.NET Framework 4.7.2中调用RSA SignData时出现“密钥集不存在”异常

你的核心问题是错误地将完整PKCS#8格式的私钥字节直接赋值给RSAParameters.D字段，私钥包含多个参数（D、P、Q、DP等），不能单独拆分赋值。以下是修正后的实现：

修正后的签名生成函数 #

public static string GenerateLicenseFromUserInfo(UserLicense info)
{
    // 从Base64解码PKCS#8格式的私钥
    byte[] privateKeyBytes = Convert.FromBase64String("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");

    // 使用RSA.Create()替代RSACryptoServiceProvider，避免CSP密钥容器问题
    using var rsa = RSA.Create();
    // 直接导入完整的PKCS#8私钥
    rsa.ImportPkcs8PrivateKey(privateKeyBytes, out _);

    string userInfo = info.ToString();
    byte[] userInfoBytes = Encoding.UTF8.GetBytes(userInfo);

    // 签名数据
    byte[] signature = rsa.SignData(userInfoBytes, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
    return Convert.ToBase64String(signature);
}

修正后的验证函数 #

public static bool VerifyLicenseFromUserInfo(string receivedLicenseKey, UserLicense info)
{
    byte[] publicKeyBytes = Convert.FromBase64String("MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC8IG4CySTEOZhmDwlTdR4Yd6xoqoJGsfze/RvrZgY72HAuWK0Y3DKrNdFiM+Z2O1weArCyoTbGsZ7UcxhCFKQLSsHooZveQTTHDHvm7cIts8jEMDw/xbPDrMQH/vYjRshNo8vOsVwxQELVzvrMA7+A/3ITKvbL0PTSDxxMcHRQDwIDAQAB");

    using var rsa = RSA.Create();
    // 导入X.509格式的公钥
    rsa.ImportSubjectPublicKeyInfo(publicKeyBytes, out _);

    string userInfo = info.ToString();
    byte[] userInfoBytes = Encoding.UTF8.GetBytes(userInfo);
    byte[] receivedSignature = Convert.FromBase64String(receivedLicenseKey);

    return rsa.VerifyData(userInfoBytes, receivedSignature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
}

关键说明 #

• 你的私钥是PKCS#8格式，公钥是X.509 SubjectPublicKeyInfo格式，不需要手动拆分RSAParameters的各个字段，直接用ImportPkcs8PrivateKey和ImportSubjectPublicKeyInfo即可完整导入密钥。
• 使用RSA.Create()替代RSACryptoServiceProvider，它是.NET标准的RSA实现，避免了传统CSP密钥容器可能带来的"Keyset does not exist"问题。
• 用using语句包裹RSA对象，确保资源正确释放。

内容的提问来源于stack exchange，提问作者Hasan H