Question

我正在尝试导出没有私钥的证书，如BASE-64编码文件，与从Windows导出它相同。从Windows导出时，我可以在记事本中打开.cer文件。

当我尝试以下操作并在记事本上打开时，我会得到二进制数据......我认为它是......不可读。

X509Certificate2 cert = new X509Certificate2("c:\\myCert.pfx", "test", X509KeyStorageFlags.Exportable);

File.WriteAllBytes("c:\\testcer.cer", cert.Export(X509ContentType.Cert));

我尝试删除'X509KeyStorageFlags.Exportable'，但这不起作用。我错过了什么吗？

编辑 - 我试过了

File.WriteAllText("c:\\testcer.cer",Convert.ToBase64String(cert.Export(X509ContentType.Cert)))

然而，这似乎有效，错过了“----- BEGIN CERTIFICATE -----”和“----- END CERTIFICATE -----”

Answer 1

也许

/// <summary>
/// Export a certificate to a PEM format string
/// </summary>
/// <param name="cert">The certificate to export</param>
/// <returns>A PEM encoded string</returns>
public static string ExportToPEM(X509Certificate cert)
{
    StringBuilder builder = new StringBuilder();            

    builder.AppendLine("-----BEGIN CERTIFICATE-----");
    builder.AppendLine(Convert.ToBase64String(cert.Export(X509ContentType.Cert), Base64FormattingOptions.InsertLineBreaks));
    builder.AppendLine("-----END CERTIFICATE-----");

    return builder.ToString();
}

Answer 2

试试这个：

X509Certificate2 cerifikata = new X509Certificate2("C://certificate.pfx");
File.WriteAllBytes("D://Test.cer",cerifikata.Export(X509ContentType.Cert));

Answer 3

对于那些在.NET Core中实现类似功能的人来说，这里是基于tyranid所做的代码。 Base64FormattingOptions.InsertLineBreaks并不存在于.NET Core中，因此我必须以自己的方式实现换行。

    // Certificates content has 64 characters per lines
    private const int MaxCharactersPerLine = 64;

    /// <summary>
    /// Export a certificate to a PEM format string
    /// </summary>
    /// <param name="cert">The certificate to export</param>
    /// <returns>A PEM encoded string</returns>
    public static string ExportToPem(this X509Certificate2 cert)
    {
        var builder = new StringBuilder();
        var certContentBase64 = Convert.ToBase64String(cert.Export(X509ContentType.Cert));
        // Calculates the max number of lines this certificate will take.
        var certMaxNbrLines = Math.Ceiling((double)certContentBase64.Length / MaxCharactersPerLine);

        builder.AppendLine("-----BEGIN CERTIFICATE-----");
        for (var index = 0; index < certMaxNbrLines; index++)
        {
            var maxSubstringLength = index * MaxCharactersPerLine + MaxCharactersPerLine > certContentBase64.Length
                ? certContentBase64.Length - index * MaxCharactersPerLine
                : MaxCharactersPerLine;
            builder.AppendLine(certContentBase64.Substring(index * MaxCharactersPerLine, maxSubstringLength));
        }
        builder.AppendLine("-----END CERTIFICATE-----");

        return builder.ToString();
    }

Answer 4

//然而，错过了“----- BEGIN CERTIFICATE -----”和“----- END CERTIFICATE -----”

这些缺失的行是可选的。 CA可能会生成它们，具体取决于设置。出于所有实际原因，可以从Base64编码文件中删除它们。

将证书导出为BASE-64编码的.cer

4 个答案: