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MichaelsPlayground · Apr 7, 2023 · 9873997 · 9873997
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diff --git a/app/src/main/java/de/androidcrypto/talktoyourcreditcard/MainActivity.java b/app/src/main/java/de/androidcrypto/talktoyourcreditcard/MainActivity.java
@@ -153,6 +153,36 @@ public void onTagDiscovered(Tag tag) {
                     // proceed only when te do have a positive read result = 0x'9000' at the end of response data
                     if (selectPpseResponseOk != null) {
 
+                        /**
+                         * step 2 code start
+                         */
+
+                        //writeToUiAppend("");
+                        printStepHeader(2, "search applications on card");
+                        writeToUiAppend("02 analyze select PPSE response and search for tag 0x4F (applications on card)");
+
+                        BerTlvParser parser = new BerTlvParser();
+                        BerTlvs tlv4Fs = parser.parse(selectPpseResponseOk);
+                        // find all entries for tag 0x4f
+                        List<BerTlv> tag4fList = tlv4Fs.findAll(new BerTag(0x4F));
+                        if (tag4fList.size() < 1) {
+                            writeToUiAppend("there is no tag 0x4F available, stopping here");
+                            startEndSequence(nfc);
+                        }
+                        writeToUiAppend("Found tag 0x4F " + tag4fList.size() + (tag4fList.size() == 1 ? " time:" : " times:"));
+                        ArrayList<byte[]> aidList = new ArrayList<>();
+                        for (int i4f = 0; i4f < tag4fList.size(); i4f++) {
+                            BerTlv tlv4f = tag4fList.get(i4f);
+                            byte[] tlv4fBytes = tlv4f.getBytesValue();
+                            aidList.add(tlv4fBytes);
+                            writeToUiAppend("application Id (AID): " + bytesToHexNpe(tlv4fBytes));
+                        }
+                        writeToUiAppend(etData, "02 analyze select PPSE response completed");
+
+                        /**
+                         * step 2 code end
+                         */
+
                     } else {
                         // if (isoDepInTechList) {
                         writeToUiAppend("The discovered NFC tag does not have an IsoDep interface.");

diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
@@ -21,7 +21,7 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:padding="10dp"
-        android:text="Talk to your CreditCard part 1"
+        android:text="Talk to your CreditCard part 2"
         android:textAlignment="center"
         android:textSize="20sp"
         android:textStyle="bold" />

diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
@@ -2,5 +2,5 @@
     <string name="app_name">Talk to your Credit Card</string>
     <string name="action_licenses">Used libraries and their licenses</string>
     <string name="copy_right" translatable="false">Copyrights © %1$d</string>
-    <string name="app_description">This is the first app (part 1) for the \"Talk to your Credit Card\" application.\n\nThe full app reads your Credit Card and retrieves the card number and expiration date.</string>
+    <string name="app_description">This is the second app (part 2) for the \"Talk to your Credit Card\" application.\n\nThe full app reads your Credit Card and retrieves the card number and expiration date.</string>
 </resources>
diff --git a/docs/app01.png b/docs/app01.png
diff --git a/docs/app02a.png b/docs/app02a.png
diff --git a/docs/app02b.png b/docs/app02b.png
diff --git a/docs/full/app01.png b/docs/full/app01.png
diff --git a/docs/full/app02a.png b/docs/full/app02a.png
diff --git a/docs/full/app02b.png b/docs/full/app02b.png
diff --git a/logfile.md b/logfile.md
@@ -41,6 +41,14 @@ timeout new: 10000 ms
 ------------------------------------
 
 
+*********************************
+************ step 02 ************
+* search applications on card   *
+*********************************
+02 analyze select PPSE response and search for tag 0x4F (applications on card)
+Found tag 0x4F 1 time:
+application Id (AID): a0000000041010
+
 *********************************
 ************ step 99 ************
 * our journey ends              *

diff --git a/readme.md b/readme.md
@@ -1,4 +1,4 @@
-# Talk to your Credit Card part 1
+# Talk to your Credit Card part 2
 
 This app shows how to talk with a Credit Card and get information's like the Credit Card number, 
 the card's expiration date and some other data.
@@ -18,7 +18,7 @@ The app uses the NFC **ReaderMode** to get access to the card.
 
 There are apps available for each step in my GitHub repository - the naming shows the step that has the code including this step.
 
-This is the app for the first step 1: **select the Paypass Payment System Environment (PPSE)** in **TalkToYourCreditCardPart1**.
+This is the app for the first step 2: **identify applications on the card** in **TalkToYourCreditCardPart2**.
 
 The app is tested on real Android devices running Android versions 5.0.1, 8.0 and 13.
 
@@ -31,7 +31,7 @@ These are the steps to read a payment card, it is a kind of "question & answer"
 - read all files given in the AFL list and find the file where there are the elements "Application Primary Account Number" and "Application Expiration Date"
 - print out the "Application Primary Account Number" ("PAN") = card number and "Application Expiration Date" = expiration date of the card.
 
-![step 1: after reading a Credit Card](docs/app01.png?raw=true)
+![step 2: after reading a Credit Card](docs/app02a.png?raw=true) ![step 2: after reading a Credit Card](docs/app02b.png?raw=true)
 
 In AndroidManifest.xml grant these permissions:
 ```plaintext