The stunnelprogram worksas SSLencryptionwrapper betweenremote andlocal networksockets orinetd-starteddaemons. Itadds SSL or TLSfunctionalityto any networkservice,commonly POP3,IMAP or HTTPservers.Stunnel usesOpenSSL forcryptography.It can itselffunction asportredirectiondeamon, or astemporarytrafficinterceptor,and requires noadaption of theshadowedprograms.
x509viewer is asimple commandlineapplication,written inPerl, that canbe used todecode one ormultiple X.509certificatesper given file,such as e.g.SSLcertificates,CSRs(certificatesigningrequests), butalso privatekeys.
x509watch is asimple commandlineapplicationthat can beused to listsoon expiringor alreadyexpired X.509certificates,such as SSLcertificates.Allcertificatesare searched bydefault in thestandard PKIdirectory, butany otherdirectory canbe specified asa parameter.Only Base64encoded DER andPEM X.509certificatesare supported.
The OpenSSLProject is acollaborativeeffort todevelop arobust,commercial-grade,fully featured,and Open Sourcetoolkitimplementingthe SecureSockets Layer(SSLv2/v3) andTransport LayerSecurity(TLSv1) as wellas afull-strengthgeneral-purposecryptographylibrary.
PolarSSL is alight-weightcryptographicand SSL/TLSlibrary writtenin C. PolarSSLmakes it easyfor developersto includecryptographicand SSL/TLScapabilities intheir(embedded)applicationswith as littlehassle aspossible. Loosecoupling of thecomponentsinside thelibrary meansthat it is easyto separate theparts that areneeded, withoutneeding toinclude thetotal library.PolarSSL iswritten withembeddedsystems in mindand has beenported on anumber ofarchitectures,including