Implement cip 67

cip/build.gradle

@@ -4,6 +4,7 @@ dependencies {
     api project(':cip:cip25')
     api project(':cip:cip27')
     api project(':cip:cip30')
+    api project(':cip:cip67')
 }
 
 publishing {

cip/cip67/README.md

@@ -0,0 +1,5 @@
+# CIP-67 (cardano-client-cip67)
+
+[CIP 67 - Asset Name Label Registry](https://cips.cardano.org/cip/CIP-0067) 
+
+**Dependencies:** crypto

cip/cip67/build.gradle

@@ -0,0 +1,15 @@
+dependencies {
+    api project(':crypto')
+    api project(':common')
+}
+
+publishing {
+    publications {
+        mavenJava(MavenPublication) {
+            pom {
+                name = 'Cardano Client CIP67'
+                description = 'Cardano Client Lib - CIP67 Implementation'
+            }
+        }
+    }
+}

cip/cip67/src/main/java/com/bloxbean/cardano/client/cip/cip67/CIP67.java

@@ -0,0 +1,82 @@
+package com.bloxbean.cardano.client.cip.cip67;
+
+import com.bloxbean.cardano.client.crypto.CRC8;
+import com.bloxbean.cardano.client.util.IntUtil;
+
+import java.nio.ByteBuffer;
+
+public class CIP67 {
+
+    private CIP67() {
+        throw new IllegalStateException("Utility class");
+    }
+
+    /**
+     * Converts a label to the CIP67 asset name
+     * @param label decimal range: [0, 65535]
+     * @return prefix as bytes representation
+     */
+    public static byte[] labelToPrefix(int label) {
+        int crc = CRC8.applyCRC8(IntUtil.intToByteArray(label));
+
+        int value = 1;
+        value = label << 12;
+        value += crc << 4;
+        return IntUtil.intToByteArray(value);
+    }
+
+    /**
+     * Gets the asset name label from CIP67 asset name. In this method no verification is done.
+     * @param labelBytes prefix as byte representation
+     * @return decimal range: [0, 65535]
+     */
+    public static int prefixToLabel(byte[] labelBytes) {
+        int assetName = ByteBuffer.wrap(labelBytes).getInt();
+        int labelNum = assetName >> 12;
+        labelNum = labelNum & 0x3FFFFFF; // to avoid wrong padding
+        return labelNum;
+    }
+
+    /**
+     * Verifies if the asset name is valid with CIP67. 
+     * @param assetName prefix to check
+     * @return true if valid padding and checksum check passed
+     */
+    public static boolean isValidAssetName(int assetName) {
+        return isValidPadding(assetName) && verifyCheckSum(assetName);
+    }
+
+    /**
+     * Verification if the asset name contains leading and following 0000 
+     * @param assetName prefix to check
+     * @return true if padding is valid
+     */
+    private static boolean isValidPadding(int assetName) {
+        return (assetName & 0xC000003) == 0;
+    }
+
+    /**
+     * Verification if the label and CRC-8 checksum are valid within the asset name
+     * @param assetName prefix to check
+     * @return true if checksum is verified
+     */
+    private static boolean verifyCheckSum(int assetName) {
+        byte[] labelAsBytes = IntUtil.intToByteArray(assetName);
+        int label = prefixToLabel(labelAsBytes);
+        int checkSum = getCheckSum(labelAsBytes);
+        return checkSum == CRC8.applyCRC8(IntUtil.intToByteArray(label));
+    }
+
+    /**
+     * Extracts the checksum out of the asset name
+     * @param labelBytes asset label as bytes
+     * @return calculated checksum according to CRC-8
+     */
+    private static int getCheckSum(byte[] labelBytes) {
+        int assetName = ByteBuffer.wrap(labelBytes).getInt();
+        assetName = assetName >> 4;
+        byte[] intToByteArray = IntUtil.intToByteArray(assetName);
+        return intToByteArray[3]; // get the last Byte from label without the zero padding
+    }
+
+}

cip/cip67/src/main/java/com/bloxbean/cardano/client/cip/cip67/README.md

@@ -0,0 +1 @@
+Implementation of CIP67 to get labels and verify it from the asset name.

cip/cip67/src/test/java/com/bloxbean/cardano/client/cip/cip67/CIP67Test.java

@@ -0,0 +1,46 @@
+package com.bloxbean.cardano.client.cip.cip67;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class CIP67Test {
+
+    @Test
+    void labelToPrefixTest() {
+        byte[] prefixAsBytes = CIP67.labelToPrefix(222);
+        byte[] expectedValue = {0, 13, -31, 64};
+        assertTrue(Arrays.equals(prefixAsBytes, expectedValue)); // corresponding to 0x000de140
+    }
+
+    @Test
+    void prefixToLabelTest() {
+        int label = 0;
+        label = CIP67.prefixToLabel(new byte[]{0, 13, -31, 64});
+        assertEquals(222, label);
+    }
+
+    @Test
+    void isValidAssetNameTestCorrectName() {
+        boolean isValid = CIP67.isValidAssetName(0x000de140);
+        assertEquals(true, isValid);
+    }
+
+    @Test
+    void isValidAssetNameTestWrongPadding() {
+        boolean isValid = CIP67.isValidAssetName(0x000de141);
+        assertEquals(false, isValid);
+
+        isValid = CIP67.isValidAssetName(0x100de140);
+        assertEquals(false, isValid);
+    }
+
+    @Test
+    void isValidAssetNameWrongChecksum() {
+        boolean isValid = CIP67.isValidAssetName(0x000de130);
+        assertEquals(false, isValid);
+    }
+}

common/src/main/java/com/bloxbean/cardano/client/util/IntUtil.java

@@ -0,0 +1,20 @@
+package com.bloxbean.cardano.client.util;
+
+public class IntUtil {
+
+    public static byte[] intToByteArray(int value) {
+        return new byte[] {
+                (byte)(value >>> 24),
+                (byte)(value >>> 16),
+                (byte)(value >>> 8),
+                (byte)value};
+    }
+
+    public static int byteArrayToInt(byte[] input) {
+        int value = 0;
+        for(byte b : input) {
+            value = (value << 8) + (b & 0xFF);
+        }
+        return value;
+    }
+}

crypto/src/main/java/com/bloxbean/cardano/client/crypto/CRC8.java

@@ -0,0 +1,30 @@
+package com.bloxbean.cardano.client.crypto;
+
+import com.bloxbean.cardano.client.util.IntUtil;
+
+public class CRC8 {
+
+    public static int[] LOOKUP =  new int[] {
+        0x00,0x07,0x0e,0x09,0x1c,0x1b,0x12,0x15,0x38,0x3f,0x36,0x31,0x24,0x23,0x2a,0x2d,0x70,0x77,0x7e,0x79,0x6c,0x6b,0x62,0x65,0x48,0x4f,0x46,0x41,0x54,0x53,0x5a,0x5d,
+        0xe0,0xe7,0xee,0xe9,0xfc,0xfb,0xf2,0xf5,0xd8,0xdf,0xd6,0xd1,0xc4,0xc3,0xca,0xcd,0x90,0x97,0x9e,0x99,0x8c,0x8b,0x82,0x85,0xa8,0xaf,0xa6,0xa1,0xb4,0xb3,0xba,0xbd,
+        0xc7,0xc0,0xc9,0xce,0xdb,0xdc,0xd5,0xd2,0xff,0xf8,0xf1,0xf6,0xe3,0xe4,0xed,0xea,0xb7,0xb0,0xb9,0xbe,0xab,0xac,0xa5,0xa2,0x8f,0x88,0x81,0x86,0x93,0x94,0x9d,0x9a,
+        0x27,0x20,0x29,0x2e,0x3b,0x3c,0x35,0x32,0x1f,0x18,0x11,0x16,0x03,0x04,0x0d,0x0a,0x57,0x50,0x59,0x5e,0x4b,0x4c,0x45,0x42,0x6f,0x68,0x61,0x66,0x73,0x74,0x7d,0x7a,
+        0x89,0x8e,0x87,0x80,0x95,0x92,0x9b,0x9c,0xb1,0xb6,0xbf,0xb8,0xad,0xaa,0xa3,0xa4,0xf9,0xfe,0xf7,0xf0,0xe5,0xe2,0xeb,0xec,0xc1,0xc6,0xcf,0xc8,0xdd,0xda,0xd3,0xd4,
+        0x69,0x6e,0x67,0x60,0x75,0x72,0x7b,0x7c,0x51,0x56,0x5f,0x58,0x4d,0x4a,0x43,0x44,0x19,0x1e,0x17,0x10,0x05,0x02,0x0b,0x0c,0x21,0x26,0x2f,0x28,0x3d,0x3a,0x33,0x34,
+        0x4e,0x49,0x40,0x47,0x52,0x55,0x5c,0x5b,0x76,0x71,0x78,0x7f,0x6a,0x6d,0x64,0x63,0x3e,0x39,0x30,0x37,0x22,0x25,0x2c,0x2b,0x06,0x01,0x08,0x0f,0x1a,0x1d,0x14,0x13,
+        0xae,0xa9,0xa0,0xa7,0xb2,0xb5,0xbc,0xbb,0x96,0x91,0x98,0x9f,0x8a,0x8d,0x84,0x83,0xde,0xd9,0xd0,0xd7,0xc2,0xc5,0xcc,0xcb,0xe6,0xe1,0xe8,0xef,0xfa,0xfd,0xf4,0xf3,
+    };
+
+    public static int applyCRC8(byte[] input) {
+        int crc = 0;
+        for (int i = 0; i < input.length; i ++) {
+            crc = LOOKUP[(crc ^ input[i]) & 0xFF] & 0xFF;
+        }
+        return crc;
+    }
+
+    public static int applyCRC8(int input) {
+        byte[] inputAsBytes = IntUtil.intToByteArray(input);
+        return applyCRC8(inputAsBytes);
+    }
+}

crypto/src/test/java/com/bloxbean/cardano/client/crypto/CRC8Test.java

@@ -0,0 +1,15 @@
+package com.bloxbean.cardano.client.crypto;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class CRC8Test {
+
+    @Test
+    public void testCRC8Encoding() {
+        int crc8CheckSum = CRC8.applyCRC8(222);
+        assertEquals(crc8CheckSum, 0x14);
+    }
+
+}

settings.gradle

@@ -21,6 +21,7 @@ include 'cip:cip25'
 include 'cip:cip8'
 include 'cip:cip27'
 include 'cip:cip30'
+include 'cip:cip67'
 
 //Backend modules
 include 'backend'