New in Kestrel: End of the Extended (Validation) wait
Tuesday, April 8, 2008 3:54:39 PM
As I've written before, Extended Validation is a new way to indicate, in a Web site certificate, that the identity of the company behind the Web site has been verified according to a rigorous standard. The guidelines for this process is defined by the CA/Browser forum, which is a group consisting of many certificate issuers (CAs), browser vendors, and others.
We are now ready to start public alpha testing.
So, how does it work?
When a Web site is recognized as an EV site, Opera will change the background color of the security toolbar to green, instead of yellow as it is for normal secure Web sites. There will be a few further adjustments done in this area, the most major being that we have stopped displaying the Organization Name field and country in the security toolbar for non-EV sites, because this name might not have been properly verified for non-EV certificates.
What is required to be permitted to issue EV certificates?
Root CAs that want to issue EV certificates must first pass a rigorous audit to prove that they have the proper procedures in place to identify accurately the company requesting a certificate, and that this company is in control of the given server. Further, an agreement between the Root CA and the browser vendor is required before the browser can recognize the CA's certificates as EV certificates.
How does Opera know it is an EV certificate?
All EV certificates contain an identifier (called an EV-OID, actually a Certificate Policy identifier). The CA will insert this identifier when it has verified all the information. Only certificates issued from specific Roots are allowed to use these identifiers.
How does Opera know that a Root is allowed to issue EV certificates?
Each Opera instance will regularly download a digitally-signed list identifying the CA, its certificate, and which EV-OID(s) it is permitted to use (different CAs can use different EV-OIDs). When Opera verifies a certificate issued from this Root, it will "sift" through the data where the EV-OIDs are stored to see if it contains one of the EV-OIDs recognized for this Root. If such an EV-OID is present, Opera will proceed to check if the other requirements (see below) for saying the Web site is an EV site are fulfilled.
What is required by a Web site to be considered an EV site?
The primary requirement is, of course, that it is eligible to get an EV certificate, and that it has purchased and installed one. The certificate, and all the intermediate certificates must (of course) still be valid, and cannot have been revoked by the issuer (we now check both OCSP and CRLs). Further, there must be no problems verifying the certificate; that is, there must be no unknown issuers, no mismatch of server name, and no weak encryption.
There are also a couple of specific encryption key requirements: The Web site's key should (for RSA) be at least 2048 bits long, but non-root certificates which expire before 23:59:59 UTC/GMT December 31, 2010 MAY use RSA keys of at least 1024 bits. Except for the Root key, which (for RSA) must be at least 2048 bit long, all signing keys must be at least as long as the key of the certificate it is used to sign.
And lastly, if the Web site includes content from other Web servers, those servers must *also* be hosting EV-sites. This is a point at which we are much stricter than the other EV-capable browsers currently. As I said earlier: "It ain't EV 'til it is EV, all EV".
The reason for this requirement is that these other servers may provide content that directly controls the appearance of the entire site, either through frames or external Ecmascript embedded in the page (and the latter has full control of the site's content).
Considering how many click-wrap licensed Web services (such as for Web statistics) there are, it is not likely that the Web designers signing their sites up for these services will have done anything close to good-enough legal identity check of the service. Also, don't forget all the liability disclaimers such contracts include. It is impossible to check the contracts, but we can check that the sites have been able to get an EV certificate.
EV is intended to give you better information about who provided the content with which you are viewing and interacting. If not all the servers providing the content are providing this kind of information, do you really know who provided the important part of the content? Our answer is that you don't, therefore such sites, which at the moment include Paypal.com, will not get the EV indication unless they either remove all references to the non-EV content, or those providers upgrade to provide EV content, as well.
Which Root CAs are currently recognized as issuing EV certificates?
During the test period starting with this release we have provisonally configured three Roots as EV Roots (in alphabetic order)
- Entrust's EV Root
- GlobalSign's EV Root
- VeriSign's G5 Class 3 (EV) Root
Other CAs and Roots may be added later.
About the online repository
As mentioned above, Opera retrieves information about which CAs are recognized as EV-issuers from an online repository. This repository, hosted at https://certs.opera.com/, contains a digitally-signed file listing all the EV issuers and a (separately) signed list of the EV-OIDs they are using.
This repository is refreshed every 6 hours, so we can start updating clients very quickly. At present Opera will check this repository immediately when it starts, but the final version will only check once a week at the same time as we check for other updates.
Examples of EV sites