Add an `OpenSSL::X509::Extension#inspect` method

从 OpenSSL::X509::Extension 类开始，检查拟议的 inspect 实现所使用的现有 oid、value 和 critical? 方法。比较 issue 中当前的输出和拟议的输出，然后验证 inspect 一个 extension 会以所示格式公开这三个值。

Not being able to inspect the contents of OpenSSL::X509::Extension objects is confusing.

Current Output

cert.extensions
=> 
[#<OpenSSL::X509::Extension:0x00007f8ef961b798>,      
 #<OpenSSL::X509::Extension:0x00007f8ef961b770>,      
 #<OpenSSL::X509::Extension:0x00007f8ef961b748>,      
 #<OpenSSL::X509::Extension:0x00007f8ef961b720>,      
 #<OpenSSL::X509::Extension:0x00007f8ef961b6f8>,      
 #<OpenSSL::X509::Extension:0x00007f8ef961b6d0>,      
 #<OpenSSL::X509::Extension:0x00007f8ef961b6a8>,      
 #<OpenSSL::X509::Extension:0x00007f8ef961b680>,      
 #<OpenSSL::X509::Extension:0x00007f8ef961b658>,      
 #<OpenSSL::X509::Extension:0x00007f8ef961b630>]

Proposed New Output

cert.extensions
# => [#<OpenSSL::X509::Extension: @oid="authorityKeyIdentifier" @value="keyid:B7:6B:A2:EA:A8:AA:84:8C:79:EA:B4:DA:0F:98:B2:C5:95:76:B9:F4\n" @critical=false>,
#<OpenSSL::X509::Extension: @oid="subjectKeyIdentifier" @value="F7:2A:09:D0:24:5B:11:71:EE:BA:BE:F4:3E:1C:3D:56:12:88:16:BB" @critical=false>,
#<OpenSSL::X509::Extension: @oid="subjectAltName" @value="DNS:www.example.org, DNS:example.net, DNS:example.edu, DNS:example.com, DNS:example.org, DNS:www.example.com, DNS:www.example.edu, DNS:www.example.net" @critical=false>,
#<OpenSSL::X509::Extension: @oid="keyUsage" @value="Digital Signature, Key Encipherment" @critical=true>,
#<OpenSSL::X509::Extension: @oid="extendedKeyUsage" @value="TLS Web Server Authentication, TLS Web Client Authentication" @critical=false>,
#<OpenSSL::X509::Extension: @oid="crlDistributionPoints" @value="\nFull Name:\n  URI:http://crl3.digicert.com/DigiCertTLSRSASHA2562020CA1-4.crl\n\nFull Name:\n  URI:http://crl4.digicert.com/DigiCertTLSRSASHA2562020CA1-4.crl\n" @critical=false>,
#<OpenSSL::X509::Extension: @oid="certificatePolicies" @value="Policy: 2.23.140.1.2.2\n  CPS: http://www.digicert.com/CPS\n" @critical=false>,
#<OpenSSL::X509::Extension: @oid="authorityInfoAccess" @value="OCSP - URI:http://ocsp.digicert.com\nCA Issuers - URI:http://cacerts.digicert.com/DigiCertTLSRSASHA2562020CA1-1.crt\n" @critical=false>,
#<OpenSSL::X509::Extension: @oid="basicConstraints" @value="CA:FALSE" @critical=false>,
#<OpenSSL::X509::Extension: @oid="ct_precert_scts" @value="Signed Certificate Timestamp:\n    Version   : v1 (0x0)\n    Log ID    : E8:3E:D0:DA:3E:F5:06:35:32:E7:57:28:BC:89:6B:C9:\n                03:D3:CB:D1:11:6B:EC:EB:69:E1:77:7D:6D:06:BD:6E\n    Timestamp : Mar 14 22:48:46.197 2022 GMT\n    Extensions: none\n    Signature : ecdsa-with-SHA256\n                30:44:02:20:31:78:F3:53:EB:46:7F:BD:32:53:3D:5A:\n                F2:88:6C:D7:AC:BC:42:34:94:2A:B5:E5:0B:92:0B:81:\n                10:C6:C6:FE:02:20:47:74:30:BC:82:C9:21:60:14:7E:\n                F4:9F:25:0F:F3:32:6A:AB:D8:90:DA:9D:61:3C:BB:36:\n                C2:E0:45:9B:73:00\nSigned Certificate Timestamp:\n    Version   : v1 (0x0)\n    Log ID    : 35:CF:19:1B:BF:B1:6C:57:BF:0F:AD:4C:6D:42:CB:BB:\n                B6:27:20:26:51:EA:3F:E1:2A:EF:A8:03:C3:3B:D6:4C\n    Timestamp : Mar 14 22:48:46.204 2022 GMT\n    Extensions: none\n    Signature : ecdsa-with-SHA256\n                30:44:02:20:3B:29:4F:1C:24:50:1A:44:A1:E0:3E:22:\n                89:4D:63:03:8A:97:D6:31:9B:09:3C:D7:AC:9D:D0:ED:\n                88:24:F6:5C:02:20:15:F1:35:A1:A0:E2:E2:8A:A1:8A:\n                9D:8D:36:09:D7:06:5C:EC:C0:CC:2E:ED:4F:A9:BB:3A:\n                D2:C0:92:ED:BE:58\nSigned Certificate Timestamp:\n    Version   : v1 (0x0)\n    Log ID    : B3:73:77:07:E1:84:50:F8:63:86:D6:05:A9:DC:11:09:\n                4A:79:2D:B1:67:0C:0B:87:DC:F0:03:0E:79:36:A5:9A\n    Timestamp : Mar 14 22:48:46.215 2022 GMT\n    Extensions: none\n    Signature : ecdsa-with-SHA256\n                30:45:02:20:29:1E:EA:C0:F2:D0:6F:A5:13:DB:E4:BB:\n                C3:BB:90:B1:BB:03:65:F6:55:5F:F8:3C:16:40:6D:02:\n                5B:5A:4E:90:02:21:00:CB:76:D7:9D:44:D1:8D:86:EC:\n                D8:A4:1E:A0:98:10:72:76:1B:52:42:2E:58:64:BB:29:\n                16:F6:95:1E:97:96:D7" @critical=false>]

Proposed Code

module OpenSSL
  module X509
    class Extension

      def inspect
        "#<#{self.class}: @oid=#{oid.inspect} @value=#{value.inspect} @critical=#{critical?.inspect}>"
      end

    end
  end
end