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using System;
using System.IO;
using Org.BouncyCastle.Utilities;
namespace Org.BouncyCastle.Asn1
{
/**
* Base class for an application specific object
*/
public class DerApplicationSpecific
: Asn1Object
{
private readonly bool isConstructed;
private readonly int tag;
private readonly byte[] octets;
internal DerApplicationSpecific(
bool isConstructed,
int tag,
byte[] octets)
{
this.isConstructed = isConstructed;
this.tag = tag;
this.octets = octets;
}
public DerApplicationSpecific(
int tag,
byte[] octets)
: this(false, tag, octets)
{
}
public DerApplicationSpecific(
int tag,
Asn1Encodable obj)
: this(true, tag, obj)
{
}
public DerApplicationSpecific(
bool isExplicit,
int tag,
Asn1Encodable obj)
{
Asn1Object asn1Obj = obj.ToAsn1Object();
byte[] data = asn1Obj.GetDerEncoded();
this.isConstructed = Asn1TaggedObject.IsConstructed(isExplicit, asn1Obj);
this.tag = tag;
if (isExplicit)
{
this.octets = data;
}
else
{
int lenBytes = GetLengthOfHeader(data);
byte[] tmp = new byte[data.Length - lenBytes];
Array.Copy(data, lenBytes, tmp, 0, tmp.Length);
this.octets = tmp;
}
}
public DerApplicationSpecific(
int tagNo,
Asn1EncodableVector vec)
{
this.tag = tagNo;
this.isConstructed = true;
MemoryStream bOut = new MemoryStream();
for (int i = 0; i != vec.Count; i++)
{
try
{
byte[] bs = vec[i].GetDerEncoded();
bOut.Write(bs, 0, bs.Length);
}
catch (IOException e)
{
throw new InvalidOperationException("malformed object", e);
}
}
this.octets = bOut.ToArray();
}
private int GetLengthOfHeader(
byte[] data)
{
int length = data[1]; // TODO: assumes 1 byte tag
if (length == 0x80)
{
return 2; // indefinite-length encoding
}
if (length > 127)
{
int size = length & 0x7f;
// Note: The invalid long form "0xff" (see X.690 8.1.3.5c) will be caught here
if (size > 4)
{
throw new InvalidOperationException("DER length more than 4 bytes: " + size);
}
return size + 2;
}
return 2;
}
public bool IsConstructed()
{
return isConstructed;
}
public byte[] GetContents()
{
return octets;
}
public int ApplicationTag
{
get { return tag; }
}
/**
* Return the enclosed object assuming explicit tagging.
*
* @return the resulting object
* @throws IOException if reconstruction fails.
*/
public Asn1Object GetObject()
{
return FromByteArray(GetContents());
}
/**
* Return the enclosed object assuming implicit tagging.
*
* @param derTagNo the type tag that should be applied to the object's contents.
* @return the resulting object
* @throws IOException if reconstruction fails.
*/
public Asn1Object GetObject(
int derTagNo)
{
if (derTagNo >= 0x1f)
throw new IOException("unsupported tag number");
byte[] orig = this.GetEncoded();
byte[] tmp = ReplaceTagNumber(derTagNo, orig);
if ((orig[0] & Asn1Tags.Constructed) != 0)
{
tmp[0] |= Asn1Tags.Constructed;
}
return FromByteArray(tmp);
}
internal override void Encode(Asn1OutputStream asn1Out, bool withID)
{
int flags = Asn1Tags.Application;
if (isConstructed)
{
flags |= Asn1Tags.Constructed;
}
asn1Out.WriteEncodingDL(withID, flags, tag, octets);
}
protected override bool Asn1Equals(
Asn1Object asn1Object)
{
DerApplicationSpecific other = asn1Object as DerApplicationSpecific;
if (other == null)
return false;
return this.isConstructed == other.isConstructed
&& this.tag == other.tag
&& Arrays.AreEqual(this.octets, other.octets);
}
protected override int Asn1GetHashCode()
{
return isConstructed.GetHashCode() ^ tag.GetHashCode() ^ Arrays.GetHashCode(octets);
}
private byte[] ReplaceTagNumber(
int newTag,
byte[] input)
{
int tagNo = input[0] & 0x1f;
int index = 1;
// with tagged object tag number is bottom 5 bits, or stored at the start of the content
if (tagNo == 0x1f)
{
int b = input[index++];
// X.690-0207 8.1.2.4.2
// "c) bits 7 to 1 of the first subsequent octet shall not all be zero."
if ((b & 0x7f) == 0) // Note: -1 will pass
throw new IOException("corrupted stream - invalid high tag number found");
while ((b & 0x80) != 0)
{
b = input[index++];
}
}
int remaining = input.Length - index;
byte[] tmp = new byte[1 + remaining];
tmp[0] = (byte)newTag;
Array.Copy(input, index, tmp, 1, remaining);
return tmp;
}
}
}
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