Swift MD5 加密字符串

包含桥接头文件

#import <CommonCrypto/CommonDigest.h>

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)
    }
}