Swift scripting and CommonCrypto

Question

GalinKardzhilov OP

Created Feb ’16

Replies 3

Boosts 0

Views 4.8k

Participants 4

Hi,

I am writing a swift build script for my app which needs to calculate md5 checksum of a string. The issue I am facing is I am unable to link to CommonCrypto so i can use CC's functions. Any advice would be helpful.

P.S. My script looks something like this

#!/usr/bin/swift
import Foundation
import Darwin

/*
... code code code
*/

// Here we get a compile error CC_MD5_DIGEST_LENGTH & CC_MD5 are unresolved udentifiers
extension String {
    func md5() -> String! {
        let str = self.cStringUsingEncoding(NSUTF8StringEncoding)
        let strLen = CUnsignedInt(self.lengthOfBytesUsingEncoding(NSUTF8StringEncoding))
        let digestLen = Int(CC_MD5_DIGEST_LENGTH)
        let result = UnsafeMutablePointer<CUnsignedChar>.alloc(digestLen)
     
        CC_MD5(str!, strLen, result)
     
        let hash = NSMutableString()
        for i in 0..<digestLen {
            hash.appendFormat("%02x", result[i])
        }
     
        result.destroy()
     
        return String(format: hash as String)
    }
}

Boost

Answer 1

liszt OP

Feb ’16

AFAIK, CommonCrypto is not included in the Darwin module. I have successfully used the following method for system headers that are not in the Darwin module.

You can create a modulemap for CommonCrypto so that you can import it.

Create a directory (e.g. CommonCrypto) in a location of your choice. Inside the directory, create a file called

module.modulemap

with the following contents:

module CommonCrypto [system] [extern_c] {
  umbrella "/usr/include/CommonCrypto"
  export *
}

Change the first line of your script to

#!/usr/bin/swift -I module-dir

. Replace

module-dir

with the path to the directory you created that contains the module map file.

You can read more about modules here.

0

Answer 2

Romain OP

Feb ’16

Hi,

In your bridging-header ([YourProjectName]-Bridging-Header.h), just import <CommonCrypto/CommonCrypto.h>:

//
//  Use this file to import your target's public headers that you would like to expose to Swift.
//

#import <CommonCrypto/CommonCrypto.h> // required for MD5

To create a bridging-header if you don't already have one:

The easy way

File > New > File...

Choose Objective-C File.

Give it a name and click on "Finish".

Click on the "Create Bridging Header" button in the dialog box.

Eventually, remove the temporary Objective-C file.

The manual way

Add a header file to your project, named [YourProjectName]-Bridging-Header.h.

In your project build settings, find Swift Compiler – Code Generation, and next to Objective-C Bridging Header, add the path to your bridging header file, from the project’s root folder.

0

Answer 3

MickeySha OP

Nov ’16

running a sub process to caculate checksum may be better?

0