Free Sockets and Winsock Libraries

TurboPower Internet Professional (iPRO)

TurboPower Internet Professional is a set of VCL components (which means that you need to use Borland Delphi or Borland C++Builder to use it) that allows your program to access the Internet in numerous ways. In terms of email, it supports POP3, SMTP, and NNTP, attachments (encoding and decoding), MIME, etc. It also handles Instant Messaging (IM), multiple HTTP requests at the same time, rendering of HTML with support for PNG, JPEG, BMP, WMF, ICO (etc), non-visual HTML scanners (for writing web spiders and robots), logging, data conversion, address lookups, Remote Access Server (RAS) support, VT100 terminal emulation, Internet Control Message Protocol (ICMP) components (for ping and trace), FTP (including an FTP directory tree component), SNTP (for time clients/servers), troubleshooting protocols components (Echo, Discard, CharGen), client/server components for finger and whois, etc.

TurboPower Async Professional (FTP, VOIP, etc)

If you need to add speech to your programs, or enable it to process speech input, TurboPower's Async Professional provides you an easy access to Microsoft's Speech API (SAPI) allowing you to integrate voice/speech recognition and speech synthesis in your programs. It also handles the sending and receiving (as well as viewing and printing) of faxes (and converts BMP, DCX, PCX and TIF files automatically), alphanumeric and text (GSM/SMS) paging, high speed file transfers (including the major file transfer protocols like Zmodem and FTP), IP telephony (audio and video, Voice Over IP or VOIP), Internet communications (Winsock access), supports ISDN modems, RS-232 and RS-485 standards, and includes an XML-based modem database. And so on. Like most of the TurboPower tools, this open source toolkit may be used with Delphi and Borland C++ Builder and ActiveX environments like Microsoft Visual C++ and Visual Basic. If you use Borland Kylix on Linux, you might want to try the TurboPower Async Professional CLX version.

TurboPower Sy

sTools (with email MIME encoding/decoding) TurboPower SysTools contain numerous utility functions and classes for Borland Delphi and Borland C++ Builder as well as programming environments that support COM objects (like Microsoft Visual Basic, Microsoft Visual C++. Among the routines included in this library are string manipulation routines, date and time math routines, high-speed sorting, high-precision maths, runtime math expression analyzer, Microsoft Excel-like finance and statistical routines, email attachment MIME encoding and decoding, reusable containers (stacks, queues, trees, deques, hash tables), CRC data integrity checking, 1 dimensional and 2 dimensional (1-D and 2-D) bar codes, money routines, logging classes, patterns, random number distributions, text data manipulation and more. SysTools is open source, released by TurboPower under the Mozilla Public License. It works on Windows systems. There is also a version of TurboPower SysTools for Kylix.

The Standard Function Library

The Standard Function Library, or SFL, contains routines for compression, encryption, encoding, data type conversion, data output formatting, process control, dates, times, calendars, symbol tables, linked lists, configuration files, error message files, string manipulation, searching, Internet socket access, MIME, CGI, SMTP, batch programming, debug tracing, directory access, environment access, etc. It is designed with portability in mind. The library is written in ANSI C and is supported on MSDOS, Windows, OS/2, Linux, AIX, SunOS, HP/UX, Solaris, NetBSD, FreeBSD, SCO OpenServer, Digital Unix, and OpenVMS. The source code is also available.

Putty: Win32 SSH / SFTP Client with Source Code

Putty is not a library, but a set of programs that implement Secure Shell access, Secure FTP (SFTP), Telnet, etc. Since it is open source, employing things like strong authentication and secure sessions, it may be a useful source of information for your own internet software.

OpenSSL

If you are writing an application (browser, email, server, etc) that requires the use of either Secure Sockets Layer (SSL versions 2 or 3), or Transport Layer Security (TLS version 1), you can obtain this free open source "commercial-grade" OpenSSL library. The library allows you to add cryptographic functionality to your programs, apparently both server programs as well as SSL supporting clients. You can use it in both commercial and non-commercial programs.

OpenSSH

This is not a library but an open source suite of programs that support Secure Shell access (SSH), namely ssh (which replaces telnet and rlogin), scp (which replaces rcp and ftp), sftp (Secure FTP, which also replaces ftp), sftp-server, sshd (server-side), etc. Since the program is open source, providing strong authentication and secure sessions, it may presumably provide the base for your implementation of SSH. It is supports a wide number of operating systems: OpenBSD, NetBSD, FreeBSD, AIX, HP-UX, IRIX, Linux, NeXT, SCO, SNI/Reliant Unix, Solaris, Digital Unix/Tru64/OSF, and Mac OS X. In SSH1 mode, the encryption algorithms supported include 3DES and Blowfish. In SSH2, 3DES, Blowfish, CAST128, Arcfour, and AES are supported.

WindowSIL / X-SIL

WindowSIL and X-SIL are interface libraries to Winsock and the Unix Socket API. It allows you to use sockets in your programs using functions much like the standard ANSI C library functions, such as sockprintf() and sockgets(). WindowsSIL runs on Windows 95/98/ME/NT/2000 while X-SIL runs on Unix and Linux systems with TCP/IP networking. The source code is available.

Network Security Services

Used in Netscape and Mozilla products, NSS (Network Security Services a.k.a Netscape Security Services) allows you to develop security-enabled server applications that support SSL v2 and v3, TLS, PKCS #5, PKCS #7, PKCS #8, PKCS #9, PKCS #10, PKCS #11, PKCS #12, S/MIME, X 509 v3 certificates, RSA, DSA, Triple DES, DES, RC2, RC4, SHA-1, MD2, MD5, etc. The software is released under the Mozilla Public License and the GNU General Public License.

LCRZO Network Library

This library provides support for UDP/TCP clients and servers, sniff, spoof, packet creation, packet decoding, packet printing, address conversion, etc. Platforms supported include Linux, FreeBSD and Solaris. The library is apparently released under the GNU LGPL.

Datareel Database C++ Library

This is a collection of C/C++ libraries that purportedly "simplifies complex time-consuming database, socket, multithreaded programming tasks". It supports the Windows and Unix platforms.

MIMELite MIME C Library

This C library supports the subset of MIME that is required for the encoding and transfer of European character sets. Specifically, it supports the Content-Transfer-Encodings 7BIT, 8BIT, BASE64, and QUOTED-PRINTABLE. It also handles the conversion between the ISO Latin 1 character set and PC based character sets (eg CP-850, CP-437 and Macintosh). It was designed originally to work on MSDOS, where resources are scarce, but is apparently general enough for other contexts. The C source code is provided.

CYRUS SASL Library

To quote, "the Cyrus SASL library is a generic library for SASL authentication, as used in SMTP and IMAP protocols. It's used for authentication by the Cyrus IMAP server as well as the Sendmail 8.10 release." It also includes a Java SASL library. Note that the link above is to an FTP directory. Look for a file like "cyrus-sasl-1.5.20.tar.gz" (the numbers may change when newer versions are released) there.

MIME++ C++ Library

This C++ class library allows you to parse, create and edit messages in the MIME format. Their website notes that the library has a proven track record from field testing and is perfect for developing email, Usenet or web applications. It handles the quote-printable, base64, uuencode/uudecode, Binhex 4.0, MacMIME (applesingle and appledouble) encodings. It also supports SMTP, POP and NNTP protocols, multipart messages, messages with attachments. You can customize the class or extend it through inheritance and polymorphism. Price? Free for non-commercial, educational and personal use. It supports Win32 (Windows 95, 98 and NT), Linux, SGI Irix, Digital Unix, AIX, HP/UX, Solaris, and SunOS. If your application needs email capabilities, you can't afford not to check this out! Source code is available.

POP3 Client

Get the files POP3.ASC and POP3.ZIP from that page to obtain a C++ POP3 client that uses Winsock. The package is distributed in the form of C++ source code.

GNU Common C++

GNU Common C++ is a C++ framework for developing portable threaded applications. It has abstractions for threads, sockets, XML parsing, serialization, config files, and so on, hiding the differences between platforms in its classes so that you can write code that is (hopefully) portable. It is released under the GNU GPL license.

OPP C++ Class Library

A C++ class library that has a number of features, including classes for retrieving files via HTTP, sending and receiving email, etc. It supports Unix systems. The C++ source code is available.

LibTCP++ TCP/IP Client/Server Class Library

A C++ TCP client/server class library that is supposed to simplify and speed development of TCP/IP client/server applications. The Linux platform is supported. The C++ source code is available.

SMTP SendMail() (WDJ June 98)

Add email capabilities to your application by simply including the source code to this function in your application and calling the SendMail() function. This function sends email using the SMTP protocol (ie, it does not rely on MAPI being installed). This code is intended for the Windows platform. The actual source code is contained in one of the ZIP files in the archive downloaded (each ZIP file has a README.TXT file that explains its contents).

HTTP Client (WDJ Oct 99)

Add the ability to get web pages to your program. The source code here is short, so it is easy to read and understand, and will help you get started in understanding how to code for Winsock. Note though that the code is actually too simplistic and is not able to handle situations where the program has to use a proxy to access the outside world. The actual source code is contained in one of the ZIP files in the archive downloaded (each ZIP file has a README.TXT file that explains its contents).

Scanning TCP/IP Ports (WDJ Feb 98)

Source code for a utility program that will scan the TCP/IP ports under Windows 95 and NT. The actual source code is contained in one of the ZIP files in the archive downloaded (each ZIP file has a README.TXT file that explains its contents).

HTTP Client with MFC (WDJ Nov 97)

This is an MFC class for multithreaded HTTP downloads. Note that it requires your users to have the WININET.DLL installed. If they do not, you probably have to tell them to install Internet Explorer. Yeah, I know... I guess it depends on your user base. The actual source code is contained in one of the ZIP files in the archive downloaded (each ZIP file has a README.TXT file that explains its contents).

SendEmail() using MAPI (WDJ Nov 97)

Give your application email capabilities via MAPI (implying of course, that this package only applies to the Windows platform). Just call SendEmail() in your application with the addressee's email address, the subject and the text of your message and you're done. The actual source code is contained in one of the ZIP files in the archive downloaded (each ZIP file has a README.TXT file that explains its contents).

Copying files via FTP, HTTP, Gopher using Wininet.dll (WDJ Nov 96) With this library your Windows program can have the capability to get files from the internet using FTP, HTTP and Gopher. Alas, this tool relies on Microsoft's wininet.dll which is not necessarily present in every Windows platform. It is installed with Internet Explorer though, so if your users do not have it, you may have to persuade them to make a 70+MB download (for IE) before they can use your program! The actual source code is contained in one of the ZIP files in the archive downloaded (each ZIP file has a README.TXT file that explains its contents).

Mozilla Web Browser

If you've not heard of this, you must be truly new on the scene or you've been on a really long vacation. This is the source code for the free portions of Netscape (yup), released free of charge under an open source license. Writing an application that involves the HTTP protocol? Need code for an email client that supports SMTP, authenticated SMTP, POP3, IMAP, etc? Well, what are you waiting for?

War FTP Daemon

The source code for a FTP daemon that can only be used in freeware programs (but not if you are the government, military or any political organisation). You have to fill in a form and the author will inform you where to get the code.

Inettransferlib (HTTP and FTP Library)

InetTransferLib is a free library for Access 97 for obtaining documents via HTTP and FTP.

Apache Web Server

Source code for the most widely used Apache web server is freely available. It can be compiled and used on Unix systems as well as Windows (although at the time of this writing, the Windows code is not as stable as the Unix one).