Java tutorial
package org.bouncycastle.asn1.util; import java.io.IOException; import java.util.Enumeration; import org.bouncycastle.asn1.ASN1ApplicationSpecific; import org.bouncycastle.asn1.ASN1Boolean; import org.bouncycastle.asn1.ASN1Encodable; import org.bouncycastle.asn1.ASN1Enumerated; import org.bouncycastle.asn1.ASN1External; import org.bouncycastle.asn1.ASN1GeneralizedTime; import org.bouncycastle.asn1.ASN1Integer; import org.bouncycastle.asn1.ASN1ObjectIdentifier; import org.bouncycastle.asn1.ASN1OctetString; import org.bouncycastle.asn1.ASN1Primitive; import org.bouncycastle.asn1.ASN1Sequence; import org.bouncycastle.asn1.ASN1Set; import org.bouncycastle.asn1.ASN1TaggedObject; import org.bouncycastle.asn1.ASN1UTCTime; import org.bouncycastle.asn1.BERApplicationSpecific; import org.bouncycastle.asn1.BEROctetString; import org.bouncycastle.asn1.BERSequence; import org.bouncycastle.asn1.BERSet; import org.bouncycastle.asn1.BERTaggedObject; import org.bouncycastle.asn1.BERTags; import org.bouncycastle.asn1.DERApplicationSpecific; import org.bouncycastle.asn1.DERBMPString; import org.bouncycastle.asn1.DERBitString; import org.bouncycastle.asn1.DERGraphicString; import org.bouncycastle.asn1.DERIA5String; import org.bouncycastle.asn1.DERNull; import org.bouncycastle.asn1.DERPrintableString; import org.bouncycastle.asn1.DERSequence; import org.bouncycastle.asn1.DERSet; import org.bouncycastle.asn1.DERT61String; import org.bouncycastle.asn1.DERUTF8String; import org.bouncycastle.asn1.DERVideotexString; import org.bouncycastle.asn1.DERVisibleString; import org.bouncycastle.asn1.DLApplicationSpecific; import org.bouncycastle.util.Strings; import org.bouncycastle.util.encoders.Hex; /** * Utility class for dumping ASN.1 objects as (hopefully) human friendly strings. */ public class ASN1Dump { private static final String TAB = " "; private static final int SAMPLE_SIZE = 32; /** * dump a DER object as a formatted string with indentation * * @param obj the ASN1Primitive to be dumped out. */ static void _dumpAsString(String indent, boolean verbose, ASN1Primitive obj, StringBuffer buf) { String nl = Strings.lineSeparator(); if (obj instanceof ASN1Sequence) { Enumeration e = ((ASN1Sequence) obj).getObjects(); String tab = indent + TAB; buf.append(indent); if (obj instanceof BERSequence) { buf.append("BER Sequence"); } else if (obj instanceof DERSequence) { buf.append("DER Sequence"); } else { buf.append("Sequence"); } buf.append(nl); while (e.hasMoreElements()) { Object o = e.nextElement(); if (o == null || o.equals(DERNull.INSTANCE)) { buf.append(tab); buf.append("NULL"); buf.append(nl); } else if (o instanceof ASN1Primitive) { _dumpAsString(tab, verbose, (ASN1Primitive) o, buf); } else { _dumpAsString(tab, verbose, ((ASN1Encodable) o).toASN1Primitive(), buf); } } } else if (obj instanceof ASN1TaggedObject) { String tab = indent + TAB; buf.append(indent); if (obj instanceof BERTaggedObject) { buf.append("BER Tagged ["); } else { buf.append("Tagged ["); } ASN1TaggedObject o = (ASN1TaggedObject) obj; buf.append(Integer.toString(o.getTagNo())); buf.append(']'); if (!o.isExplicit()) { buf.append(" IMPLICIT "); } buf.append(nl); _dumpAsString(tab, verbose, o.getObject(), buf); } else if (obj instanceof ASN1Set) { Enumeration e = ((ASN1Set) obj).getObjects(); String tab = indent + TAB; buf.append(indent); if (obj instanceof BERSet) { buf.append("BER Set"); } else if (obj instanceof DERSet) { buf.append("DER Set"); } else { buf.append("Set"); } buf.append(nl); while (e.hasMoreElements()) { Object o = e.nextElement(); if (o == null) { buf.append(tab); buf.append("NULL"); buf.append(nl); } else if (o instanceof ASN1Primitive) { _dumpAsString(tab, verbose, (ASN1Primitive) o, buf); } else { _dumpAsString(tab, verbose, ((ASN1Encodable) o).toASN1Primitive(), buf); } } } else if (obj instanceof ASN1OctetString) { ASN1OctetString oct = (ASN1OctetString) obj; if (obj instanceof BEROctetString) { buf.append(indent + "BER Constructed Octet String" + "[" + oct.getOctets().length + "] "); } else { buf.append(indent + "DER Octet String" + "[" + oct.getOctets().length + "] "); } if (verbose) { buf.append(dumpBinaryDataAsString(indent, oct.getOctets())); } else { buf.append(nl); } } else if (obj instanceof ASN1ObjectIdentifier) { buf.append(indent + "ObjectIdentifier(" + ((ASN1ObjectIdentifier) obj).getId() + ")" + nl); } else if (obj instanceof ASN1Boolean) { buf.append(indent + "Boolean(" + ((ASN1Boolean) obj).isTrue() + ")" + nl); } else if (obj instanceof ASN1Integer) { buf.append(indent + "Integer(" + ((ASN1Integer) obj).getValue() + ")" + nl); } else if (obj instanceof DERBitString) { DERBitString bt = (DERBitString) obj; buf.append(indent + "DER Bit String" + "[" + bt.getBytes().length + ", " + bt.getPadBits() + "] "); if (verbose) { buf.append(dumpBinaryDataAsString(indent, bt.getBytes())); } else { buf.append(nl); } } else if (obj instanceof DERIA5String) { buf.append(indent + "IA5String(" + ((DERIA5String) obj).getString() + ") " + nl); } else if (obj instanceof DERUTF8String) { buf.append(indent + "UTF8String(" + ((DERUTF8String) obj).getString() + ") " + nl); } else if (obj instanceof DERPrintableString) { buf.append(indent + "PrintableString(" + ((DERPrintableString) obj).getString() + ") " + nl); } else if (obj instanceof DERVisibleString) { buf.append(indent + "VisibleString(" + ((DERVisibleString) obj).getString() + ") " + nl); } else if (obj instanceof DERBMPString) { buf.append(indent + "BMPString(" + ((DERBMPString) obj).getString() + ") " + nl); } else if (obj instanceof DERT61String) { buf.append(indent + "T61String(" + ((DERT61String) obj).getString() + ") " + nl); } else if (obj instanceof DERGraphicString) { buf.append(indent + "GraphicString(" + ((DERGraphicString) obj).getString() + ") " + nl); } else if (obj instanceof DERVideotexString) { buf.append(indent + "VideotexString(" + ((DERVideotexString) obj).getString() + ") " + nl); } else if (obj instanceof ASN1UTCTime) { buf.append(indent + "UTCTime(" + ((ASN1UTCTime) obj).getTime() + ") " + nl); } else if (obj instanceof ASN1GeneralizedTime) { buf.append(indent + "GeneralizedTime(" + ((ASN1GeneralizedTime) obj).getTime() + ") " + nl); } else if (obj instanceof BERApplicationSpecific) { buf.append(outputApplicationSpecific("BER", indent, verbose, obj, nl)); } else if (obj instanceof DERApplicationSpecific) { buf.append(outputApplicationSpecific("DER", indent, verbose, obj, nl)); } else if (obj instanceof DLApplicationSpecific) { buf.append(outputApplicationSpecific("", indent, verbose, obj, nl)); } else if (obj instanceof ASN1Enumerated) { ASN1Enumerated en = (ASN1Enumerated) obj; buf.append(indent + "DER Enumerated(" + en.getValue() + ")" + nl); } else if (obj instanceof ASN1External) { ASN1External ext = (ASN1External) obj; buf.append(indent + "External " + nl); String tab = indent + TAB; if (ext.getDirectReference() != null) { buf.append(tab + "Direct Reference: " + ext.getDirectReference().getId() + nl); } if (ext.getIndirectReference() != null) { buf.append(tab + "Indirect Reference: " + ext.getIndirectReference().toString() + nl); } if (ext.getDataValueDescriptor() != null) { _dumpAsString(tab, verbose, ext.getDataValueDescriptor(), buf); } buf.append(tab + "Encoding: " + ext.getEncoding() + nl); _dumpAsString(tab, verbose, ext.getExternalContent(), buf); } else { buf.append(indent + obj.toString() + nl); } } private static String outputApplicationSpecific(String type, String indent, boolean verbose, ASN1Primitive obj, String nl) { ASN1ApplicationSpecific app = ASN1ApplicationSpecific.getInstance(obj); StringBuffer buf = new StringBuffer(); if (app.isConstructed()) { try { ASN1Sequence s = ASN1Sequence.getInstance(app.getObject(BERTags.SEQUENCE)); buf.append(indent + type + " ApplicationSpecific[" + app.getApplicationTag() + "]" + nl); for (Enumeration e = s.getObjects(); e.hasMoreElements();) { _dumpAsString(indent + TAB, verbose, (ASN1Primitive) e.nextElement(), buf); } } catch (IOException e) { buf.append(e); } return buf.toString(); } return indent + type + " ApplicationSpecific[" + app.getApplicationTag() + "] (" + Strings.fromByteArray(Hex.encode(app.getContents())) + ")" + nl; } /** * dump out a DER object as a formatted string, in non-verbose mode. * * @param obj the ASN1Primitive to be dumped out. * @return the resulting string. */ public static String dumpAsString(Object obj) { return dumpAsString(obj, false); } /** * Dump out the object as a string. * * @param obj the object to be dumped * @param verbose if true, dump out the contents of octet and bit strings. * @return the resulting string. */ public static String dumpAsString(Object obj, boolean verbose) { StringBuffer buf = new StringBuffer(); if (obj instanceof ASN1Primitive) { _dumpAsString("", verbose, (ASN1Primitive) obj, buf); } else if (obj instanceof ASN1Encodable) { _dumpAsString("", verbose, ((ASN1Encodable) obj).toASN1Primitive(), buf); } else { return "unknown object type " + obj.toString(); } return buf.toString(); } private static String dumpBinaryDataAsString(String indent, byte[] bytes) { String nl = Strings.lineSeparator(); StringBuffer buf = new StringBuffer(); indent += TAB; buf.append(nl); for (int i = 0; i < bytes.length; i += SAMPLE_SIZE) { if (bytes.length - i > SAMPLE_SIZE) { buf.append(indent); buf.append(Strings.fromByteArray(Hex.encode(bytes, i, SAMPLE_SIZE))); buf.append(TAB); buf.append(calculateAscString(bytes, i, SAMPLE_SIZE)); buf.append(nl); } else { buf.append(indent); buf.append(Strings.fromByteArray(Hex.encode(bytes, i, bytes.length - i))); for (int j = bytes.length - i; j != SAMPLE_SIZE; j++) { buf.append(" "); } buf.append(TAB); buf.append(calculateAscString(bytes, i, bytes.length - i)); buf.append(nl); } } return buf.toString(); } private static String calculateAscString(byte[] bytes, int off, int len) { StringBuffer buf = new StringBuffer(); for (int i = off; i != off + len; i++) { if (bytes[i] >= ' ' && bytes[i] <= '~') { buf.append((char) bytes[i]); } } return buf.toString(); } }