加密API RSA公钥可以解密数据，不像预期的那样不对称

Question

我遇到的问题是我能够使用用于加密数据的相同RSA 2048位公钥解密数据。在我看来，如果一个公钥可以解密它，这首先会破坏加密数据的全部目的。我此时唯一可以考虑的是，当我认为我正在生成非对称对时，我正在生成对称密钥交换对。

最终用户的目的是稍后使用它来传输用户凭证，以便在远离办公室使用应用程序时进行身份验证，此时我无法使用域中工作站的缓存凭据。理论上，我只能使用私钥解密这些凭据。

我已经制作了一个简单的测试类和代码来重现我的问题。我正在采取的步骤如下：

1. 获取Microsoft Enhanced Cryptographic Provider v1.0的上下文
2. 生成公钥/私钥对。
3. 将公钥和私钥BLOB导出为单独的文件。
4. 加载公钥并加密一些简单的文本。
5. 尝试使用公钥解密相同的加密文本（我希望它在这里失败，除非我使用私钥时 - 但两者都有效）。

TestEncryptDecrypt帮助程序类：TestEncryptDecrypt.h

#pragma once
#include <Windows.h>
#include <wincrypt.h>

class TestEncryptDecrypt
{
public:
    TestEncryptDecrypt()
    {
    }
    ~TestEncryptDecrypt()
    {
        if (hKey != NULL)
            CryptDestroyKey(hKey);

        if (hProvider != NULL)
            CryptReleaseContext(hProvider, 0);
    }

    BOOL InitializeProvider(LPCTSTR pszProvider, DWORD dwProvType)
    {
        if (hProvider != NULL)
        {
            if (!CryptReleaseContext(hProvider, 0))
                return 0;
        }

        return CryptAcquireContext(&hProvider, NULL, pszProvider, dwProvType, 0);
    }

    BOOL Generate2048BitKeys(ALG_ID Algid)
    {
        DWORD dwFlags = (0x800 << 16) | CRYPT_EXPORTABLE;
        return CryptGenKey(hProvider, Algid, dwFlags, &hKey);
    }

    VOID ExportPrivatePublicKey(LPTSTR lpFileName)
    {
        if (hKey == NULL)
            return;

        DWORD dwDataLen = 0;
        BOOL exportResult = CryptExportKey(hKey, NULL, PRIVATEKEYBLOB, 0, NULL, &dwDataLen);
        LPBYTE lpKeyBlob = (LPBYTE)malloc(dwDataLen);
        exportResult = CryptExportKey(hKey, NULL, PRIVATEKEYBLOB, 0, lpKeyBlob, &dwDataLen);
        WriteBytesFile(lpFileName, lpKeyBlob, dwDataLen);
        free(lpKeyBlob);
    }

    VOID ExportPublicKey(LPTSTR lpFileName)
    {
        if (hKey == NULL)
            return;

        DWORD dwDataLen = 0;
        BOOL exportResult = CryptExportKey(hKey, NULL, PUBLICKEYBLOB, 0, NULL, &dwDataLen);
        LPBYTE lpKeyBlob = (LPBYTE)malloc(dwDataLen);
        exportResult = CryptExportKey(hKey, NULL, PUBLICKEYBLOB, 0, lpKeyBlob, &dwDataLen);
        WriteBytesFile(lpFileName, lpKeyBlob, dwDataLen);
        free(lpKeyBlob);
    }

    BOOL ImportKey(LPTSTR lpFileName)
    {
        if (hProvider == NULL)
            return 0;

        if (hKey != NULL)
            CryptDestroyKey(hKey);

        LPBYTE lpKeyContent = NULL;
        DWORD dwDataLen = 0;
        ReadBytesFile(lpFileName, &lpKeyContent, &dwDataLen);
        BOOL importResult = CryptImportKey(hProvider, lpKeyContent, dwDataLen, 0, 0, &hKey);

        delete[] lpKeyContent;

        return importResult;
    }

    BOOL EncryptDataWriteToFile(LPTSTR lpSimpleDataToEncrypt, LPTSTR lpFileName)
    {
        DWORD SimpleDataToEncryptLength = _tcslen(lpSimpleDataToEncrypt)*sizeof(TCHAR);
        DWORD BufferLength = SimpleDataToEncryptLength * 10;
        BYTE *EncryptedBuffer = new BYTE[BufferLength];
        SecureZeroMemory(EncryptedBuffer, BufferLength);
        CopyMemory(EncryptedBuffer, lpSimpleDataToEncrypt, SimpleDataToEncryptLength);

        BOOL cryptResult = CryptEncrypt(hKey, NULL, TRUE, 0, EncryptedBuffer, &SimpleDataToEncryptLength, BufferLength);
        DWORD dwGetLastError = GetLastError();

        WriteBytesFile(lpFileName, EncryptedBuffer, SimpleDataToEncryptLength);

        delete[] EncryptedBuffer;

        return cryptResult;
    }

    BOOL DecryptDataFromFile(LPBYTE *lpDecryptedData, LPTSTR lpFileName, DWORD *dwDecryptedLen)
    {
        if (hKey == NULL)
            return 0;

        LPBYTE lpEncryptedData = NULL;
        DWORD dwDataLen = 0;
        ReadBytesFile(lpFileName, &lpEncryptedData, &dwDataLen);
        BOOL decryptResult = CryptDecrypt(hKey, NULL, TRUE, 0, lpEncryptedData, &dwDataLen);
        *dwDecryptedLen = dwDataLen;
        //WriteBytesFile(L"decryptedtest.txt", lpEncryptedData, dwDataLen);
        *lpDecryptedData = new BYTE[dwDataLen + 1];
        SecureZeroMemory(*lpDecryptedData, dwDataLen + 1);
        CopyMemory(*lpDecryptedData, lpEncryptedData, dwDataLen);

        delete[]lpEncryptedData;

        return decryptResult;
    }

    VOID WriteBytesFile(LPTSTR lpFileName, BYTE *content, DWORD dwDataLen)
    {
        HANDLE hFile = CreateFile(lpFileName, GENERIC_READ | GENERIC_WRITE, 0x7, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
        DWORD dwBytesWritten = 0;
        WriteFile(hFile, content, dwDataLen, &dwBytesWritten, NULL);
        CloseHandle(hFile);
    }

private:
    HCRYPTPROV hProvider = NULL;
    HCRYPTKEY hKey = NULL;

    VOID ReadBytesFile(LPTSTR lpFileName, BYTE **content, DWORD *dwDataLen)
    {
        HANDLE hFile = CreateFile(lpFileName, GENERIC_READ, 0x7, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
        DWORD dwFileLength = 0;
        DWORD dwBytesToRead = GetFileSize(hFile, NULL);
        DWORD dwBytesRead = 0;

        *content = new BYTE[dwBytesToRead + 1];
        SecureZeroMemory(*content, dwBytesToRead + 1);

        ReadFile(hFile, *content, dwBytesToRead, &dwBytesRead, NULL);

        *dwDataLen = dwBytesRead;

        CloseHandle(hFile);
    }
};

测试代码：主.cpp文件

#include "stdafx.h"
#include "TestEncryptDecrypt.h"
#include <Windows.h>
#include <wincrypt.h>

int main()
{
    TestEncryptDecrypt *edc = new TestEncryptDecrypt();
    //Initialize the provider
    edc->InitializeProvider(MS_ENHANCED_PROV, PROV_RSA_FULL);

    //Generate a 2048-bit asymmetric key pair
    edc->Generate2048BitKeys(CALG_RSA_KEYX);

    //Export the private / public key pair
    edc->ExportPrivatePublicKey(L"privpubkey.txt");

    //Export only the public key
    edc->ExportPublicKey(L"pubkey.txt");

    //Import the public key (destroys the private/public key pair already set)
    edc->ImportKey(L"pubkey.txt");

    //Encrypt and write some test data to file
    edc->EncryptDataWriteToFile(TEXT("Hello World!ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"), L"encrypteddata.txt");

    //Decrypt the data from file using the same public key (this should fail but it doesn't)
    DWORD dwDataLen = 0;
    LPBYTE lpDecryptedData = NULL;
    edc->DecryptDataFromFile(&lpDecryptedData, L"encrypteddata.txt", &dwDataLen);

    //Write the supposedly decrypted data to another file
    edc->WriteBytesFile(L"decrypteddata.txt", lpDecryptedData, dwDataLen);

    //Clear data
    delete[] lpDecryptedData;
    delete edc;

    return 0;
}

不幸的是，我没有机会经常使用C ++，所以你可能会注意到一些问题。随意批评建设性。

有谁知道为什么我能够使用相同的公钥解密数据？我的目标是能够在客户端进行不可逆转的加密，只能在服务器上解密，私钥将隐藏在服务器上。

编辑：我曾考虑过importKey方法没有正确销毁hKey，所以我编写了这个测试用例（相同的结果 - 公钥可以加密和解密数据）：

// CPPTests.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "TestEncryptDecrypt.h"
#include <Windows.h>
#include <wincrypt.h>

int main()
{
    TestEncryptDecrypt *edc = new TestEncryptDecrypt();
    //Initialize the provider
    edc->InitializeProvider(MS_ENHANCED_PROV, PROV_RSA_FULL);

    //Generate a 2048-bit asymmetric key pair
    edc->Generate2048BitKeys(CALG_RSA_KEYX);

    //Export the private / public key pair
    edc->ExportPrivatePublicKey(L"privpubkey.txt");

    //Export only the public key
    edc->ExportPublicKey(L"pubkey.txt");

    //Destroy everything and load up only the public key to write some encrypted data
    delete edc;
    edc = new TestEncryptDecrypt();
    edc->InitializeProvider(MS_ENHANCED_PROV, PROV_RSA_FULL);
    edc->ImportKey(L"pubkey.txt");

    //Encrypt and write some test data to file
    edc->EncryptDataWriteToFile(TEXT("Hello World!ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"), L"encrypteddata.txt");

    //Destroy everything and load up only the public key to read some encrypted data
    delete edc;
    edc = new TestEncryptDecrypt();
    edc->InitializeProvider(MS_ENHANCED_PROV, PROV_RSA_FULL);
    edc->ImportKey(L"pubkey.txt");

    //Decrypt the data from file using the same public key (this should fail but it doesn't)
    DWORD dwDataLen = 0;
    LPBYTE lpDecryptedData = NULL;
    edc->DecryptDataFromFile(&lpDecryptedData, L"encrypteddata.txt", &dwDataLen);

    //Write the supposedly decrypted data to another file
    edc->WriteBytesFile(L"decrypteddata.txt", lpDecryptedData, dwDataLen);

    //Clear data
    delete[] lpDecryptedData;
    delete edc;

    return 0;
}

Answer 1

经过一些与同样问题的斗争，我意识到错误在哪里。

在您的第一个代码中，您获取了上下文，并将最后一个标志设置为零：

CryptAcquireContext(&hProvider, NULL, pszProvider, dwProvType, 0);

但是在您的解决方案中，您将其更改为CRYPT_VERIFYCONTEXT。

CryptAcquireContext(&hProvider, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);

您通过更改此标志解决了您的问题，而不是从OpenSSL导入密钥。我很确定如果你在初始代码中测试它，它将按预期工作。

此CRYPT_VERIFYCONTEXT标志负责不允许密钥在系统中实现持久性，这种持久性使公共RSA能够加密和解密。

Answer 2

问题是由于某种原因，Crypto API使用带有RSA的Microsoft增强提供程序生成对称密钥。我无法让它产生不对称的键。然而，该算法将使用非对称密钥。所以这对我们来说是个好消息。这意味着要使其工作，我们只需要生成密钥。您也可以从自签名证书中导出这些证书，使用您的公司CA等。

为了解决这个问题，我使用OpenSSL生成了一个公钥/私钥对。我编译OpenSSL for Windows只是为了好玩，然后运行以下语句来获取一对未加密的公钥/私钥文件：

1. openssl genpkey -out private2.pem -outform PEM -des3 -algorithm RSA -pkeyopt rsa_keygen_bits：2048 要么 openssl genrsa -des3 -out private.pem 2048
2. openssl rsa -in private.pem -outform PEM -poutout -out public.pem
3. openssl rsa -in private.pem -outform PEM -out private_unencrypted.pem

有了这些，我在测试助手类中添加了2个新函数，ImportPublicKey和ImportPrivateKey。这些只会在没有密码短语的情况下导入PEM文件。考虑到公众是公共的，私人应隐藏在某个地方的安全服务器上，或许用哈希编码，我不会考虑那么多的安全威胁。

TestEncryptDecrypt.h

#pragma once
#include <Windows.h>
#include <wincrypt.h>

class TestEncryptDecrypt
{
public:
    TestEncryptDecrypt()
    {
    }
    ~TestEncryptDecrypt()
    {
        if (hKey != NULL)
            CryptDestroyKey(hKey);

        if (hProvider != NULL)
            CryptReleaseContext(hProvider, 0);
    }

    BOOL InitializeProvider(LPCTSTR pszProvider, DWORD dwProvType)
    {
        if (hProvider != NULL)
        {
            if (!CryptReleaseContext(hProvider, 0))
                return 0;
        }

        return CryptAcquireContext(&hProvider, NULL, pszProvider, dwProvType, CRYPT_VERIFYCONTEXT);
    }

    BOOL Generate2048BitKeys(ALG_ID Algid)
    {
        DWORD dwFlags = (0x800 << 16) | CRYPT_EXPORTABLE;
        return CryptGenKey(hProvider, Algid, dwFlags, &hKey);
    }

    VOID ExportPrivatePublicKey(LPTSTR lpFileName)
    {
        if (hKey == NULL)
            return;

        DWORD dwDataLen = 0;
        BOOL exportResult = CryptExportKey(hKey, NULL, PRIVATEKEYBLOB, 0, NULL, &dwDataLen);
        LPBYTE lpKeyBlob = (LPBYTE)malloc(dwDataLen);
        exportResult = CryptExportKey(hKey, NULL, PRIVATEKEYBLOB, 0, lpKeyBlob, &dwDataLen);
        WriteBytesFile(lpFileName, lpKeyBlob, dwDataLen);
        free(lpKeyBlob);
    }

    VOID ExportPublicKey(LPTSTR lpFileName)
    {
        if (hKey == NULL)
            return;

        DWORD dwDataLen = 0;
        BOOL exportResult = CryptExportKey(hKey, NULL, PUBLICKEYBLOB, 0, NULL, &dwDataLen);
        LPBYTE lpKeyBlob = (LPBYTE)malloc(dwDataLen);
        exportResult = CryptExportKey(hKey, NULL, PUBLICKEYBLOB, 0, lpKeyBlob, &dwDataLen);
        WriteBytesFile(lpFileName, lpKeyBlob, dwDataLen);
        free(lpKeyBlob);
    }

    BOOL ImportKey(LPTSTR lpFileName)
    {
        if (hProvider == NULL)
            return 0;

        if (hKey != NULL)
            CryptDestroyKey(hKey);

        LPBYTE lpKeyContent = NULL;
        DWORD dwDataLen = 0;
        ReadBytesFile(lpFileName, &lpKeyContent, &dwDataLen);
        BOOL importResult = CryptImportKey(hProvider, lpKeyContent, dwDataLen, 0, 0, &hKey);

        delete[] lpKeyContent;

        return importResult;
    }

    BOOL ImportPublicKey(LPTSTR lpFileName)
    {
        //If a context doesn't exist acquire one
        if (hProvider == NULL)
        {
            BOOL result = CryptAcquireContext(&hProvider, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
            if (!result)
                return result;
        }

        if (hKey != NULL)
            CryptDestroyKey(hKey);

        //Load the PEM 
        LPBYTE PublicBytes = NULL;
        DWORD dwDataLen = 0;
        ReadBytesFile(lpFileName, &PublicBytes, &dwDataLen);

        //Convert to Unicode
        int PublicPEMSize = MultiByteToWideChar(CP_ACP, 0, (LPCCH)PublicBytes, -1, NULL, 0);
        TCHAR *PublicPEM = new TCHAR[PublicPEMSize];
        MultiByteToWideChar(CP_ACP, 0, (LPCCH)PublicBytes, -1, PublicPEM, PublicPEMSize);
        delete[]PublicBytes;

        //Convert PEM to DER
        LPBYTE PublicDER = NULL;
        DWORD dwPublicDERLen = 0;

        BOOL result = CryptStringToBinary(PublicPEM, 0, CRYPT_STRING_BASE64HEADER, NULL, &dwPublicDERLen, NULL, NULL);
        if (!result)
            return result;

        PublicDER = new BYTE[dwPublicDERLen];
        result = CryptStringToBinary(PublicPEM, 0, CRYPT_STRING_BASE64HEADER, PublicDER, &dwPublicDERLen, NULL, NULL);
        if (!result)
            return result;

        delete[] PublicPEM;

        //Decode the object into a public key info struct
        CERT_PUBLIC_KEY_INFO *PublicKeyInfo = NULL;
        DWORD dwPublicKeyInfoLen = 0;

        result = CryptDecodeObjectEx(X509_ASN_ENCODING, X509_PUBLIC_KEY_INFO, PublicDER, dwPublicDERLen, CRYPT_ENCODE_ALLOC_FLAG, NULL, &PublicKeyInfo, &dwPublicKeyInfoLen);
        if (!result)
            return result;

        //Import the public key
        result = CryptImportPublicKeyInfo(hProvider, X509_ASN_ENCODING, PublicKeyInfo, &hKey);
        if (!result)
            return result;


        //cleanup
        delete[] PublicDER;
        LocalFree(PublicKeyInfo);

        return result;
    }

    BOOL ImportPrivateKey(LPTSTR lpFileName)
    {
        //If a context doesn't exist acquire one
        if (hProvider == NULL)
        {
            BOOL result = CryptAcquireContext(&hProvider, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
            if (!result)
                return result;
        }

        if (hKey != NULL)
            CryptDestroyKey(hKey);

        //Load the PEM 
        LPBYTE PrivateBytes = NULL;
        DWORD dwDataLen = 0;
        ReadBytesFile(lpFileName, &PrivateBytes, &dwDataLen);

        //Convert to Unicode
        int PrivatePEMSize = MultiByteToWideChar(CP_ACP, 0, (LPCCH)PrivateBytes, -1, NULL, 0);
        TCHAR *PrivatePEM = new TCHAR[PrivatePEMSize];
        MultiByteToWideChar(CP_ACP, 0, (LPCCH)PrivateBytes, -1, PrivatePEM, PrivatePEMSize);
        delete[]PrivateBytes;

        //Convert PEM to DER
        LPBYTE PrivateDER = NULL;
        DWORD dwPrivateDERLen = 0;

        BOOL result = CryptStringToBinary(PrivatePEM, 0, CRYPT_STRING_BASE64HEADER, NULL, &dwPrivateDERLen, NULL, NULL);
        if (!result)
            return result;

        PrivateDER = new BYTE[dwPrivateDERLen];
        result = CryptStringToBinary(PrivatePEM, 0, CRYPT_STRING_BASE64HEADER, PrivateDER, &dwPrivateDERLen, NULL, NULL);
        if (!result)
            return result;

        delete[] PrivatePEM;

        //Decode the object into a private key info struct
        BYTE *PrivateKeyInfo = NULL;
        DWORD dwPrivateKeyInfoLen = 0;

        result = CryptDecodeObjectEx(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, PKCS_RSA_PRIVATE_KEY, PrivateDER, dwPrivateDERLen, 0, NULL, NULL, &dwPrivateKeyInfoLen);
        if (!result)
            return result;

        PrivateKeyInfo = new BYTE[dwPrivateKeyInfoLen];

        result = CryptDecodeObjectEx(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, PKCS_RSA_PRIVATE_KEY, PrivateDER, dwPrivateDERLen, 0, NULL, PrivateKeyInfo, &dwPrivateKeyInfoLen);
        if (!result)
            return result;



        //Import the private key
        result = CryptImportKey(hProvider, PrivateKeyInfo, dwPrivateKeyInfoLen, NULL, 0, &hKey);
        if (!result)
            return result;


        //cleanup
        delete[] PrivateDER;
        delete[] PrivateKeyInfo;

        return result;
    }

    BOOL EncryptDataWriteToFile(LPTSTR lpSimpleDataToEncrypt, LPTSTR lpFileName)
    {
        DWORD SimpleDataToEncryptLength = _tcslen(lpSimpleDataToEncrypt)*sizeof(TCHAR);
        DWORD BufferLength = SimpleDataToEncryptLength * 10;
        BYTE *EncryptedBuffer = new BYTE[BufferLength];
        SecureZeroMemory(EncryptedBuffer, BufferLength);
        CopyMemory(EncryptedBuffer, lpSimpleDataToEncrypt, SimpleDataToEncryptLength);

        BOOL cryptResult = CryptEncrypt(hKey, NULL, TRUE, 0, EncryptedBuffer, &SimpleDataToEncryptLength, BufferLength);
        DWORD dwGetLastError = GetLastError();

        WriteBytesFile(lpFileName, EncryptedBuffer, SimpleDataToEncryptLength);

        delete[] EncryptedBuffer;

        return cryptResult;
    }

    BOOL DecryptDataFromFile(LPBYTE *lpDecryptedData, LPTSTR lpFileName, DWORD *dwDecryptedLen)
    {
        if (hKey == NULL)
            return 0;

        LPBYTE lpEncryptedData = NULL;
        DWORD dwDataLen = 0;
        ReadBytesFile(lpFileName, &lpEncryptedData, &dwDataLen);
        BOOL decryptResult = CryptDecrypt(hKey, NULL, TRUE, 0, lpEncryptedData, &dwDataLen);
        *dwDecryptedLen = dwDataLen;
        //WriteBytesFile(L"decryptedtest.txt", lpEncryptedData, dwDataLen);
        *lpDecryptedData = new BYTE[dwDataLen + 1];
        SecureZeroMemory(*lpDecryptedData, dwDataLen + 1);
        CopyMemory(*lpDecryptedData, lpEncryptedData, dwDataLen);

        delete[]lpEncryptedData;

        return decryptResult;
    }

    VOID WriteBytesFile(LPTSTR lpFileName, BYTE *content, DWORD dwDataLen)
    {
        HANDLE hFile = CreateFile(lpFileName, GENERIC_READ | GENERIC_WRITE, 0x7, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
        DWORD dwBytesWritten = 0;
        WriteFile(hFile, content, dwDataLen, &dwBytesWritten, NULL);
        CloseHandle(hFile);
    }

private:
    HCRYPTPROV hProvider = NULL;
    HCRYPTKEY hKey = NULL;

    VOID ReadBytesFile(LPTSTR lpFileName, BYTE **content, DWORD *dwDataLen)
    {
        HANDLE hFile = CreateFile(lpFileName, GENERIC_READ, 0x7, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
        DWORD dwFileLength = 0;
        DWORD dwBytesToRead = GetFileSize(hFile, NULL);
        DWORD dwBytesRead = 0;

        *content = new BYTE[dwBytesToRead + 1];
        SecureZeroMemory(*content, dwBytesToRead + 1);

        ReadFile(hFile, *content, dwBytesToRead, &dwBytesRead, NULL);

        *dwDataLen = dwBytesRead;

        CloseHandle(hFile);
    }
};

这是测试，提供证据证明它不能使用公钥解密，而是使用私钥.pem：

int main()
{
    TestEncryptDecrypt *edc = new TestEncryptDecrypt();
    edc->ImportPublicKey(L"public.pem");
    edc->EncryptDataWriteToFile(L"Hello world! hahahahah", L"encrypted.txt");

    LPBYTE decodedData = NULL; DWORD decodedLen = 0;
    BOOL result = edc->DecryptDataFromFile(&decodedData, L"encrypted.txt", &decodedLen);
    if (result == 1)
        OutputDebugString(L"We were able to decrypt from a public key! That's not good.");

    result = edc->ImportPrivateKey(L"private_unencrypted.pem");
    result = edc->DecryptDataFromFile(&decodedData, L"encrypted.txt", &decodedLen);
    edc->WriteBytesFile(L"decrypted.txt", decodedData, decodedLen);
    return 0;
}