base64.pas

说明：支持标准MD5、SHA1、Inno密码、QQ密码、Serv-U密码。 支持多线程。 支持进度保存、读取。 源码说明：源码中仅使用了Raize系列三方控件包。

Unit Base64;

Interface

Uses SysUtils, Classes;

Function Base64EnCodeStr(Const S: String): String; stdcall;
Function Base64DeCodeStr(Const S: String): String; stdcall;
Function IsBase64(Const S: String): boolean;
Implementation

Const
  Base64Table: String = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

Function Base64EnStr(Const S, Base64String: String; IsCustom: boolean): String;
Var
  i, c1, c2, c3: Integer;
  m, n: Integer;
Begin
  Result := '';
  If S = '' Then Exit;
  m := 1;
  n := 0;
  For i := 1 To (Length(S) Div 3) Do
  Begin
    c1 := Ord(S[m]);
    c2 := Ord(S[m + 1]);
    c3 := Ord(S[m + 2]);
    m := m + 3;
    Result := Result + Base64String[(c1 Shr 2) And $3F + 1];
    Result := Result + Base64String[((c1 Shl 4) And $30) Or ((c2 Shr 4) And $0F) + 1];
    Result := Result + Base64String[((c2 Shl 2) And $3C) Or ((c3 Shr 6) And $03) + 1];
    Result := Result + Base64String[c3 And $3F + 1];
    n := n + 4;
    If (n = 76) Then n := 0;
    {Begin
      Result := Result + #13#10;
    End;}
  End;

  If (Length(S) Mod 3) = 1 Then
  Begin
    c1 := Ord(S[m]);
    Result := Result + Base64String[(c1 Shr 2) And $3F + 1];
    Result := Result + Base64String[(c1 Shl 4) And $30 + 1];
    If Not IsCustom Then
    Begin
      Result := Result + '=';
      Result := Result + '=';
    End;
  End;

  If (Length(S) Mod 3) = 2 Then
  Begin
    c1 := Ord(S[m]);
    c2 := Ord(S[m + 1]);
    Result := Result + Base64String[(c1 Shr 2) And $3F + 1];
    Result := Result + Base64String[((c1 Shl 4) And $30) Or ((c2 Shr 4) And $0F) + 1];
    Result := Result + Base64String[(c2 Shl 2) And $3C + 1];
    If Not IsCustom Then Result := Result + '=';
  End;
End;

Function Base64DeStr(Const S, Base64String: String; IsCustom: boolean): String;
Var                                     //解密
  i, m, n: Integer;
  c1, c2, c3, c4: Integer;
Begin
  Result := '';
  If S = '' Then Exit;
  n := 1;
  m := Length(S);
  If Not IsCustom Then
  Begin
    If S[m] = '=' Then m := m - 1;
    If S[m] = '=' Then m := m - 1;
  End;
  For i := 1 To m Div 4 Do
  Begin
    c1 := Pos(S[n], Base64String) - 1;
    c2 := Pos(S[n + 1], Base64String) - 1;
    c3 := Pos(S[n + 2], Base64String) - 1;
    c4 := Pos(S[n + 3], Base64String) - 1;
    n := n + 4;
    Result := Result + Chr(((c1 Shl 2) And $FC) Or ((c2 Shr 4) And $3));
    Result := Result + Chr(((c2 Shl 4) And $F0) Or ((c3 Shr 2) And $0F));
    Result := Result + Chr(((c3 Shl 6) And $C0) Or c4);
  End;

  If m Mod 4 = 2 Then
  Begin
    c1 := Pos(S[n], Base64String) - 1;
    c2 := Pos(S[n + 1], Base64String) - 1;
    Result := Result + Chr(((c1 Shl 2) And $FC) Or ((c2 Shr 4) And $3));
  End;

  If m Mod 4 = 3 Then
  Begin
    c1 := Pos(S[n], Base64String) - 1;
    c2 := Pos(S[n + 1], Base64String) - 1;
    c3 := Pos(S[n + 2], Base64String) - 1;
    Result := Result + Chr(((c1 Shl 2) And $FC) Or ((c2 Shr 4) And $3));
    Result := Result + Chr(((c2 Shl 4) And $F0) Or ((c3 Shr 2) And $0F));
  End;
End;

Function Base64EnCodeStr(Const S: String): String; Stdcall;
Begin
  Result := Base64EnStr(S, Base64Table, false);
End;

Function Base64DeCodeStr(Const S: String): String; Stdcall;
Begin
  Result := Base64DeStr(S, Base64Table, false);
End;

//==============================================================================
Function IsBase64(Const S: String): boolean;
Var
  LIntLoop: Integer;
Begin
  Result := Trim(S) <> '';
  If Result Then
    For LIntLoop := 1 To Length(S) Do
      If Pos(S[LIntLoop], Base64Table + '=') = 0 Then
      Begin
        Result := false;
        Break;
      End;
End;

End.