Ace:TokenStore: Difference between revisions
From Adapt
No edit summary |
No edit summary |
||
| Line 9: | Line 9: | ||
<pre> | <pre> | ||
[token-store] ::= [token-entry] | [token-store] | [token-store] ::= [token-entry] | [token-store] | ||
[token-entry] ::= [entry-header] [identifier-list] [newline] [proof] | [token-entry] ::= [entry-header] [identifier-list] [newline] [proof-list] | ||
[entry-header] ::= [digest-algorithm] [token-class] [round] [timestamp] [length] [newline] | [entry-header] ::= [digest-algorithm] [whitespace] [ims] [whitespace] [token-class] [whitespace] [round] [whitespace] [timestamp] [whitespace] [length] [whitespace] [newline] | ||
[identifier-list] ::= [file-identifier] [newline]| [identifier-list] | [identifier-list] ::= [file-identifier] [newline]| [identifier-list] | ||
[proof] ::= | [proof-list] ::= [proof] [newline]| [proof-list] | ||
[proof] ::= [proof-element] | [proof-element] ':' [proof] | |||
[proof-element] ::= [digest] | X | |||
</pre> | </pre> | ||
| Line 19: | Line 21: | ||
* digest-algorithm - from IMS token result, algorithm used to calculate hash tree. | * digest-algorithm - from IMS token result, algorithm used to calculate hash tree. | ||
* token-class - from IMS token result, name of token service on IMS which issued this token | * token-class - from IMS token result, name of token service on IMS which issued this token | ||
* timestamp - from IMS token result, timestamp token was issues | * timestamp[1] - from IMS token result, timestamp token was issues | ||
* length - length of entry starting after newline containing identifiers and proof. Users should be able to seek(length) and be positioned at the next token-entry | * length - length of entry starting after newline containing identifiers and proof. Users should be able to seek(length) and be positioned at the next token-entry | ||
* file identifier - url, unix pathname, windows structure, PURL, which an external system may refer to this file as. When packaging token stores for inclusion in a zip or tar-like package, the identifier should the path to the file relative to the token store. | * file identifier - url, unix pathname, windows structure, PURL, which an external system may refer to this file as. When packaging token stores for inclusion in a zip or tar-like package, the identifier should the path to the file relative to the token store. | ||
* digest - hex-encoded proof element digest, length is dictated by the specified digest algorithm. | |||
Sample Entry | Sample Entry | ||
<pre> | <pre> | ||
SHA-256 SHA-256-0 953886 2009-04-28T11:18:49.570-0400 | SHA-256 ims.umiacs.umd.edu SHA-256-0 953886 2009-04-28T11:18:49.570-0400 316 | ||
/fatcat.jpg | /fatcat.jpg | ||
http://www.myserver.com/fatcat.jpg | http://www.myserver.com/fatcat.jpg | ||
2770181de2b2a2ecf1de4c6c472401fcc8798f7542025764f94de1b99492e258:X | |||
08c5fe43499eeaa3426d4b5c31524393b01209796014cab00c7591fe8497a49b:X | |||
X:61c97995995935e60aa5bdeeff3a0ebb16cf1b694f03a0bfb991ac6bc15321d7 | |||
aa91ea42b4e4b850275ce8d0ebcca74a1d4dde6f1731bcb61adc1bd8d7e8302b:X | |||
</pre> | </pre> | ||
Please note, the timestamp is just for metadata purposes and should be considered trusted as it is not cryptographically linked to the proof. ACE only allows time assertions against a witness value. | The above sample shows a token generated using the SHA-256 hash algorithm, generated by the | ||
[1] Please note, the timestamp is just for metadata purposes and should be considered trusted as it is not cryptographically linked to the proof. ACE only allows time assertions against a witness value. | |||
Revision as of 20:25, 8 December 2010
Several versions of the ACE token store format exist to allow the export and interchange of tokens between the ACE Audit Manager and command line tools.
- UNDER DEVELOPMENT*
The token store serves two purposes, first it stores a list of tokens which can used to certify the integrity of an object. Second it stores linking information that links some external identifier to a token. While the token issued by an IMS contains a name used by token requesters in order to identify token responses, this may not be adequate to identify token/file pairing as files move between systems.
The proposed format is based on a modification of the arc file format.
[token-store] ::= [token-entry] | [token-store] [token-entry] ::= [entry-header] [identifier-list] [newline] [proof-list] [entry-header] ::= [digest-algorithm] [whitespace] [ims] [whitespace] [token-class] [whitespace] [round] [whitespace] [timestamp] [whitespace] [length] [whitespace] [newline] [identifier-list] ::= [file-identifier] [newline]| [identifier-list] [proof-list] ::= [proof] [newline]| [proof-list] [proof] ::= [proof-element] | [proof-element] ':' [proof] [proof-element] ::= [digest] | X
- newline - carriage return \n
- round - from IMS token result, round number in which this token was generated
- digest-algorithm - from IMS token result, algorithm used to calculate hash tree.
- token-class - from IMS token result, name of token service on IMS which issued this token
- timestamp[1] - from IMS token result, timestamp token was issues
- length - length of entry starting after newline containing identifiers and proof. Users should be able to seek(length) and be positioned at the next token-entry
- file identifier - url, unix pathname, windows structure, PURL, which an external system may refer to this file as. When packaging token stores for inclusion in a zip or tar-like package, the identifier should the path to the file relative to the token store.
- digest - hex-encoded proof element digest, length is dictated by the specified digest algorithm.
Sample Entry
SHA-256 ims.umiacs.umd.edu SHA-256-0 953886 2009-04-28T11:18:49.570-0400 316 /fatcat.jpg http://www.myserver.com/fatcat.jpg 2770181de2b2a2ecf1de4c6c472401fcc8798f7542025764f94de1b99492e258:X 08c5fe43499eeaa3426d4b5c31524393b01209796014cab00c7591fe8497a49b:X X:61c97995995935e60aa5bdeeff3a0ebb16cf1b694f03a0bfb991ac6bc15321d7 aa91ea42b4e4b850275ce8d0ebcca74a1d4dde6f1731bcb61adc1bd8d7e8302b:X
The above sample shows a token generated using the SHA-256 hash algorithm, generated by the
[1] Please note, the timestamp is just for metadata purposes and should be considered trusted as it is not cryptographically linked to the proof. ACE only allows time assertions against a witness value.
