从 x509 C# 中提取 RSA 公钥

Question

我正在尝试从 X509Certificate base64 中提取 RSA 公钥 PKCS#1。为 zatca 第 2 阶段生成 8 个标签，但我的代码输出不正确，任何人都可以帮助我。我在这里缺少什么？

我使用了以下代码：-

string X509CertificateBase64 = "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";
    
         public string ExtractFromX509Certificate(string certificateStr)
         {
             byte[] data = Convert.FromBase64String(certificateStr);
             var x509 = new X509Certificate2(data);
             
             return Convert.ToBase64String(x509.PublicKey.EncodedKeyValue.RawData);
         }

public string Test1(){
   return   ExtractFromX509Certificate(X509CertificateBase64);

}

输出=“BGGDDKDmhWAITDv7LXqLX2cmr6+qddUkpcLCvWs5rC2O29W/hS4ajAK4Qdnahym6MaijX75Cg3j4aao7ouYXJ9E=”;

但实际输出应该是=“MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAEYYMMoOaFYAhMO/steotfZyavr6p11SSlwsK9azmsLY7b1b+FLhqMArhB2dqHKboxqKNfvkKDePhpqjui5hcn0Q==”;

Answer 1

从证书中可以看出该密钥是 secp256k1 的 EC 公钥。

x509.PublicKey.EncodedKeyValue.RawData

返回未压缩格式的公钥：

0x04 + <32 bytes x coordinate> + <32 bytes y coordinate>

。

MFYw...

指定 X.509/SPKI 格式的公共 EC 密钥。可以以这种格式导出，例如与

x509.GetECDsaPublicKey().ExportSubjectPublicKeyInfo()

。这将返回 DER 编码形式的密钥。如果 DER 编码是 Base64 编码，则返回预期结果

MFYw...

。

using System;
using System.Security.Cryptography.X509Certificates;

...

string X509CertificateBase64 = "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";
byte[] x509CertificateRaw = Convert.FromBase64String(X509CertificateBase64);
X509Certificate2 x509Certificate = new X509Certificate2(x509CertificateRaw);

Console.WriteLine(Convert.ToHexString(x509Certificate.PublicKey.EncodedKeyValue.RawData)); // 0461830CA0E68560084C3BFB2D7A8B5F6726AFAFAA75D524A5C2C2BD6B39AC2D8EDBD5BF852E1A8C02B841D9DA8729BA31A8A35FBE428378F869AA3BA2E61727D1
Console.WriteLine(Convert.ToBase64String(x509Certificate.GetECDsaPublicKey().ExportSubjectPublicKeyInfo())); // MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAEYYMMoOaFYAhMO/steotfZyavr6p11SSlwsK9azmsLY7b1b+FLhqMArhB2dqHKboxqKNfvkKDePhpqjui5hcn0Q==