asn1inputstream.java

进行与数字证书相关开发必须的java源码

// Decompiled by Jad v1.5.7g. Copyright 2000 Pavel Kouznetsov.
// Jad home page: http://www.geocities.com/SiliconValley/Bridge/8617/jad.html
// Decompiler options: packimports(3) fieldsfirst ansi 
// Source File Name:   ASN1InputStream.java

package jit.asn1;

import java.io.*;
import java.util.Vector;

// Referenced classes of package jit.asn1:
//            DERInputStream, DERNull, ASN1EncodableVector, DERObject, 
//            DERSequence, DERSet, DERBoolean, DERInteger, 
//            DEREnumerated, DERObjectIdentifier, DERBitString, DERUTF8String, 
//            DERPrintableString, DERIA5String, DERT61String, DERVisibleString, 
//            DERUniversalString, DERBMPString, DEROctetString, DERUTCTime, 
//            DERGeneralizedTime, DERTaggedObject, DEREncodable, DERUnknownTag, 
//            BERConstructedOctetString, BERNull, BERSequence, BERSet, 
//            BERTaggedObject, DEROutputStream

public class ASN1InputStream extends DERInputStream
{

    private DERObject END_OF_STREAM;
    boolean eofFound;

    public ASN1InputStream(InputStream is)
    {
        super(is);
        END_OF_STREAM = ((ASN1InputStream)this). new DERObject() {

            void encode(DEROutputStream out)
                throws IOException
            {
                throw new IOException("Eeek!");
            }

        };
        eofFound = false;
    }

    protected int readLength()
        throws IOException
    {
        int length = read();
        if(length < 0)
            throw new IOException("EOF found when length expected");
        if(length == 128)
            return -1;
        if(length > 127)
        {
            int size = length & 0x7f;
            length = 0;
            for(int i = 0; i < size; i++)
            {
                int next = read();
                if(next < 0)
                    throw new IOException("EOF found reading length");
                length = (length << 8) + next;
            }

        }
        return length;
    }

    protected void readFully(byte bytes[])
        throws IOException
    {
        int left = bytes.length;
        if(left == 0)
            return;
        int len;
        while((len = read(bytes, bytes.length - left, left)) > 0) 
            if((left -= len) == 0)
                return;
        if(left != 0)
            throw new EOFException("EOF encountered in middle of object");
        else
            return;
    }

    protected DERObject buildObject(int tag, byte bytes[])
        throws IOException
    {
        switch(tag)
        {
        case 5: // '\005'
            return new DERNull();

        case 48: // '0'
            ByteArrayInputStream bIn = new ByteArrayInputStream(bytes);
            ASN1InputStream aIn = new ASN1InputStream(bIn);
            ASN1EncodableVector v = new ASN1EncodableVector();
            for(DERObject obj = aIn.readObject(); obj != null; obj = aIn.readObject())
                v.add(obj);

            return new DERSequence(v);

        case 49: // '1'
            ByteArrayInputStream bIn = new ByteArrayInputStream(bytes);
            ASN1InputStream aIn = new ASN1InputStream(bIn);
            ASN1EncodableVector v = new ASN1EncodableVector();
            for(DERObject obj = aIn.readObject(); obj != null; obj = aIn.readObject())
                v.add(obj);

            return new DERSet(v);

        case 1: // '\001'
            return new DERBoolean(bytes);

        case 2: // '\002'
            return new DERInteger(bytes);

        case 10: // '\n'
            return new DEREnumerated(bytes);

        case 6: // '\006'
            return new DERObjectIdentifier(bytes);

        case 3: // '\003'
            int padBits = bytes[0];
            byte data[] = new byte[bytes.length - 1];
            System.arraycopy(bytes, 1, data, 0, bytes.length - 1);
            return new DERBitString(data, padBits);

        case 12: // '\f'
            return new DERUTF8String(bytes);

        case 19: // '\023'
            return new DERPrintableString(bytes);

        case 22: // '\026'
            return new DERIA5String(bytes);

        case 20: // '\024'
            return new DERT61String(bytes);

        case 26: // '\032'
            return new DERVisibleString(bytes);

        case 28: // '\034'
            return new DERUniversalString(bytes);

        case 30: // '\036'
            return new DERBMPString(bytes);

        case 4: // '\004'
            return new DEROctetString(bytes);

        case 23: // '\027'
            return new DERUTCTime(bytes);

        case 24: // '\030'
            return new DERGeneralizedTime(bytes);
        }
        if((tag & 0x80) != 0)
        {
            int tagNo = tag & 0x1f;
            if(tagNo == 31)
            {
                int idx = 0;
                for(tagNo = 0; (bytes[idx] & 0x80) != 0; tagNo <<= 7)
                    tagNo |= bytes[idx++] & 0x7f;

                tagNo |= bytes[idx] & 0x7f;
                byte tmp[] = bytes;
                bytes = new byte[tmp.length - (idx + 1)];
                System.arraycopy(tmp, idx + 1, bytes, 0, bytes.length);
            }
            if(bytes.length == 0)
                if((tag & 0x20) == 0)
                    return new DERTaggedObject(false, tagNo, new DERNull());
                else
                    return new DERTaggedObject(false, tagNo, new DERSequence());
            if((tag & 0x20) == 0)
                return new DERTaggedObject(false, tagNo, new DEROctetString(bytes));
            ByteArrayInputStream bIn = new ByteArrayInputStream(bytes);
            ASN1InputStream aIn = new ASN1InputStream(bIn);
            DEREncodable dObj = aIn.readObject();
            if(aIn.available() == 0)
                return new DERTaggedObject(tagNo, dObj);
            ASN1EncodableVector v = new ASN1EncodableVector();
            for(; dObj != null; dObj = aIn.readObject())
                v.add(dObj);

            return new DERTaggedObject(false, tagNo, new DERSequence(v));
        } else
        {
            return new DERUnknownTag(tag, bytes);
        }
    }

    private byte[] readIndefiniteLengthFully()
        throws IOException
    {
        ByteArrayOutputStream bOut = new ByteArrayOutputStream();
        int b;
        for(int b1 = read(); (b = read()) >= 0 && (b1 != 0 || b != 0); b1 = b)
            bOut.write(b1);

        return bOut.toByteArray();
    }

    private BERConstructedOctetString buildConstructedOctetString()
        throws IOException
    {
        Vector octs = new Vector();
        do
        {
            DERObject o = readObject();
            if(o != END_OF_STREAM)
                octs.addElement(o);
            else
                return new BERConstructedOctetString(octs);
        } while(true);
    }

    public DERObject readObject()
        throws IOException
    {
        int tag = read();
        if(tag == -1)
            if(eofFound)
            {
                throw new EOFException("attempt to read past end of file.");
            } else
            {
                eofFound = true;
                return null;
            }
        int length = readLength();
        if(length < 0)
        {
            switch(tag)
            {
            case 5: // '\005'
                return new BERNull();

            case 48: // '0'
                ASN1EncodableVector v = new ASN1EncodableVector();
                do
                {
                    DERObject obj = readObject();
                    if(obj != END_OF_STREAM)
                        v.add(obj);
                    else
                        return new BERSequence(v);
                } while(true);

            case 49: // '1'
                ASN1EncodableVector v = new ASN1EncodableVector();
                do
                {
                    DERObject obj = readObject();
                    if(obj != END_OF_STREAM)
                        v.add(obj);
                    else
                        return new BERSet(v);
                } while(true);

            case 36: // '$'
                return buildConstructedOctetString();
            }
            if((tag & 0x80) != 0)
            {
                int tagNo = tag & 0x1f;
                if(tagNo == 31)
                {
                    int b = read();
                    tagNo = 0;
                    for(; b >= 0 && (b & 0x80) != 0; b = read())
                    {
                        tagNo |= b & 0x7f;
                        tagNo <<= 7;
                    }

                    tagNo |= b & 0x7f;
                }
                if((tag & 0x20) == 0)
                {
                    byte bytes[] = readIndefiniteLengthFully();
                    return new BERTaggedObject(false, tagNo, new DEROctetString(bytes));
                }
                DERObject dObj = readObject();
                if(dObj == END_OF_STREAM)
                    return new DERTaggedObject(tagNo);
                DERObject next = readObject();
                if(next == END_OF_STREAM)
                    return new BERTaggedObject(tagNo, dObj);
                ASN1EncodableVector v = new ASN1EncodableVector();
                v.add(dObj);
                do
                {
                    v.add(next);
                    next = readObject();
                } while(next != END_OF_STREAM);
                return new BERTaggedObject(false, tagNo, new BERSequence(v));
            } else
            {
                throw new IOException("unknown BER object encountered");
            }
        }
        if(tag == 0 && length == 0)
        {
            return END_OF_STREAM;
        } else
        {
            byte bytes[] = new byte[length];
            readFully(bytes);
            return buildObject(tag, bytes);
        }
    }
}