Opera Information

From IDNwiki

[edit] Opera Browser IDN Support

Opera have supported IDNA since v7.20.

Since introducing this feature several security restrictions have been added in order to reduce the spoofing potential made possible by combining various scripts in the name or by using special characters or sequences that are visually similar to syntax elements in URLs.

Depending on the severity, a name can be presented to the user as an A-Label, not a U-Label, or access to the IRI is forbidden and an error message displayed (the URI of the error page is changed to a safe name on the form opera:illegal-url).

[edit] Fatal Errors

Several ranges of codepoints have been added to the forbidden list because they are visually similar to characters with special meaning in URIs, or because they can be used to mislead the user.

These characers will not be permitted in a URI, and the URI is changed to the form opera:illegal-url-1 and an error page is displayed to the user.

[edit] Non-fatal Errors

These rules, based on the Unicode IDN recommendations, include:

• Mixing characters from the Latin, Cyrillic, Greek and Cherokee scripts are not permitted
• Using combining characters are not permitted (Such characters are used in the Tamil and Hebrew labels)

If a problem with one of these rules is detected the user will not see a U-Label version of the name, only the A-Label.

[edit] TLD Whitelisting

The above non-fatal restrictions can be disabled for specific TLDs by updating the IDNA Whitelist preference [opera:config#Network|IDNAWhiteList opera:config#Network|IDNAWhiteList]. This preference uses the following syntax:

• A colon (":") separated list of TLD labels, in A-Label form, with a leading and trailing ":", e.g. ":no:de:". IDN names that are registered in the TLDs listed will be displayed as U-Labels, without checking the non-fatal rules.
• If the first character in the preference is "~" and followed by the colon separated list as described above, the list becomes a blacklist, and names registered in the TLDs listed are displayed as A-Labels to the user if name does not follow the non-fatal rules.
• No items or just "::" means all labels will be displayed as A-Labels
• If the preference is ":*:" all labels are presented as U-Labels

This preference is updated weekly from Opera's update server when the new version check is enabled, and the update removes all user entered changes. To disable, set [opera:config#UserPrefs|CheckForNewOpera opera:config#UserPrefs|CheckForNewOpera] to 0)

[edit] Automatic TLD whitelist update

The list of IDN test TLDs as of October 10, 2007 are being distributed automatically to all Opera installations in the weekly updates. To force an update go to the Help menu and select "Check for Updates". A restart may be needed before the update take full effect.