Network Working Group E. Foudil
Internet-Draft
Intended status: Informational Y. Shafranovich
Expires: August 13, 2018 Nightwatch Cybersecurity
February 09, 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 August 13, 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: . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.7. Acknowledgments: . . . . . . . . . . . . . . . . . . . . 6
3.8. Hiring: . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.9. Example . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Location of the security.txt file . . . . . . . . . . . . . . 7
4.1. Web-based services . . . . . . . . . . . . . . . . . . . 7
4.2. Filesystems . . . . . . . . . . . . . . . . . . . . . . . 8
4.3. Internal hosts . . . . . . . . . . . . . . . . . . . . . 8
4.4. Extensibility . . . . . . . . . . . . . . . . . . . . . . 8
5. File Format Description . . . . . . . . . . . . . . . . . . . 8
6. Security considerations . . . . . . . . . . . . . . . . . . . 9
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
7.1. Well-Known URIs registry . . . . . . . . . . . . . . . . 10
7.2. Registry for security.txt Header Fields . . . . . . . . . 10
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
9.1. Normative References . . . . . . . . . . . . . . . . . . 12
9.2. Informative References . . . . . . . . . . . . . . . . . 13
Appendix A. Note to Readers . . . . . . . . . . . . . . . . . . 13
Appendix B. Document History . . . . . . . . . . . . . . . . . . 14
B.1. Since draft-foudil-securitytxt-00 . . . . . . . . . . . . 14
B.2. Since draft-foudil-securitytxt-01 . . . . . . . . . . . . 14
B.3. Since draft-foudil-securitytxt-02 . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
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> 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 IPv4 address of 192.0.2.0.
http://192.0.2.0/.well-known/security.txt
# This security.txt file applies to IPv6 address of 2001:db8:8:4::2.
http://[2001:db8:8:4::2]/.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 either
with a carriage return and line feed characters (CRLF / %x0D %x0A) or
just a line feed character (LF / %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.
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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.
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 point to an encryption key that you want
security researchers to use for encrypted communication. You MUST
NOT directly add your key to the field, instead the value of this
field MUST be a URI pointing to a location where the key can be
retrieved from. If the key is being retrieved from a website, then
the key MUST be loaded over HTTPS.
When it comes to verifying the authenticity of the key, it is always
the security researcher's responsibility to make sure the key being
specified is indeed one they trust. Researchers MUST NOT assume that
this key is used to generate the signature file referenced in
Section 3.5.
Example of a PGP key available from a web server:
Encryption: https://example.com/pgp-key.txt
Example of a PGP key available from an OPENPGPKEY DNS record under
"security@example.com" (as per [RFC7553] and [RFC7929]):
Encryption: dns:5d2d3ceb7abe552344276d47d36._openpgpkey.example.com?type=OPENPGPKEY
3.5. Signature:
In order to ensure the authenticity of the security.txt file one
SHOULD use the "Signature:" directive, which allows you to link to an
external signature by specifying the full URI where the signature is
located as per [RFC3986]. 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.
When it comes to verifying the authenticity of the file, it is always
the security researcher's responsibility to make sure the key being
specified is indeed one they trust.
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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:
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. Hiring:
The "Hiring" directive is for linking to the vendor's security-
related job positions.
Hiring: https://example.com/jobs.html
3.9. Example
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# 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 | |
| | | |
| +------------------+ |
| |
+------------------------+
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.
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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 = <Email address as per {{RFC5322}}>
phone = "+" *1(DIGIT / "-" / "(" / ")" / SP)
uri = <URI as per {{RFC3986}}>
encryption-field = "Encryption" fs SP uri
signature-field = "Signature" fs SP uri
policy-field = "Policy" fs SP uri
acknowledgments-field = "Acknowledgments" fs SP uri
hiring-field = "Hiring" fs SP uri
ext-field = field-name fs SP unstructured
field-name = <as per section 3.6.8 of {{RFC5322}}>
unstructured = <as per section 3.2.5 of {{RFC5322}}>
"ext-field" refers to extension fields, which are discussed in
Section 4.4
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
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how it is served. Organizations SHOULD also monitor their
security.txt files regularly to detect tampering.
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.
Websites 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 and 2001:db8:8:4::2 are used in this document following the
uses indicated in [RFC6890].
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:
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1. Name of the field being registered or updated
2. Short description of the field
3. Whether the field can appear more than once
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
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8. Contributors
The editors would like to acknowledge the help provided during the
development of this document by Tom Hudson, Joel Margolis, Jobert
Abma, Gerben Janssen van Doorn, Austin Heap, Justin Calmus, and Casey
Ellis.
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, <https://www.rfc-
editor.org/info/rfc1945>.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046,
DOI 10.17487/RFC2046, November 1996, <https://www.rfc-
editor.org/info/rfc2046>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, <https://www.rfc-
editor.org/info/rfc2119>.
[RFC2142] Crocker, D., "Mailbox Names for Common Services, Roles and
Functions", RFC 2142, DOI 10.17487/RFC2142, May 1997,
<https://www.rfc-editor.org/info/rfc2142>.
[RFC2606] Eastlake 3rd, D. and A. Panitz, "Reserved Top Level DNS
Names", BCP 32, RFC 2606, DOI 10.17487/RFC2606, June 1999,
<https://www.rfc-editor.org/info/rfc2606>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <https://www.rfc-editor.org/info/rfc3629>.
[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,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC5198] Klensin, J. and M. Padlipsky, "Unicode Format for Network
Interchange", RFC 5198, DOI 10.17487/RFC5198, March 2008,
<https://www.rfc-editor.org/info/rfc5198>.
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[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008, <https://www.rfc-
editor.org/info/rfc5234>.
[RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322,
DOI 10.17487/RFC5322, October 2008, <https://www.rfc-
editor.org/info/rfc5322>.
[RFC5785] Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known
Uniform Resource Identifiers (URIs)", RFC 5785,
DOI 10.17487/RFC5785, April 2010, <https://www.rfc-
editor.org/info/rfc5785>.
[RFC6890] Cotton, M., Vegoda, L., Bonica, R., Ed., and B. Haberman,
"Special-Purpose IP Address Registries", BCP 153,
RFC 6890, DOI 10.17487/RFC6890, April 2013,
<https://www.rfc-editor.org/info/rfc6890>.
[RFC7553] Faltstrom, P. and O. Kolkman, "The Uniform Resource
Identifier (URI) DNS Resource Record", RFC 7553,
DOI 10.17487/RFC7553, June 2015, <https://www.rfc-
editor.org/info/rfc7553>.
[RFC7929] Wouters, P., "DNS-Based Authentication of Named Entities
(DANE) Bindings for OpenPGP", RFC 7929,
DOI 10.17487/RFC7929, August 2016, <https://www.rfc-
editor.org/info/rfc7929>.
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,
<https://www.rfc-editor.org/info/rfc8126>.
Appendix A. 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
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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)
o Cleaning up text based on the NITS tools suggestions (#82)
o Added clarification for newline values
o Clarified the encryption field language, added examples of DNS-
stored encryption keys (#28 and #94)
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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