No additional files are required. You need a bridging header first of all, which you already have but for those who don't the easiest way to achieve this is to add an Objective-C file to your project and to accept when it offers to create a bridging header. You can then either import the whole of CommonCrypto (thanks @zaph - see comments) to the bridging header:
#import <CommonCrypto/CommonCrypto.h>
Or the constituent parts:
#import <CommonCrypto/CommonCryptor.h>
#import <CommonCrypto/CommonDigest.h>
#import <CommonCrypto/CommonHMAC.h>
#import <CommonCrypto/CommonKeyDerivation.h>
#import <CommonCrypto/CommonSymmetricKeywrap.h>
You can now use CommonCrypto in Swift. For example code see here.
Edit
In Xcode 10 a bridging header is no longer required to import CommonCrypto in Swift. You can simply use:
import CommonCrypto
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