Question

对于我正在进行的项目，我需要使用Blowfish以NSIS和PHP的兼容方式加密和解密字符串。

目前我正在使用Blowfish++ plugin用于NSIS和mcrypt库使用PHP。问题是，我不能让它们都产生相同的输出。

让我们从NSIS Blowfish ++插件开始。基本上API是：

; Second argument needs to be base64 encoded
; base64_encode("12345678") == "MTIzNDU2Nzg="

blowfish::encrypt "test@test.com***" "MTIzNDU2Nzg="
Pop $0 ; 0 on success, 1 on failure
Pop $1 ; encrypted message on success, error message on failure

没有提及它是CBC，ECB，CFB等，而且我对Blowfish不够熟悉，无法通过阅读mostly undocumented source来讲述。我认为它是PHP docs for mcrypt tells me that ECB doesn't need an IV以后的ECB。

我还通过阅读源代码了解到Blowfish ++插件将Base64解码第二个加密参数（我不知道为什么）。它还返回Base64编码的字符串。

对于PHP方面，我基本上使用此代码进行加密：

$plainText = "test@test.com***";
$cipher = mcrypt_module_open(MCRYPT_BLOWFISH, '', MCRYPT_MODE_ECB, '');   
$iv = '00000000';  // Show not be used anyway.
$key = "12345678";

$cipherText = "";
if (mcrypt_generic_init($cipher, $key, $iv) != -1)
{
    $cipherText = mcrypt_generic($cipher, $plainText);
    mcrypt_generic_deinit($cipher);        
}

echo base64_encode($cipherText);

但是，如果我做了所有这些事情，我会得到以下每个输出：

NSIS: GyCyBcUE0s5gqVDshVUB8w==
PHP:  BQdlPd19zEkX5KT9tnF8Ng==

我做错了什么？ NSIS插件不使用ECB吗？如果不是，它用于IV的是什么？

Answer 1

好的，我已经完成了代码并重现了你的结果。问题不在于密码模式 - 使用ECB的NSIS 。问题是NSIS Blowfish代码在小端机器上只是破解。

Blowfish算法在两个32位无符号整数上运行。要在64位明文或密文块与这两个整数之间进行转换，该块应该被解释为两个Big Endian整数。相反，NSIS Blowfish插件以主机字节顺序解释它们 - 因此它无法在小端主机（如x86）上做正确的事情。这意味着它将与自身互操作，但不能与真正的Blowfish实现（如mcrypt）互操作。

我修补了Blowfish ++以使其做正确的事情 - 修改后的Blowfish::Encrypt和Blowfish::Decrypt位于下方，新版blowfish.cpp为here on Pastebin

void Blowfish::Encrypt(void *Ptr,unsigned int N_Bytes)
{
    unsigned int i;
    unsigned char *Work;

    if (N_Bytes%8)
    {
            return;
    }

    Work = (unsigned char *)Ptr;

    for (i=0;i<N_Bytes;i+=8)
    {
        Word word0, word1;

        word0.byte.zero = Work[i];
        word0.byte.one = Work[i+1];
        word0.byte.two = Work[i+2];
        word0.byte.three = Work[i+3];

        word1.byte.zero = Work[i+4];
        word1.byte.one = Work[i+5];
        word1.byte.two = Work[i+6];
        word1.byte.three = Work[i+7];

        BF_En(&word0, &word1);

        Work[i] = word0.byte.zero;
        Work[i+1] = word0.byte.one;
        Work[i+2] = word0.byte.two;
        Work[i+3] = word0.byte.three;

        Work[i+4] = word1.byte.zero;
        Work[i+5] = word1.byte.one;
        Work[i+6] = word1.byte.two;
        Work[i+7] = word1.byte.three;
    }

    Work = NULL;
}

void Blowfish::Decrypt(void *Ptr, unsigned int N_Bytes)
{
    unsigned int i;
    unsigned char *Work;

    if (N_Bytes%8)
    {
            return;
    }

    Work = (unsigned char *)Ptr;
    for (i=0;i<N_Bytes;i+=8)
    {
        Word word0, word1;

        word0.byte.zero = Work[i];
        word0.byte.one = Work[i+1];
        word0.byte.two = Work[i+2];
        word0.byte.three = Work[i+3];

        word1.byte.zero = Work[i+4];
        word1.byte.one = Work[i+5];
        word1.byte.two = Work[i+6];
        word1.byte.three = Work[i+7];

        BF_De(&word0, &word1);

        Work[i] = word0.byte.zero;
        Work[i+1] = word0.byte.one;
        Work[i+2] = word0.byte.two;
        Work[i+3] = word0.byte.three;

        Work[i+4] = word1.byte.zero;
        Work[i+5] = word1.byte.one;
        Work[i+6] = word1.byte.two;
        Work[i+7] = word1.byte.three;
    }

    Work = NULL;
}

NSIS和PHP之间的Blowfish加密消息

1 个答案: