Creating the Android App Catalog Application

The device owners can search for applications that are made available in the Organizations App store, and install them on the device. The functionality of the app catalog application is similar to the Android play store. 

In this section let's look at how to generate the APK file for the app catalog application and then publish it to the store via the App Publisher.

Generating the App Catalog APK file

Follow the steps given below to generate the APK file of the app catalog application that is required to create and publish the application:

1. Get a GIT clone of the Android App Catalog application from GitHub.

2. Update the Android Software Development Kit with the following:

   • SDK Versions 22 and 16. 

   • Build Tools Version 22.0.1.

   • Install or update Android Support Library.

   • Install or update Google Play Services.

   • Install Google USB Driver, if you are on a Windows platform.

3. By default, the Android agent communicates with the server through HTTP. For production, this needs to be changed to HTTPS, by configuring the following parameters in the Java class named Constants.java, which is in the org.wso2.EMM.agent.utils package: SERVER_PORT and SERVER_PROTOCOL.

   For more information see below:

    Generating a BKS File

   The Android agent must have the CA certificate inside the application when configuring the Secure Sockets Layer (SSL). The CA certificate is stored in a BKS (bouncycastle) file. Follow the steps given below to create and generate a BKS file: 

   • Prerequisites
   • Step 1: Creating a BKS file
   • Step 2: Generating a BKS file

   Prerequisites 

   • OpenSSL version 3.0.0.

     For more information, see how to download and install OpenSSL.

   • Set up the required environment variables when running on Windows.

      For more information, see setting paths on Windows.

   • The bcprov-jdk16-1.46.jar file.

     Download the bcprov-jdk16-1.46.jar file from the maven repository.

   Step 1: Creating a BKS file

   If you configured EMM for iOS, you can skip this step and move to Step 2 by using the already generated and imported Certificate Authority (CA), Registration Authority (RA), and SSL certificate files.

   1. Navigate to the openssl.cnf file of the OpenSSL installation. 

   2. Make a copy of the  openssl.cnf  file, move it to another location, and configure the file to generate version 3 certificates as shown below:

      [ v3_req ] 
      # Extensions to add to a certificate request 
      basicConstraints=CA:TRUE 
      keyUsage = Digital Signature, Key Encipherment 
      
      [ v3_ca ] 
      # Extensions for a typical CA 
      # PKIX recommendation. 
      subjectKeyIdentifier=hash 
      authorityKeyIdentifier=keyid:always,issuer 
      # This is what PKIX recommends but some broken software chokes on critical 
      # extensions. 
      basicConstraints = critical,CA:true 
      # So we do this instead. 
      #basicConstraints = CA:true 
      # Key usage: this is typical for a CA certificate. However since it will 
      # prevent it being used as an test self-signed certificate it is best 
      # left out by default. 
      keyUsage = Digital Signature, Certificate Sign, CRL Sign

   3. In the location where you modified and saved the openssl.cnf file, run the following commands to generate a self-signed Certificate Authority (CA) certificate (version 3) and convert the certificate to the .pem format:

      1. openssl genrsa -out <CA PRIVATE KEY> 4096
         For example: openssl genrsa -out ca_private.key 4096
      2. openssl req -new -key <CA PRIVATE KEY> -out <CA CSR>
         For example: openssl req -new -key ca_private.key -out ca.csr
      3. openssl x509 -req -days <DAYS> -in <CA CSR> -signkey <CA PRIVATE KEY> -out <CA CRT> -extensions v3_ca -extfile <PATH-TO-MODIFIED-openssl.cnf-FILE>
         For example: openssl x509 -req -days 365 -in ca.csr -signkey ca_private.key -out ca.crt -extensions v3_ca -extfile ./openssl.cnf
      4. openssl rsa -in <CA PRIVATE KEY> -text > <CA PRIVATE PEM>
         For example:  openssl rsa -in ca_private.key -text > ca_private.pem
      5. openssl x509 -in <CA CRT> -out <CA CERT PEM>
         For example: openssl x509 -in ca.crt -out ca_cert.pem

   4. In the same location, run the following commands to generate a Registration Authority (RA) certificate (version 3), sign it with the CA, and convert the certificate to the .pem  format. 

      1. openssl genrsa -out <RA PRIVATE KEY> 4096
         For example:  openssl genrsa -out ra_private.key 4096

      2. openssl req -new -key <RA PRIVATE KEY> -out <RA CSR>
         For example: openssl req -new -key ra_private.key -out ra.csr
      3. openssl x509 -req -days <DAYS> -in <RA CSR> -CA <CA CRT> -CAkey <CA PRIVATE KEY> -set_serial <SERIAL NO> -out <RA CRT> -extensions v3_req -extfile <PATH-TO-MODIFIED- openssl.cnf-FILE >
         For example: openssl x509 -req -days 365 -in ra.csr -CA ca.crt -CAkey ca_private.key -set_serial 02 -out ra.crt -extensions v3_req -extfile ./openssl.cnf
      4. openssl rsa -in <CA PRIVATE KEY> -text > <RA PRIVATE PEM>
         For example: openssl rsa -in ra_private.key -text > ra_private.pem
      5. openssl x509 -in <RA CRT> -out <RA CERT PEM>
         For example: openssl x509 -in ra.crt -out ra_cert.pem

   5. Generate the SSL certificate (version 3) based on your domain/IP address:

      You must add your IP address/domain as the Common Name. Otherwise, provisioning will fail. 

      1. Generate an RSA key.
         openssl genrsa -out <RSA_key>.key 4096
         For example:
         openssl genrsa -out ia.key 4096
      2. Generate a CSR file.
         openssl req -new -key <RSA_key>.key -out <CSR>.csr
         For example:
         openssl req -new -key ia.key -out ia.csr
         Enter your server IP address/domain name (e.g., 192.168.1.157) as the Common Name else provisioning will fail.
      3. Generate the SSL certificate.
         openssl x509 -req -days 730 -in <CSR>.csr -CA ca_cert.pem -CAkey ca_private.pem -set_serial <serial number> -out ia.crt
         For example: 
         openssl x509 -req -days 730 -in ia.csr -CA ca_cert.pem -CAkey ca_private.pem -set_serial 044324343 -out ia.crt

   6. Export the SSL, CA, and RA files as PKCS12 files with an alias.

      1. Export the SSL file as a PKCS12 file with "wso2carbon" as the alias. 
         openssl pkcs12 -export -out <KEYSTORE>.p12 -inkey <RSA_key>.key -in ia.crt -CAfile ca_cert.pem -name "<alias>"
         For example:
         openssl pkcs12 -export -out KEYSTORE.p12 -inkey ia.key -in ia.crt -CAfile ca_cert.pem -name "wso2carbon"

      2. Export the CA file as a PKCS12 file with an alias.
         openssl pkcs12 -export -out <CA>.p12 -inkey <CA private key>.pem -in <CA Cert>.pem -name "<alias>"
         For example:
         openssl pkcs12 -export -out ca.p12 -inkey ca_private.pem -in ca_cert.pem -name "cacert"
         In the above example, cacert has been used as the CA alias. 
      3. Export the RA file as a PKCS12 file with an alias.
         openssl pkcs12 -export -out <RA>.p12 -inkey <RA private key>.pem -in <RA Cert>.pem -chain -CAfile <CA cert>.pem -name "<alias>"
         For example:
         openssl pkcs12 -export -out ra.p12 -inkey ra_private.pem -in ra_cert.pem -chain -CAfile ca_cert.pem -name "racert"
         In the above example, racert has been used as the RA alias. 
   7. Copy the three P12 files to the <EMM_HOME>/repository/resources/security directory.
   8. Import the generated P12 files as follows:
      

      1. Import the generated <KEYSTORE>.p12 file into the wso2carbon.jks and client-truststore.jks in the <EMM_HOME>/repository/resources/security directory.
         keytool -importkeystore -srckeystore <KEYSTORE>.p12 -srcstoretype PKCS12 -destkeystore <wso2carbon.jks/client-truststore.jks>

         When prompted, enter the keystore password and keystore key password as wso2carbon.

         For example:
         keytool -importkeystore -srckeystore KEYSTORE.p12 -srcstoretype PKCS12 -destkeystore wso2carbon.jks
keytool -importkeystore -srckeystore KEYSTORE.p12 -srcstoretype PKCS12 -destkeystore client-truststore.jks

      2. Import the generated <CA>.p12 and <RA>.p12 files into the wso2certs.jks file, which is in the <EMM_HOME>/repository/resources/security directory.
         keytool -importkeystore -srckeystore <CA/RA>.p12 -srcstoretype PKCS12 -destkeystore wso2emm.jks
         
         For example:
         keytool -importkeystore -srckeystore ca.p12 -srcstoretype PKCS12 -destkeystore wso2certs.jks 
         Enter the keystore password as wso2carbon and keystore key password as cacert.

         keytool -importkeystore -srckeystore ra.p12 -srcstoretype PKCS12 -destkeystore wso2certs.jks 
         Enter the keystore password as  wso2carbon  and keystore key password as racert.

         Troubleshooting

         Why does the following error occur: " keytool error: java.io.IOException: Invalid keystore format"?

         If you enter the wrong private key password when importing the <CA>.p12 or <RA>.p12 files, the wso2certs.jks file will get corrupted and the above error message will appear.

         In such a situation, delete the wso2certs.jks file and execute the following command to import the generated <CA>.p12 and <RA>.p12 files into the wso2certs.jks file again.
         keytool -importkeystore -srckeystore <CA/RA>.p12 -srcstoretype PKCS12 -destkeystore wso2certs.jks
         
         When the above command is executed, EMM will automatically create a new wso2certs.jks file with the imported file.

   Step 2: Generating a BKS file

   Follow all the steps given under step 1 before generating the BKS file to avoid errors.

   1. Generate the BKS file:

      Ensure that you have the bcprov-jdk16-146.jar file in the same folder where you will be generating the BKS file before you run this command.

      keytool -noprompt -import -v -trustcacerts -alias 'openssl x509 -inform PEM -subject_hash -noout -in ca_cert.pem' -file ca_cert.pem -keystore emm_truststore.bks -storetype BKS -providerclass org.bouncycastle.jce.provider.BouncyCastleProvider -providerpath bcprov-jdk16-146.jar -storepass 'wso2carbon'

      If you are using an SSL certificate by a trusted authority such as GoDaddy, the cert.crt defined in the command should be the interim certificate. 
      Example:

      keytool -noprompt -import -v -trustcacerts -alias godaddy -file cert.crt -keystore emm_truststore.bks -storetype BKS -providerclass org.bouncycastle.jce.provider.BouncyCastleProvider -providerpath bcprov-jdk16-146.jar -storepass 'wso2carbon'

   2. Optionally, view the list of certificates in the BKS form using the following command:

      keytool -list -v -keystore "emm_truststore.bks" -provider org.bouncycastle.jce.provider.BouncyCastleProvider -providerpath "bcprov-jdk16-1.46.jar" -storetype BKS -storepass "wso2carbon"

   3. Copy the generated emm_truststore.bks file to the Android res/raw folder. 
   4. Navigate to the Constants.java file, which is in the Android folder and configure the following:
      • Provide the HTTPS_HOST_IP as the value for the SERVER_PORT parameter.
        Example: 9443.
      • Change the SERVER_PROTOCOL to https://.
      • Provide the BKS file password as the value for the TRUSTSTORE_PASSWORD parameter.
      Sample

      	public static boolean DEBUG_MODE_ENABLED = false;
      	public static boolean LOCAL_NOTIFICATIONS_ENABLED = true;
      	public static boolean GCM_ENABLED = false;
      
      	public static String SERVER_IP = "";
      
      	public static String SERVER_PORT = "9443";
      	public static String SERVER_PROTOCOL = "https://";
      	public static String API_VERSION = "1.0.0";
      	
      	public static String SERVER_APP_ENDPOINT = "/EMM/api/";
      
      	public static String OAUTH_ENDPOINT = "/oauth2/token";
      	public static String SENDER_ID_ENDPOINT = "devices/sender_id/";
      	public static String IS_REGISTERED_ENDPOINT = "devices/isregistered/";
      	public static String LICENSE_ENDPOINT = "devices/license/";
      	public static String REGISTER_ENDPOINT = "devices/register/";
      	public static String UNREGISTER_ENDPOINT = "devices/unregister/";
      	public static String NOTIFICATION_ENDPOINT = "notifications/pendingOperations/";
      	
      	public static String SERVER_URL = SERVER_PROTOCOL + SERVER_IP + ":"
      			+ SERVER_PORT + SERVER_APP_ENDPOINT;
      
      	public static final String TRUSTSTORE_PASSWORD = "";
      	public static final String EULA_TITLE = "POLICY AGREEMENT";

4. Import the project on Android Studio, clean and build the project.

5. Run the project on a device.

   The .apk file can be found in the  <EMM_HOME>/repository/deployment/server/jaggeryapps/emm-web-agent/units/asset-download-agent-android/public/asset  directory.

Get the APK file you generate and get ready to create the app catalog application in the APP Publisher.

Create the App Catalog Application in the App Publisher

Follow the steps given below to create an app in the App publisher.

Publishing the App Catalog Application

Device owners will not see this application in the App Store until it is published. Follow the steps given below to publish the application:

1. Click Submit for Review for the App Catalog catalog application.

2. Click Approve > Publish.