用 bouncycastle 解析 asn.1答案

【问题标题】：parsing asn.1 with bouncycastle用 bouncycastle 解析 asn.1
【发布时间】：2016-03-05 00:54:45
【问题描述】：

我有一些 asn.1 编码数据。我用 bouncycastle 解码它取得了一些成功，但我用相当复杂的例子碰壁了。一定是可行的，但不能更进一步，希望你能帮助我，这里是示例数据：

A1 81 A9 02 02 1C 1F 02 01 15 30 81 9F 55 02 01 14 A0 81 98 A4 81 95 6B 10 30 0E 80 04 00 00 01 1F A1 06 30 04 80 02 33 32 63 06 30 04 80 02 33 32 61 0E 30 0C 80 0A 30 32 32 33 37 38 33 36 31 30 62 06 30 04 80 02 33 32 64 02 87 00 6B 13 30 11 80 04 00 00 01 1F A1 09 30 07 80 05 23 23 37 30 30 4E 01 02 0A 01 16 67 12 30 10 A3 0E 81 0C 2B 34 38 32 32 33 37 38 33 36 31 30 68 0F 30 0D A3 0B 82 09 32 32 38 36 35 33 33 39 38 65 09 30 07 80 05 23 23 37 30 30 7E 12 A0 10 18 0E 32 30 31 36 30 33 30 32 32 32 30 31 33 36

CSTA Browser decoded:

rOSE.roiv-apdu
{ -- SEQUENCE -- 
    invokeID = 7199,
    operation-value = 21 (cSTAEventReport),
    argument
    { -- SEQUENCE -- 
        crossRefIdentifier = '01 14'H,
        eventSpecificInfo.callControlEvents.delivered
        { -- SEQUENCE -- 
            connection.both
            { -- SEQUENCE -- 
                callID = '00 00 01 1F'H,
                deviceID.staticID
                { -- SEQUENCE -- 
                    deviceIdentifier.dialingNumber = "32" '33 32'H
                }
            },
            alertingDevice.deviceIdentifier
            { -- SEQUENCE -- 
                deviceIdentifier.dialingNumber = "32" '33 32'H
            },
            callingDevice.deviceIdentifier
            { -- SEQUENCE -- 
                deviceIdentifier.dialingNumber = "0223783610" '30 32 32 33 37 38 33 36 31 30'H
            },
            calledDevice.deviceIdentifier
            { -- SEQUENCE -- 
                deviceIdentifier.dialingNumber = "32" '33 32'H
            },
            lastRedirectionDevice.notKnown NULL,
            originatingNIDConnection.both
            { -- SEQUENCE -- 
                callID = '00 00 01 1F'H,
                deviceID.staticID
                { -- SEQUENCE -- 
                    deviceIdentifier.dialingNumber = "##700" '23 23 37 30 30'H
                }
            },
            localConnectionInfo = 2 (alerting),
            cause = 22 (newCall),
            networkCallingDevice.deviceIdentifier
            { -- SEQUENCE -- 
                deviceIdentifier.explicitPublic.international = "+48223783610" '2B 34 38 32 32 33 37 38 33 36 31 30'H
            },
            networkCalledDevice.deviceIdentifier
            { -- SEQUENCE -- 
                deviceIdentifier.explicitPublic.national = "228653398" '32 32 38 36 35 33 33 39 38'H
            },
            associatedCallingDevice.deviceIdentifier
            { -- SEQUENCE -- 
                deviceIdentifier.dialingNumber = "##700" '23 23 37 30 30'H
            },
            extensions
            { -- SEQUENCE -- 
                security
                { -- SEQUENCE -- 
                    timestamp = "20160302220136" '32 30 31 36 30 33 30 32 32 32 30 31 33 36'H
                }
            }
        }
    }
}

bouncycastle 的转储会产生类似的结果：

00 AC A1 81 A9 02 02 5F B9 02 01 15 30 81 9F 55 02 01 91 A0 81 98 A4 81 95 6B 10 30 0E 80 04 00 00 03 98 A1 06 30 04 80 02 33 32 63 06 30 04 80 02 33 32 61 0E 30 0C 80 0A 30 32 32 33 37 38 33 36 31 30 62 06 30 04 80 02 33 32 64 02 87 00 6B 13 30 11 80 04 00 00 03 98 A1 09 30 07 80 05 23 23 37 30 30 4E 01 02 0A 01 16 67 12 30 10 A3 0E 81 0C 2B 34 38 32 32 33 37 38 33 36 31 30 68 0F 30 0D A3 0B 82 09 32 32 38 36 35 33 33 39 38 65 09 30 07 80 05 23 23 37 30 30 7E 12 A0 10 18 0E 32 30 31 36 30 33 30 34 31 35 32 32 34 30 
buf:Tagged [1] IMPLICIT 
    Sequence
        Integer(24505)
        Integer(21)
        DER Sequence
            DER ApplicationSpecific[21] (0191)
            Tagged [0]
                Tagged [4] IMPLICIT 
                    Sequence
                        DER ApplicationSpecific[11]
                            Sequence
                                Tagged [0] IMPLICIT 
                                    DER Octet String[4] 
                                Tagged [1]
                                    DER Sequence
                                        Tagged [0] IMPLICIT 
                                            DER Octet String[2] 
                        DER ApplicationSpecific[3]
                            Sequence
                                Tagged [0] IMPLICIT 
                                    DER Octet String[2] 
                        DER ApplicationSpecific[1]
                            Sequence
                                Tagged [0] IMPLICIT 
                                    DER Octet String[10] 
                        DER ApplicationSpecific[2]
                            Sequence
                                Tagged [0] IMPLICIT 
                                    DER Octet String[2] 
                        DER ApplicationSpecific[4]
                            Tagged [7] IMPLICIT 
                                DER Octet String[0] 
                        DER ApplicationSpecific[11]
                            Sequence
                                Tagged [0] IMPLICIT 
                                    DER Octet String[4] 
                                Tagged [1]
                                    DER Sequence
                                        Tagged [0] IMPLICIT 
                                            DER Octet String[5] 
                        DER ApplicationSpecific[14] (02)
                        DER Enumerated(22)
                        DER ApplicationSpecific[7]
                            Sequence
                                Tagged [3]
                                    Tagged [1] IMPLICIT 
                                        DER Octet String[12] 
                        DER ApplicationSpecific[8]
                            Sequence
                                Tagged [3]
                                    Tagged [2] IMPLICIT 
                                        DER Octet String[9] 
                        DER ApplicationSpecific[5]
                            Sequence
                                Tagged [0] IMPLICIT 
                                    DER Octet String[5] 
                        DER ApplicationSpecific[30]
                            Tagged [0]
                                GeneralizedTime(20160304152240GMT+01:00)

我正在尝试解析它：

protected void parse() {
    logger.trace("Executing parse()");

    try {

        ASN1InputStream input = new ASN1InputStream(asn1Data);
        ASN1Primitive p;

        if ((p = input.readObject()) != null) {
            ASN1TaggedObject o1 = ASN1TaggedObject.getInstance(p);
            ASN1Sequence s1 = ASN1Sequence.getInstance(o1.getObject());
            invokeID = Integer.parseInt(s1.getObjectAt(0).toString());
            operationValue = Integer.parseInt(s1.getObjectAt(1).toString());

            DERSequence ders = (DERSequence) DERSequence.getInstance(s1.getObjectAt(2));
            DERApplicationSpecific das = (DERApplicationSpecific) ders.getObjectAt(0);
            crossRefIdentifier = das.getContents();



     //here are some experiments, but can't get the right objects I could parse / walk through

            ASN1TaggedObject o2 = ASN1TaggedObject.getInstance(ders.getObjectAt(1));
            DERTaggedObject dto = (DERTaggedObject) o2.getObject();

            ASN1Sequence s2 = ASN1Sequence.getInstance(dto.getObject());
            DERApplicationSpecific das1 = (DERApplicationSpecific) s2.getObjectAt(0);
            ASN1Sequence s3 = (ASN1Sequence) das1.getObject();

            }
    } catch (Exception ex) {
        logger.warn("exception while parsing ASN1 data", ex);
    }

}

如您所见，我已经能够解码一些基本标签（即invokeID、操作值和crossRefIdentifier），但无法更深入地了解树（callId、callingNumber ...）。如果您有这方面的经验，我将不胜感激。

【问题讨论】：

标签： decode bouncycastle asn.1

【解决方案1】：

这是一个非常复杂的 ASN.1 对象。由于结构差异，有几个地方可能会与另一个样本出错。这是一个例子。

using System;
using System.Collections;
using System.IO;
using Org.BouncyCastle.Asn1;

namespace Asn1ParseBouncy
{
    class Program
    {
        static void Main(string[] args)
        {
            var bytes2Parse = File.ReadAllBytes(@"c:\a.req");

            // (0,169) CONTEXT SPECIFIC(1)
            DerTaggedObject rootObj = (DerTaggedObject)Asn1Object.FromByteArray(bytes2Parse);

            if (rootObj.TagNo == 1)
            {
                ParseAtRootLevel(rootObj);
            }
            else
            {
                throw new Exception("Expected Tag number to be 1");
            }
        }

        private static void ParseAtRootLevel(DerTaggedObject rootObj)
        {
            // SEQUENCE under CONTEXT SPECIFIC(1)
            var seq = (Asn1Sequence)rootObj.GetObject();

            IEnumerator e = seq.GetEnumerator();
            bool hasNext;
            hasNext = e.MoveNext();

            // (3,2) INTEGER -> invokeID 
            {
                Asn1Encodable obj;

                if (!hasNext)
                {
                    throw new Exception("more entries expected in sequence");
                }
                obj = (Asn1Encodable)e.Current;

                // TODO: put in a property of class that represents whole ASN.1 message
                var invokeID = DerInteger.GetInstance(obj);

                hasNext = e.MoveNext();

            }

            // (7,1) INTEGER -> operation-value
            {
                Asn1Encodable obj;

                if (!hasNext)
                {
                    throw new Exception("more entries expected in sequence");
                }
                obj = (Asn1Encodable)e.Current;

                // TODO: put in a property of class that represents whole ASN.1 message
                var operationValue = DerInteger.GetInstance(obj);

                hasNext = e.MoveNext();

            }

            // (10,159) SEQUENCE -> argument
            {
                Asn1Encodable obj;

                if (!hasNext)
                {
                    throw new Exception("more entries expected in sequence");
                }
                obj = (Asn1Encodable)e.Current;

                var argumentSeq = Asn1Sequence.GetInstance(obj);

                // argumentData is parsed asn.1 object - argument 
                var argumentData = ParseArgumentData(argumentSeq);

                hasNext = e.MoveNext();
            }

            if (hasNext)
            {
                throw new Exception("no more entries expected in sequence");
            }
        }

        private static object ParseArgumentData(Asn1Sequence argumentSeq)
        {
            IEnumerator e = argumentSeq.GetEnumerator();
            bool hasNext;
            hasNext = e.MoveNext();

            // (13,2) APPLICATION (21) -> crossRefIdentifier  
            {
                Asn1Encodable obj;

                if (!hasNext)
                {
                    throw new Exception("more entries expected in sequence");
                }
                obj = (Asn1Encodable)e.Current;

                var crossRefIdentifierAppSpecific = (DerApplicationSpecific)obj;
                if (crossRefIdentifierAppSpecific.ApplicationTag != 21)
                    throw new Exception("Expected application tag 21");

                // TODO: put in a property of class that represents whole ASN.1 message
                var crossRefIdentifier = crossRefIdentifierAppSpecific.GetContents();

                hasNext = e.MoveNext();

            }

            // (17,152) CONTEXT SPECIFIC (0) -> eventSpecificInfo.callControlEvents.delivered  
            {
                Asn1Encodable obj;

                if (!hasNext)
                {
                    throw new Exception("more entries expected in sequence");
                }
                obj = (Asn1Encodable)e.Current;

                var eventSpecificInfo = ((DerTaggedObject)obj);

                if (eventSpecificInfo.TagNo != 0)
                    throw new Exception("Expected Context specific tag number to be 0");

                // TODO: put in a property of class that represents whole ASN.1 message
                var eventSpecificInfoData = ParseEventSpecificInfo(eventSpecificInfo);

                hasNext = e.MoveNext();

            }

            if (hasNext)
            {
                throw new Exception("no more entries expected in sequence");
            }

            // TODO: return parsed values in some class
            return null;
        }

        private static object ParseEventSpecificInfo(DerTaggedObject obj)
        {
            // still (17,152) CONTEXT SPECIFIC (0)
            var connectionBothData = ParseConnectionBoth(obj);

            return connectionBothData;
        }

        private static object ParseConnectionBoth(DerTaggedObject connectionBoth)
        {
            // (20,149) CONTEXT SPECIFIC (4)->connection.both
            var connectionBothTagged = (DerTaggedObject)connectionBoth.GetObject();

            if (connectionBothTagged.TagNo != 4)
                throw new Exception("Expected Context specific tag number to be 4");

            // Sequence under (20,149) CONTEXT SPECIFIC (4) -> connection.both
            var connectionBothSeq = (DerSequence)connectionBothTagged.GetObject();

            IEnumerator e = connectionBothSeq.GetEnumerator();
            bool hasNext;
            hasNext = e.MoveNext();

            // callID   
            {
                Asn1Encodable obj;

                if (!hasNext)
                {
                    throw new Exception("more entries expected in sequence");
                }
                obj = (Asn1Encodable)e.Current;

                // (23,16) APPLICATION (11)
                // TODO: put in a property of class that represents whole ASN.1 message
                var callIDTagged = (DerApplicationSpecific)obj;
                if (callIDTagged.ApplicationTag != 11)
                    throw new Exception("Expected tag number 11");

                // (25,14) SEQUENCE
                var callIdSeq = callIDTagged.GetObject().GetDerEncoded();

                // TODO: parse CallIdSeq -> (27,4) ContextSpecific(0), (33,6) ContextSpecific(1)

                hasNext = e.MoveNext();

            }

            // TODO: continue with (41,6) Application (3)
            // TODO: continue with (49,14) Application (1)
            // TODO: continue with (65,6) Application (2)
            // etc.

            // TOOD: return something useful
            throw new NotImplementedException();
        }
    }
}

我根据ASN.1 Editor的转储在代码示例中添加了注释

如果您有对象的 ASN.1 定义，您的生活会轻松很多。在Binary Notes 的帮助下，您可以生成类来解析 ASN.1 数据对象。

【讨论】：

感谢您的推荐。 BinaryNotes 为我生成了类。现在我只是在寻找有关如何使用它们的信息或示例。
写在page 12的文档中
谢谢，它看起来很有希望。不幸的是，更复杂的方法会导致异常（通常是空指针）。由于我正在尝试与 PBX 通信，因此我与 PBX 供应商进行了交谈，并正在寻找完整的 asn.1 包。看起来我已经找到的东西不能用于我的目的。我很好奇 BinaryNotes 是否会处理这些 asn.1 文件。使用 asn.1 文件，我找到了简单的方法 MonitorStart，生成了非常简单的输出： 03 03 00 33 32 ，这只是我应该收到的代码的一小部分。
恐怕我无法进一步帮助您解决这个问题。我必须有权访问您拥有的所有东西（测试环境、PBX ...）。至于 BinaryNotes，我们已经对其进行了修改以使用充气城堡生成类（它看起来像我写的示例），所以也许调试和发现问题会更好。 BinaryNotes 将 ASN.1 表示法解析为 xml 结构，然后使用 xslt 转换生成代码类。默认情况下，它会生成自己的带有注释的类，但也许值得研究和更改以生成有弹性的类。
我理解并感谢您的努力。也许当我从供应商那里收到 asn1 时，您可以尝试为我生成 bouncycastle 可解析类，仅用于 EventReport 一种方法。我的项目所需的不太复杂的结构我已经自己完成了，坦率地说，这个结构也几乎完成了。在某些时候，我在从 DERTaggedObject 读取二进制八位位组时遇到问题，但经过一些试验和错误并以不同的方式转换对象后，我终于读到了我想要的内容。我的课程不太像 OOP，但应该足以简单地读取从 PBX 接收到的事件。