How to use CC_MD5 method in swift language

Question

in Objective-c, we can hash a string like this:

const char *cStr = [someString UTF8String]; unsigned char result[16]; CC_MD5( cStr, strlen(cStr), result ); md5String = [NSString stringWithFormat:         @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",         result[0], result[1], result[2], result[3],         result[4], result[5], result[6], result[7],         result[8], result[9], result[10], result[11],         result[12], result[13], result[14], result[15]         ]; 

But CC_MD5 doesn't work in Swift. How do we deal with this?

Answer 1

This is what I came up with. It's an extension to String. Don't forget to add #import <CommonCrypto/CommonCrypto.h> to the ObjC-Swift bridging header that Xcode creates.

extension String  {     var md5: String! {         let str = self.cStringUsingEncoding(NSUTF8StringEncoding)         let strLen = CC_LONG(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.dealloc(digestLen)          return String(format: hash as String)     }  } 

Answer 2

Here's my version in Swift 3.0, I believe it to be safer and faster than the other answers here.

A bridging header with #import <CommonCrypto/CommonCrypto.h> is required.

func MD5(_ string: String) -> String? {     let length = Int(CC_MD5_DIGEST_LENGTH)     var digest = [UInt8](repeating: 0, count: length)      if let d = string.data(using: String.Encoding.utf8) {         _ = d.withUnsafeBytes { (body: UnsafePointer<UInt8>) in             CC_MD5(body, CC_LONG(d.count), &digest)         }     }      return (0..<length).reduce("") {         $0 + String(format: "%02x", digest[$1])     } }