ACM Certificate Characteristics
Certificates provided by ACM have the characteristics described on this page.
These characteristics apply only to certificates provided by ACM. They might not apply to certificates that you import into ACM.
- Domain Validation (DV)
ACM Certificates are domain validated. That is, the subject field of an ACM Certificate identifies a domain name and nothing more. Email is sent to the registered owner for each domain name in the request. The domain owner or an authorized representative can approve the certificate request by following the instructions in the email. For more information, see Validate Domain Ownership.
- Validity Period
The validity period for ACM Certificates is currently 13 months.
- Managed Renewal and Deployment
ACM manages the process of renewing ACM Certificates and provisioning the certificates after they are renewed. Automatic renewal can help you avoid downtime due to misconfigured, revoked, or expired certificates. For more information, see Managed Renewal for ACM's Amazon-Issued Certificates.
- Browser and Application Trust
ACM Certificates are trusted by all major browsers including Google Chrome, Microsoft Internet Explorer and Microsoft Edge, Mozilla Firefox, and Apple Safari. Browsers that trust ACM Certificates display a lock icon in their status bar or address bar when connected by SSL/TLS to sites that use ACM Certificates. ACM Certificates are also trusted by Java.
- Multiple Domain Names
Each ACM Certificate must include at least one fully qualified domain name (FQDN), and you can add additional names if you want. For example, when you are creating an ACM Certificate for
www.example.com, you can also add the name
www.example.netif customers can reach your site by using either name. This is also true of bare domains (also known as the zone apex or naked domains). That is, you can request an ACM Certificate for www.example.com and add the name example.com. For more information, see Request a Certificate.
- Wildcard Names
ACM allows you to use an asterisk (*) in the domain name to create an ACM Certificate containing a wildcard name that can protect several sites in the same domain. For example,
When you request a wildcard certificate, the asterisk (
*) must be in the leftmost position of the domain name and can protect only one subdomain level. For example,
test.example.com, but it cannot protect
test.login.example.com. Also note that
*.example.comprotects only the subdomains of
example.com, it does not protect the bare or apex domain (
example.com). However, you can request a certificate that protects a bare or apex domain and its subdomains by specifying multiple domain names in your request. For example, you can request a certificate that protects
Currently, ACM supports the RSA-2048 encryption and SHA-256 hashing algorithms.
Note the following:
ACM does not provide extended validation (EV) certificates or organization validation (OV) certificates.
ACM does not provide certificates for anything other than the SSL/TLS protocols.
You cannot use ACM Certificates for code signing or email encryption.
ACM allows only UTF-8 encoded ASCII for domain names, including labels that contain "xn--" (Punycode). ACM does not accept Unicode input (u-labels) for domain names.
ACM does not currently permit you to opt out of managed certificate renewal for certificates provided by ACM. Managed renewal is not available for certificates that you import into ACM.
You cannot request certificates for Amazon-owned domain names such as those ending in amazonaws.com, cloudfront.net, or elasticbeanstalk.com.
You cannot download the private key for an ACM Certificate.
You cannot associate ACM Certificates with Amazon Elastic Compute Cloud (Amazon EC2) instances.