Get string md5 in Swift 5

Swift 5 version: Use UnsafeRawBufferPointer as type of the closure argument, and bytes.baseAddress to pass address to the Common Crypto function:

import Foundationimport CommonCryptoextension String {    var md5: String {        let data = Data(self.utf8)        let hash = data.withUnsafeBytes { (bytes: UnsafeRawBufferPointer) -> [UInt8] in            var hash = [UInt8](repeating: 0, count: Int(CC_MD5_DIGEST_LENGTH))            CC_MD5(bytes.baseAddress, CC_LONG(data.count), &hash)            return hash        }        return hash.map { String(format: "%02x", $0) }.joined()    }}

(Note that the conversion of a string to UTF-8 data cannot fail, there is no need to return an optional.)

CC_MD5 has been deprecated with the iOS 13. Instead, you can use CC_SHA256.

In iOS 13 and above there is a framework CryptoKit which is a wrapper around CommonCrypto framework and around the MD5 hash function.

import CryptoKitlet d = "Hello"let r = Insecure.MD5.hash(data: d.data(using: .utf8)!)print(r)/*Output: MD5 digest: 8b1a9953c4611296a827abf8c47804d7*/

Eskimo's solution

Below is a variant based on a solution proposed by Eskimo from Apple in Swift Forum post withUnsafeBytes Data API confusion:

extension String {    func md5() -> String {        let data = Data(utf8)        var hash = [UInt8](repeating: 0, count: Int(CC_MD5_DIGEST_LENGTH))        data.withUnsafeBytes { buffer in            _ = CC_MD5(buffer.baseAddress, CC_LONG(buffer.count), &hash)        }        return hash.map { String(format: "%02hhx", $0) }.joined()    }}

Note it is effectively the same as Martin R's solution, but a line shorter (no return hash).

Solution using NSData

This is an even shorter solution using bridging to NSData.

extension String {    func md5() -> String {        let data = Data(utf8) as NSData        var hash = [UInt8](repeating: 0, count: Int(CC_MD5_DIGEST_LENGTH))        CC_MD5(data.bytes, CC_LONG(data.length), &hash)        return hash.map { String(format: "%02hhx", $0) }.joined()    }}