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The Long Term Stable (LTS) Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains the JCA/JCE provider and low-level API for the BC LTS version 2.73.7 for Java 8 and later.

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package org.bouncycastle.asn1;

import java.io.IOException;

/**
 * ASN.1 OctetStrings, with indefinite length rules, and constructed form support.
 * 

* The Basic Encoding Rules (BER) format allows encoding using so called "constructed form", * which DER and CER formats forbid allowing only "primitive form". *

* This class always produces the constructed form with underlying segments * in an indefinite length array. If the input wasn't the same, then this output * is not faithful reproduction. *

*

* See {@link ASN1OctetString} for X.690 encoding rules of OCTET-STRING objects. *

*/ public class BEROctetString extends ASN1OctetString { private static final int DEFAULT_SEGMENT_LIMIT = 1000; private final int segmentLimit; private final ASN1OctetString[] elements; /** * Convert a vector of octet strings into a single byte string */ static byte[] flattenOctetStrings(ASN1OctetString[] octetStrings) { int count = octetStrings.length; switch (count) { case 0: return EMPTY_OCTETS; case 1: return octetStrings[0].string; default: { int totalOctets = 0; for (int i = 0; i < count; ++i) { totalOctets += octetStrings[i].string.length; } byte[] string = new byte[totalOctets]; for (int i = 0, pos = 0; i < count; ++i) { byte[] octets = octetStrings[i].string; System.arraycopy(octets, 0, string, pos, octets.length); pos += octets.length; } // assert pos == totalOctets; return string; } } } /** * Create an OCTET-STRING object from a byte[] * @param string the octets making up the octet string. */ public BEROctetString(byte[] string) { this(string, DEFAULT_SEGMENT_LIMIT); } /** * Multiple {@link ASN1OctetString} data blocks are input, * the result is constructed form. * * @param elements an array of OCTET STRING to construct the BER OCTET STRING from. */ public BEROctetString(ASN1OctetString[] elements) { this(elements, DEFAULT_SEGMENT_LIMIT); } /** * Create an OCTET-STRING object from a byte[] * @param string the octets making up the octet string. * @param segmentLimit the number of octets stored in each DER encoded component OCTET STRING. */ public BEROctetString(byte[] string, int segmentLimit) { this(string, null, segmentLimit); } /** * Multiple {@link ASN1OctetString} data blocks are input, * the result is constructed form. * * @param elements an array of OCTET STRING to construct the BER OCTET STRING from. * @param segmentLimit the number of octets stored in each DER encoded component OCTET STRING. */ public BEROctetString(ASN1OctetString[] elements, int segmentLimit) { this(flattenOctetStrings(elements), elements, segmentLimit); } private BEROctetString(byte[] string, ASN1OctetString[] elements, int segmentLimit) { super(string); this.elements = elements; this.segmentLimit = segmentLimit; } boolean encodeConstructed() { return true; } int encodedLength(boolean withTag) throws IOException { int totalLength = withTag ? 4 : 3; if (null != elements) { for (int i = 0; i < elements.length; ++i) { totalLength += elements[i].encodedLength(true); } } else { int fullSegments = string.length / segmentLimit; totalLength += fullSegments * DEROctetString.encodedLength(true, segmentLimit); int lastSegmentLength = string.length - (fullSegments * segmentLimit); if (lastSegmentLength > 0) { totalLength += DEROctetString.encodedLength(true, lastSegmentLength); } } return totalLength; } void encode(ASN1OutputStream out, boolean withTag) throws IOException { out.writeIdentifier(withTag, BERTags.CONSTRUCTED | BERTags.OCTET_STRING); out.write(0x80); if (null != elements) { out.writePrimitives(elements); } else { int pos = 0; while (pos < string.length) { int segmentLength = Math.min(string.length - pos, segmentLimit); DEROctetString.encode(out, true, string, pos, segmentLength); pos += segmentLength; } } out.write(0x00); out.write(0x00); } }




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