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Appendix A: System Functions
Cert_ID
Similar to AsymKey_ID, this returns an ID that relates to the name of a certificate name. The syntax is
simple:
Cert_ID(‘’)
You must have permissions to the certificate in question to use this function.
CertProperty
Allows you to fetch various properties of a given certificate (as identified by the certificate’s ID). Valid
properties include the start date, expiration date, certificate issuer’s name, serial number, security ID
(the “SID,” which can also be returned as a string), and the subject of the certificate (who or what is
being certified). The syntax looks like this:
CertProperty ( ,
'' | '' | '' | '' | '' | '' | '' )
The data type returned will vary depending on the specific property you’re looking for (datetime,
nvarchar, or varbinary as appropriate).
DecryptByAsmKey
As you can imagine by the name, this one decrypts a chunk of data utilizing an asymmetric key. It
requires the key (by ID), the encrypted data (either as a literal string or a string coercible variable), and
the password used to encrypt the asymmetric key (if one was used when the key was created). The
syntax is straightforward enough:
DecryptByAsymKey(, {‘’|}
[, ‘’])
Keep in mind that, if a password was utilized when creating the asymmetric key, the same password is
going to be required to properly decrypt data utilizing that key.
DecryptByCert
600
This is basically the same as DecryptByAsmKey, except that it expects a certificate rather than an asymmetric
key. Like DecryptByAsmKey, this one decrypts a chunk of data utilizing a key. It requires the certificate
(by ID), the encrypted data (either as a literal string or a string coercible variable), and the password used
to further encrypt the data (if one was used). The syntax looks almost just like DecryptByAsymKey:
DecryptByCert(, {‘’|}
[, ‘’])
Again, any password utilized when encrypting the data will be needed to properly decrypt it.