NSString & NSData to MD5

MD5.swift

import Foundation

extension NSData {
    func MD5() -> NSString {
        let digestLength = Int(CC_MD5_DIGEST_LENGTH)
        let md5Buffer = UnsafeMutablePointer<CUnsignedChar>.alloc(digestLength)

        CC_MD5(bytes, CC_LONG(length), md5Buffer)
        var output = NSMutableString(capacity: Int(CC_MD5_DIGEST_LENGTH * 2))
        for i in 0..<digestLength {
            output.appendFormat("%02x", md5Buffer[i])
        }

        return NSString(format: output)
    }
}

extension NSString {
    func MD5() -> NSString {
        let digestLength = Int(CC_MD5_DIGEST_LENGTH)
        let md5Buffer = UnsafeMutablePointer<CUnsignedChar>.alloc(digestLength)
        CC_MD5(UTF8String, CC_LONG(strlen(UTF8String)), md5Buffer)

        var output = NSMutableString(capacity: Int(CC_MD5_DIGEST_LENGTH * 2))
        for i in 0..<digestLength {
            output.appendFormat("%02x", md5Buffer[i])
        }

        return NSString(format: output)
    }
}

what CC_MD5_DIGEST_LENGTH?

@longxianlin Add: #import <CommonCrypto/CommonCrypto.h>to the ObjC-Swift bridging header that Xcode creates.