extensions

OCFL Community Extension 0009: Digest Algorithms

• Extension Name: 0009-digest-algorithms
• Authors: OCFL Editors, T. Wrobel
• Minimum OCFL Version: 1.0
• OCFL Community Extensions Version: 1.0
• Obsoletes: 0001-digest-algorithms
• Obsoleted by: n/a

Overview

This extension is an index of additional digest algorithms. It provides a controlled vocabulary of digest algorithm names that may be used to indicate the given algorithm in fixity blocks of OCFL Objects, and links their defining extensions.

Digest Algorithms Defined in Community Extensions

Digest Algorithm Name	Note
blake2b-160	BLAKE2 digest using the 2B variant (64 bit) with size 160 bits as defined by RFC7693. MUST be encoded using hex (base16) encoding RFC4648. For example, the blake2b-160 digest of a zero-length bitstream is 3345524abf6bbe1809449224b5972c41790b6cf2 (40 hex digits long).
blake2b-256	BLAKE2 digest using the 2B variant (64 bit) with size 256 bits as defined by RFC7693. MUST be encoded using hex (base16) encoding RFC4648. For example, the blake2b-256 digest of a zero-length bitstream starts as follows 0e5751c026e543b2e8ab2eb06099daa1d1e5df47... (64 hex digits long).
blake2b-384	BLAKE2 digest using the 2B variant (64 bit) with size 384 bits as defined by RFC7693. MUST be encoded using hex (base16) encoding RFC4648. For example, the blake2b-384 digest of a zero-length bitstream starts as follows b32811423377f52d7862286ee1a72ee540524380... (96 hex digits long).
sha512/256	SHA-512 algorithm with 256 output as defined by FIPS-180-4. MUST be encoded using hex (base16) encoding RFC4648. For example, the sha512/256 digest of a zero-length bitstream starts c672b8d1ef56ed28ab87c3622c5114069bdd3ad7... (64 hex digits long).
size	The size of the binary file in bytes, expressed as a string representation of the integer in decimal notation, with no padding. For example, the size digest of a zero-length bitstream is 0 (>= 1 digit long).

Maintenance

In order to have an additional digest algorithm listed here, please submit a pull request on this extension that:

• Adds the algorithm to the table. New entries should have a name that does not conflict with those defined in the OCFL Specification or this community extension, and is preferably in common use for the given algorithm.
• Creates a new version of this extension with the next available extension number, obsoleting the current one
• If a long algorithm description is required it may be appropriate to submit an additional new extension describing the algorithm along with an update to this extension that links to it.