Description from the cryptlib website [1]:
cryptlib is a powerful security toolkit that allows even inexperienced crypto programmers to easily add encryption and authentication services to their software. The high-level interface provides anyone with the ability to add strong security capabilities to an application in as little as half an hour, without needing to know any of the low-level details that make the encryption or authentication work. Because of this, cryptlib dramatically reduces the cost involved in adding security to new or existing applications.
At the highest level, cryptlib provides implementations of complete security services such as S/MIME and PGP/OpenPGP secure enveloping, SSL/TLS and SSH secure sessions, CA services such as CMP, SCEP, RTCS, and OCSP, and other security operations such as secure timestamping. Since cryptlib uses industry-standard X.509, S/MIME, PGP/OpenPGP, and SSH/SSL/TLS data formats, the resulting encrypted or signed data can be easily transported to other systems and processed there, and cryptlib itself runs on virtually any operating system - cryptlib doesn't tie you to a single system. This allows email, files, and EDI transactions to be authenticated with digital signatures and encrypted in an industry-standard format.
cryptlib provides an extensive range of other capabilities including full X.509/PKIX certificate handling (all X.509 versions from X.509v1 to X.509v3) with additional support for SET, Microsoft AuthentiCode, Identrus, SigG, S/MIME, SSL, and Qualified certificates, PKCS #7 certificate chains, handling of certification requests and CRLs including automated checking of certificates against CRLs and online checking using RTCS and OCSP, and issuing and revoking certificates using CMP and SCEP. In addition cryptlib implements a full range of certification authority (CA) functions, as well as providing complete CMP, SCEP, RTCS, and OCSP server implementations to handle online certificate enrolment/issue/revocation and certificate status checking. Alongside the certificate handling, cryptlib provides a sophisticated key storage interface that allows the use of a wide range of key database types ranging from PKCS #11 devices, PKCS #15 key files, and PGP/OpenPGP key rings through to commercial-grade RDBMS' and LDAP directories with optional SSL protection.
In addition to its built-in capabilities, cryptlib can make use of the crypto capabilities of a variety of external crypto devices such as hardware crypto accelerators, Fortezza cards, PKCS #11 devices, hardware security modules (HSMs), and crypto smart cards. For particularly demanding applications cryptlib can be used with a variety of crypto devices that have received appropriate FIPS 140 or ITSEC/Common Criteria certification. The crypto device interface also provides a convenient general-purpose plug-in capability for adding new functionality that will be automatically used by cryptlib.
cryptlib is supplied as source code for BeOS, DOS, IBM MVS, Macintosh/OS X, OS/2, Tandem, a variety of Unix versions (including AIX, Digital Unix, DGUX, FreeBSD/NetBSD/OpenBSD, HP-UX, IRIX, Linux, MP-RAS, OSF/1, QNX, SCO/UnixWare, Solaris, SunOS, Ultrix, and UTS4), VM/CMS, Windows 3.x, Windows 95/98/ME, Windows CE/PocketPC/SmartPhone and Windows NT/2000/XP/Vista/7. cryptlib's highly portable nature means that it is also being used in a variety of custom embedded system environments including AMX, ChorusOS, eCos, FreeRTOS/OpenRTOS, uITRON, MQX, PalmOS, RTEMS, ThreadX, T-Kernel, uC/OS II, VDK, VxWorks, and XMK. In addition, cryptlib is available as a standard Windows DLL and an ActiveX control. Language bindings are available for C / C++, C# / .NET, Delphi, Java, Python, and Visual Basic (VB).
This is the unmodified source code of cryptlib version 3.4.2 with a Xcode project file added.
See COPYING for license of this source.