Beta Unofficial
`security.txt` Spec



Network Working Group                                          E. Foudil
Internet-Draft
Intended status: Informational                           Y. Shafranovich
Expires: July 15, 2018                          Nightwatch Cybersecurity
                                                        January 11, 2018


                   A Method for Web Security Policies
                      draft-foudil-securitytxt-03

Abstract

   When security risks in web services are discovered by independent
   security researchers who understand the severity of the risk, they
   often lack the channels to disclose them properly.  As a result,
   security issues may be left unreported. security.txt defines a
   standard to help organizations describe the process for security
   researchers to disclose security vulnerabilities securely.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on July 15, 2018.

Copyright Notice

   Copyright (c) 2018 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of



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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Motivation  . . . . . . . . . . . . . . . . . . . . . . .   2
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Note to Readers . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  The Specification . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Comments  . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Separate Fields . . . . . . . . . . . . . . . . . . . . .   4
     3.3.  Contact:  . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.4.  Encryption: . . . . . . . . . . . . . . . . . . . . . . .   5
     3.5.  Signature:  . . . . . . . . . . . . . . . . . . . . . . .   5
     3.6.  Policy: . . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.7.  Acknowledgments:  . . . . . . . . . . . . . . . . . . . .   5
     3.8.  Example . . . . . . . . . . . . . . . . . . . . . . . . .   6
   4.  Location of the security.txt file . . . . . . . . . . . . . .   6
     4.1.  Web-based services  . . . . . . . . . . . . . . . . . . .   7
     4.2.  Filesystems . . . . . . . . . . . . . . . . . . . . . . .   7
     4.3.  Internal hosts  . . . . . . . . . . . . . . . . . . . . .   7
     4.4.  Extensibility . . . . . . . . . . . . . . . . . . . . . .   7
   5.  File Format Description . . . . . . . . . . . . . . . . . . .   7
   6.  Security considerations . . . . . . . . . . . . . . . . . . .   8
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
     7.1.  Well-Known URIs registry  . . . . . . . . . . . . . . . .   9
     7.2.  Registry for security.txt Header Fields . . . . . . . . .   9
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  10
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  12
     9.3.  URIs  . . . . . . . . . . . . . . . . . . . . . . . . . .  12
   Appendix A.  Note to Readers  . . . . . . . . . . . . . . . . . .  12
   Appendix B.  Document History . . . . . . . . . . . . . . . . . .  13
     B.1.  Since draft-foudil-securitytxt-00 . . . . . . . . . . . .  13
     B.2.  Since draft-foudil-securitytxt-01 . . . . . . . . . . . .  13
     B.3.  Since draft-foudil-securitytxt-02 . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

1.1.  Motivation

   Many security researchers encounter situations where they are unable
   to responsibly disclose security issues to companies because there is
   no course of action laid out. security.txt is designed to help assist




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   in this process by making it easier for companies to designate the
   preferred steps for researchers to take when trying to reach out.

   As per section 4 of [RFC2142], there is an existing convention of
   using the SECURITY@domain [1] email address for communications
   regarding security issues.  That convention provides only a single,
   email-based channel of communication for security issues per domain,
   and does not provide a way for domain owners to publish information
   about their security disclosure policies.

   In this document, we propose a richer, machine-parsable and more
   extensible way for companies to communicate information about their
   security disclosure policies, which is not limited to email and also
   allows for additional features such as encryption.

1.2.  Terminology

   In this document, the key words "MUST", "MUST NOT", "REQUIRED",
   "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
   and "OPTIONAL" are to be interpreted as described in [RFC2119].

2.  Note to Readers

      *Note to the RFC Editor:* Please remove this section prior to
      publication.

   Development of this draft takes place on Github at:
   https://github.com/securitytxt/security-txt

3.  The Specification

   security.txt is a text file that SHOULD be located under the /.well-
   known/ path ("/.well-known/security.txt") [RFC5785] for web
   properties.  If it is not possible to place the security.txt file in
   the /.well-known/ path or setup a redirect, web-based services MAY
   place the file in the top-level path as a fall back option.  For web-
   based services, the instructions must be accessible via the Hypertext
   Transfer Protocol [RFC1945] as a resource of Internet Media Type
   "text/plain" with the default charset parameter set to "utf-8" per
   section 4.1.3 of [RFC2046].  For file systems and version control
   repositories a .security.txt file SHOULD be placed in the root
   directory.

   This text file contains multiple directives with different values.
   The "directive" is the first part of a field all the way up to the
   colon ("Contact:").  Directives are case-insensitive.  The "value"
   comes after the directive ("https://example.com/security").  A
   "field" always consists of a directive and a value ("Contact:



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   https://example.com/security").  A security.txt file can have an
   unlimited number of fields.  It is important to note that you need a
   separate line for every field.  One MUST NOT chain multiple values
   for a single directive.  Everything MUST be in a separate field.

   A security.txt file MUST only apply to the domain in the URI used to
   retrieve it, not to any of its subdomains or parent domains.

   # The following only applies to example.com.
   https://example.com/.well-known/security.txt

   # This only applies to subdomain.example.com.
   https://subdomain.example.com/.well-known/security.txt

   # This security.txt file applies to 192.0.2.0.
   http://192.0.2.0/.well-known/security.txt

3.1.  Comments

   Comments can be added using the # symbol:

   # This is a comment.

   You MAY use one or more comments as descriptive text immediately
   before the field.  Parsers can then associate the comments with the
   respective field.

3.2.  Separate Fields

   A separate line is required for every new value and field.  You MUST
   NOT chain everything into a single field.  Every line must end with a
   line feed character (%x0A).

3.3.  Contact:

   Add an address that researchers MAY use for reporting security
   issues.  The value can be an email address, a phone number and/or a
   contact page with more information.  The "Contact:" directive MUST
   always be present in a security.txt file.  URIs SHOULD be loaded over
   HTTPS.  Security email addresses SHOULD use the conventions defined
   in section 4 of [RFC2142], but there is no requirement for this
   directive to be an email address.

   The value MUST follow the general syntax described in [RFC3986].
   This means that "mailto" and "tel" URI schemes MUST be used when
   specifying email addresses and telephone numbers.





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   The precedence is in listed order.  The first field is the preferred
   method of contact.  In the example below, the e-mail address is the
   preferred method of contact.

   Contact: mailto:security@example.com
   Contact: tel:+1-201-555-0123
   Contact: https://example.com/security-contact.html

3.4.  Encryption:

   This directive allows you to add your key for encrypted
   communication.  You MUST NOT directly add your key.  The value MUST
   be a link to a page which contains your key.  Keys SHOULD be loaded
   over HTTPS.

   Encryption: https://example.com/pgp-key.txt

3.5.  Signature:

   In order to ensure the authenticty of the security.txt file one
   SHOULD use the "Signature:" directive, which allows you to link to an
   external signature.  External signature files SHOULD be named
   "security.txt.sig" and also be placed under the /.well-known/ path.
   External signature files SHOULD be loaded over HTTPS.

   Here is an example of an external signature file.

   Signature: https://example.com/.well-known/security.txt.sig

3.6.  Policy:

   With the Policy directive, you can link to where your security policy
   and/or disclosure policy is located.  This can help security
   researchers understand what you are looking for and how to report
   security vulnerabilities.

   Policy: https://example.com/security-policy.html

3.7.  Acknowledgments:

   This directive allows you to link to a page where security
   researchers are recognized for their reports.  The page should list
   individuals or companies that disclosed security vulnerabilities and
   worked with you to remediate the issue.

   Acknowledgments: https://example.com/hall-of-fame.html

   Example security acknowledgments page:



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   We would like to thank the following researchers:

   (2017-04-15) Frank Denis - Reflected cross-site scripting
   (2017-01-02) Alice Quinn  - SQL injection
   (2016-12-24) John Buchner - Stored cross-site scripting
   (2016-06-10) Anna Richmond - A server configuration issue

3.8.  Example

   # Our security address
   Contact: mailto:security@example.com

   # Our PGP key
   Encryption: https://example.com/pgp-key.txt

   # Our security policy
   Policy: https://example.com/security-policy.html

   # Our security acknowledgments page
   Acknowledgments: https://example.com/hall-of-fame.html

   # Verify this security.txt file
   Signature: https://example.com/.well-known/security.txt.sig

4.  Location of the security.txt file

                             External
   +----------------------------------------------------------------+
   |              Default                                           |
   |  +-----------------------------+          +-----------------+  |
   |  |                             | Redirect |                 |  |
   |  |  /.well-known/security.txt  <----------+  /security.txt  |  |
   |  |                             |          |                 |  |
   |  +-----------------------------+          +-----------------+  |
   |                                                                |
   +----------------------------------------------------------------+

           Internal
   +------------------------+
   |                        |
   |  +------------------+  |
   |  |                  |  |
   |  |  /.security.txt  |  |
   |  |                  |  |
   |  +------------------+  |
   |                        |
   +------------------------+




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4.1.  Web-based services

   Web-based services SHOULD place the security.txt file under the
   /.well-known/ path; e.g. https://example.com/.well-known/
   security.txt.  A security.txt file located under the top-level path
   SHOULD either redirect to the security.txt file under the /.well-
   known/ path or be used as a fall back.

4.2.  Filesystems

   File systems SHOULD place the security.txt file under the root
   directory; e.g., /.security.txt, C:.security.txt.

   user:/$ l
   .security.txt
   example-directory-1/
   example-directory-2/
   example-directory-3/
   example-file

4.3.  Internal hosts

   A .security.txt file SHOULD be placed in the root directory of an
   internal host to trigger incident response.

4.4.  Extensibility

   Like many other formats and protocols, this format may need to be
   extended over time to fit the ever-changing landscape of the
   Internet.  Therefore, extensibility is provided via an IANA registry
   for headers fields as defined in Section 7.2.  Any fields registered
   via that process MUST be considered optional.  To encourage
   extensibility and interoperability, implementors MUST ignore any
   fields they do not explicitly support.

5.  File Format Description

   The expected file format of the security.txt file is plain text (MIME
   type "text/plain") as defined in section 4.1.3 of [RFC2046] and is
   encoded using UTF-8 [RFC3629] in Net-Unicode form [RFC5198].

   The following is an ABNF definition of the security.txt format, using
   the conventions defined in [RFC5234].








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body                   = *line (contact-field eol) *line

line                   = *1(field / comment) eol

eol                    = *WSP \[CR\] LF

field                  = contact-field /
                         encryption-field /
                         acknowledgments-field /
                         ext-field

fs                     = ":"

comment                = "#" *(WSP / VCHAR / %xA0-E007F)

contact-field          = "Contact" fs SP (email / uri / phone)

email                  = 

phone                  = "+" *1(DIGIT / "-" / "(" / ")" / SP)

uri                    = 

encryption-field       = "Encryption" fs SP uri

signature-field        = "Signature" fs SP uri

policy-field           = "Policy" fs SP uri

Acknowledgments-field  = "Acknowledgments" fs SP uri

ext-field              = field-name fs SP unstructured

field-name             = 

unstructured           = 

"ext-field" refers to extension fields, which are discussed in {{extensibility}}

6.  Security considerations

   Organizations creating security.txt files will need to consider
   several security-related issues.  These include exposure to sensitive
   information and attacks where limited access to a server could grant
   the ability to modify the contents of the security.txt file or affect
   how it is served.  Organizations SHOULD also monitor their
   security.txt files regularly to detect tampering.




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   To ensure the authenticity of the security.txt file, organizations
   SHOULD sign the file and include the signature using the "Signature:"
   directive.

   As stated in Section 3.4 and Section 3.5, both encryption keys and
   external signature files SHOULD be loaded over HTTPS.

   Web services MUST reserve the security.txt namespace to ensure no
   third-party can create a page with the "security.txt" name.

7.  IANA Considerations

   example.com is used in this document following the uses indicated in
   [RFC2606].

   192.0.2.0 is used in this document following the uses indicated in
   [RFC5735].

7.1.  Well-Known URIs registry

   The "Well-Known URIs" registry should be updated with the following
   additional values (using the template from [RFC5785]):

   URI suffix: security.txt URI suffix: security.txt.sig

   Change controller: IETF

   Specification document(s): this document

7.2.  Registry for security.txt Header Fields

   IANA is requested to create the "security.txt Header Fields" registry
   in accordance with [RFC8126].  This registry will contain header
   fields for use in security.txt files, defined by this specification.

   New registrations or updates MUST be published in accordance with the
   "Specification Required" guidelines as described in section 4.6 of
   [RFC8126].  Any new field thus registered is considered optional by
   this specification unless a new version of this specification is
   published.

   New registrations and updates MUST contain the following information:

   1.  Name of the field being registered or updated

   2.  Short description of the field

   3.  Whether the field can appear more than once



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   4.  The document in which the specification of the field is published

   5.  New or updated status, which MUST be one of: current: The field
       is in current use deprecated: The field is in current use, but
       its use is discouraged historic: The field is no longer in
       current use

   An update may make a notation on an existing registration indicating
   that a registered field is historical or deprecated if appropriate.

   The initial registry contains these values:

   Field Name: Acknowledgment
   Description: link to page where security researchers are recognized
   Multiple Appearances: Yes
   Published in: this document
   Status: current

   Field Name: Contact
   Description: contact information to use for reporting security issues
   Multiple Appearances: Yes
   Published in: this document
   Status: current

   Field Name: Encryption
   Description: link to a key to be used for encrypted communication
   Multiple Appearances: Yes
   Published in: this document
   Status: current

   Field Name: Signature
   Description: signature used to verify the authenticity of the file
   Multiple Appearances: No
   Published in: this document
   Status: current

   Field Name: Policy
   Description: link to security policy page
   Multiple Appearances: No
   Published in: this document
   Status: current

8.  Contributors

   The editor would like to acknowledge the help provided during the
   development of this document by the following individuals:





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   o  Tom Hudson helped writing the "File Format Description" and wrote
      several security.txt parsers.

   o  Joel Margolis was a big help when it came to wording this document
      appropriately.

   o  Jobert Abma for raising issues and concerns that might arise when
      using certain directives.

   o  Gerben Janssen van Doorn for reviewing this document multiple
      times.

   o  Austin Heap for helping improve the Internet drafts.

   o  Justin Calmus was always there to answer questions related to
      writing this document.

   o  Casey Ellis had several ideas related to security.txt that helped
      shape security.txt itself.

9.  References

9.1.  Normative References

   [RFC1945]  Berners-Lee, T., Fielding, R., and H. Frystyk, "Hypertext
              Transfer Protocol -- HTTP/1.0", RFC 1945,
              DOI 10.17487/RFC1945, May 1996, .

   [RFC2046]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part Two: Media Types", RFC 2046,
              DOI 10.17487/RFC2046, November 1996, .

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997, .

   [RFC2142]  Crocker, D., "Mailbox Names for Common Services, Roles and
              Functions", RFC 2142, DOI 10.17487/RFC2142, May 1997,
              .

   [RFC2606]  Eastlake 3rd, D. and A. Panitz, "Reserved Top Level DNS
              Names", BCP 32, RFC 2606, DOI 10.17487/RFC2606, June 1999,
              .





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   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
              10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
              2003, .

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              .

   [RFC5198]  Klensin, J. and M. Padlipsky, "Unicode Format for Network
              Interchange", RFC 5198, DOI 10.17487/RFC5198, March 2008,
              .

   [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234,
              DOI 10.17487/RFC5234, January 2008, .

   [RFC5322]  Resnick, P., Ed., "Internet Message Format", RFC 5322,
              DOI 10.17487/RFC5322, October 2008, .

   [RFC5735]  Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses",
              RFC 5735, DOI 10.17487/RFC5735, January 2010,
              .

   [RFC5785]  Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known
              Uniform Resource Identifiers (URIs)", RFC 5785,
              DOI 10.17487/RFC5785, April 2010, .

9.2.  Informative References

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              .

9.3.  URIs

   [1] mailto:SECURITY@domain

Appendix A.  Note to Readers

      *Note to the RFC Editor:* Please remove this section prior to
      publication.





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   Development of this draft takes place on Github at
   https://github.com/securitytxt/security-txt

Appendix B.  Document History

      *Note to the RFC Editor:* Please remove this section prior to
      publication.

B.1.  Since draft-foudil-securitytxt-00

   o  Moved to use IETF's markdown tools for draft updates

   o  Added table of contents and a fuller list of references

   o  Moved file to .well-known URI and added IANA registration (#3)

   o  Added extensibility with an IANA registry for fields (#34)

   o  Added text explaining relationship to RFC 2142 / security@ email
      address (#25)

   o  Scope expanded to include internal hosts, domains, IP addresses
      and file systems

   o  Support for digital signatures added (#19)

   The full list of changes can be viewed via the IETF document tracker:
   https://tools.ietf.org/html/draft-foudil-securitytxt-01

B.2.  Since draft-foudil-securitytxt-01

   o  Added appendix with pointer to Github and document history

   o  Added external signature file to the well known URI registry (#59)

   o  Added policy field (#53)

   o  Added diagram explaining the location of the file on public vs.
      internal systems

   o  Added recommendation that external signature files should use
      HTTPS (#55)

   o  Added recommendation that organizations should monitor their
      security.txt files (#14)

   The full list of changes can be viewed via the IETF document tracker:
   https://tools.ietf.org/html/draft-foudil-securitytxt-02



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B.3.  Since draft-foudil-securitytxt-02

   o  Use "mailto" and "tel" (#62)

   o  Fix typo in the "Example" section (#64)

   o  Clarified that the root directory is a fall back option (#72)

   o  Defined content-type for the response (#68)

   o  Clarify the scope of the security.txt file (#69)

   Full list of changes can be viewed via the IETF document tracker:
   https://tools.ietf.org/html/draft-foudil-securitytxt-03

Authors' Addresses

   Edwin Foudil

   Email: contact@edoverflow.com


   Yakov Shafranovich
   Nightwatch Cybersecurity

   Email: yakov+ietf@nightwatchcybersecurity.com

























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