Extension 0001 - list of digest algorithms

docs/0000-example-extension.md

@@ -1,6 +1,7 @@
 # OCFL Community Extension 0000: Example Extension
 
   * Authors: A Person, Other Person
+  * Minimum OCFL Version: 1.0
   * Obsoletes: n/a
   * Obsoleted by: n/a
 

docs/0001-digest-algorithms.md

@@ -0,0 +1,23 @@
+# OCFL Community Extension 0001: Digest Algorithms
+
+  * Authors: OCFL Editors
+  * Minimum OCFL Version: 1.0
+  * Obsoletes: n/a
+  * 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](https://tools.ietf.org/html/rfc7693). MUST be encoded using hex (base16) encoding [RFC4648](https://tools.ietf.org/html/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](https://tools.ietf.org/html/rfc7693). MUST be encoded using hex (base16) encoding [RFC4648](https://tools.ietf.org/html/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](https://tools.ietf.org/html/rfc7693). MUST be encoded using hex (base16) encoding [RFC4648](https://tools.ietf.org/html/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](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf). MUST be encoded using hex (base16) encoding [RFC4648](https://tools.ietf.org/html/rfc4648). For example, the `sha512/256` digest of a zero-length bitstream starts `c672b8d1ef56ed28ab87c3622c5114069bdd3ad7...` (64 hex digits long). |
+
+## Maintenance
+
+In order to have an additional digest algorithm listed here, please submit a pull request on this extension that adds it to the table. New entries should have a name that does not conflict with those defined in the [OCFL Specification](https://ocfl.io/latest/spec/) or this community extension, and is preferably in common use for the given algorithm. In the case that long description is required it may be appropriate to submit a new extension describing the algorithm along with an update to this extension that links to it.

docs/index.md

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 # OCFL Community Extensions	
 
-  * [0000: Example Extension](0000-example-extension)
+  * [0001: Digest Algorithms](0001-digest-algorithms)