www.pudn.com > POLL_SRC.rar > AES.pas

(**************************************************) 
(*                                                *) 
(*     Advanced Encryption Standard (AES)         *) 
(*     Interface Unit v1.3                        *) 
(*                                                *) 
(*                                                *) 
(*     Copyright (c) 2002 Jorlen Young            *) 
(*                                                *) 
(*                                                *) 
(*                                                *) 
(*说明：                                          *) 
(*                                                *) 
(*   基于 ElASE.pas 单元封装                      *) 
(*                                                *) 
(*   这是一个 AES 加密算法的标准接口。            *) 
(*                                                *) 
(*                                                *) 
(*   作者：杨泽晖      2004.12.04                 *) 
(*                                                *) 
(*   支持 128 / 192 / 256 位的密匙                *)                 
(*   默认情况下按照 128 位密匙操作                *) 
(*                                                *) 
(**************************************************) 
 
unit AES;                   
 
interface 
 
uses 
  SysUtils, Classes, Math, ElAES; 
 
type 
  TKeyBit = (kb128, kb192, kb256); 
 
function StrToHex(Value: string): string; 
function HexToStr(Value: string): string; 
function EncryptString(Value: string; Key: string; 
  KeyBit: TKeyBit = kb128): string; 
function DecryptString(Value: string; Key: string; 
  KeyBit: TKeyBit = kb128): string; 
function EncryptStream(Stream: TStream; Key: string; 
  KeyBit: TKeyBit = kb128): TStream; 
function DecryptStream(Stream: TStream; Key: string; 
  KeyBit: TKeyBit = kb128): TStream; 
procedure EncryptFile(SourceFile, DestFile: string; 
  Key: string; KeyBit: TKeyBit = kb128); 
procedure DecryptFile(SourceFile, DestFile: string; 
  Key: string; KeyBit: TKeyBit = kb128); 
   
implementation 
 
function StrToHex(Value: string): string; 
var 
  I: Integer; 
begin 
  Result := ''; 
  for I := 1 to Length(Value) do 
    Result := Result + IntToHex(Ord(Value[I]), 2); 
end; 
 
function HexToStr(Value: string): string; 
var 
  I: Integer; 
begin 
  Result := ''; 
  for I := 1 to Length(Value) do 
  begin 
    if ((I mod 2) = 1) then 
      Result := Result + Chr(StrToInt('0x'+ Copy(Value, I, 2))); 
  end; 
end; 
 
{  --  字符串加密函数 默认按照 128 位密匙加密 --  } 
function EncryptString(Value: string; Key: string; 
  KeyBit: TKeyBit = kb128): string; 
var 
  SS, DS: TStringStream; 
  Size: Int64; 
  AESKey128: TAESKey128; 
  AESKey192: TAESKey192; 
  AESKey256: TAESKey256; 
begin 
  Result := ''; 
  SS := TStringStream.Create(Value); 
  DS := TStringStream.Create(''); 
  try 
    Size := SS.Size; 
    DS.WriteBuffer(Size, SizeOf(Size)); 
    {  --  128 位密匙最大长度为 16 个字符 --  } 
    if KeyBit = kb128 then 
    begin 
      FillChar(AESKey128, SizeOf(AESKey128), 0 ); 
      Move(PChar(Key)^, AESKey128, Min(SizeOf(AESKey128), Length(Key))); 
      EncryptAESStreamECB(SS, 0, AESKey128, DS); 
    end; 
    {  --  192 位密匙最大长度为 24 个字符 --  } 
    if KeyBit = kb192 then 
    begin 
      FillChar(AESKey192, SizeOf(AESKey192), 0 ); 
      Move(PChar(Key)^, AESKey192, Min(SizeOf(AESKey192), Length(Key))); 
      EncryptAESStreamECB(SS, 0, AESKey192, DS); 
    end; 
    {  --  256 位密匙最大长度为 32 个字符 --  } 
    if KeyBit = kb256 then 
    begin 
      FillChar(AESKey256, SizeOf(AESKey256), 0 ); 
      Move(PChar(Key)^, AESKey256, Min(SizeOf(AESKey256), Length(Key))); 
      EncryptAESStreamECB(SS, 0, AESKey256, DS); 
    end; 
    Result := StrToHex(DS.DataString); 
  finally 
    SS.Free; 
    DS.Free; 
  end; 
end; 
 
{  --  字符串解密函数 默认按照 128 位密匙解密 --  } 
function DecryptString(Value: string; Key: string; 
  KeyBit: TKeyBit = kb128): string; 
var 
  SS, DS: TStringStream; 
  Size: Int64; 
  AESKey128: TAESKey128; 
  AESKey192: TAESKey192; 
  AESKey256: TAESKey256; 
begin 
  Result := ''; 
  SS := TStringStream.Create(HexToStr(Value)); 
  DS := TStringStream.Create(''); 
  try 
    Size := SS.Size; 
    SS.ReadBuffer(Size, SizeOf(Size)); 
    {  --  128 位密匙最大长度为 16 个字符 --  } 
    if KeyBit = kb128 then 
    begin 
      FillChar(AESKey128, SizeOf(AESKey128), 0 ); 
      Move(PChar(Key)^, AESKey128, Min(SizeOf(AESKey128), Length(Key))); 
      DecryptAESStreamECB(SS, SS.Size - SS.Position, AESKey128, DS); 
    end; 
    {  --  192 位密匙最大长度为 24 个字符 --  } 
    if KeyBit = kb192 then 
    begin 
      FillChar(AESKey192, SizeOf(AESKey192), 0 ); 
      Move(PChar(Key)^, AESKey192, Min(SizeOf(AESKey192), Length(Key))); 
      DecryptAESStreamECB(SS, SS.Size - SS.Position, AESKey192, DS); 
    end; 
    {  --  256 位密匙最大长度为 32 个字符 --  } 
    if KeyBit = kb256 then 
    begin 
      FillChar(AESKey256, SizeOf(AESKey256), 0 ); 
      Move(PChar(Key)^, AESKey256, Min(SizeOf(AESKey256), Length(Key))); 
      DecryptAESStreamECB(SS, SS.Size - SS.Position, AESKey256, DS); 
    end; 
    Result := DS.DataString; 
  finally 
    SS.Free; 
    DS.Free; 
  end; 
end; 
 
{  --  流加密函数 默认按照 128 位密匙解密 --  } 
function EncryptStream(Stream: TStream; Key: string; 
  KeyBit: TKeyBit = kb128): TStream; 
var 
  Count: Int64; 
  OutStrm: TStream; 
  AESKey128: TAESKey128; 
  AESKey192: TAESKey192; 
  AESKey256: TAESKey256; 
begin 
  OutStrm := TStream.Create; 
  Stream.Position := 0; 
  Count := Stream.Size; 
  OutStrm.Write(Count, SizeOf(Count)); 
  try 
    {  --  128 位密匙最大长度为 16 个字符 --  } 
    if KeyBit = kb128 then 
    begin 
      FillChar(AESKey128, SizeOf(AESKey128), 0 ); 
      Move(PChar(Key)^, AESKey128, Min(SizeOf(AESKey128), Length(Key))); 
      EncryptAESStreamECB(Stream, 0, AESKey128, OutStrm); 
    end; 
    {  --  192 位密匙最大长度为 24 个字符 --  } 
    if KeyBit = kb192 then 
    begin 
      FillChar(AESKey192, SizeOf(AESKey192), 0 ); 
      Move(PChar(Key)^, AESKey192, Min(SizeOf(AESKey192), Length(Key))); 
      EncryptAESStreamECB(Stream, 0, AESKey192, OutStrm); 
    end; 
    {  --  256 位密匙最大长度为 32 个字符 --  } 
    if KeyBit = kb256 then 
    begin 
      FillChar(AESKey256, SizeOf(AESKey256), 0 ); 
      Move(PChar(Key)^, AESKey256, Min(SizeOf(AESKey256), Length(Key))); 
      EncryptAESStreamECB(Stream, 0, AESKey256, OutStrm); 
    end; 
    Result := OutStrm; 
  finally 
    OutStrm.Free; 
  end; 
end; 
 
{  --  流解密函数 默认按照 128 位密匙解密 --  } 
function DecryptStream(Stream: TStream; Key: string; 
  KeyBit: TKeyBit = kb128): TStream; 
var 
  Count, OutPos: Int64; 
  OutStrm: TStream; 
  AESKey128: TAESKey128; 
  AESKey192: TAESKey192; 
  AESKey256: TAESKey256; 
begin 
  OutStrm := TStream.Create; 
  Stream.Position := 0; 
  OutPos :=OutStrm.Position; 
  Stream.ReadBuffer(Count, SizeOf(Count)); 
  try 
    {  --  128 位密匙最大长度为 16 个字符 --  } 
    if KeyBit = kb128 then 
    begin 
      FillChar(AESKey128, SizeOf(AESKey128), 0 ); 
      Move(PChar(Key)^, AESKey128, Min(SizeOf(AESKey128), Length(Key))); 
      DecryptAESStreamECB(Stream, Stream.Size - Stream.Position, 
        AESKey128, OutStrm); 
    end; 
    {  --  192 位密匙最大长度为 24 个字符 --  } 
    if KeyBit = kb192 then 
    begin 
      FillChar(AESKey192, SizeOf(AESKey192), 0 ); 
      Move(PChar(Key)^, AESKey192, Min(SizeOf(AESKey192), Length(Key))); 
      DecryptAESStreamECB(Stream, Stream.Size - Stream.Position, 
        AESKey192, OutStrm); 
    end; 
    {  --  256 位密匙最大长度为 32 个字符 --  } 
    if KeyBit = kb256 then 
    begin 
      FillChar(AESKey256, SizeOf(AESKey256), 0 ); 
      Move(PChar(Key)^, AESKey256, Min(SizeOf(AESKey256), Length(Key))); 
      DecryptAESStreamECB(Stream, Stream.Size - Stream.Position, 
        AESKey256, OutStrm); 
    end; 
    OutStrm.Size := OutPos + Count; 
    OutStrm.Position := OutPos; 
    Result := OutStrm; 
  finally 
    OutStrm.Free; 
  end; 
end; 
 
{  --  文件加密函数 默认按照 128 位密匙解密 --  } 
procedure EncryptFile(SourceFile, DestFile: string; 
  Key: string; KeyBit: TKeyBit = kb128); 
var 
  SFS, DFS: TFileStream; 
  Size: Int64; 
  AESKey128: TAESKey128; 
  AESKey192: TAESKey192; 
  AESKey256: TAESKey256; 
begin 
  SFS := TFileStream.Create(SourceFile, fmOpenRead); 
  try 
    DFS := TFileStream.Create(DestFile, fmCreate); 
    try 
      Size := SFS.Size; 
      DFS.WriteBuffer(Size, SizeOf(Size)); 
      {  --  128 位密匙最大长度为 16 个字符 --  } 
      if KeyBit = kb128 then 
      begin 
        FillChar(AESKey128, SizeOf(AESKey128), 0 ); 
        Move(PChar(Key)^, AESKey128, Min(SizeOf(AESKey128), Length(Key))); 
        EncryptAESStreamECB(SFS, 0, AESKey128, DFS); 
      end; 
      {  --  192 位密匙最大长度为 24 个字符 --  } 
      if KeyBit = kb192 then 
      begin 
        FillChar(AESKey192, SizeOf(AESKey192), 0 ); 
        Move(PChar(Key)^, AESKey192, Min(SizeOf(AESKey192), Length(Key))); 
        EncryptAESStreamECB(SFS, 0, AESKey192, DFS); 
      end; 
      {  --  256 位密匙最大长度为 32 个字符 --  } 
      if KeyBit = kb256 then 
      begin 
        FillChar(AESKey256, SizeOf(AESKey256), 0 ); 
        Move(PChar(Key)^, AESKey256, Min(SizeOf(AESKey256), Length(Key))); 
        EncryptAESStreamECB(SFS, 0, AESKey256, DFS); 
      end; 
    finally 
      DFS.Free; 
    end; 
  finally 
    SFS.Free; 
  end; 
end; 
 
{  --  文件解密函数 默认按照 128 位密匙解密 --  } 
procedure DecryptFile(SourceFile, DestFile: string; 
  Key: string; KeyBit: TKeyBit = kb128); 
var 
  SFS, DFS: TFileStream; 
  Size: Int64; 
  AESKey128: TAESKey128; 
  AESKey192: TAESKey192; 
  AESKey256: TAESKey256; 
begin 
  SFS := TFileStream.Create(SourceFile, fmOpenRead); 
  try 
    SFS.ReadBuffer(Size, SizeOf(Size)); 
    DFS := TFileStream.Create(DestFile, fmCreate); 
    try 
      {  --  128 位密匙最大长度为 16 个字符 --  } 
      if KeyBit = kb128 then 
      begin 
        FillChar(AESKey128, SizeOf(AESKey128), 0 ); 
        Move(PChar(Key)^, AESKey128, Min(SizeOf(AESKey128), Length(Key))); 
        DecryptAESStreamECB(SFS, SFS.Size - SFS.Position, AESKey128, DFS); 
      end; 
      {  --  192 位密匙最大长度为 24 个字符 --  } 
      if KeyBit = kb192 then 
      begin 
        FillChar(AESKey192, SizeOf(AESKey192), 0 ); 
        Move(PChar(Key)^, AESKey192, Min(SizeOf(AESKey192), Length(Key))); 
        DecryptAESStreamECB(SFS, SFS.Size - SFS.Position, AESKey192, DFS); 
      end; 
      {  --  256 位密匙最大长度为 32 个字符 --  } 
      if KeyBit = kb256 then 
      begin 
        FillChar(AESKey256, SizeOf(AESKey256), 0 ); 
        Move(PChar(Key)^, AESKey256, Min(SizeOf(AESKey256), Length(Key))); 
        DecryptAESStreamECB(SFS, SFS.Size - SFS.Position, AESKey256, DFS); 
      end; 
      DFS.Size := Size; 
    finally 
      DFS.Free; 
    end; 
  finally 
    SFS.Free; 
  end; 
end; 
end.