1 files changed, 163 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/asn1/x509/BasicConstraints.java b/core/src/main/java/org/spongycastle/asn1/x509/BasicConstraints.java
new file mode 100644
index 00000000..32f81cc9
--- /dev/null
+++ b/core/src/main/java/org/spongycastle/asn1/x509/BasicConstraints.java
@@ -0,0 +1,163 @@
+package org.spongycastle.asn1.x509;
+
+import java.math.BigInteger;
+
+import org.spongycastle.asn1.ASN1Boolean;
+import org.spongycastle.asn1.ASN1EncodableVector;
+import org.spongycastle.asn1.ASN1Integer;
+import org.spongycastle.asn1.ASN1Object;
+import org.spongycastle.asn1.ASN1Primitive;
+import org.spongycastle.asn1.ASN1Sequence;
+import org.spongycastle.asn1.ASN1TaggedObject;
+import org.spongycastle.asn1.DERSequence;
+
+public class BasicConstraints
+    extends ASN1Object
+{
+    ASN1Boolean  cA = ASN1Boolean.getInstance(false);
+    ASN1Integer  pathLenConstraint = null;
+
+    public static BasicConstraints getInstance(
+        ASN1TaggedObject obj,
+        boolean          explicit)
+    {
+        return getInstance(ASN1Sequence.getInstance(obj, explicit));
+    }
+
+    public static BasicConstraints getInstance(
+        Object  obj)
+    {
+        if (obj instanceof BasicConstraints)
+        {
+            return (BasicConstraints)obj;
+        }
+        if (obj instanceof X509Extension)
+        {
+            return getInstance(X509Extension.convertValueToObject((X509Extension)obj));
+        }
+        if (obj != null)
+        {
+            return new BasicConstraints(ASN1Sequence.getInstance(obj));
+        }
+
+        return null;
+    }
+
+    public static BasicConstraints fromExtensions(Extensions extensions)
+    {
+        return BasicConstraints.getInstance(extensions.getExtensionParsedValue(Extension.basicConstraints));
+    }
+
+    private BasicConstraints(
+        ASN1Sequence   seq)
+    {
+        if (seq.size() == 0)
+        {
+            this.cA = null;
+            this.pathLenConstraint = null;
+        }
+        else
+        {
+            if (seq.getObjectAt(0) instanceof ASN1Boolean)
+            {
+                this.cA = ASN1Boolean.getInstance(seq.getObjectAt(0));
+            }
+            else
+            {
+                this.cA = null;
+                this.pathLenConstraint = ASN1Integer.getInstance(seq.getObjectAt(0));
+            }
+            if (seq.size() > 1)
+            {
+                if (this.cA != null)
+                {
+                    this.pathLenConstraint = ASN1Integer.getInstance(seq.getObjectAt(1));
+                }
+                else
+                {
+                    throw new IllegalArgumentException("wrong sequence in constructor");
+                }
+            }
+        }
+    }
+
+    public BasicConstraints(
+        boolean cA)
+    {
+        if (cA)
+        {
+            this.cA = ASN1Boolean.getInstance(true);
+        }
+        else
+        {
+            this.cA = null;
+        }
+        this.pathLenConstraint = null;
+    }
+
+    /**
+     * create a cA=true object for the given path length constraint.
+     * 
+     * @param pathLenConstraint
+     */
+    public BasicConstraints(
+        int     pathLenConstraint)
+    {
+        this.cA = ASN1Boolean.getInstance(true);
+        this.pathLenConstraint = new ASN1Integer(pathLenConstraint);
+    }
+
+    public boolean isCA()
+    {
+        return (cA != null) && cA.isTrue();
+    }
+
+    public BigInteger getPathLenConstraint()
+    {
+        if (pathLenConstraint != null)
+        {
+            return pathLenConstraint.getValue();
+        }
+
+        return null;
+    }
+
+    /**
+     * Produce an object suitable for an ASN1OutputStream.
+     * <pre>
+     * BasicConstraints := SEQUENCE {
+     *    cA                  BOOLEAN DEFAULT FALSE,
+     *    pathLenConstraint   INTEGER (0..MAX) OPTIONAL
+     * }
+     * </pre>
+     */
+    public ASN1Primitive toASN1Primitive()
+    {
+        ASN1EncodableVector  v = new ASN1EncodableVector();
+
+        if (cA != null)
+        {
+            v.add(cA);
+        }
+
+        if (pathLenConstraint != null)  // yes some people actually do this when cA is false...
+        {
+            v.add(pathLenConstraint);
+        }
+
+        return new DERSequence(v);
+    }
+
+    public String toString()
+    {
+        if (pathLenConstraint == null)
+        {
+            if (cA == null)
+            {
+                return "BasicConstraints: isCa(false)";
+            }
+            return "BasicConstraints: isCa(" + this.isCA() + ")";
+        }
+        return "BasicConstraints: isCa(" + this.isCA() + "), pathLenConstraint = " + pathLenConstraint.getValue();
+    }
+}