---
title: "SecKeyCreateFromData(_:_:_:)"
framework: security
role: symbol
role_heading: Function
path: "security/seckeycreatefromdata(_:_:_:)"
---

# SecKeyCreateFromData(_:_:_:)

Constructs a SecKeyRef object for a symmetric key.

## Declaration

```swift
func SecKeyCreateFromData(_ parameters: CFDictionary, _ keyData: CFData, _ error: UnsafeMutablePointer<Unmanaged<CFError>?>?) -> SecKey?
```

## Parameters

- `parameters`: A parameter dictionary that describes the key. See the discussion for details.
- `keyData`: A CFDataRef object that contains the raw key data.
- `error`: A pointer to a doc://com.apple.documentation/documentation/CoreFoundation/CFError variable where an error object is stored upon failure. If not NULL, the caller is responsible for checking this variable and releasing the resulting object if it exists.

## Return Value

Return Value A symmetric key. In Objective-C, call the CFRelease function to free the key’s memory when you are done with it.

## Discussion

Discussion The parameters dictionary must contain (at minimum) an entry for the kSecAttrKeyType key with a value of kSecAttrKeyTypeAES or any other key type defined in Key Type Value. The keys below may be optionally set in the parameters dictionary (with a CFBooleanRef value) to override the default key usage values: kSecAttrCanEncrypt kSecAttrCanDecrypt kSecAttrCanWrap kSecAttrCanUnwrap These values default to true if no value is specified.