[Trans] Add get_entries_max_limit attribute to get-sth request

[Václav Jirovský <[e-mail]>]

Hello all,

I would like to propose modification Retrieve Latest Signed Tree Head section
of RFC6962 - adding new attribute *get_entries_max_limit.*

Reason for this change - 4.6 section actual version:

* Logs MAY restrict the number of entries that can be retrieved per
   "get-entries" request.  If a client requests more than the permitted
   number of entries, the log SHALL return the maximum number of entries
   permissible.  These entries SHALL be sequential beginning with the
   entry specified by "start".
*


If you want to download all entries from CT server, you don't what number
of entries will server return to you by request - so you have to process,
count real number of returned entries and after that, you can do another
request. This is not efficient, you could do these request in parallel, if
you would have garanteed number of returned entries.

*Proposed modification:*


4.3 <https://tools.ietf.org/html/rfc6962#section-4.3>.  Retrieve
Latest Signed Tree Head

GET https://<log server>/ct/v1/get-sth
No inputs.

Outputs:

      tree_size:  The size of the tree, in entries, in decimal.
      timestamp:  The timestamp, in decimal.
      sha256_root_hash:  The Merkle Tree Hash of the tree, in base64.

*      get_entries_max_limit: Maximum entries count provided by server
get-entries method.*

tree_head_signature: A TreeHeadSignature for the above data.


4.6 <https://tools.ietf.org/html/rfc6962#section-4.6>.  Retrieve
Entries from Log

GET https://<log server>/ct/v1/get-entries


Inputs:
      start:  0-based index of first entry to retrieve, in decimal.
      end:  0-based index of last entry to retrieve, in decimal.


.....


   Logs MAY restrict the number of entries that can be retrieved per
   "get-entries" request.  *If a client requests more than the permitted
   number of entries ("get_entries_max_limit" output of "get-sth" request),*

*   the log SHALL return the maximum number of entries
   permissible. If a client requests less or equal than the permitted
   number of entries ("get_entries_max_limit" output of "get-sth" request),
   the log MUST return the maximum number of entries permissible. *
   These entries SHALL be sequential beginning with the

   entry specified by "start".



Best,

Vaclav Jirovsky