Want to convert a string to a SHA512 Base64 value

Question

I am having trouble converting this:

"333"

Into this:

"XjFVd0052XxfnhfBCMKz4EhaQ64069GW9hpvi/cy73GknlcQWUz8c5HbEU7fmfXaPtlu8dbKXlmOhfkb1B5+6w=="

It is for a web based program (I need to get a signature for authentication) and using online converters to check if what I am doing is right, I have managed to successfully convert "333" both into SHA512 and Base64 in Mathematica.

(* String to SHA512 *)
In[1]=  IntegerString[
          Hash["333", "SHA512"],
          16
        ]
Out[1]= 5e3155774d39d97c5f9e17c108c2b3e0485a43ae34ebd196f61a6f8bf732ef71a49e5710594cfc7391db114edf99f5da3ed96ef1d6ca5e598e85f91bd41e7eeb
(* verified correct using http://www.unit-conversion.info/texttools/sha/#data *)

(* String to Base64 *)
In[2]=  ExportString[
          "333",
          "Base64"
        ]
Out[2]= MzMz
(* verified correct using http://www.unit-conversion.info/texttools/base64/#data *)

But when I combine the two, I get this:

(* String to SHA512 Base64 *)
In[3]=  ExportString[
          IntegerString[Hash["333", "SHA512"], 16],
          "Base64"
        ]
Out[3]= NWUzMTU1Nzc0ZDM5ZDk3YzVmOWUxN2MxMDhjMmIzZTA0ODVhNDNhZTM0ZWJkMTk2ZjYxYTZmOGJmNzMyZWY3MWE0OWU1NzEwNTk0Y2ZjNzM5MWRiMTE0ZWRmOTlmNWRhM2VkOTZlZjFkNmNhNWU1OThlODVmOTFiZDQxZTdlZWI=

Instead of:

"XjFVd0052XxfnhfBCMKz4EhaQ64069GW9hpvi/cy73GknlcQWUz8c5HbEU7fmfXaPtlu8dbKXlmOhfkb1B5+6w=="

>_<.

Any ideas on how this could be done?

PS: I found a function for Mathematica 11.2 called "SecuredAuthenticationKey" that could be related to what I am trying to do. I am currently using Mathematica 9.

Answer 1

ExportString[
  FromCharacterCode[
    IntegerDigits[
      Hash["333", "SHA512"],
      256]
    ],
  "Base64"]
(* XjFVd0052XxfnhfBCMKz4EhaQ64069GW9hpvi/cy73GknlcQWUz8c5HbEU7fmfXaPtlu8dbKXlmOhfkb1B5+6w== *)

Your use of IntegerString converts it to base-16 first, but it looks like you want to convert it on a per-bit level, so divide it into bytes (with IntegerDigits), convert to string (FromCharacterCode), and apply ExportString there.

Answer 2

This is much easier to do as of the recently released version 11.3.0:

BaseEncode[Hash["333", "SHA512", "ByteArray"]]

(* "XjFVd0052XxfnhfBCMKz4EhaQ64069GW9hpvi/cy73GknlcQWUz8c5HbEU7fmfXaPtlu8dbKXlmOhfkb1B5+6w==" *)