Remove local reuse in CredentialHelper.isCa

While reviewing to isCa to understand how the NullPointerException
handling changed since Honeycomb, rewrite isCa to be clearer about
reusing local variables to be clearer about what is what and when.

Change-Id: Icf0c3d08666e2be18da4f12f93e92ab998d18fd7

1 files changed, 8 insertions, 6 deletions

diff --git a/src/com/android/certinstaller/CredentialHelper.java b/src/com/android/certinstaller/CredentialHelper.java
index b03a210..7c7abfb 100644
--- a/src/com/android/certinstaller/CredentialHelper.java
+++ b/src/com/android/certinstaller/CredentialHelper.java
@@ -161,14 +161,16 @@ class CredentialHelper {
     private boolean isCa(X509Certificate cert) {
         try {
             // TODO: add a test about this
-            byte[] basicConstraints = cert.getExtensionValue("2.5.29.19");
-            if (basicConstraints == null) {
+            byte[] asn1EncodedBytes = cert.getExtensionValue("2.5.29.19");
+            if (asn1EncodedBytes == null) {
                 return false;
             }
-            Object obj = new ASN1InputStream(basicConstraints).readObject();
-            basicConstraints = ((DEROctetString) obj).getOctets();
-            obj = new ASN1InputStream(basicConstraints).readObject();
-            return new BasicConstraints((ASN1Sequence) obj).isCA();
+            DEROctetString derOctetString = (DEROctetString)
+                    new ASN1InputStream(asn1EncodedBytes).readObject();
+            byte[] octets = derOctetString.getOctets();
+            ASN1Sequence sequence = (ASN1Sequence)
+                    new ASN1InputStream(octets).readObject();
+            return new BasicConstraints(sequence).isCA();
         } catch (IOException e) {
             return false;
         }