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# SSLCopyDistinguishedNames(_:_:)

Retrieves the distinguished names of acceptable certification authorities.

```
func SSLCopyDistinguishedNames(_ context: SSLContext, _ names: UnsafeMutablePointer<CFArray?>) -> OSStatus
```

## Parameters

`context`

An SSL session context reference.

`names`

On return, an array of `CFDataRef` objects, each representing one DER-encoded relative distinguished name of an acceptable certification authority. You must call the `CFRelease` function to release this array when you are finished with it.

## Return Value

A result code. See [Secure Transport Result Codes](/documentation/Security/secure-transport-result-codes).

## Discussion

The list of distinguished names is provided by the server if the context reference represents a client; if the context reference represents a server, the list of distinguished names is specified with the [`SSLSetCertificateAuthorities(_:_:_:)`](/documentation/Security/SSLSetCertificateAuthorities(_:_:_:)) function.

The array retrieved by this function is suitable for use in finding a client identity (that is, a certificate and associated private key) that matches a server’s requirements.

## See Also

[`SSLSetCertificateAuthorities(_:_:_:)`](/documentation/Security/SSLSetCertificateAuthorities(_:_:_:))

Adds one or more certificates to a server’s list of certification authorities (CAs) acceptable for client authentication.

[`SSLCopyCertificateAuthorities(_:_:)`](/documentation/Security/SSLCopyCertificateAuthorities(_:_:))

Retrieves the current list of certification authorities.


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