Wildcard EV certificates supported by major browsers

Extended Validation, or EV, certificates are designed to provide evidence of a greater level of verification by the Certificate Authority of the legal identity of the company in control of the SSL certificate and domain name. By way of contrast, the most common type of certificate, domain-validated, only requires the CA to verify control of the domain name. Browsers display EV-specific cues within the user interface to highlight this additional verification: most notably, the company name is displayed in the address bar, often with a green padlock or a green bar.

An Extended Validation certificate for login.live.com in Google Chrome

EV certificates are subject to additional requirements, over and above those specified in the Baseline Requirements. As with the Baseline Requirements, the EV guidelines were drawn up by the CA/B forum, an industry group of both browser vendors and CAs. The EV guidelines prohibit EV certificates from using wildcards (i.e. www.example.com, mail.example.com, and paypal.example.com would all match *.example.com) and explicitly mention this restriction twice "Wildcard certificates are not allowed for EV Certificates".

Nevertheless, Verizon Business has chosen to test browsers' approach to wildcard EV certificates by issuing a certificate to Accenture for *.cclearning.accenture.com. Verizon Business — which is not a member of the CA/B forum — is known for its maverick approach to certificate issuance having issued certificates (including EV certificates) which violate the Baseline Requirements.

Despite the EV guidelines prohibiting wildcard EV certificate issuance, presently most major browsers fail to enforce this restriction. Google Chrome, Firefox, Internet Explorer, Opera, and Safari (Desktop) all retain the EV browser cues when visiting a website using this EV certificate.

Clockwise from top left: Google Chrome, Internet Explorer, Opera, and Firefox. All display the conventional EV browser cues.

The only exception was Safari — Desktop Safari displays the EV browser cues as normal, as do the remainder of the desktop browsers; however, Safari on iOS 7 does not display the EV UI.

Safari (Desktop)

Safari on iOS 7 does not display the conventional EV UI for the wildcard EV certificate. An example of the EV UI in iOS 7.

Netcraft offers a Baseline Requirements checking service for CAs to provide third-party verification of Baseline Requirements conformance. For more information contact sales@netcraft.com

Certificate Authorities struggle to comply with Baseline Requirements

SSL Certificate Authorities (CAs) are responsible for issuing the SSL certificates which are used to protect billions of secure transactions across the internet against eavesdroppers and impersonators. The CA/B forum — a group of CAs and browser vendors — drew up the Baseline Requirements in 2011 outlining a set of minimum standards to which all CAs should operate.

Since the "effective date" of the document, 1st July 2012, compliance with the Baseline Requirements has been mixed — Netcraft has previously discovered non-compliant certificates, including short RSA public keys and irrevocable certificates. More than a year on and several months after Mozilla incorporated the Baseline Requirements into its CA policy (albeit with a transition period allowed) CAs are still issuing non-compliant certificates.

By examining the certificates found in Netcraft's SSL Survey and evaluating them against a small subset of rules extracted from the Baseline Requirements document, Netcraft found more than 2,500 non-compliant certificates. The non-complaint certificates fall into one or more of the categories described below: some of the problems are serious security vulnerabilities, and others are less critical but are still violations of the Baseline Requirements.

  • Short RSA public key — the shorter a public key is; the easier it is for an attacker (such as the NSA) to brute-force the secret private key, and hence decrypt communication. NIST recommended that certificates should not use RSA public keys shorter than 2048 bits after December 2013 and the CA/B forum imposes the same rule.
  • Missing OCSP URL — OCSP is one of the two available revocation mechanisms available to CAs to disable the certificate after it has been issued. As web-browser support for certificate revocation varies, non-EV certificates without an OCSP URL are effectively irrevocable in Firefox. Without the ability to revoke certificates, if the certificate were ever to be compromised — by criminals or government agencies — it could be used for up to five years. The Baseline Requirements do allow certificates to omit the OCSP URL if and only if they are used on "high traffic" websites and the website staples the OCSP response to the TLS handshake — none of the websites with missing OCSP URLs highlighted here did so.
  • SAN extension — the Baseline Requirements document discourages the use of the Subject Common Name field to contain the hostname for which the certificate is valid. Instead, the Subject Alternative Name extension should be used and it must contain at least one record. Additionally, any hostname in the Subject CN field must also be duplicated in the SAN extension — a multi-domain certificate intended for www1.example.com and www2.example.com must contain both in the SAN extension and at most one in the Subject CN (for backwards compatibility).
  • Validity Period — as of the effective date, the Baseline Requirements limit the maximum validity period of a certificate to 5 years (60 months). Whilst exceeding this validity period constraint isn't itself a security problem it slows downs the pace of change within the industry — with a shorter maximum validity period, browsers can rely on legacy behaviour disappearing and can remove insecure functionality more rapidly.

A short key warning for a 512-bit certificate in Google Chrome. This type of warning is proposed to be applied to certificates violating the maximum validity period.

Several large CAs have issued non-compliant certificates since July 2013, a year after the original deadline, including Symantec, Go Daddy, and Verizon Business.

  • Symantec — a BMW certificate issued by TC Trust Center (a Symantec company) is missing an OCSP URL and does not include a stapled OCSP response, making it irrevocable in Firefox. An SSL certificate used for online banking was issued by VeriSign on August 2nd 2013 without the required SAN extension.
  • Verizon Business — a certificate issued by Etisalat (a UAE-based telecoms provider which operates a Verizon Business signed sub-CA) for ADCO, an onshore oil drilling company, violates a number of Baseline Requirements: it has a short RSA key valid after 31st December 2013, it has no OCSP URL and it does not have the mandatory SAN extension. Etisalat has previously been associated with SSL interception. Cybertrust, operated directly by Verizon Business, has also issued more than its fair share of non-compliant certificates including certificates belonging to Target [Short Key, no OCSP URL], the US Dept. for Homeland Security [no SAN, no OCSP URL], and American Express [an EV certificate without an OCSP URL!]. A number of other sub-CAs signed by Verizon Business have issued non-compliant certificates including Microsoft [missing SAN, no OCSP URL] and Vodafone [missing SAN].
  • SwissSign — Nestlé, a customer of SwissSign with its own intermediate certificate, has issued non-compliant certificates including: those missing SAN records and OCSP URLs.
  • Go Daddy — a significant number of Go Daddy certificates exceed the maximum permitted validity period of 5 years. These certificates are likely "re-issued" (the meaning of which is debated by Google, see below) and otherwise do not obviously violate the Baseline Requirements. Go Daddy have proposed a modification to the Baseline Requirements to allow such re-issued certificates to be exempt from maximum validity period constraints.

Google Chrome, in the first quarter of 2014, will reject all certificates issued after the effective date, 1st July 2012, which violate the maximum validity period (60 months). A number of CAs have issued such certificates, often as part of a re-issuance process, which Google deems to be non-compliant with the Baseline Requirements.

In the September 2013 SSL Survey, using the criteria from the proposed Google Chrome patch, Netcraft found 3,243 certificates which will be considered invalid in Google Chrome as a result of this change. Go Daddy issued over three-quarters of these certificates (2,498) and Comodo also issued a significant number (606). The longest-lived non-compliant certificate issued by a member of the CA/B Forum and discovered by the SSL Survey has a validity period of over 82 months.

Furthermore, Google's technical enforcement is set to get tougher: Ryan Sleevi has stated that certificates with short public keys – that is, RSA public keys shorter than 2048 bits expiring after 31st December 2013 are “next up” on Google’s list. Google's proposal to use the original July 2012 date as a threshold for enforcement isn't popular with some of the CAs in the CA/B forum: GlobalSign and Comodo have argued that such technical constraints should only be enforced for certificates issued after the announcement.

Despite Google's aggressive stance, many of Google's own certificates did not comply with some of the Baseline Requirements: in the September 2013 Netcraft SSL survey, almost 500 Google certificates did not contain a URL to an OCSP responder or include a stapled OCSP response (making the certificates irrevocable in Firefox). Since the survey ran in mid-August, a large number of Google's certificates have been replaced and now contain an OCSP URL, but a few non-compliant certificates are still in use including one on Zagat.com. The Zagat.com certificate also has an incomplete SAN record (it does not contain the hostname from the Subject Common Name field).


[Read this article in English]






Metric Sep 2012 Mar 2013 Jun 2013 Jul 2013 Aug 2013 Sep 2013
Hostnames 91,553 205,824 382,342 381,989 368,948 389,171
Active sites 23,596 55,654 119,089 116,835 146,310 150,089
Web-facing computers 2,670 8,038 15,931 16,846 17,670 17,934

Detailed view of Aliyun in terms of hostnames (web sites), active sites, and web-facing computers.



TLD share by domains of websites at Aliyun in September 2013



  • 和最廉价的外国云主机提供商相比,中国云主机提供商在价格和操作系统等配置选择的多样性上都没有优势。以阿里云为例,除非选择2核或4核的CPU,否则按量付费的云主机不支持Windows操作系统,而且其价格也不比那些更成熟的竞争对手便宜。最廉价的按量付费的阿里云主机为单核CPU,512M内存,1Mbps带宽,价格每小时0.27元(约合0.04美金),几乎是亚马逊最便宜的云主机价格的两倍,而配置相近的DigitalOcean云主机的价格仅为每小时0.007美金。但是,由于定价模式的差异,包年包月的阿里云主机在某些情况下会比包年包月的亚马逊或DigitalOcean更便宜。
  • 从海外访问中国境内的网站有时不够顺畅 - 从英国发送到阿里云官方网站的数据包往返几乎要耗时半秒钟,而从美国访问的效果也没有好很多。在过去20天,有多达4%的来自荷兰的访问请求都以失败告终。

  • Performance of www.aliyun.com from a Netcraft performance collector located in the Netherlands

  • 很多中国主机服务提供商只支持中文。以阿里云为例,无论是官方网站、控制面板还是技术支持,中文都是其唯一的语言。不过,亚马逊云对中文的支持也几乎一样有限 - 只有首页有中文版。
  • 有些中国主机服务提供商只面向中国客户。例如:申请使用阿里云服务的用户必须要有一个中国的手机号来接收验证码以完成注册。按量付费的用户必须通过身份验证,而只有中国或个别亚太地区国家的公民或者中国的企业可以做这样的验证。想使用阿里云服务的客户还必须有一张与支付宝兼容的中国的银行卡。如果服务器需要通过域名访问,那么还必须在工信部备案,而这样的备案并不向外国企业开放。


Netcraft提供国际互联网基础设施方面的信息,包括主机服务提供商、网页技术等等。想了解更多关于云计算行业的信息,请访问 http://www.netcraft.com/internet-data-mining/

Building the Great Cloud of China


China, the world's largest trading nation in 2012, has long been a desirable location for outsourcing labour and services, even within the technology and IT sector where it is not far behind India. The growth of cloud computing providers in Europe and the United States — particularly Amazon and DigitalOcean — may foretell cloud computing infrastructure becoming a commodity and outsourced to the cheapest provider.

The ever-increasing number of internet users in China (591 million at the end of June 2013) requires the development of home-grown internet infrastructure: hosting web applications and other content within a target user's own country typically speeds up requests and improves reliability. The number of internet users in China is greater than either the United States or Europe.

Stratospheric growth in Chinese cloud hosting

Although the number of web-facing computers in China has grown by 8.3% over the last year — the majority of this growth has occurred within the cloud hosting market. Aliyun (云, pronounced 'yun', is the Chinese word for cloud) is the largest cloud computing provider in China in terms of the number of web-facing computers, and remarkably, Aliyun now has six times more web-facing computers than it did a year ago, reaching a total of 17,934 in September 2013. Worldwide, only the cloud computing giant Amazon gained a greater number of web-facing computers.

Although China's cloud computing infrastructure is still in its infancy, Aliyun's future looks particularly promising, as it is owned by the Alibaba Group. This group is the largest hosting provider in China, features within the top 30 hosting providers worldwide, and has already established a strong internet presence with its better known e-commerce platforms, Taobao and Alibaba.com. Aliyun now makes up almost 92% of the web-facing computers at Alibaba Group.

Metric Sep 2012 Mar 2013 Jun 2013 Jul 2013 Aug 2013 Sep 2013
Hostnames 91,553 205,824 382,342 381,989 368,948 389,171
Active sites 23,596 55,654 119,089 116,835 146,310 150,089
Web-facing computers 2,670 8,038 15,931 16,846 17,670 17,934

Detailed view of Aliyun in terms of hostnames (web sites), active sites, and web-facing computers.

Indigenous market and the Great Firewall of China

Despite the strong growth of the Chinese cloud hosting market, most of the growth seen by Netcraft is hosting sites aimed at the Chinese market. Hosting content as close to the end-users as possible increases the performance of the web site, and this effect is particularly prominent in China: internet traffic crossing the border can sometimes appear to be slow, unstable, or even blocked, perhaps as a side-effect of blocks enforced by the Golden Shield Project (also known as the Great Firewall of China). In September 2013, more than half of the domains of websites hosted at Aliyun were in the .cn TLD, around 41% in .com, whilst domains in other ccTLDs appeared to be very rare. Unlike Amazon's global reach, Aliyun's reach appears to be limited to the local market — at least for the time being.

TLD share by domains of websites at Aliyun in September 2013

Obstacles holding back the Chinese cloud

Using cloud hosting in China could make sense for non-Chinese companies looking to increase their presence in China; however, a number of obstacles remain. These explain why the Chinese cloud is still mostly indigenous, and is likely to remain so for some time:

  • Neither the pricing models nor the variety or operating systems are as attractive as those offered by the cheapest non-Chinese cloud hosting companies. Taking Aliyun as an example, its on-demand instances do not support Windows operating systems unless you opt for a 2-core or 4-core CPU, and they are not significantly cheaper than its more established competitors. The cheapest on-demand option at Aliyun is ¥0.27 ($0.04) per hour which buys you a single core, 512MB of RAM, and a 1Mbps internet connection. This is almost twice the price of Amazon's cheapest option and a comparable DigitalOcean instance can be had for just $0.007 per hour. However, as pricing models vary, reserved instances at Aliyun can be cheaper in some circumstances.
  • Internet connectivity from outside China can be patchy — packets sent to www.aliyun.com from the United Kingdom take almost half a second to make the journey and back again, and the performance in the United States is not much better. More than 4% of requests to www.aliyun.com from the Netherlands failed during the past 20 days.

  • Performance of www.aliyun.com from a Netcraft performance collector located in the Netherlands

  • Many Chinese hosting services are only available in the Chinese language. This is the only language available for Aliyun's brochure website, control panel, and technical support. However, Amazon's support for the Chinese language is almost as limited — a single marketing site appears to be the sole Chinese-language site for AWS.
  • Some Chinese hosting companies only accept business from Chinese customers. For example, Aliyun's customers are required to have a Chinese mobile phone number in order to receive a verification code to complete the signup process. Customers wishing to buy an on-demand instance at Aliyun must go through an identity verification process, which requires the registrant to be a national of China or one of a few other Asia-Pacific countries, or to represent a Chinese company. Customers must also hold a credit or debit card issued by a Chinese bank compatible with Alipay. Customers must also register with the Chinese Ministry of Industry and Information Technology if they wish to associate a domain name with an Aliyun cloud server, but such registration is currently unavailable to foreign enterprises.

The current obstacles suggest that the cloud is unlikely to be outsourced to China yet. However, the availability of cloud computers in China is likely to increase to match its rapidly increasing local demand with competition both from local providers like Aliyun and overseas players like Microsoft and Amazon. Microsoft has collaborated with a partner company in China, 21Vianet, in order to bring its Cloud to China, and is making competitive price plans customised for the Chinese market. Perhaps by following this model, other non-Chinese companies such as Amazon could enter the Chinese market, providing local data centres and support to Chinese-speaking customers within the stricter regulatory environment. Equally, if some red tape were cut and network connectivity improved, Aliyun and other Chinese cloud providers could be poised to take a larger share of the global cloud computing market.

Netcraft provides information on the internet's infrastructure, including the hosting industry and web content technologies. For information on the cloud computing industry, please see http://www.netcraft.com/internet-data-mining/.

Perfect Forward Secrecy in the Netcraft Extension

Netcraft has added a Perfect Forward Secrecy (PFS) indicator to the Netcraft Extension for Firefox, Chrome and Opera. This lets users see which websites would allow encrypted traffic to be decrypted en mass at a later date if the site's private key were to be compromised — a danger previously highlighted by Netcraft in June.

PFS, when implemented correctly, ensures that if the long-term private key of a site served over SSL is compromised, historical encrypted traffic cannot be decrypted in bulk. Instead, an eavesdropper would have to break each individual connection independently, which would be incredibly time consuming.

With the recent revelations from Edward Snowden that the NSA is able to read encrypted internet traffic, PFS support is very desirable for privacy-conscious internet users, particularly in countries that also have key disclosure laws.

Currently, most of the major web browsers make it difficult to tell whether or not a website supports PFS. For example, Chrome, Opera 15, and Internet Explorer display information about the current cipher suite in a pop-up, but checking for PFS support relies on in-depth knowledge. Firefox and Opera 12 display part of the cipher suite in their user interfaces; however, they crucially lack the key exchange mechanism, which means it is not possible for the user to tell whether the site supports PFS. Safari fares the worst, as it does not display any information at all about the current cipher suite.

The Netcraft Extension — which blocks phishing attacks and displays metadata about visited websites — now clearly indicates whether the site you are visiting supports PFS. This is displayed in the user interface as a green tick if the site supports PFS, and a red cross if it does not. In addition, in both Chrome and Opera, a small indicator is displayed beside the Netcraft badge when visiting an SSL site which does not support PFS.

The following screenshots show the PFS indicator in the Netcraft Extension when visiting the DuckDuckGo search engine, which enabled the use of PFS cipher suites after the lack of PFS was highlighted in Netcraft's previous analysis of PFS support.

PFS indicator in the Netcraft Extension for Google Chrome™
(The Opera version looks similar)

PFS indicator in the Netcraft Extension for Firefox

The Netcraft Extension is available for Firefox, Chrome and Opera, and can be downloaded from toolbar.netcraft.com. More information about the PFS indicator can be found on the Netcraft Extension FAQ page.

Note: The new version of the Firefox extension is currently awaiting approval from Mozilla; however, it can be manually installed from the version history page by selecting version 1.8.1.

Deceptive domain and SSL certificate issued by Network Solutions

Network Solutions allowed a fraudster to register a deceptive domain name earlier this week: secure-chaseonline.com. Network Solutions also issued a valid SSL certificate for the domain, which was used for a phishing attack which targeted customers of Chase Bank.

Phishing attack targeting Chase bank on secure-chaseonline.com

The phishing site added further credibility to the attack by using an encrypted HTTPS connection. The fraudster obtained a domain-validated SSL certificate from Network Solutions, and, as with the domain, it was valid for one year from 3rd September 2013.

The SSL certificate used on secure-chaseonline.com

Although opportunities were missed to prevent the suspicious domain name being registered and the corresponding SSL certificate being issued, the certificate used by the site does at least support OCSP, which can allow the issuer to instantly revoke the certificate. However, the efficacy of this mechanism largely depends on which browser the victim is using, and how it has been configured. For example, Firefox — which does performs OCSP checks by default — will only display content from https://secure-chaseonline.com if the certificate has not been revoked. Google Chrome, on the other hand, does not perform such checks by default (for non-EV certificates).

However, as Network Solutions was also the registrar of the domain, it would have been more effective to simply suspend the domain, which is what appears to have happened yesterday:

>>> Last update of whois database: Thu, 05 Sep 2013 12:56:58 UTC <<<

The fraudulent SSL certificate was later revoked — the certificate's serial number can be found on Network Solutions' certificate revocation list at http://crl.netsolssl.com/NetworkSolutionsDVServerCA.crl

The CA/Browser Forum's Baseline Requirements for the Issuance and Management of Publicly-Trusted Certificates [PDF] says that certificate authorities SHALL subject high risk requests — which includes names at high risk of being used in a phishing attack — to further scrutiny prior to issuance. Netcraft's Domain Registration Risk service is ideal for both domain registrars and certificate authorities, as it judges the likelihood of a new domain being used for fraudulent activities. It identifies domains which are deceptively similar to legitimate websites run by banks and other institutions that are commonly targeted by phishing attackers.

While some phishing attacks can be identified prior to domain registration or SSL certificate issuance (such as the one described above), a significant proportion of phishing attacks make use of compromised web sites (often exploiting vulnerabilities in commonly deployed software platforms, such as WordPress). Netcraft can alert registries, SSL certificate authorities, or registrars and hosting companies of phishing sites discovered using their infrastructure to conduct a phishing attack.

Please get in touch (sales@netcraft.com) if you would like to try out this service or for subscription information.