Fix handling of hidden access points

We now get raw hex data from the supplicant and we convert it into
printable format.

For hidden access point, we always used to return a single empty string.
We need to make sure we maintain that behavior for apps to not start
displaying empty strings.

Bug: 7310749
Change-Id: I2599b9b5e15be91fc34e9af629ad893b1a0357fc

1 files changed, 13 insertions, 2 deletions

diff --git a/wifi/java/android/net/wifi/WifiSsid.java b/wifi/java/android/net/wifi/WifiSsid.java
index 6f36111..3e5f10f 100644
--- a/wifi/java/android/net/wifi/WifiSsid.java
+++ b/wifi/java/android/net/wifi/WifiSsid.java
@@ -156,7 +156,11 @@ public class WifiSsid implements Parcelable {
 
     @Override
     public String toString() {
-        if (octets.size() <= 0) return "";
+        byte[] ssidBytes = octets.toByteArray();
+        // Supplicant returns \x00\x00\x00\x00\x00\x00\x00\x00 hex string
+        // for a hidden access point. Make sure we maintain the previous
+        // behavior of returning empty string for this case.
+        if (octets.size() <= 0 || isArrayAllZeroes(ssidBytes)) return "";
         // TODO: Handle conversion to other charsets upon failure
         Charset charset = Charset.forName("UTF-8");
         CharsetDecoder decoder = charset.newDecoder()
@@ -164,7 +168,7 @@ public class WifiSsid implements Parcelable {
                 .onUnmappableCharacter(CodingErrorAction.REPLACE);
         CharBuffer out = CharBuffer.allocate(32);
 
-        CoderResult result = decoder.decode(ByteBuffer.wrap(octets.toByteArray()), out, true);
+        CoderResult result = decoder.decode(ByteBuffer.wrap(ssidBytes), out, true);
         out.flip();
         if (result.isError()) {
             return NONE;
@@ -172,6 +176,13 @@ public class WifiSsid implements Parcelable {
         return out.toString();
     }
 
+    private boolean isArrayAllZeroes(byte[] ssidBytes) {
+        for (int i = 0; i< ssidBytes.length; i++) {
+            if (ssidBytes[i] != 0) return false;
+        }
+        return true;
+    }
+
     /** @hide */
     public byte[] getOctets() {
         return  octets.toByteArray();