* The name constraints extension provides permitted and excluded subtrees that place restrictions on names that may be * included within a certificate issued by a given CA. Restrictions may apply to the subject distinguished name or * subject alternative names. Any name matching a restriction in the excluded subtrees field is invalid regardless of * information appearing in the permitted subtrees. *
* The ASN.1 syntax for this is: * *
* NameConstraints ::= SEQUENCE {
* permittedSubtrees [0] GeneralSubtrees OPTIONAL,
* excludedSubtrees [1] GeneralSubtrees OPTIONAL
* }
* GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree
* GeneralSubtree ::== SEQUENCE {
* base GeneralName,
* minimum [0] BaseDistance DEFAULT 0,
* maximum [1] BaseDistance OPTIONAL }
* BaseDistance ::== INTEGER (0..MAX)
*
*
* @author Amit Kapoor
* @author Hemma Prafullchandra
* @version 1.10
* @see Extension
* @see CertAttrSet
*/
public class NameConstraintsExtension extends Extension implements CertAttrSet {
/**
*
*/
private static final long serialVersionUID = -3506940192931244539L;
/**
* Identifier for this attribute, to be used with the
* get, set, delete methods of Certificate, x509 type.
*/
public static final String IDENT = "x509.info.extensions.NameConstraints";
/**
* Attribute names.
*/
public static final String NAME = "NameConstraints";
public static final String PERMITTED_SUBTREES = "permitted_subtrees";
public static final String EXCLUDED_SUBTREES = "excluded_subtrees";
// Private data members
private static final byte TAG_PERMITTED = 0;
private static final byte TAG_EXCLUDED = 1;
private GeneralSubtrees permitted;
private GeneralSubtrees excluded;
private transient PrettyPrintFormat pp = new PrettyPrintFormat(":");
// Encode this extension value.
private void encodeThis() throws IOException {
DerOutputStream seq = new DerOutputStream();
DerOutputStream tagged = new DerOutputStream();
if ((permitted != null) && (permitted.getSubtrees().size() > 0)) {
DerOutputStream tmp = new DerOutputStream();
permitted.encode(tmp);
tagged.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT,
true, TAG_PERMITTED), tmp);
}
if ((excluded != null) && (excluded.getSubtrees().size() > 0)) {
DerOutputStream tmp = new DerOutputStream();
excluded.encode(tmp);
tagged.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT,
true, TAG_EXCLUDED), tmp);
}
if (permitted == null && excluded == null) {
extensionValue = null; // no need to encode this extension
} else {
seq.write(DerValue.tag_Sequence, tagged);
this.extensionValue = seq.toByteArray();
}
}
/**
* The default constructor for this class. Either parameter
* can be set to null to indicate it is omitted but both
* cannot be null.
*
* @param permitted the permitted GeneralSubtrees (null for optional).
* @param excluded the excluded GeneralSubtrees (null for optional).
*/
public NameConstraintsExtension(GeneralSubtrees permitted,
GeneralSubtrees excluded)
throws IOException {
init(false, permitted, excluded);
}
public NameConstraintsExtension(boolean critical,
GeneralSubtrees permitted, GeneralSubtrees excluded)
throws IOException {
init(critical, permitted, excluded);
}
private void init(boolean critical,
GeneralSubtrees permitted, GeneralSubtrees excluded)
throws IOException {
if (permitted == null && excluded == null) {
throw new IOException("NameConstraints: Invalid arguments");
}
this.permitted = permitted;
this.excluded = excluded;
this.extensionId = PKIXExtensions.NameConstraints_Id;
this.critical = critical;
encodeThis();
}
/**
* Create the extension from the passed DER encoded value.
*
* @param critical true if the extension is to be treated as critical.
* @param value Array of DER encoded bytes of the actual value.
* @exception IOException on error.
*/
public NameConstraintsExtension(Boolean critical, Object value)
throws IOException {
this.extensionId = PKIXExtensions.NameConstraints_Id;
this.critical = critical.booleanValue();
if (!(value instanceof byte[]))
throw new IOException("Illegal argument type");
int len = Array.getLength(value);
byte[] extValue = new byte[len];
System.arraycopy(value, 0, extValue, 0, len);
this.extensionValue = extValue;
DerValue val = new DerValue(extValue);
if (val.tag != DerValue.tag_Sequence) {
throw new IOException("Invalid encoding for" +
" NameConstraintsExtension.");
}
// NB. this is always encoded with the IMPLICIT tag
// The checks only make sense if we assume implicit tagging,
// with explicit tagging the form is always constructed.
while (val.data.available() != 0) {
DerValue opt = val.data.getDerValue();
if (opt.isContextSpecific(TAG_PERMITTED) && opt.isConstructed()) {
if (permitted != null) {
throw new IOException("Duplicate permitted " +
"GeneralSubtrees in NameConstraintsExtension.");
}
opt.resetTag(DerValue.tag_Sequence);
permitted = new GeneralSubtrees(opt);
} else if (opt.isContextSpecific(TAG_EXCLUDED) &&
opt.isConstructed()) {
if (excluded != null) {
throw new IOException("Duplicate excluded " +
"GeneralSubtrees in NameConstraintsExtension.");
}
opt.resetTag(DerValue.tag_Sequence);
excluded = new GeneralSubtrees(opt);
} else
throw new IOException("Invalid encoding of " +
"NameConstraintsExtension.");
}
}
/**
* Return the printable string.
*/
public String toString() {
return (super.toString() + "NameConstraints: [" +
((permitted == null) ? "" :
("\n Permitted:" + permitted.toString())) +
((excluded == null) ? "" :
("\n Excluded:" + excluded.toString())) + " ]\n");
}
public String toPrint(int indent) {
return ("GeneralSubtrees: " +
((permitted == null) ? "" :
("\n" + pp.indent(indent + 2) + "Permitted:" + permitted.toPrint(indent + 4))) +
((excluded == null) ? "" :
("\n" + pp.indent(indent + 2) + "Excluded:" + excluded.toPrint(indent + 4))) + "\n");
}
/**
* Decode the extension from the InputStream.
*
* @param in the InputStream to unmarshal the contents from.
* @exception IOException on decoding or validity errors.
*/
public void decode(InputStream in) throws IOException {
throw new IOException("Method not to be called directly.");
}
/**
* Write the extension to the OutputStream.
*
* @param out the OutputStream to write the extension to.
* @exception IOException on encoding errors.
*/
public void encode(OutputStream out) throws IOException {
DerOutputStream tmp = new DerOutputStream();
if (this.extensionValue == null) {
this.extensionId = PKIXExtensions.NameConstraints_Id;
encodeThis();
}
super.encode(tmp);
out.write(tmp.toByteArray());
}
/**
* Set the attribute value.
*/
public void set(String name, Object obj) throws IOException {
clearValue();
if (name.equalsIgnoreCase(PERMITTED_SUBTREES)) {
if (!(obj instanceof GeneralSubtrees)) {
throw new IOException("Attribute value should be"
+ " of type GeneralSubtrees.");
}
permitted = (GeneralSubtrees) obj;
} else if (name.equalsIgnoreCase(EXCLUDED_SUBTREES)) {
if (!(obj instanceof GeneralSubtrees)) {
throw new IOException("Attribute value should be "
+ "of type GeneralSubtrees.");
}
excluded = (GeneralSubtrees) obj;
} else {
throw new IOException("Attribute name not recognized by " +
"CertAttrSet:NameConstraintsExtension.");
}
}
/**
* Get the attribute value.
*/
public Object get(String name) throws IOException {
if (name.equalsIgnoreCase(PERMITTED_SUBTREES)) {
return (permitted);
} else if (name.equalsIgnoreCase(EXCLUDED_SUBTREES)) {
return (excluded);
} else {
throw new IOException("Attribute name not recognized by " +
"CertAttrSet:NameConstraintsExtension.");
}
}
/**
* Delete the attribute value.
*/
public void delete(String name) throws IOException {
if (name.equalsIgnoreCase(PERMITTED_SUBTREES)) {
permitted = null;
} else if (name.equalsIgnoreCase(EXCLUDED_SUBTREES)) {
excluded = null;
} else {
throw new IOException("Attribute name not recognized by " +
"CertAttrSet:NameConstraintsExtension.");
}
}
/**
* Return an enumeration of names of attributes existing within this
* attribute.
*/
public Enumeration