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DERInputStream.javaAPI DocAndroid 1.5 API7461Wed May 06 22:41:06 BST 2009org.bouncycastle.asn1

DERInputStream

public class DERInputStream extends FilterInputStream implements DERTags
Don't use this class. It will eventually disappear, use ASN1InputStream.
This class is scheduled for removal.
deprecated
use ASN1InputStream

Fields Summary
Constructors Summary
public DERInputStream(InputStream is)

deprecated
use ASN1InputStream

        super(is);
    
Methods Summary
protected DERObjectbuildObject(int tag, byte[] bytes)
build an object given its tag and a byte stream to construct it from.

        switch (tag)
        {
        case NULL:
            return null;   
        case SEQUENCE | CONSTRUCTED:
            ByteArrayInputStream    bIn = new ByteArrayInputStream(bytes);
            BERInputStream          dIn = new BERInputStream(bIn);
            DERConstructedSequence  seq = new DERConstructedSequence();

            try
            {
                for (;;)
                {
                    DERObject   obj = dIn.readObject();

                    seq.addObject(obj);
                }
            }
            catch (EOFException ex)
            {
                return seq;
            }
        case SET | CONSTRUCTED:
            bIn = new ByteArrayInputStream(bytes);
            dIn = new BERInputStream(bIn);

            ASN1EncodableVector    v = new ASN1EncodableVector();

            try
            {
                for (;;)
                {
                    DERObject   obj = dIn.readObject();

                    v.add(obj);
                }
            }
            catch (EOFException ex)
            {
                return new DERConstructedSet(v);
            }
        case BOOLEAN:
            // BEGIN android-changed
            return DERBoolean.getInstance(bytes);
            // BEGIN android-changed
        case INTEGER:
            return new DERInteger(bytes);
        case ENUMERATED:
            return new DEREnumerated(bytes);
        case OBJECT_IDENTIFIER:
            return new DERObjectIdentifier(bytes);
        case BIT_STRING:
            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 UTF8_STRING:
            return new DERUTF8String(bytes);
        case PRINTABLE_STRING:
            return new DERPrintableString(bytes);
        case IA5_STRING:
            return new DERIA5String(bytes);
        case T61_STRING:
            return new DERT61String(bytes);
        case VISIBLE_STRING:
            return new DERVisibleString(bytes);
        case UNIVERSAL_STRING:
            return new DERUniversalString(bytes);
        case GENERAL_STRING:
            return new DERGeneralString(bytes);
        case BMP_STRING:
            return new DERBMPString(bytes);
        case OCTET_STRING:
            return new DEROctetString(bytes);
        case UTC_TIME:
            return new DERUTCTime(bytes);
        case GENERALIZED_TIME:
            return new DERGeneralizedTime(bytes);
        default:
            //
            // with tagged object tag number is bottom 5 bits
            //
            if ((tag & TAGGED) != 0)  
            {
                if ((tag & 0x1f) == 0x1f)
                {
                    throw new IOException("unsupported high tag encountered");
                }

                if (bytes.length == 0)        // empty tag!
                {
                    if ((tag & CONSTRUCTED) == 0)
                    {
                        // BEGIN android-changed
                        return new DERTaggedObject(false, tag & 0x1f, DERNull.THE_ONE);
                        // END android-changed
                    }
                    else
                    {
                        return new DERTaggedObject(false, tag & 0x1f, new DERConstructedSequence());
                    }
                }

                //
                // simple type - implicit... return an octet string
                //
                if ((tag & CONSTRUCTED) == 0)
                {
                    return new DERTaggedObject(false, tag & 0x1f, new DEROctetString(bytes));
                }

                bIn = new ByteArrayInputStream(bytes);
                dIn = new BERInputStream(bIn);

                DEREncodable dObj = dIn.readObject();

                //
                // explicitly tagged (probably!) - if it isn't we'd have to
                // tell from the context
                //
                if (dIn.available() == 0)
                {
                    return new DERTaggedObject(tag & 0x1f, dObj);
                }

                //
                // another implicit object, we'll create a sequence...
                //
                seq = new DERConstructedSequence();

                seq.addObject(dObj);

                try
                {
                    for (;;)
                    {
                        dObj = dIn.readObject();

                        seq.addObject(dObj);
                    }
                }
                catch (EOFException ex)
                {
                    // ignore --
                }

                return new DERTaggedObject(false, tag & 0x1f, seq);
            }

            return new DERUnknownTag(tag, bytes);
        }
    
protected voidreadFully(byte[] bytes)

        int     left = bytes.length;

        if (left == 0)
        {
            return;
        }

        while (left > 0)
        {
            int    l = read(bytes, bytes.length - left, left);
            
            if (l < 0)
            {
                throw new EOFException("unexpected end of stream");
            }
            
            left -= l;
        }
    
protected intreadLength()

        int length = read();
        if (length < 0)
        {
            throw new IOException("EOF found when length expected");
        }

        if (length == 0x80)
        {
            return -1;      // indefinite-length encoding
        }

        if (length > 127)
        {
            int size = length & 0x7f;

            if (size > 4)
            {
                throw new IOException("DER length more than 4 bytes");
            }
            
            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;
            }
            
            if (length < 0)
            {
                throw new IOException("corrupted steam - negative length found");
            }
        }

        return length;
    
public DERObjectreadObject()

        int tag = read();
        if (tag == -1)
        {
            throw new EOFException();
        }

        int     length = readLength();
        byte[]  bytes = new byte[length];

        readFully(bytes);

        return buildObject(tag, bytes);