Merge pull request #577 from T-eli/fixes/emv-ac-data-builder

Added a padding option to cryptogram builder
jpos · Dec 24, 2023 · 41cd7e0 · 41cd7e0
2 parents 97e4a88 + 944c009
commit 41cd7e0
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Showing 17 changed files with 505 additions and 35 deletions.
diff --git a/jpos/src/main/java/org/jpos/emv/IssuerApplicationData.java b/jpos/src/main/java/org/jpos/emv/IssuerApplicationData.java
@@ -70,7 +70,7 @@ public IssuerApplicationData(String hexIAD) {
             //Therefore, the length of the Issuer Application Data is 18 bytes and for 
             // M/Chip Advance it may be 18, 20, 26, or 28.
             unpackMCHIP(iad);
-        } else if (len == 32 && iad.startsWith("0F") && iad.startsWith("0F", 32)) {
+        } else if (len == 32 && (iad.startsWith("0F") || iad.startsWith("0f")) && (iad.startsWith("0F", 32) || iad.startsWith("0f", 32))) {
             // EMV_v4.3_Book_3
             // C7.2 Issuer Application Data for Format Code 'A'
             unpackEMVFormatA(iad);

diff --git a/jpos/src/main/java/org/jpos/emv/cryptogram/CPACryptogram.java b/jpos/src/main/java/org/jpos/emv/cryptogram/CPACryptogram.java
@@ -0,0 +1,35 @@
+package org.jpos.emv.cryptogram;
+
+import org.jpos.security.ARPCMethod;
+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;
+    }
+
+    @Override
+    public SKDMethod getSKDMethod() {
+        return SKDMethod.EMV_CSKD;
+    }
+
+    @Override
+    public ARPCMethod getARPCMethod() {
+        return ARPCMethod.METHOD_2;
+    }
+
+    @Override
+    public CryptogramDataBuilder getDataBuilder() {
+        return new CVNCPADataBuilder();
+    }
+}
diff --git a/jpos/src/main/java/org/jpos/emv/cryptogram/CVN10DataBuilder.java b/jpos/src/main/java/org/jpos/emv/cryptogram/CVN10DataBuilder.java
@@ -30,7 +30,7 @@
  * @author Rainer Reyes
  */
 public class CVN10DataBuilder implements CryptogramDataBuilder {
-    
+
     @Override
     public String getDefaultARPCRequest(boolean approved) {
         return approved ? "0000" : "9900";
@@ -44,4 +44,9 @@ public String buildARQCRequest(TLVList data, IssuerApplicationData iad) {
         sb.append(iad.getCardVerificationResults());
         return sb.toString();
     }
+
+    @Override
+    public String buildARQCRequest_padded(TLVList data, IssuerApplicationData iad, PaddingMethod paddingMethod){
+        return paddingMethod.apply(buildARQCRequest(data, iad));
+    }
 }
diff --git a/jpos/src/main/java/org/jpos/emv/cryptogram/CVN18DataBuilder.java b/jpos/src/main/java/org/jpos/emv/cryptogram/CVN18DataBuilder.java
@@ -28,7 +28,7 @@
  * @author Rainer Reyes
  */
 public class CVN18DataBuilder implements CryptogramDataBuilder {
-    
+
     @Override
     public String getDefaultARPCRequest(boolean approved) {
         /* for success:
@@ -47,4 +47,9 @@ public String buildARQCRequest(TLVList data, IssuerApplicationData iad) {
         sb.append(iad.toString());
         return sb.toString();
     }
+
+    @Override
+    public String buildARQCRequest_padded(TLVList data, IssuerApplicationData iad, PaddingMethod paddingMethod) {
+        return paddingMethod.apply(buildARQCRequest(data, iad));
+    }
 }
diff --git a/jpos/src/main/java/org/jpos/emv/cryptogram/CVNCPADataBuilder.java b/jpos/src/main/java/org/jpos/emv/cryptogram/CVNCPADataBuilder.java
@@ -0,0 +1,26 @@
+package org.jpos.emv.cryptogram;
+
+import org.jpos.emv.IssuerApplicationData;
+import org.jpos.tlv.TLVList;
+import static org.jpos.emv.cryptogram.CryptogramDataBuilder.minimumSetOfDataElement;
+
+public class CVNCPADataBuilder implements CryptogramDataBuilder {
+
+    @Override
+    public String getDefaultARPCRequest(boolean approved) {
+        return approved ? "3030" : "3031";
+    }
+
+    @Override
+    public String buildARQCRequest(TLVList data, IssuerApplicationData iad) {
+        StringBuilder sb = new StringBuilder();
+        minimumSetOfDataElement(data).stream().forEach(sb::append);
+        sb.append(iad.toString());
+        return sb.toString();
+    }
+
+    @Override
+    public String buildARQCRequest_padded(TLVList data, IssuerApplicationData iad, PaddingMethod paddingMethod) {
+        return paddingMethod.apply(buildARQCRequest(data, iad));
+    }
+}
diff --git a/jpos/src/main/java/org/jpos/emv/cryptogram/CVNMCDataBuilder.java b/jpos/src/main/java/org/jpos/emv/cryptogram/CVNMCDataBuilder.java
@@ -48,9 +48,14 @@ 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";
     }
-    
+
 }
diff --git a/jpos/src/main/java/org/jpos/emv/cryptogram/CryptogramDataBuilder.java b/jpos/src/main/java/org/jpos/emv/cryptogram/CryptogramDataBuilder.java
@@ -20,11 +20,10 @@
 
 import org.jpos.emv.EMVStandardTagType;
 import org.jpos.emv.IssuerApplicationData;
+import org.jpos.iso.ISOUtil;
 import org.jpos.tlv.TLVList;
 
-import java.util.Arrays;
-import java.util.List;
-import java.util.Optional;
+import java.util.*;
 
 
 /**
@@ -34,6 +33,36 @@
  */
 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();
+    };
+
+
     /**
      * Method that selects the  minimum set of data elements recommended for
      * the generation of application cryptograms described in EMV Book 2 sec 8.1.1
@@ -67,7 +96,7 @@ static List<String> minimumSetOfDataElement(TLVList data) {
     String getDefaultARPCRequest(boolean approved);
 
     /**
-     * Select necessary data elements and create the string used to generate the ARQC
+     * Select necessary data elements and create the string used to generate the ARQC with no padding
      * <p>
      *
      * @param data ICC data received
@@ -76,4 +105,22 @@ 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);
+
+    /**
+     * Padding Method Interface
+     */
+    interface PaddingMethod {
+        String apply(String data);
+    }
 }
diff --git a/jpos/src/main/java/org/jpos/security/BaseSMAdapter.java b/jpos/src/main/java/org/jpos/security/BaseSMAdapter.java
@@ -2035,7 +2035,7 @@ protected boolean verifyCVC3Impl(T imkcvc3, String accountNo, String acctSeqNo,
      * @param atc
      * @param upn
      * @param txnData
-     * @return true if ARQC/TC/AAC is falid or false if not
+     * @return true if ARQC/TC/AAC is valid or false if not
      * @throws SMException
      */
     protected boolean verifyARQCImpl(MKDMethod mkdm, SKDMethod skdm, T imkac

diff --git a/jpos/src/main/java/org/jpos/security/SKDMethod.java b/jpos/src/main/java/org/jpos/security/SKDMethod.java
@@ -32,33 +32,34 @@
  */
 public enum SKDMethod {
 
-   /**
-    * Visa Smart Debit/Credit or UKIS in England
-    * <br>
-    * Described in Visa Integrated Circuit Card
-    * Specification (VIS) Version 1.5 - May 2009, section B.4
-    */
-   VSDC
+    /**
+     * Visa Smart Debit/Credit or UKIS in England
+     * <br>
+     * Described in Visa Integrated Circuit Card
+     * Specification (VIS) Version 1.5 - May 2009, section B.4
+     */
+    VSDC,
 
-   /**
-    * MasterCard Proprietary SKD method
-    */
-  ,MCHIP
-   /**
-    * American Express
-    */
-  ,AEPIS_V40
+    /**
+     * MasterCard Proprietary SKD method
+     */
+    MCHIP,
 
-   /**
-    * EMV Common Session Key Derivation Method
-    * Described in EMV v4.2 Book 2 - June 2008, Annex A1.3
-    */
-  ,EMV_CSKD
+    /**
+     * American Express
+     */
+    AEPIS_V40,
 
-   /**
-    * EMV2000 Session Key Method
-    * Described in EMV 2000 v4.0 Book 2 - December 2000, Annex A1.3
-    */
-  ,EMV2000_SKM
+    /**
+     * EMV Common Session Key Derivation Method
+     * Described in EMV v4.2 Book 2 - June 2008, Annex A1.3
+     */
+    EMV_CSKD,
+
+    /**
+     * EMV2000 Session Key Method
+     * Described in EMV 2000 v4.0 Book 2 - December 2000, Annex A1.3
+     */
+    EMV2000_SKM,
 
 }
diff --git a/jpos/src/main/java/org/jpos/security/jceadapter/JCESecurityModule.java b/jpos/src/main/java/org/jpos/security/jceadapter/JCESecurityModule.java
@@ -675,7 +675,7 @@ private static byte[] preparePANPSN(String pan, String psn){
      * </ul>
      * @param pan application primary account number
      * @param psn PAN Sequence Number
-     * @return 8-bytes representing first 16 digits
+     * @return 8-bytes representing rightmost 16 digits
      */
     private static byte[] formatPANPSNOptionA(String pan, String psn){
         if ( pan.length() < 14 )

diff --git a/jpos/src/test/java/org/jpos/emv/cryptogram/CPACryptogramTest.java b/jpos/src/test/java/org/jpos/emv/cryptogram/CPACryptogramTest.java
@@ -0,0 +1,21 @@
+package org.jpos.emv.cryptogram;
+
+import org.jpos.security.ARPCMethod;
+import org.jpos.security.MKDMethod;
+import org.jpos.security.SKDMethod;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+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);
+    }
+}
diff --git a/jpos/src/test/java/org/jpos/emv/cryptogram/CVN10DataBuilderTest.java b/jpos/src/test/java/org/jpos/emv/cryptogram/CVN10DataBuilderTest.java
@@ -56,6 +56,11 @@ void testBuildARQCRequest() {
                 builder.buildARQCRequest(data, iad)
         );
 
+        assertEquals(
+                "00000000010000000000000008400000000000084018123101ABCDEF101800000203000000000000",
+                builder.buildARQCRequest_padded(data, iad, builder.ISO9797Method1)
+        );
+
 
     }
 }
diff --git a/jpos/src/test/java/org/jpos/emv/cryptogram/CVN18DataBuilderTest.java b/jpos/src/test/java/org/jpos/emv/cryptogram/CVN18DataBuilderTest.java
@@ -56,6 +56,11 @@ void testBuildARQCRequest() {
                 builder.buildARQCRequest(data, iad)
         );
 
+        assertEquals(
+                "00000000010000000000000008400000000000084018123101ABCDEF101800000106011203000000",
+                builder.buildARQCRequest_padded(data, iad, builder.ISO9797Method1)
+        );
+
 
     }
 }
diff --git a/jpos/src/test/java/org/jpos/emv/cryptogram/CVNCPADataBuilderTest.java b/jpos/src/test/java/org/jpos/emv/cryptogram/CVNCPADataBuilderTest.java
@@ -0,0 +1,43 @@
+package org.jpos.emv.cryptogram;
+
+import org.jpos.emv.IssuerApplicationData;
+import org.jpos.tlv.TLVList;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class CVNCPADataBuilderTest {
+    private final CVNCPADataBuilder builder = new CVNCPADataBuilder();
+
+    /**
+     *  Test Data is based of EMV Issuer and Application Security Guidelines v3.0  Annex A.3.3 - Example of ARQC Generation
+     */
+    @Test
+    void testBuildARQCRequest() {
+
+        TLVList data = new TLVList();
+        data.append(0x9F02, "000000010000");
+        data.append(0x9F03, "000000001000");
+        data.append(0x9F1A, "0840");
+        data.append(0x95, "0000001080");
+        data.append(0x5F2A, "0840");
+        data.append(0x9A, "980704");
+        data.append(0x9C, "00");
+        data.append(0x9F37, "11111111");
+        data.append(0x82, "5800");
+        data.append(0x9F36, "3456");
+        data.append(0x9f10, "0FA500A03800000000000000000000000F010000000000000000000000000000");
+
+        IssuerApplicationData iad = new IssuerApplicationData(data.getString(0x9f10));
+
+        assertEquals(
+                "0000000100000000000010000840000000108008409807040011111111580034560FA500A03800000000000000000000000F010000000000000000000000000000",
+                builder.buildARQCRequest(data, iad)
+        );
+
+        assertEquals(
+                "0000000100000000000010000840000000108008409807040011111111580034560FA500A03800000000000000000000000F01000000000000000000000000000080000000000000",
+                builder.buildARQCRequest_padded(data, iad, builder.ISO9797Method2)
+        );
+    }
+}