How to encode string (use encrypt MessageDigest in Java) to Base64 string in swift? -

in java, used this:

public void encryptdata() {     string data = "hello world";     messagedigest md = null;     try {         md = messagedigest.getinstance("md5");     } catch (nosuchalgorithmexception e) {         e.printstacktrace();     }     if (md == null) {         return;     }     md.update(data.getbytes());     string dataencoded = base64.encodetostring(md.digest(), 11);     return dataencoded; //print: sqqnswtgdueft6mb5y4_5q } 

how do have same results in swift?

updated:

func test() -> void {     var data: string = "hello world"     data = md5(data)     data = base64encode(data)     print("data = \(data)") //yjewythkyje2nguwnzu0mta1yjdhotliztcyztnmztu=  } 

md5 , base64encode function used md5 here , base64 here

any hints helpful.

your code not produce expected result because referenced md5() function returns message digest hex-encoded string, base64 encoded. instead of

 string -> utf-8 data -> md5 digest -> base64 encoding 

you doing

 string -> utf-8 data -> md5 digest -> hex encoding -> base64 encoding 

a small modification of function returns message digest data:

func md5(string string: string) -> nsdata {     var digest = [uint8](count: int(cc_md5_digest_length), repeatedvalue: 0)     let data = string.datausingencoding(nsutf8stringencoding)! // conversion utf-8 cannot fail     cc_md5(data.bytes, cc_long(data.length), &digest)     return nsdata(bytes: digest, length: digest.count) } 

now can compute base 64 encoded md5 digest:

let string = "hello world"  // compute md5 message digest: let md5data = md5(string: string) print("md5data = \(md5data)") // md5data = <b10a8db1 64e07541 05b7a99b e72e3fe5>  // convert base 64 encoded string: let base64 = md5data.base64encodedstringwithoptions([]) print("base64 = \(base64)") // base64 = sqqnswtgdueft6mb5y4/5q== 

this almost expect. java code apparently produces so-called "base64url" variant without padding (compare https://en.wikipedia.org/wiki/base64#variants_summary_table).

therefore have modify 2 characters , remove padding:

let base64url = base64     .stringbyreplacingoccurrencesofstring("+", withstring: "-")     .stringbyreplacingoccurrencesofstring("/", withstring: "_")     .stringbyreplacingoccurrencesofstring("=", withstring: "") print("base64url = \(base64url)") // base64url = sqqnswtgdueft6mb5y4_5q 

now result sqqnswtgdueft6mb5y4_5q, , identical got java code.