![Subject Alt Names on Firefox 90 screenshot](https://upload.wikimedia.org/wikipedia/commons/7/75/Subject_Alt_Names_on_Firefox_90_screenshot.png)
Subject Alternative Name (SAN) is an
extension
Extension, extend or extended may refer to:
Mathematics
Logic or set theory
* Axiom of extensionality
* Extensible cardinal
* Extension (model theory)
* Extension (predicate logic), the set of tuples of values that satisfy the predicate
* E ...
to
X.509
In cryptography, X.509 is an International Telecommunication Union (ITU) standard defining the format of public key certificates. X.509 certificates are used in many Internet protocols, including TLS/SSL, which is the basis for HTTPS, the secu ...
that allows various values to be associated with a security certificate using a
subjectAltName
field. These values are called ''Subject Alternative Names'' (SANs). Names include:
[: 4.2.1.6. Subject Alternative Name]
*
Email addresses
An email address identifies an email box to which messages are delivered. While early messaging systems used a variety of formats for addressing, today, email addresses follow a set of specific rules originally standardized by the Internet Engineer ...
*
IP address
An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...
es
*
URI Uri may refer to:
Places
* Canton of Uri, a canton in Switzerland
* Úri, a village and commune in Hungary
* Uri, Iran, a village in East Azerbaijan Province
* Uri, Jammu and Kashmir, a town in India
* Uri (island), an island off Malakula Islan ...
s
*
DNS name
The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned t ...
s: this is usually also provided as the Common Name
RDN within the Subject field of the main certificate.
* Directory names: alternative
Distinguished Names to that given in the Subject.
* Other names, given as a ''General Name'' or ''Universal Principal Name'': a registered
object identifier
In computing, object identifiers or OIDs are an identifier mechanism standardized by the International Telecommunication Union (ITU) and ISO/IEC for naming any object, concept, or "thing" with a globally unambiguous persistent name.
Syntax and le ...
followed by a value.
(May 2000) specifies Subject Alternative Names as the preferred method of adding DNS names to certificates, deprecating the previous method of putting DNS names in the
commonName
field.
Google Chrome
Google Chrome is a cross-platform web browser developed by Google. It was first released in 2008 for Microsoft Windows, built with free software components from Apple WebKit and Mozilla Firefox. Versions were later released for Linux, macOS ...
version 58 (March 2017) removed support for checking the
commonName
field at all, instead only looking at the SANs.
See also
*
Wildcard certificate
In computer networking, a wildcard certificate is a public key certificate which can be used with multiple subdomain, sub-domains of a domain. The principal use is for securing web sites with HTTPS, but there are also applications in many other ...
References
Public-key cryptography
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