lazarus sha256 string hash

// installa DCPCrypt
// il form contiene due edit ed un button
unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, Forms, Controls, Graphics, DCPsha256, StdCtrls;

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    DCP_sha256_1: TDCP_sha256;
    Edit1: TEdit;
    Edit2: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { private declarations }
  public

    { public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }

function getsha256(S: String): String;
var
    Hash: TDCP_sha256;
    Digest: array[0..31] of byte;  // sha256 produces a 256bit digest (32bytes)
    Source: string;
    i: integer;
    str1: string;
  begin
    Source:= S;  // here your string for get sha256

    if Source <> '' then
    begin
      Hash:= TDCP_sha256.Create(nil);  // create the hash
      Hash.Init;                        // initialize it
      Hash.UpdateStr(Source);
      Hash.Final(Digest);               // produce the digest
      str1:= '';
      for i:= 0 to 31 do
        str1:= str1 + IntToHex(Digest[i],2);
      //form1.Edit2.Text:= s;                   // display the digest in lower case
      Result:=UpperCase(str1);         // display the digest in capital letter
    end;
  end;

procedure TForm1.Button1Click(Sender: TObject);
  begin
    Edit2.Text:=getsha256(Edit1.Text);  // show the sha256 of string in edit1
end;
end.