* The RFC 6960 defines a ResponderID structure as: *
* ResponderID ::= CHOICE {
* byName [1] Name,
* byKey [2] KeyHash }
*
* KeyHash ::= OCTET STRING -- SHA-1 hash of responder's public key
* (excluding the tag and length fields)
*
* Name is defined in RFC 5280.
*
*
* @see ResponderId.Type
* @since 9
*/
public final class ResponderId {
/**
* A {@code ResponderId} enumeration describing the accepted forms for a
* {@code ResponderId}.
*
* @see ResponderId
* @since 9
*/
public static enum Type {
/**
* A BY_NAME {@code ResponderId} will be built from a subject name,
* either as an {@code X500Principal} or a DER-encoded byte array.
*/
BY_NAME(1, "byName"),
/**
* A BY_KEY {@code ResponderId} will be built from a public key
* identifier, either derived from a {@code PublicKey} or directly
* from a DER-encoded byte array containing the key identifier.
*/
BY_KEY(2, "byKey");
private final int tagNumber;
private final String ridTypeName;
private Type(int value, String name) {
this.tagNumber = value;
this.ridTypeName = name;
}
public int value() {
return tagNumber;
}
@Override
public String toString() {
return ridTypeName;
}
}
private Type type;
private X500Principal responderName;
private KeyIdentifier responderKeyId;
private byte[] encodedRid;
/**
* Constructs a {@code ResponderId} object using an {@code X500Principal}.
* When encoded in DER this object will use the BY_NAME option.
*
* @param subjectName the subject name of the certificate used
* to sign OCSP responses.
*
* @throws IOException if the internal DER-encoding of the
* {@code X500Principal} fails.
*/
public ResponderId(X500Principal subjectName) throws IOException {
responderName = subjectName;
responderKeyId = null;
encodedRid = principalToBytes();
type = Type.BY_NAME;
}
/**
* Constructs a {@code ResponderId} object using a {@code PublicKey}.
* When encoded in DER this object will use the byKey option, a
* SHA-1 hash of the responder's public key.
*
* @param pubKey the the OCSP responder's public key
*
* @throws IOException if the internal DER-encoding of the
* {@code KeyIdentifier} fails.
*/
public ResponderId(PublicKey pubKey) throws IOException {
responderKeyId = new KeyIdentifier(pubKey);
responderName = null;
encodedRid = keyIdToBytes();
type = Type.BY_KEY;
}
/**
* Constructs a {@code ResponderId} object from its DER-encoding.
*
* @param encodedData the DER-encoded bytes
*
* @throws IOException if the encodedData is not properly DER encoded
*/
public ResponderId(byte[] encodedData) throws IOException {
DerValue outer = new DerValue(encodedData);
if (outer.isContextSpecific((byte)Type.BY_NAME.value())
&& outer.isConstructed()) {
// Use the X500Principal constructor as a way to sanity
// check the incoming data.
responderName = new X500Principal(outer.getDataBytes());
encodedRid = principalToBytes();
type = Type.BY_NAME;
} else if (outer.isContextSpecific((byte)Type.BY_KEY.value())
&& outer.isConstructed()) {
// Use the KeyIdentifier constructor as a way to sanity
// check the incoming data.
responderKeyId =
new KeyIdentifier(new DerValue(outer.getDataBytes()));
encodedRid = keyIdToBytes();
type = Type.BY_KEY;
} else {
throw new IOException("Invalid ResponderId content");
}
}
/**
* Encode a {@code ResponderId} in DER form
*
* @return a byte array containing the DER-encoded representation for this
* {@code ResponderId}
*/
public byte[] getEncoded() {
return encodedRid.clone();
}
/**
* Return the type of {@ResponderId}
*
* @return a number corresponding to the context-specific tag number
* used in the DER-encoding for a {@code ResponderId}
*/
public ResponderId.Type getType() {
return type;
}
/**
* Get the length of the encoded {@code ResponderId} (including the tag and
* length of the explicit tagging from the outer ASN.1 CHOICE).
*
* @return the length of the encoded {@code ResponderId}
*/
public int length() {
return encodedRid.length;
}
/**
* Obtain the underlying {@code X500Principal} from a {@code ResponderId}
*
* @return the {@code X500Principal} for this {@code ResponderId} if it
* is a BY_NAME variant. If the {@code ResponderId} is a BY_KEY
* variant, this routine will return {@code null}.
*/
public X500Principal getResponderName() {
return responderName;
}
/**
* Obtain the underlying key identifier from a {@code ResponderId}
*
* @return the {@code KeyIdentifier} for this {@code ResponderId} if it
* is a BY_KEY variant. If the {@code ResponderId} is a BY_NAME
* variant, this routine will return {@code null}.
*/
public KeyIdentifier getKeyIdentifier() {
return responderKeyId;
}
/**
* Compares the specified object with this {@code ResponderId} for equality.
* A ResponderId will only be considered equivalent if both the type and
* data value are equal. Two ResponderIds initialized by name and
* key ID, respectively, will not be equal even if the
* ResponderId objects are created from the same source certificate.
*
* @param obj the object to be compared against
*
* @return true if the specified object is equal to this {@code Responderid}
*/
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (this == obj) {
return true;
}
if (obj instanceof ResponderId) {
ResponderId respObj = (ResponderId)obj;
return Arrays.equals(encodedRid, respObj.getEncoded());
}
return false;
}
/**
* Returns the hash code value for this {@code ResponderId}
*
* @return the hash code value for this {@code ResponderId}
*/
@Override
public int hashCode() {
return Arrays.hashCode(encodedRid);
}
/**
* Create a String representation of this {@code ResponderId}
*
* @return a String representation of this {@code ResponderId}
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
switch (type) {
case BY_NAME:
sb.append(type).append(": ").append(responderName);
break;
case BY_KEY:
sb.append(type).append(": ");
for (byte keyIdByte : responderKeyId.getIdentifier()) {
sb.append(String.format("%02X", keyIdByte));
}
break;
default:
sb.append("Unknown ResponderId Type: ").append(type);
}
return sb.toString();
}
/**
* Convert the responderName data member into its DER-encoded form
*
* @return the DER encoding for a responder ID byName option, including
* explicit context-specific tagging.
*
* @throws IOException if any encoding error occurs
*/
private byte[] principalToBytes() throws IOException {
DerValue dv = new DerValue(DerValue.createTag(DerValue.TAG_CONTEXT,
true, (byte)Type.BY_NAME.value()),
responderName.getEncoded());
return dv.toByteArray();
}
/**
* Convert the responderKeyId data member into its DER-encoded form
*
* @return the DER encoding for a responder ID byKey option, including
* explicit context-specific tagging.
*
* @throws IOException if any encoding error occurs
*/
private byte[] keyIdToBytes() throws IOException {
// Place the KeyIdentifier bytes into an OCTET STRING
DerValue inner = new DerValue(DerValue.tag_OctetString,
responderKeyId.getIdentifier());
// Mark the OCTET STRING-wrapped KeyIdentifier bytes
// as EXPLICIT CONTEXT 2
DerValue outer = new DerValue(DerValue.createTag(DerValue.TAG_CONTEXT,
true, (byte)Type.BY_KEY.value()), inner.toByteArray());
return outer.toByteArray();
}
}