| package org.bouncycastle.asn1.x9; |
| |
| import java.util.Enumeration; |
| |
| import org.bouncycastle.asn1.ASN1EncodableVector; |
| import org.bouncycastle.asn1.ASN1Object; |
| import org.bouncycastle.asn1.ASN1ObjectIdentifier; |
| import org.bouncycastle.asn1.ASN1OctetString; |
| import org.bouncycastle.asn1.ASN1Primitive; |
| import org.bouncycastle.asn1.ASN1Sequence; |
| import org.bouncycastle.asn1.DERSequence; |
| |
| /** |
| * ASN.1 def for Diffie-Hellman key exchange KeySpecificInfo structure. See |
| * RFC 2631, or X9.42, for further details. |
| * <pre> |
| * KeySpecificInfo ::= SEQUENCE { |
| * algorithm OBJECT IDENTIFIER, |
| * counter OCTET STRING SIZE (4..4) |
| * } |
| * </pre> |
| */ |
| public class KeySpecificInfo |
| extends ASN1Object |
| { |
| private ASN1ObjectIdentifier algorithm; |
| private ASN1OctetString counter; |
| |
| /** |
| * Base constructor. |
| * |
| * @param algorithm algorithm identifier for the CEK. |
| * @param counter initial counter value for key derivation. |
| */ |
| public KeySpecificInfo( |
| ASN1ObjectIdentifier algorithm, |
| ASN1OctetString counter) |
| { |
| this.algorithm = algorithm; |
| this.counter = counter; |
| } |
| |
| /** |
| * Return a KeySpecificInfo object from the passed in object. |
| * |
| * @param obj an object for conversion or a byte[]. |
| * @return a KeySpecificInfo |
| */ |
| public static KeySpecificInfo getInstance(Object obj) |
| { |
| if (obj instanceof KeySpecificInfo) |
| { |
| return (KeySpecificInfo)obj; |
| } |
| else if (obj != null) |
| { |
| return new KeySpecificInfo(ASN1Sequence.getInstance(obj)); |
| } |
| |
| return null; |
| } |
| |
| private KeySpecificInfo( |
| ASN1Sequence seq) |
| { |
| Enumeration e = seq.getObjects(); |
| |
| algorithm = (ASN1ObjectIdentifier)e.nextElement(); |
| counter = (ASN1OctetString)e.nextElement(); |
| } |
| |
| /** |
| * The object identifier for the CEK wrapping algorithm. |
| * |
| * @return CEK wrapping algorithm OID. |
| */ |
| public ASN1ObjectIdentifier getAlgorithm() |
| { |
| return algorithm; |
| } |
| |
| /** |
| * The initial counter value for key derivation. |
| * |
| * @return initial counter value as a 4 byte octet string (big endian). |
| */ |
| public ASN1OctetString getCounter() |
| { |
| return counter; |
| } |
| |
| /** |
| * Return an ASN.1 primitive representation of this object. |
| * |
| * @return a DERSequence containing the KeySpecificInfo values. |
| */ |
| public ASN1Primitive toASN1Primitive() |
| { |
| ASN1EncodableVector v = new ASN1EncodableVector(); |
| |
| v.add(algorithm); |
| v.add(counter); |
| |
| return new DERSequence(v); |
| } |
| } |