Appendix VI: External Repository Identifiers

This specification allows external resources to be referenced from SPDX documents. The identifiers are a combination of a category, a type and a locator.

There are currently four defined categories:

  • Security
  • Package-Manager
  • Persistent-Id
  • Other

The following sections provide details on the available types and the locator formats for each of the categories.

Security

cpe22Type

Locator Format:

[c][pP][eE]:/[AHOaho]?(:[A-Za-z0-9\._\-~%]*){0,6}

Contextual Example:

cpe:/o:canonical:ubuntu_linux:10.04:-:lts

External Reference Site: https://nvd.nist.gov/cpe

Documentation: https://cpe.mitre.org/files/cpe-specification_2.2.pdf

cpe23Type

Locator Format:

cpe:2\.3:[aho\*\­]
(:(((\?*|\*?)([a­zA­Z0­9\­\._]|(\\[\\\*\?!
"#$$%&'\(\)\+,/:;<=>@\[\]\^`\{\|}~])
)+(\?*|\*?))|[\*\­])){5}
(:(([a­zA­Z]{2,3}(­([a­zA­Z]{2}|[0­9]{3
}))?)|[\*\­]))
(:(((\?*|\*?)([a­zA­Z0­9\­\._]|(\\[\\\*\?!
"#$$%&'\(\)\+,/:;<=>@\[\]\^`\{\|}~])
)+(\?*|\*?))|[\*\­])){4}

Contextual Example:

cpe:2.3:o:canonical:ubuntu_linux:10.04:­:lts:*:*:*:*:*

External Reference Site: https://nvd.nist.gov/cpe

Documentation: http://csrc.nist.gov/publications/nistir/ir7695/NISTIR-7695-CPE-Naming.pdf

Package-Manager

maven-central

Locator Format:

group:artifact[:version]
^[^:]+:[^:]+(:[^:]+)?$

Contextual Example:

org.apache.tomcat:tomcat:9.0.0.M4

External Reference Site: http://repo1.maven.org/maven2/

Documentation: https://maven.apache.org

npm

Locator Format:

package@version
^[^@]+@[^@]+$

Contextual Example:

http-server@0.3.0

External Reference Site: https://www.npmjs.com/

Documentation: https://docs.npmjs.com/files/package.json

nuget

Locator Format:

package/version
^[^\/]+\/[^\/]+$

Contextual Example:

Microsoft.AspNet.MVC/5.0.0

External Reference Site: https://www.nuget.org/

Documentation: https://docs.nuget.org/

bower

Locator Format:

package#version
^[^#]+#[^#]+$

Contextual Example:

modernizr#2.6.2

External Reference Site: http://bower.io/

Documentation: http://bower.io/docs/api/#install

purl

Locator Format:

scheme:type/namespace/name@version?qualifiers#subpath

Contextual Example:

pkg:docker/debian@sha256:2f04d3d33b6027bb74ecc81397abe780649ec89f1a2af18d7022737d0482cefe

External Reference Site: https://github.com/package-url/purl-spec

Documentation: https://github.com/package-url/purl-spec

Persistent-Id

swh

These point to objects present in the Software Heritage archive by the means of SoftWare Heritage persistent Identifiers (SWHID), that are guaranteed to remain stable (persistent) over time. Their syntax is described below. Note that they are identifiers and not URLs.

A persistent identifier can point to any software artifact (or “object”) available in the Software Heritage archive. Objects come in different types, and most notably:

  • contents
  • directories
  • revisions
  • releases
  • snapshots

The SWHID follow the swh: IANA-registered URI scheme.

Grammar for locator format:

<locator> ::= "swh" ":" <scheme_version> ":" <object_type> ":" <object_id> ;
<scheme_version> ::= "1" ;
<object_type> ::= "cnt" | "dir" | "rev" | "rel" | "snp" ;
<object_id> ::= 40 * <hex_digit> ;  *intrinsic object id, as hex-encoded SHA1*
<hex_digit> ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" | "a" | "b" | "c" | "d" | "e" | "f" ;

Examples:

  • swh:1:cnt:94a9ed024d3859793618152ea559a168bbcbb5e2 points to the content of a file containing the full text of the GPL3 license
  • swh:1:dir:d198bc9d7a6bcf6db04f476d29314f157507d505 points to a directory containing the source code of the Darktable photography application as it was at some point on 4 May 2017
  • swh:1:rev:309cf2674ee7a0749978cf8265ab91a60aea0f7d points to a commit in the development history of Darktable, dated 16 January 2017, that added undo/redo supports for masks
  • swh:1:rel:22ece559cc7cc2364edc5e5593d63ae8bd229f9f points to Darktable release 2.3.0, dated 24 December 2016
  • swh:1:snp:c7c108084bc0bf3d81436bf980b46e98bd338453 points to a snapshot of the entire Darktable Git repository taken on 4 May 2017 from GitHub

External documentation: Software Heritage

Other

[idstring]

Locator Format:

No spaces, but anything else goes