Define padding method for each CryptogramDataBuilder

jpos/src/main/java/org/jpos/emv/cryptogram/CPACryptogram.java

@@ -4,15 +4,11 @@
 import org.jpos.security.MKDMethod;
 import org.jpos.security.SKDMethod;
 
-import org.jpos.emv.cryptogram.CryptogramDataBuilder.PaddingMethod;
-
 /**
  * Common Payment Application (CPA) Cryptogram Specification
  */
 public class CPACryptogram implements CryptogramSpec {
 
-    final PaddingMethod paddingMethod = CryptogramDataBuilder.ISO9797Method2;
-
     @Override
     public MKDMethod getMKDMethod() {
         return MKDMethod.OPTION_A;

jpos/src/main/java/org/jpos/emv/cryptogram/CVN10DataBuilder.java

@@ -36,7 +36,6 @@ public String getDefaultARPCRequest(boolean approved) {
         return approved ? "0000" : "9900";
     }
 
-
     @Override
     public String buildARQCRequest(TLVList data, IssuerApplicationData iad) {
         StringBuilder sb = new StringBuilder();
@@ -46,7 +45,7 @@ public String buildARQCRequest(TLVList data, IssuerApplicationData iad) {
     }
 
     @Override
-    public String buildARQCRequest_padded(TLVList data, IssuerApplicationData iad, PaddingMethod paddingMethod){
-        return paddingMethod.apply(buildARQCRequest(data, iad));
+    public PaddingMethod getPaddingMethod() {
+        return PaddingMethod.ISO9797Method1;
     }
 }

jpos/src/main/java/org/jpos/emv/cryptogram/CVN18DataBuilder.java

@@ -49,7 +49,7 @@ public String buildARQCRequest(TLVList data, IssuerApplicationData iad) {
     }
 
     @Override
-    public String buildARQCRequest_padded(TLVList data, IssuerApplicationData iad, PaddingMethod paddingMethod) {
-        return paddingMethod.apply(buildARQCRequest(data, iad));
+    public PaddingMethod getPaddingMethod() {
+        return PaddingMethod.ISO9797Method1;
     }
 }

jpos/src/main/java/org/jpos/emv/cryptogram/CVNCPADataBuilder.java

@@ -20,7 +20,7 @@ public String buildARQCRequest(TLVList data, IssuerApplicationData iad) {
     }
 
     @Override
-    public String buildARQCRequest_padded(TLVList data, IssuerApplicationData iad, PaddingMethod paddingMethod) {
-        return paddingMethod.apply(buildARQCRequest(data, iad));
+    public PaddingMethod getPaddingMethod() {
+        return PaddingMethod.ISO9797Method2;
     }
 }

jpos/src/main/java/org/jpos/emv/cryptogram/CVNMCDataBuilder.java

@@ -48,14 +48,13 @@ public String buildARQCRequest(TLVList data, IssuerApplicationData iad) {
         return sb.toString();
     }
 
-    @Override
-    public String buildARQCRequest_padded(TLVList data, IssuerApplicationData iad, PaddingMethod paddingMethod) {
-        return paddingMethod.apply(buildARQCRequest(data, iad));
-    }
-
     @Override
     public String getDefaultARPCRequest(boolean approved) {
         return approved ? "0012" : "9900";
     }
 
+    @Override
+    public PaddingMethod getPaddingMethod() {
+        return PaddingMethod.ISO9797Method2;
+    }
 }

jpos/src/main/java/org/jpos/emv/cryptogram/CryptogramDataBuilder.java

@@ -33,35 +33,53 @@
  */
 public interface CryptogramDataBuilder {
 
-    final PaddingMethod NO_PADDING = data -> data;
-
-    /**
-     * ISO/IEC 9797-1 padding method 1
-     * for Block size 8,  n = 64
-     */
-    final PaddingMethod ISO9797Method1 = data -> data.isEmpty() ?
-            "0000000000000000" :
-            ISOUtil.zeropadRight(data, data.length() % 16 == 0 ? data.length() : data.length() + 16 - data.length() % 16);
-
-    /**
-     * ISO/IEC 9797-1 padding method 2
-     * for Block size 8,  n = 64
-     */
-    final PaddingMethod ISO9797Method2 = data -> ISO9797Method1.apply(data + "80");
-
-    /**
-     * ISO/IEC 9797-1 padding method 3
-     * for Block size 8,  n = 64
-     */
-    final PaddingMethod ISO9797Method3 = data -> {
-        StringBuilder sb = new StringBuilder();
-        String D = ISO9797Method1.apply(data);
-        String Ld = ISOUtil.byte2hex(ISOUtil.int2byte(data.length() / 2));
-        String Lp = ISO9797Method1.apply(Ld);
-        Lp = Ld.length() % 16 == 0 ? "" : Lp.substring(Ld.length());
-        return sb.append(Lp).append(Ld).append(D).toString();
-    };
-
+    enum PaddingMethod {
+        NO_PADDING,
+
+        /**
+         * ISO/IEC 9797-1 padding method 1
+         * for Block size 8,  n = 64
+         */
+        ISO9797Method1 {
+            @Override
+            public String apply(String data) {
+                return data.isEmpty() ?
+                        "0000000000000000" :
+                        ISOUtil.zeropadRight(data, data.length() % 16 == 0 ? data.length() : data.length() + 16 - data.length() % 16);
+            }
+        },
+
+        /**
+         * ISO/IEC 9797-1 padding method 2
+         * for Block size 8,  n = 64
+         */
+        ISO9797Method2 {
+            @Override
+            public String apply(String data) {
+                return ISO9797Method1.apply(data + "80");
+            }
+        },
+
+        /**
+         * ISO/IEC 9797-1 padding method 3
+         * for Block size 8,  n = 64
+         */
+        ISO9797Method3 {
+            @Override
+            public String apply(String data) {
+                StringBuilder sb = new StringBuilder();
+                String D = ISO9797Method1.apply(data);
+                String Ld = ISOUtil.byte2hex(ISOUtil.int2byte(data.length() / 2));
+                String Lp = ISO9797Method1.apply(Ld);
+                Lp = Ld.length() % 16 == 0 ? "" : Lp.substring(Ld.length());
+                return sb.append(Lp).append(Ld).append(D).toString();
+            }
+        };
+
+        public String apply(String data) {
+            return data;
+        }
+    }
 
     /**
      * Method that selects the  minimum set of data elements recommended for
@@ -86,7 +104,6 @@ static List<String> minimumSetOfDataElement(TLVList data) {
         );
     }
 
-
     /**
      * Method that returns default issuer response data (ARC or CSU)
      *
@@ -105,22 +122,21 @@ static List<String> minimumSetOfDataElement(TLVList data) {
      */
     String buildARQCRequest(TLVList data, IssuerApplicationData iad);
 
-
     /**
      * Select necessary data elements and create the string used to generate the ARQC with padding
      * <p>
      *
      * @param data          ICC data received
      * @param iad           Issuer application Data
-     * @param paddingMethod Padding method to use
      * @return String used to generate the ARQC
      */
-    String buildARQCRequest_padded(TLVList data, IssuerApplicationData iad, PaddingMethod paddingMethod);
+    default String buildARQCRequest_padded(TLVList data, IssuerApplicationData iad) {
+        return getPaddingMethod().apply(buildARQCRequest(data, iad));
+    }
 
-    /**
-     * Padding Method Interface
+    /** Defines how to pad the request data when generating the ARQC.
+     * @return PaddingMethod this builder uses
      */
-    interface PaddingMethod {
-        String apply(String data);
-    }
+    PaddingMethod getPaddingMethod();
+
 }

jpos/src/test/java/org/jpos/emv/cryptogram/CPACryptogramTest.java

@@ -12,10 +12,10 @@ public class CPACryptogramTest {
     @Test
     void test(){
         CPACryptogram spec = new CPACryptogram();
-        assertEquals(spec.paddingMethod, CryptogramDataBuilder.ISO9797Method2);
         assertEquals(spec.getMKDMethod(), MKDMethod.OPTION_A);
         assertEquals(spec.getSKDMethod(), SKDMethod.EMV_CSKD);
         assertEquals(spec.getARPCMethod(), ARPCMethod.METHOD_2);
         assertTrue(spec.getDataBuilder() instanceof CVNCPADataBuilder);
+        assertEquals(CryptogramDataBuilder.PaddingMethod.ISO9797Method2, spec.getDataBuilder().getPaddingMethod());
     }
 }

jpos/src/test/java/org/jpos/emv/cryptogram/CVN10DataBuilderTest.java

@@ -58,7 +58,7 @@ void testBuildARQCRequest() {
 
         assertEquals(
                 "00000000010000000000000008400000000000084018123101ABCDEF101800000203000000000000",
-                builder.buildARQCRequest_padded(data, iad, builder.ISO9797Method1)
+                builder.buildARQCRequest_padded(data, iad)
         );
 
 

jpos/src/test/java/org/jpos/emv/cryptogram/CVN18DataBuilderTest.java

@@ -58,7 +58,7 @@ void testBuildARQCRequest() {
 
         assertEquals(
                 "00000000010000000000000008400000000000084018123101ABCDEF101800000106011203000000",
-                builder.buildARQCRequest_padded(data, iad, builder.ISO9797Method1)
+                builder.buildARQCRequest_padded(data, iad)
         );
 
 

jpos/src/test/java/org/jpos/emv/cryptogram/CVNCPADataBuilderTest.java

@@ -37,7 +37,7 @@ void testBuildARQCRequest() {
 
         assertEquals(
                 "0000000100000000000010000840000000108008409807040011111111580034560FA500A03800000000000000000000000F01000000000000000000000000000080000000000000",
-                builder.buildARQCRequest_padded(data, iad, builder.ISO9797Method2)
+                builder.buildARQCRequest_padded(data, iad)
         );
     }
 }

jpos/src/test/java/org/jpos/emv/cryptogram/CryptogramDataBuilderTest.java

@@ -7,7 +7,7 @@
 import java.util.Arrays;
 import java.util.Random;
 
-import static org.jpos.emv.cryptogram.CryptogramDataBuilder.*;
+import static org.jpos.emv.cryptogram.CryptogramDataBuilder.PaddingMethod.*;
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;