Ed2k URI scheme: Difference between revisions

Revision as of 04:07, 25 May 2021

Revision as of 03:08, 21 November 2022

Line 12:

Like other URI protocols, web browsers can be configured to automatically handle ed2k URIs. After installing an [[Comparison of eDonkey software|eD2k client]], the eD2k protocol is optionally registered so that clicking on it in the browser automatically starts the download or asks whether the user wants to start downloading.

== File link format ==ccccccc

File links are preceded with the "file" token, which indicates that this is a file link, as opposed to a <code>server</code>, <code>serverlist</code>, <code>nodelist</code> or <code>friend</code> link. The typical eD2k file link also includes the [[filename]] and the file size. An example (a link to the 15&nbsp;MB Purist Edit trailer) is provided below:

Line 27:

The eD2k hash function is a [[hash list|root hash]] of a list of [[MD4]] [[hash function|hashes]]. It gives a different result than a simple usage of the MD4 algorithm.

The file data is divided into full ''chunks'' of 9500 KiB (9728000 bytes) plus a remainder chunk, and a separate 128-bit MD4 checksum is computed for each. If the file is greater thanthancc 9500 KiB (which means that there is more than one chunk), the eD2k hash is computed by concatenating the chunks' MD4 checksums in order and hashing the result again using MD4. Otherwise, the MD4 hash of the only chunk of the file is used with no further modifications.<ref>emule source, method <code>CKnownFile::CreateFromFile</code>.</ref>

This method of hashing allows the recipient to verify that a hash list corresponds to an original eD2k file hash, without the need to actually have the file present on disk.