Proxomitron 4.5

Proxomitron is a free local HTTP web-filtering proxy.

For those who have not yet been introduced, meet the Proxomitron: a free, highly flexible, user-configurable, small but very powerful, local HTTP web-filtering proxy. To become better acquainted, please see our online version of the Proxomitron Help files for a more comprehensive overview.

In SSLeay/OpenSSL mode Proxomitron decrypt incoming data, filters it, then re-encrypts it before sending it on. This allows for nearly transparent filtering and full control over https connections. This feat is accomplished using the
very nice Open Source SSLeay/OpenSSL libraries (not included - see below).

Proxomitron 4.5 -- May vs. June
Operational differences between the two Naoko 4.5 releases

The Remote Proxy "Direct Connection Fallback" Feature
The May version contains an undocumented new feature related to remote proxy connections: In the event of a connection failure with a remote proxy, Proxomitron will "fall back" to a direct connection with the requested URL.
(A warning is initiated when the connection to the remote proxy has failed, but there is no warning that Proxomitron is about to establish a direct connection with the site.)

Due to a bug, however, this behavior is not exhibited if Proxomitron is set to rotate through multiple proxies: Should connection failure occur with one of the proxies during rotation, Proxomitron will then attempt connection with the next proxy in the list. In the event that all listed proxies suffer connection failure, Proxomitron will become caught in an "infinite loop" as it continues to attempt connection with each proxy in rotation, instead of falling back to a direct connection.

The June version of 4.5 does not contain the feature to "fall back" to a direct connection, nor does it contain the "infinite loop" proxy-rotation bug.

The Merge Bug
The May release also contains a notable Merge bug: After merging an input file, the current config name displayed by Proxomitron in its title bar is changed to the name of the input file -- afterwards, when the user saves their config using the "green disk" icon, the input file is overwritten instead of the users config file. When Proxomitron is restarted, naturally the user is perplexed to find that merged filters and subsequent edits were apparently not saved.

The user can correct the problem during the bug-occurring session by using the File dropdown menus "Save Config File" and resaving to their current configs filename (which will also restore the display of the configs filename in the programs title bar) -- or, if Proxomitron was already closed and restarted, the user can Load (not Merge!) the overwritten input file and then use the File dropdown menu to save it to their usual configs filename.

To avoid problems with the Merge bug, the user should just use the dropdown menu to save the config after each Merge, not the green disk icon.
The June version of 4.5 does not contain the Merge bug.

The May versions feature to "fall back" to a direct connection should provide the user of a remote proxy (such as a caching proxy) with a direct-accessing connection in the event of proxy failure; however, this feature is impractical for use with a remote "anonymizing" proxy since the main purpose for using one is to avoid revealing the users true IP.

The June version was primarily released to resolve this issue with anonymizing proxies, which is why the fallback feature is removed from it -- but it has also been corrected for bugs found in the May version. The June version is therefore the "final" 4.5 release, while the May version remains available for those who specifically need the fallback behavior when using a single remote proxy. The May release of Naoko 4.5 is the only version of Proxomitron having this "direct connection fallback" feature.