package org.bouncycastle.asn1;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.bouncycastle.util.Arrays;
import org.bouncycastle.util.Strings;
import org.bouncycastle.util.encoders.Hex;
/**
* Abstract base for the ASN.1 OCTET STRING data type
* <p>
* This supports BER, and DER forms of the data.
* </p><p>
* DER form is always primitive single OCTET STRING, while
* BER support includes the constructed forms.
* </p>
* <hr>
* <p><b>X.690</b></p>
* <p><b>8: Basic encoding rules</b></p>
* <p><b>8.7 Encoding of an octetstring value</b></p>
* <p>
* <b>8.7.1</b> The encoding of an octetstring value shall be
* either primitive or constructed at the option of the sender.
* <blockquote>
* NOTE — Where it is necessary to transfer part of an octet string
* before the entire OCTET STRING is available, the constructed encoding
* is used.
* </blockquote>
* <p>
* <b>8.7.2</b> The primitive encoding contains zero,
* one or more contents octets equal in value to the octets
* in the data value, in the order they appear in the data value,
* and with the most significant bit of an octet of the data value
* aligned with the most significant bit of an octet of the contents octets.
* </p>
* <p>
* <b>8.7.3</b> The contents octets for the constructed encoding shall consist
* of zero, one, or more encodings.
* <blockquote>
* NOTE — Each such encoding includes identifier, length, and contents octets,
* and may include end-of-contents octets if it is constructed.
* </blockquote>
* </p>
* <p>
* <b>8.7.3.1</b> To encode an octetstring value in this way,
* it is segmented. Each segment shall consist of a series of
* consecutive octets of the value. There shall be no significance
* placed on the segment boundaries.
* <blockquote>
* NOTE — A segment may be of size zero, i.e. contain no octets.
* </blockquote>
* </p>
* <p>
* <b>8.7.3.2</b> Each encoding in the contents octets shall represent
* a segment of the overall octetstring, the encoding arising from
* a recursive application of this subclause.
* In this recursive application, each segment is treated as if it were
* a octetstring value. The encodings of the segments shall appear in the contents
* octets in the order in which their octets appear in the overall value.
* <blockquote>
* NOTE 1 — As a consequence of this recursion,
* each encoding in the contents octets may itself
* be primitive or constructed.
* However, such encodings will usually be primitive.
* <br />
* NOTE 2 — In particular, the tags in the contents octets are always universal class, number 4.
* </blockquote>
* </p>
* <p><b>9: Canonical encoding rules</b></p>
* <p><b>9.1 Length forms</b></p>
* <p>
* If the encoding is constructed, it shall employ the indefinite-length form.
* If the encoding is primitive, it shall include the fewest length octets necessary.
* [Contrast with 8.1.3.2 b).]
* </p>
* <p><b>9.2 String encoding forms</b></p>
* <p>
* BIT STRING, OCTET STRING,and restricted character string
* values shall be encoded with a primitive encoding if they would
* require no more than 1000 contents octets, and as a constructed
* encoding otherwise. The string fragments contained in
* the constructed encoding shall be encoded with a primitive encoding.
* The encoding of each fragment, except possibly
* the last, shall have 1000 contents octets. (Contrast with 8.21.6.)
* </p><p>
* <b>10: Distinguished encoding rules</b>
* </p><p>
* <b>10.1 Length forms</b>
* The definite form of length encoding shall be used,
* encoded in the minimum number of octets.
* [Contrast with 8.1.3.2 b).]
* </p><p>
* <b>10.2 String encoding forms</b>
* For BIT STRING, OCTET STRING and restricted character string types,
* the constructed form of encoding shall not be used.
* (Contrast with 8.21.6.)
* </p>
*/
public abstract class ASN1OctetString
extends ASN1Primitive
implements ASN1OctetStringParser
{
byte[] string;
/**
* return an Octet String from a tagged object.
*
* @param obj the tagged object holding the object we want.
* @param explicit true if the object is meant to be explicitly
* tagged false otherwise.
* @exception IllegalArgumentException if the tagged object cannot
* be converted.
*/
public static ASN1OctetString getInstance(
ASN1TaggedObject obj,
boolean explicit)
{
ASN1Primitive o = obj.getObject();
if (explicit || o instanceof ASN1OctetString)
{
return getInstance(o);
}
else
{
return BEROctetString.fromSequence(ASN1Sequence.getInstance(o));
}
}
/**
* return an Octet String from the given object.
*
* @param obj the object we want converted.
* @exception IllegalArgumentException if the object cannot be converted.
*/
public static ASN1OctetString getInstance(
Object obj)
{
if (obj == null || obj instanceof ASN1OctetString)
{
return (ASN1OctetString)obj;
}
else if (obj instanceof byte[])
{
try
{
return ASN1OctetString.getInstance(ASN1Primitive.fromByteArray((byte[])obj));
}
catch (IOException e)
{
throw new IllegalArgumentException("failed to construct OCTET STRING from byte[]: " + e.getMessage());
}
}
else if (obj instanceof ASN1Encodable)
{
ASN1Primitive primitive = ((ASN1Encodable)obj).toASN1Primitive();
if (primitive instanceof ASN1OctetString)
{
return (ASN1OctetString)primitive;
}
}
throw new IllegalArgumentException("illegal object in getInstance: " + obj.getClass().getName());
}
/**
* Base constructor.
*
* @param string the octets making up the octet string.
*/
public ASN1OctetString(
byte[] string)
{
if (string == null)
{
throw new NullPointerException("string cannot be null");
}
this.string = string;
}
/**
* Return the content of the OCTET STRING as an InputStream.
*
* @return an InputStream representing the OCTET STRING's content.
*/
public InputStream getOctetStream()
{
return new ByteArrayInputStream(string);
}
/**
* Return the parser associated with this object.
*
* @return a parser based on this OCTET STRING
*/
public ASN1OctetStringParser parser()
{
return this;
}
/**
* Return the content of the OCTET STRING as a byte array.
*
* @return the byte[] representing the OCTET STRING's content.
*/
public byte[] getOctets()
{
return string;
}
public int hashCode()
{
return Arrays.hashCode(this.getOctets());
}
boolean asn1Equals(
ASN1Primitive o)
{
if (!(o instanceof ASN1OctetString))
{
return false;
}
ASN1OctetString other = (ASN1OctetString)o;
return Arrays.areEqual(string, other.string);
}
public ASN1Primitive getLoadedObject()
{
return this.toASN1Primitive();
}
ASN1Primitive toDERObject()
{
return new DEROctetString(string);
}
ASN1Primitive toDLObject()
{
return new DEROctetString(string);
}
abstract void encode(ASN1OutputStream out)
throws IOException;
public String toString()
{
return "#"+ Strings.fromByteArray(Hex.encode(string));
}
}