Шифрование RSA

function RSAEncrypt(Source: String; Key: RawByteString): RawByteString;
var
  KeyPair: TStringStream;
  RSA: HCRYPTPROV;
  HPair: HCRYPTKEY;
  DDataSize, EDataSize: DWORD;
 
begin
  Result := '';
  KeyPair := TStringStream.Create(Key);
  if CryptAcquireContext(@RSA, nil, nil, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT) then
  try
    if CryptImportKey(RSA, PByte(KeyPair.Memory), KeyPair.Size, 0, 0, @HPair) then
    try
      EDataSize := SizeOf(Source);
      if CryptEncrypt(HPair, 0, true, 0, nil, @EDataSize, 0) then
      begin
        Result := Source;
        SetLength(Result, EDataSize);
        DDataSize := Length(Source) * SizeOf(Char);
        if not(CryptEncrypt(HPair, 0, True, 0, PByte(PChar(Result)), @DDataSize, EDataSize)) then
          Result := '';
      end;
    finally
      CryptDestroyKey(HPair);
    end;
  finally
  CryptReleaseContext(RSA, 0);
  end;
  FreeAndNil(KeyPair);
end;

unit Crypt_RSA;
 
interface
 
uses
  Windows, Classes, SysUtils, WCrypt2;
 
function RSAGenerateKeys(var PrivateKey, PublicKey: String): Boolean;
function RSAEncrypt(Source, Key: String): String;
function RSADecrypt(Source, Key: String): String;
 
implementation
 
function RSAGenerateKeys(var PrivateKey, PublicKey: String): Boolean;
const
  RSA1024BIT_KEY = $04000000;
 
var
  RSA: HCRYPTPROV;
  HKeyPair: HCRYPTKEY;
  Pair: TStringStream;
  buflen: DWORD;
 
  function SetKey(BlobDef: Cardinal; var Key: String): Boolean;
  begin
    Result := Bool(CryptExportKey(HKeyPair, 0, BlobDef, 0, nil, @buflen));
    if Result then
    begin
      Pair.SetSize(buflen);
      Result := Bool(CryptExportKey(HKeyPair, 0, BlobDef, 0, PByte(Pair.Memory), @buflen));
    end;
 
    Key := Pair.ReadString(buflen);
    Pair.Seek(0, soBeginning);
  end;
 
begin
  Pair := TStringStream.Create;
 
  Result := Bool(CryptAcquireContext(@RSA, nil, nil, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT));
  if Result then
    Result := Bool(CryptGenKey(RSA, AT_KEYEXCHANGE, RSA1024BIT_KEY or CRYPT_EXPORTABLE, @HKeyPair));
 
  if Result then
    Result := SetKey(PRIVATEKEYBLOB, PrivateKey);
  if Result then
    Result := SetKey(PUBLICKEYBLOB, PublicKey);
 
  CryptDestroyKey(HKeyPair);
  CryptReleaseContext(RSA, 0);
  FreeAndNil(Pair);
end;
 
function RSAEncrypt(Source, Key: String): String;
var
  KeyPair: TStringStream;
  RSA: HCRYPTPROV;
  HPair: HCRYPTKEY;
  DDataSize, EDataSize: DWORD;
 
begin
  Result := '';
  KeyPair := TStringStream.Create(Key);
  if CryptAcquireContext(@RSA, nil, nil, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT) then
  try
    if CryptImportKey(RSA, PByte(KeyPair.Memory), KeyPair.Size, 0, 0, @HPair) then
    try
      EDataSize := SizeOf(Source);
      if CryptEncrypt(HPair, 0, true, 0, nil, @EDataSize, 0) then
      begin
        Result := Source;
        SetLength(Result, EDataSize);
        DDataSize := Length(Source) * SizeOf(Char);
        if not(CryptEncrypt(HPair, 0, True, 0, PByte(PChar(Result)), @DDataSize, EDataSize)) then
          Result := '';
      end;
    finally
      CryptDestroyKey(HPair);
    end;
  finally
  CryptReleaseContext(RSA, 0);
  end;
  FreeAndNil(KeyPair);
end;
 
function RSADecrypt(Source, Key: String): String;
var
  KeyPair: TStringStream;
  RSA: HCRYPTPROV;
  HPair: HCRYPTKEY;
  EDataSize: DWORD;
 
begin
  KeyPair := TStringStream.Create(Key);
  Result := '';
  if CryptAcquireContext(@RSA, nil, nil, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT) then
  try
    if CryptImportKey(RSA, PByte(KeyPair.Memory), KeyPair.Size, 0, 0, @HPair) then
    try
      Result := Source;
      EDataSize := Length(Result);
      if not Bool(CryptDecrypt(HPair, 0, True, 0, PByte(PChar(Result)), @EDataSize)) then
        EDataSize := 0;
      SetLength(Result, EDataSize div SizeOf(Char));
    finally
      CryptDestroyKey(HPair);
    end;
  finally
    CryptReleaseContext(RSA, 0);
  end;
  FreeAndNil(KeyPair);
end;
 
end.

procedure TRSACalculator.Calculate(const Plaintext,Modulus: ANSIString;  var Ciphertext: ANSIString);
var i:integer;
begin
  i:=0;
  while busy do begin
    inc(i);
    if i>1000 then exit;
    sleep(50);
    Application.ProcessMessages;
  end;
  //
  Password.setAttribute('value',Plaintext,0);    
  ModulusE.setAttribute('value',Modulus,0);
  web.RunJS('Go();');
  Ciphertext:=CiphertextE.getAttribute('value',0);
end;
 
constructor TRSACalculator.Create(form: TForm);
begin
  busy:=true;
  p:=TPanel.Create(Form);
  p.Parent:=Form;
  web:=TWebBrowser.Create(p);
  web.Visible:=false;
  TWinControl(web).Parent:=p;
  p.Height:=0;
  p.Width:=0;
  web.OnDocumentComplete:=self.WebDocumentComplete;
  web.OnBeforeNavigate2:=self.WebNavigate2;
  web.Navigate(iniName);
 
end;

RSA:=TRSACalculator.Create(form1);
RSA.Calculate(form1.sedit1.Text,authkey,text);

authkey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
kexp:='010001';
Base10StringToFGInt(authkey,authkeys);
Base10StringToFGInt(kexp,kexps);
rsaencrypt('радугавнебе', authkeys, kexps, passw);