Network Working Group                                         E. Rescorla
Requests for Comments: 2659                                    RTFM, Inc.
Category: Experimental                                       A. Schiffman
                                                    Terisa Systems, Inc.
                                                             August 1999


                     Security Extensions For HTML

Status of this Memo

  This memo defines an Experimental Protocol for the Internet
  community.  It does not specify an Internet standard of any kind.
  Discussion and suggestions for improvement are requested.
  Distribution of this memo is unlimited.

Copyright Notice

  Copyright (C) The Internet Society (1999).  All Rights Reserved.

Abstract

  This memo describes a syntax for embedding S-HTTP negotiation
  parameters in HTML documents.  S-HTTP, as described by RFC 2660,
  contains the concept of negotiation headers which reflect the
  potential receiver of a message's preferences as to which crypto-
  graphic enhancements should be applied to the message. This document
  describes a syntax for binding these negotiation parameters to HTML
  anchors.

  1.  Introduction

  2.  Anchor Attributes

  We define the following new anchor (and form submission) attributes:

       DN -- The distinguished name of the principal for whom the
       request should be encrypted when dereferencing the anchor's url.
       This need not be specified, but failure to do so runs the risk
       that the client will be unable to determine the DN and therefore
       will be unable to encrypt.  This should be specified in the form
       of RFC1485, using SGML quoting conventions as needed.

       NONCE -- A free-format string (appropriately SGML quoted) which
       is to be included in a SHTTP-Nonce: header (after SGML quoting
       is removed) when the anchor is dereferenced.

       CRYPTOPTS -- Cryptographic option information as described in



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       [SHTTP]. Specifically, the <cryptopt-list> production.

2.1.  CERTS Element

  A new CERTS HTML element is defined, which carries a (not necessarily
  related) group of certificates provided as advisory data. The element
  contents are not intended to be displayed to the user. Certificate
  groups may be provided appropriate for either PEM or PKCS-7
  implementations. Such certificates are supplied in the HTML document
  for the convenience of the recipient, who might otherwise be unable
  to retrieve the certificate (chain) corresponding to a DN specified
  in an anchor.

  The format should be the same as that of the 'Certificate-Info'
  header line, of [SHTTP] except that the <Cert-Fmt> specifier should
  be provided as the FMT attribute in the tag.

  Multiple CERTS elements are permitted; it is suggested that CERTS
  elements themselves be included in the HTML document's HEAD element
  (in the hope that the data will not be displayed by S-HTTP oblivious
  but HTML compliant browsers.)

2.2.  CRYPTOPTS Element

  Cryptopts may also be broken out into an element and referred to in
  anchors by name. The NAME attribute specifies the name by which this
  element may be referred to in a CRYPTOPTS attribute in an anchor.
  Names must have a # as the leading character.

2.3.  HTML Example

  An example of cryptographic data embedded in an anchor, proceeded by
  a certificate group is provided below. Note the SGML quoting syntax
  used to supply embedded quotation marks.

          <CERTS FMT=PKCS-7>
          MIAGCSqGSIb3DQEHAqCAMIACAQExADCABgkqhkiG9w0BBwEAAKCAM
          IIBrTCCAUkCAgC2MA0GCSqGSIb3DQEBAgUAME0xCzAJBgNVBAYTAlVTMSAwH
          gYDVQQKExdSU0EgRGF0YSBTZWN1cml0eSwgSW5jLjEcMBoGA1UECxMTUGVyc
          29uYSBDZXJ0aWZpY2F0ZTAeFw05NDA0MDkwMDUwMzdaFw05NDA4MDIxODM4N
          TdaMGcxCzAJBgNVBAYTAlVTMSAwHgYDVQQKExdSU0EgRGF0YSBTZWN1cml0e
          SwgSW5jLjEcMBoGA1UECxMTUGVyc29uYSBDZXJ0aWZpY2F0ZTEYMBYGA1UEA
          xMPU2V0ZWMgQXN0cm9ub215MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAMy8Q
          cW7RMrB4sTdQ8Nmb2DFmJmkWn+el+NdeamIDElX/qw9mIQu4xNj1FfepfJNx
          zPvA0OtMKhy6+bkrlyMEU8CAwEAATANBgkqhkiG9w0BAQIFAANPAAYn7jDgi
          rhiIL4wnP8nGzUisGSpsFsF4/7z2P2wqne6Qk8Cg/Dstu3RyaN78vAMGP8d8
          2H5+Ndfhi2mRp4YHiGHz0HlK6VbPfnyvS2wdjCCAccwggFRAgUCQAAAFDANB
          gkqhkiG9w0BAQIFADBfMQswCQYDVQQGEwJVUzEgMB4GA1UEChMXUlNBIERhd



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          GEgU2VjdXJpdHksIEluYy4xLjAsBgNVBAsTJUxvdyBBc3N1cmFuY2UgQ2Vyd
          GlmaWNhdGlvbiBBdXRob3JpdHkwHhcNOTQwMTA3MDAwMDAwWhcNOTYwMTA3M
          jM1OTU5WjBNMQswCQYDVQQGEwJVUzEgMB4GA1UEChMXUlNBIERhdGEgU2Vjd
          XJpdHksIEluYy4xHDAaBgNVBAsTE1BlcnNvbmEgQ2VydGlmaWNhdGUwaTANB
          gkqhkiG9w0BAQEFAANYADBVAk4GqghQDa9Xi/2zAdYEqJVIcYhlLN1FpI9tX
          Q1m6zZ39PYXK8Uhoj0Es7kWRv8hC04vqkOKwndWbzVtvoHQOmP8nOkkuBi+A
          QvgFoRcgOUCAwEAATANBgkqhkiG9w0BAQIFAANhAD/5Uo7xDdp49oZm9GoNc
          PhZcW1e+nojLvHXWAU/CBkwfcR+FSf4hQ5eFu1AjYv6Wqf430Xe9Et5+jgnM
          Tiq4LnwgTdA8xQX4elJz9QzQobkE3XVOjVAtCFcmiin80RB8AAAMYAAAAAAA
          AAAAA==
          </CERTS>
          <A name=foobar
          DN="CN=Setec Astronomy, OU=Persona Certificate,
              O=&quot;RSA Data Security, Inc.&quot;, C=US"
          CRYPTOPTS="SHTTP-Privacy-Enhancements: recv-refused=encrypt;
          SHTTP-Signature-Algorithms: recv-required=NIST-DSS"
          HREF="shttp://research.nsa.gov/skipjack-holes.html">
          Don't read this. </A>

3. Security Considerations

  This entire document is about security.

4. Authors' Addresses

  Eric Rescorla
  RTFM, Inc.
  30 Newell Road, #16
  East Palo Alto, CA 94303

  Phone: (650) 328-8631
  EMail: [email protected]


  Allan M. Schiffman
  SPYRUS/Terisa
  5303 Betsy Ross Drive
  Santa Clara, CA 95054

  Phone: (408) 327-1901
  EMail: [email protected]

5. References

  [SHTTP] Rescorla, E. and A. Schiffman, "The Secure HyperText Transfer
          Protocol", RFC 2660, August 1999.





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6. Full Copyright Statement

  Copyright (C) The Internet Society (1999).  All Rights Reserved.

  This document and translations of it may be copied and furnished to
  others, and derivative works that comment on or otherwise explain it
  or assist in its implementation may be prepared, copied, published
  and distributed, in whole or in part, without restriction of any
  kind, provided that the above copyright notice and this paragraph are
  included on all such copies and derivative works.  However, this
  document itself may not be modified in any way, such as by removing
  the copyright notice or references to the Internet Society or other
  Internet organizations, except as needed for the purpose of
  developing Internet standards in which case the procedures for
  copyrights defined in the Internet Standards process must be
  followed, or as required to translate it into languages other than
  English.

  The limited permissions granted above are perpetual and will not be
  revoked by the Internet Society or its successors or assigns.

  This document and the information contained herein is provided on an
  "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
  TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
  BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
  HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
  MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

  Funding for the RFC Editor function is currently provided by the
  Internet Society.



















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