Quick and dirty generate, export and import EC256 Key Pair (SecKey -> base64 -> SecKey).

GenerateExportImportEC256.swift

//
// Quickly and dirty generatte EC256 Key Pair, export as base64 Data/String, and then import from base64 Data/String.
// Perfect when you need an in-memory key pair for mocks/unit testing.
//

import CryptoKit

// Generate EC256 Key Pair and export as base64 String/Data
let attributes = [
    kSecAttrKeyType as String: kSecAttrKeyTypeECSECPrimeRandom,
    kSecAttrKeySizeInBits as String: 256,
    kSecAttrCanSign as String: true
] as [String: Any]

let privateKey = SecKeyCreateRandomKey(attributes as CFDictionary, nil)!
let publicKey = SecKeyCopyPublicKey(privateKey)!

let privateKeyData = SecKeyCopyExternalRepresentation(privateKey, nil)! as Data
print("Private Key Data (base64):", privateKeyData.base64EncodedString())

let publicKeyData = SecKeyCopyExternalRepresentation(publicKey, nil)! as Data
print("Public Key Data (base64):", publicKeyData.base64EncodedString())

// Import Private Key
let importedPrivateKeyData = Data(base64Encoded: privateKeyData.base64EncodedString())! as CFData

let importedPrivateKeyAttributes = [
    kSecAttrKeyType as String: kSecAttrKeyTypeECSECPrimeRandom,
    kSecAttrKeyClass as String: kSecAttrKeyClassPublic
] as CFDictionary

let importedPrivateKey = SecKeyCreateWithData(importedPrivateKeyData, importedPrivateKeyAttributes, nil)!

// Import Public Key
let importedPublicKeyData = Data(base64Encoded: publicKeyData.base64EncodedString())! as CFData

let importedPublicKeyAttributes = [
    kSecAttrKeyType as String: kSecAttrKeyTypeECSECPrimeRandom,
    kSecAttrKeyClass as String: kSecAttrKeyClassPublic
] as CFDictionary

let importedPublicKey = SecKeyCreateWithData(importedPublicKeyData, importedPublicKeyAttributes, nil)!