PHP到Delphi和使用Rijndael的加密解密 [英] PHP to Delphi and back Encryption-Decryption using Rijndael

问题描述

使用rijndael密码解密从PHP发送到Delphi的字符串的问题。
我在PHP端使用mcrypt，在Delphi端使用DCP_rijndael。

I have problems with decrypting strings sent from PHP to Delphi using the rijndael cipher. I'm using mcrypt on the PHP side and DCP_rijndael on the Delphi side.

目前我有以下代码。

PHP：

function encRJ($key, $iv, $data)
{
    $r = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $data, MCRYPT_MODE_CBC, $iv);
    $r = base64_encode($r);
    return $r;
}

在Delphi中：

function decRJ(Data: string; Key: string; IV: string): string;
var ciph: TDCP_rijndael;
begin
  Data := Base64DecodeStr(Data);

  ciph:= TDCP_rijndael.Create(Self);
  ciph.Init(Key[1], 256, @IV[1]);
  ciph.DecryptCBC(Data[1], Data[1], Length(Data));
  ciph.Free;

  Result := Data;
end;

我已经尝试在互联网上使用几个单位实施密码，发现大多数人都在说DCP组件。即使如此，我还没有妥善解密。我尝试使用Byte数组的参数，AnsiStrings，WideStrings等，但不幸的是没有运气。

I have tried using several Units on the Internet implementing the cipher, and found out most people are saying about the DCP components. Even so, I haven't managed to make it correctly decrypt. I've tried using Byte arrays for the parameters, AnsiStrings, WideStrings, etc, but unfortunately no luck.

如果我在这里丢失了一些非常明显的东西

Excuse me if I'm missing something really obvious here, as my mind isn't in good shape atm, after hours of searching for the matter.

推荐答案

我似乎花了太长时间在...但是...

I seem to have spent too long on this but...

您的问题是块大小。 TDCP_rijndael相当于MCRYPT_RIJNDAEL_128（不是_256）。 ciph.Init（...）调用中的'256'值仍然是正确的。除此之外，它看起来很好。也就是说，假设你使用的是ansistrings for key / iv或者你使用的是unicode Delphi。

对于unicode Delphi版本，我倾向于使用TBytes和key [0] / iv [0]。

Your problem is the block size. TDCP_rijndael is equivalent to MCRYPT_RIJNDAEL_128 (not _256). The '256' value in ciph.Init(...) call is still correct though. Other than that it looks pretty much ok. That is, assuming you're using ansistrings for key/iv or you're using non-unicode Delphi.
For unicode Delphi versions I'd be inclined to use TBytes and key[0] / iv[0].

填充可能仍然是一个问题。如果是这样，那么这里是我基于PHP手册页面和一些试验和错误的方法。

Padding may still be an issue. If so, then here's what I've mangled up based on the PHP manual pages and some trial and error.

PHP：

function Encrypt($src, $key, $iv)
{
  $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, 'cbc');
  //echo "Block size: " . $block . "\r\n";
  $pad = $block - (strlen($src) % $block);
  $src .= str_repeat(chr($pad), $pad);  

  $enc = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $src, MCRYPT_MODE_CBC, $iv);
  $r = base64_encode($enc);
  return $r;
}

function Decrypt($src, $key, $iv)
{
  $enc = base64_decode($src);
  $dec = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $enc, MCRYPT_MODE_CBC, $iv);

  $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, 'cbc');
  $pad = ord($dec[($len = strlen($dec)) - 1]);
  return substr($dec, 0, strlen($dec) - $pad);
}

Delphi：

function DecryptData(Data: string; AKey: AnsiString; AIv: AnsiString): string;
var
  key, iv, src, dest: TBytes;
  cipher: TDCP_rijndael;
  slen, pad: integer;
begin
  //key := Base64DecodeBytes(TEncoding.UTF8.GetBytes(AKey));
  //iv := Base64DecodeBytes(TEncoding.UTF8.GetBytes(AIv));
  key := TEncoding.ASCII.GetBytes(AKey);
  iv := TEncoding.ASCII.GetBytes(AIv);

  src := Base64DecodeBytes(TEncoding.UTF8.GetBytes(Data));

  cipher := TDCP_rijndael.Create(nil);
  try
    cipher.CipherMode := cmCBC;
    slen := Length(src);
    SetLength(dest, slen);
    cipher.Init(key[0], 256, @iv[0]); // DCP uses key size in BITS not BYTES
    cipher.Decrypt(src[0], dest[0], slen);
    // Remove the padding. Get the numerical value of the last byte and remove
    // that number of bytes
    pad := dest[slen - 1];
    SetLength(dest, slen - pad);

    // Base64 encode it
    result := TEncoding.Default.GetString(dest);
  finally
    cipher.Free;
  end;
end;

function EncryptData(Data: string; AKey: AnsiString; AIv: AnsiString): string;
var
  cipher: TDCP_rijndael;
  key, iv, src, dest, b64: TBytes;
  index, slen, bsize, pad: integer;
begin
  //key := Base64DecodeBytes(TEncoding.UTF8.GetBytes(AKey));
  //iv := Base64DecodeBytes(TEncoding.UTF8.GetBytes(AIv));
  key := TEncoding.ASCII.GetBytes(AKey);
  iv := TEncoding.ASCII.GetBytes(AIv);

  src := TEncoding.UTF8.GetBytes(Data);

  cipher := TDCP_rijndael.Create(nil);
  try
    cipher.CipherMode := cmCBC;
    // Add padding.
    // Resize the Value array to make it a multiple of the block length.
    // If it's already an exact multiple then add a full block of padding.
    slen := Length(src);
    bsize := (cipher.BlockSize div 8);
    pad := bsize - (slen mod bsize);
    Inc(slen, pad);
    SetLength(src, slen);
    for index := pad downto 1 do
    begin
      src[slen - index] := pad;
    end;

    SetLength(dest, slen);
    cipher.Init(key[0], 256, @iv[0]); // DCP uses key size in BITS not BYTES
    cipher.Encrypt(src[0], dest[0], slen);

    b64 := Base64EncodeBytes(dest);
    result := TEncoding.Default.GetString(b64);
  finally
    cipher.Free;
  end;
end;

PHP和Delphi函数现在给我一样的答案。

The PHP and Delphi functions now give me the same answer.

编辑

Base64DecodeBytes是我添加到DCP Base64单元的一些代码：

Base64DecodeBytes was a bit of code I added to the DCP Base64 unit:

function Base64DecodeBytes(Input: TBytes): TBytes;
var
  ilen, rlen: integer;
begin
  ilen := Length(Input);
  SetLength(result, (ilen div 4) * 3);
  rlen := Base64Decode(@Input[0], @result[0], ilen);
  // Adjust the length of the output buffer according to the number of valid
  // b64 characters
  SetLength(result, rlen);
end; 

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