从RSA公钥中提取数据

Question

我正在研究涉及阅读用于签署Android APK的公钥数据的项目.我能够成功地将签名提取为公钥.当我查看由此生成的二进制pubkey文件时,我会看到一些纯文本,例如名称和城市.

如何使用PHP(甚至Java或C#)安全地提取嵌入公钥内的名称/城市信息？ 并希望以这样的方式做到这一点,我确切地知道这些字段是什么(即不是盲目地抓取文本,但知道哪个字符串是一个城市,哪个是名字)

澄清:我没有私钥或证书文件.我目前对签名或加密任何东西都不感兴趣,我只想在不使用像regex这样的kludgy方法的情况下提取pubkey中的明文.

更新: 这是我的一个APK中的示例(base64编码)公钥

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

Answer 1

您输入的字符串是一个 Base 64 编码的 x509 证书，而不仅仅是一个公钥。

您需要解析专有名称字段以获取所需的信息。

这是一个 C# 示例：

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

namespace Sample
{
class Program
{
    static void Main(string[] args)
    {
        string base64EncodedX509 =
            "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";
        var rawBytes = Convert.FromBase64String(base64EncodedX509);

        X509Certificate cert = new X509Certificate(rawBytes);

        // Parse the distinguished name to get your desired fields

        Console.WriteLine(cert.Subject); // writes CN=Colin O'Dell, L=Narragansett, S=RI, C=US
        Console.WriteLine(cert.Issuer);  // writes CN=Colin O'Dell, L=Narragansett, S=RI, C=US
    }
}
}