Unified Communications Certificate (SANS UCC Certificate)
Unified Communications Certificate
-- 1. A Unified Communications Certificate (UCC) is an SSL certificate that secures multiple domain names and multiple host names within a domain name. A UCC lets you secure a primary domain name and additional Subject Alternative Names* (SANs) in a single certificate.
For example, with a UCC certificate you can secure:
-- 2. The difference between UCC and Wildcard certificate is that a wildcard certificate can protect all first-level sub-domains on an entire domain, such as *.example.com. But a wildcard cannot protect both www.example.com and www.example.org.
-- 3. How to check the Subject Alternative Names:
When we create a csr, we specify the names of the servers we would like this certificate to cover:
- /opt/zimbra/bin/zmcertmgr createcsr self -new -subjectAltNames "one.example.com,two.example.com"
Using an openssl command, we can see the names listed there:
- openssl req -text -noout -in /opt/zimbra/ssl/zimbra/server/server.csr
Data: Version: 0 (0x0) Subject: C=US, ST=N/A, L=N/A, O=Zimbra Collaboration Server, OU=Zimbra Collaboration Server, CN=one.example.com Subject Public Key Info: Public Key Algorithm: rsaEncryption Public-Key: (2048 bit) Modulus: 00:b3:f2:3c:41:3e:a6:89:34:b4:84:3f:1b:79:7f: 0c:10:c7:c1:29:4d:ab:fa:86:db:f8:7f:c5:3c:75: 1c:be:7b:3b:ea:2d:ab:58:6f:56:31:71:7d:6f:b0: e1:0a:23:5a:1c:ee:e6:56:5f:4f:68:9b:bc:54:20: 80:81:1c:9d:82:7a:fa:5c:2e:3b:bb:ca:42:5d:c3: Exponent: 65537 (0x10001) Attributes: Requested Extensions: X509v3 Basic Constraints: CA:FALSE X509v3 Key Usage: Digital Signature, Non Repudiation, Key Encipherment X509v3 Subject Alternative Name: DNS:one.domain.com, DNS:one.example.com, DNS:two.example.com Signature Algorithm: sha256WithRSAEncryption af:b4:91:8b:e5:6e:16:bd:df:ef:cc:5d:85:69:5b:dd:d2:18: 17:59:17:c7:e6:55:36:cf:2a:8c:8b:ba:2e:20:ac:c7:25:2a: 6c:b0:66:30:6f:96:ac:80:07:96:ef:6d:0c:b8:88:ab:10:50: 93:8a:a8:89:44:04:0c:78:29:93:68:cd:d2:b7:cc:b9:7f:fb:
If in doubt, the above example will hep you check the csr and possibly give you a hint.
SAN: Subject Alternative Names allow you to specify a list of host names to be protected by a single SSL certificate.