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# SecTrustSettingsKeyUsage

Allowed uses for the encryption key in a certificate.

```
struct SecTrustSettingsKeyUsage
```

## Topics

### Initializers

[`init(rawValue:)`](/documentation/Security/SecTrustSettingsKeyUsage/init(rawValue:))

Initializes a trust settings key usage structure.

### Constants

[`useSignature`](/documentation/Security/SecTrustSettingsKeyUsage/useSignature)

The key can be used to sign data or verify a signature.

[`useEnDecryptData`](/documentation/Security/SecTrustSettingsKeyUsage/useEnDecryptData)

The key can be used to encrypt or decrypt data.

[`useEnDecryptKey`](/documentation/Security/SecTrustSettingsKeyUsage/useEnDecryptKey)

The key can be used to encrypt or decrypt (wrap or unwrap) a key.

[`useSignCert`](/documentation/Security/SecTrustSettingsKeyUsage/useSignCert)

The key can be used to sign a certificate or verify a signature.

[`useSignRevocation`](/documentation/Security/SecTrustSettingsKeyUsage/useSignRevocation)

The key can be used to sign an OCSP (online certificate status protocol) message or CRL (certificate verification list), or to verify a signature.

[`useKeyExchange`](/documentation/Security/SecTrustSettingsKeyUsage/useKeyExchange)

The key is a private key that has been shared using a key exchange protocol, such as Diffie-Hellman key exchange.

[`useAny`](/documentation/Security/SecTrustSettingsKeyUsage/useAny)

The key can be used for any purpose.


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