如何获取PCCERT_CONTEXT私钥的NCRYPT_KEY_HANDLE?

How can I get a NCRYPT_KEY_HANDLE for the private key of a PCCERT_CONTEXT?

本文关键字:私钥 NCRYPT KEY HANDLE CONTEXT 获取 PCCERT 何获取      更新时间:2023-10-16

如何从 Windows 证书存储中PCCERT_CONTEXT的私钥获取使用 CNG 进行加密/解密的NCRYPT_KEY_HANDLE

CryptEncrypt函数已被NCryptEncryptBCryptEncrypt函数取代,但没有立即明显的方法可以从 Windows 证书存储中的PCCERT_CONTEXT获取这些函数的句柄。

是否可以使用CNG函数使用证书(私钥)进行加密/解密,而无需解析导出证书等暴力破解方法?

我自己回答这个问题,因为我在其他地方找不到答案:

以下代码将得到你想要的:

const HCERTSTORE store(CertOpenStore(CERT_STORE_PROV_SYSTEM_W, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, 0, CERT_SYSTEM_STORE_LOCAL_MACHINE | CERT_STORE_READONLY_FLAG, (const void*)L"MY"));
const PCCERT_CONTEXT certContext(CertFindCertificateInStore(store, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, 0, CERT_FIND_SUBJECT_STR_W, subjectName, nullptr));
if (certContext)
{
HCRYPTPROV_OR_NCRYPT_KEY_HANDLE keyHandle;
DWORD keySpec;
BOOL callerFreesKeyHandle;
// Get NCrypt key handle from certificate.
// Might fail for instance if certificate private key is not accessible to current user.
if (CryptAcquireCertificatePrivateKey(certContext, CRYPT_ACQUIRE_SILENT_FLAG | CRYPT_ACQUIRE_ONLY_NCRYPT_KEY_FLAG, nullptr, &keyHandle, &keySpec, &callerFreesKeyHandle))
{
check(keySpec == CERT_NCRYPT_KEY_SPEC); //< Should always have this value when giving CRYPT_ACQUIRE_ONLY_NCRYPT_KEY_FLAG.
UNIQUE_NCRYPT_KEY_HANDLE keyHandleKeeper;
if (callerFreesKeyHandle)
{
keyHandleKeeper.reset(keyHandle);
}
...