Secure MIME (S/MIME)

Welcome to the next generation of secure email.

email clients that support Secure/MIME are:

• Microsoft Outlook (Windows)
• Microsoft Outlook Express (Windows)
• Mozilla Thunderbird (Linux, Mac OS X, Windows, Solaris)
• Netscape Communicator (Windows, Solaris)
• Mail (Mac OS X)

Documents that relate to this work include:

• Security Multiparts for MIME (RFC 1847)
• MIME Part 1: Format of Internet Message Bodies (RFC 2045)
• MIME Part 2: Media Types (RFC 2046)
• MIME Part 3: Message Header Extensions for Non-ASCII Text (RFC 2047)
• MIME Part 4: Registration Procedures (RFC 2048)
• MIME Part 5: Conformance Criteria and Examples (RFC 2049)
• Key Words for Use in RFCs to Indicate Requirement Levels (RFC 2119)

Many S/MIME implementors are also interested in PKIX. The following links are the binary examples from the PKIX part 1 draft.

• Appendix D.1 certificate
• Appendix D.2 certificate
• Appendix D.3 certificate
• Appendix D.4 CRL

The S/MIME certificate structure is based on work being done in the IETF's PKIX Working Group. S/MIME developers should probably be familiar with the work being done in that Working Group.

The RFCs for S/MIME 2 are:

• S/MIME Version 2 Message Specification (RFC 2311)
• S/MIME Version 2 Certificate Handling (RFC 2312)
• PKCS #1: RSA Encryption Version 1.5 (RFC 2313)
• PKCS #10: Certification Request Syntax Version 1.5 (RFC 2314)
• PKCS #7: Cryptographic Message Syntax Version 1.5 (RFC 2315)
• Description of the RC2 Encryption Algorithm (RFC 2268)

• Entrust
  
• ZixCorp
  
• ZipLip
  
• MailFoundry
  
• Bawwacuda
  
• gMIME