to send
*/
public async sendMail(mail: MailOptions): Promise<string> {
// info is the response of the smtp server
let info = await this.transportAgent.sendMail(mail);
// it can be undefined (empty response)
if (typeof info === 'undefined') {
info = 'Successfully sent mail';
}
// or not of type string
if (typeof info !== 'string') {
info = JSON.stringify(info);
}
return info;
}
/**
* Verify authentication with SMTP server
*
*
* @throws error if you are in a productive environment and don't set ALLOW_NO_TRANSPORT to true
* @returns true if the transport is valid
*/
public async verify(): Promise<boolean> {
let verificationSuccessfull = false;
try {
verificationSuccessfull = await this.transportAgent.verify();
} catch (err) {
if (!isProductiveEnvironment() || process.env.ALLOW_NO_TRANSPORT !== 'true') {
throw err;
}
/* tslint:disable-next-line:no-console */
console.warn(
'SMTP verification error was ignored, because tranport failures are allowed: ',
(err as Error).message,
);
}
if (!verificationSuccessfull) {
if (!isProductiveEnvironment() || process.env.ALLOW_NO_TRANSPORT !== 'true') {
throw new Error(
'Verification of SMTP transport failed.' +
'If you want to ignore this error set' +
'`NODE_ENV=dev` or `ALLOW_NO_TRANSPORT=true`',
);
}
/* tslint:disable-next-line:no-console */
console.warn('SMTP verification error was ignored, because tranport failures are allowed.');
}
this.verified = verificationSuccessfull;
return verificationSuccessfull;
}
}