package com.lowagie.bc.asn1; import java.io.ByteArrayInputStream; import java.io.EOFException; import java.io.FilterInputStream; import java.io.IOException; import java.io.InputStream; /** * Don't use this class. It will eventually disappear, use ASN1InputStream. *
* This class is scheduled for removal. */ public class DERInputStream extends FilterInputStream implements DERTags { public DERInputStream( InputStream is) { super(is); } protected int readLength() throws IOException { 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; 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; } while (left > 0) { int l = read(bytes, bytes.length - left, left); if (l < 0) { throw new EOFException("unexpected end of stream"); } left -= l; } } /** * build an object given its tag and a byte stream to construct it * from. */ protected DERObject buildObject( int tag, byte[] bytes) throws IOException { 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: return new DERBoolean(bytes); 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) { return new DERTaggedObject(false, tag & 0x1f, new DERNull()); } 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); } } public DERObject readObject() throws IOException { int tag = read(); if (tag == -1) { throw new EOFException(); } int length = readLength(); byte[] bytes = new byte[length]; readFully(bytes); return buildObject(tag, bytes); } }