Windows XP 与 Vista/7 上的 MS Crypto API 行为

我试图了解如何在 XP、Vista 和 Windows 7 上从 PEM 格式（示例包含在下面的代码中）导入公钥。示例代码将在 XP 和 Windows Vista/7 上导入密钥，但不会一样的方法。

在 Windows XP 上，字符串“（原型）”加密提供者的名称中必需的，并允许传递对 CryptImportPublicKeyInfo 的调用。

在 Windows 7 上，“（原型）”提供程序显然存在，但不支持对 CryptImportPublicKeyInfo 的调用，这令人困惑。

这些操作系统之间的正确实现是什么样的？是否有必要检测XP并请求名称“（原型）”，并且对于其他操作系统没有它？是否有可能在某些 XP 系统上仍然会失败？

或者，有没有办法检测这种令人困惑的行为并选择哪个加密提供程序将支持必要的调用？

Windows 7 上的输出：

ANALYZING CRYPTOGRAPHIC SUPPORT FOR:
     "Microsoft Enhanced RSA and AES Cryptographic Provider"
     CryptAcquireContext success.
     CryptAcquireContext.1 success.
     CryptStringToBinary.2 success.
     CryptDecodeObjectEx success.
     CryptImportPublicKeyInfo success.
     SUCCESS.
ANALYZING CRYPTOGRAPHIC SUPPORT FOR:
     "Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)"
     CryptAcquireContext success.
     CryptAcquireContext.1 success.
     CryptStringToBinary.2 success.
     CryptDecodeObjectEx success.
     CryptImportPublicKeyInfo FAILED****.

Windows XP 上的输出：

ANALYZING CRYPTOGRAPHIC SUPPORT FOR:
     "Microsoft Enhanced RSA and AES Cryptographic Provider"
     CryptAcquireContext success.
     CryptAcquireContext.1 success.
     CryptStringToBinary.2 success.
     CryptDecodeObjectEx success.
     CryptImportPublicKeyInfo FAILED****.
ANALYZING CRYPTOGRAPHIC SUPPORT FOR:
     "Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)"
     CryptAcquireContext success.
     CryptAcquireContext.1 success.
     CryptStringToBinary.2 success.
     CryptDecodeObjectEx success.
     CryptImportPublicKeyInfo success.
     SUCCESS.

产生该输出的 C++ 源代码：（需要 crypt32.lib）

#include <stdio.h>
#include <tchar.h>
#include <windows.h>
#include <wincrypt.h>

bool windowsAcquireProviderContext(HCRYPTPROV *pHandleProv, LPCTSTR pProviderName);
bool analyzeCryptographicSupport(LPCTSTR pProviderName);

int _tmain(int argc, _TCHAR* argv[])
{
    analyzeCryptographicSupport(MS_ENH_RSA_AES_PROV);
    analyzeCryptographicSupport(L"Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)");
    return 0;
}

bool windowsAcquireProviderContext(HCRYPTPROV *pHandleProv, LPCTSTR pProviderName) {
    WCHAR *pContainerName = L"blah blah blah";
    if(!CryptAcquireContext(pHandleProv, pContainerName, pProviderName, PROV_RSA_AES, CRYPT_SILENT)) {
        if(GetLastError() == NTE_BAD_KEYSET) {
            if(CryptAcquireContext(pHandleProv, pContainerName, pProviderName, PROV_RSA_AES, CRYPT_NEWKEYSET|CRYPT_SILENT)) {
                return true;
            }
        } 
    }
    return true;
}

LPCWSTR pwszPemPublicKey = 
    L"-----BEGIN PUBLIC KEY-----\r\n"
    L"MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC6GUVcbn92bahlwOskKi8XkG9q\r\n"
    L"Vq863+C4cOWC6HzJojc011pJFFIBu8/pG1EI8FZJdBmTrFaJTriYw1/SpbOH0QqE\r\n"
    L"eHanT8qWn+S5m9xgDJoWTBJKcnu3OHOvJJU3c8jOHQQnRWLfghJH4vnwStdiwUUY\r\n"
    L"SMWpwuHObsNelGBgEQIDAQAB\r\n"
    L"-----END PUBLIC KEY-----\r\n";
int pemPublicKeySize = wcslen(pwszPemPublicKey);

bool analyzeCryptographicSupport(LPCTSTR pProviderName) {

    printf("ANALYZING CRYPTOGRAPHIC SUPPORT FOR:\r\n");
    wprintf(L"\t \"%s\"\r\n", pProviderName);

    HCRYPTPROV hProv;
    if(!windowsAcquireProviderContext(&hProv, pProviderName)) {
        wprintf(L"\t CryptAcquireContext FAILED.\r\n");
        return false;
    }
    wprintf(L"\t CryptAcquireContext success.\r\n");

    DWORD blobSize;

    if(!CryptStringToBinary(pwszPemPublicKey, pemPublicKeySize, CRYPT_STRING_BASE64_ANY,  NULL, &blobSize, NULL, NULL)) {
        CryptReleaseContext(hProv, 0);
        wprintf(L"\t CryptStringToBinary.1 FAILED****.\r\n");
        return false;
    }
    wprintf(L"\t CryptAcquireContext.1 success.\r\n");

    BYTE *pBlob = (BYTE *)malloc(blobSize);

    if(!CryptStringToBinary(pwszPemPublicKey, pemPublicKeySize, CRYPT_STRING_BASE64_ANY,  pBlob, &blobSize, NULL, NULL)) {
        free(pBlob);
        CryptReleaseContext(hProv, 0);
        wprintf(L"\t CryptStringToBinary.2 FAILED****.\r\n");
        return false;
    }
    wprintf(L"\t CryptStringToBinary.2 success.\r\n");

    CERT_PUBLIC_KEY_INFO *publicKeyInfo;
    DWORD publicKeyInfoLen;
    HCRYPTKEY hPublicKey;

    if(!CryptDecodeObjectEx(X509_ASN_ENCODING|PKCS_7_ASN_ENCODING, X509_PUBLIC_KEY_INFO, pBlob, blobSize, CRYPT_DECODE_ALLOC_FLAG, NULL, &publicKeyInfo, &publicKeyInfoLen)) {
        free(pBlob);
        CryptReleaseContext(hProv, 0);
        wprintf(L"\t CryptDecodeObjectEx FAILED****.\r\n");
        return false;
    }
    wprintf(L"\t CryptDecodeObjectEx success.\r\n");

    if(!CryptImportPublicKeyInfo(hProv, X509_ASN_ENCODING|PKCS_7_ASN_ENCODING, publicKeyInfo, &hPublicKey)) {
        LocalFree(publicKeyInfo);
        free(pBlob);
        CryptReleaseContext(hProv, 0);
        wprintf(L"\t CryptImportPublicKeyInfo FAILED****.\r\n");
        return false;
    }
    wprintf(L"\t CryptImportPublicKeyInfo success.\r\n");

    CryptDestroyKey(hPublicKey);
    LocalFree(publicKeyInfo);
    free(pBlob);
    CryptReleaseContext(hProv, 0);

    wprintf(L"\t SUCCESS.\r\n");
    return true;
}

你所描述的问题的原因很简单：Microsoft 更名为 AES 加密提供商 from

• "Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)"在 Windows XP 中
• "Microsoft Enhanced RSA and AES Cryptographic Provider"在更高版本的操作系统中。

In WinCrypt.h定义相应的常数为MS_ENH_RSA_AES_PROV and MS_ENH_RSA_AES_PROV_XP您可以使用它。

如果您不想测试操作系统的版本，您可以使用地穴获取上下文 with NULL as pszProvider（并继续使用PROV_RSA_AES as the dwProvType）。在您的代码中您可以包含analyzeCryptographicSupport(NULL);.

您还可以检查注册表项的“名称”值

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography\Defaults\Provider Types\Type 024

查看默认名称PROV_RSA_AES提供者。