1 files changed, 42 insertions, 0 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/asn1/ASN1ObjectIdentifier.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/asn1/ASN1ObjectIdentifier.java
new file mode 100644
index 000000000..d9c0fa9bc
--- /dev/null
+++ b/libraries/spongycastle/core/src/main/java/org/spongycastle/asn1/ASN1ObjectIdentifier.java
@@ -0,0 +1,42 @@
+package org.spongycastle.asn1;
+
+public class ASN1ObjectIdentifier
+    extends DERObjectIdentifier
+{
+    public ASN1ObjectIdentifier(String identifier)
+    {
+        super(identifier);
+    }
+
+    ASN1ObjectIdentifier(byte[] bytes)
+    {
+        super(bytes);
+    }
+
+    ASN1ObjectIdentifier(ASN1ObjectIdentifier oid, String branch)
+    {
+        super(oid, branch);
+    }
+
+    /**
+     * Return an OID that creates a branch under the current one.
+     *
+     * @param branchID node numbers for the new branch.
+     * @return the OID for the new created branch.
+     */
+    public ASN1ObjectIdentifier branch(String branchID)
+    {
+        return new ASN1ObjectIdentifier(this, branchID);
+    }
+
+    /**
+     * Return  true if this oid is an extension of the passed in branch, stem.
+     * @param stem the arc or branch that is a possible parent.
+     * @return  true if the branch is on the passed in stem, false otherwise.
+     */
+    public boolean on(ASN1ObjectIdentifier stem)
+    {
+        String id = getId(), stemId = stem.getId();
+        return id.length() > stemId.length() && id.charAt(stemId.length()) == '.' && id.startsWith(stemId);
+    }
+}