Q: Java code for BER TLV tag identification and Length Identification of EMV Fields from Device or HOST ??
Solution:
I tried writing stuff for myself and I thought it helps to you on reading dynamic TLV tag name and Length in java
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 | package com.ohms.rnd.emv; import java.math.BigInteger; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; import java.util.stream.Collectors; import org.apache.commons.codec.DecoderException; import org.apache.commons.codec.binary.Hex; /** * * Ref: page :173:Coding of the Tag Field of BER-TLV Data Objects * http://mech.vub.ac.be/teaching/info/mechatronica/finished_projects_2007/Groep%201/Smartcard_files/EMV%20v4.1%20Book%203.pdf * * @author * */ public class BERTLV { private static Set<String> specialtags= Arrays.stream(new String[]{/*"91","71","72"*/}).collect(Collectors.toSet());; public static void main(String[] args) { List<String> tlvs= new ArrayList<>(); //Request Tags tlvs.add("77299f2701009f360200419f2608c74d18b08248fefc9f10120110201009248400000000000000000029ff"); tlvs.add("9f2701009f360200419f2608c74d18b08248fefc9f10120110201009248400000000000000000029ff"); tlvs.add("9F4005FF80F0F001"); tlvs.add("9F0206000000012345"); tlvs.add("9F0306000000004000"); tlvs.add("9F26088E19ED4BCA5C670A"); tlvs.add("82025C00"); tlvs.add("5F340102"); tlvs.add("9F3602000A"); tlvs.add("9F0702FF00"); tlvs.add("9F080208C1"); tlvs.add("9F09021001"); tlvs.add("8A025931"); tlvs.add("9F3403A40002"); tlvs.add("9F270180"); tlvs.add("9F1E0853455249414C3132"); tlvs.add("9F0D05F040008800"); tlvs.add("9F0E05FCF8FCF8F0"); tlvs.add("9F0F05FCF8FCF8F0"); tlvs.add("5F28020840"); tlvs.add("9F390100"); tlvs.add("9F3303010101"); tlvs.add("9F1A020840"); tlvs.add("9F350122"); tlvs.add("95050000048000"); tlvs.add("5F2A020840"); tlvs.add("9A03140131"); tlvs.add("9B024800"); tlvs.add("9F2103123456");////////////////////// tlvs.add("9C0100"); tlvs.add("9F370400BC614E"); tlvs.add("4F07A0000000031010"); tlvs.add("9F0607A0000000031010"); tlvs.add("9F7C0412345678"); tlvs.add("8407A0000000031010"); tlvs.add("9F6E05123456789A"); tlvs.add("9F6E0401020304"); tlvs.add("9F6E0401020304"); tlvs.add("9F1006010A03600000"); tlvs.add("9F5B052000000000"); tlvs.add("9F4104000001B3"); tlvs.add("8C209F02069F03069F1A0295055F2A029A039C019F37049F35019F45029F34039B028D08910A8A0295059B028E1000000000000000005F0341035E030203"); tlvs.add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response tlvs.add("910A2263BCC1C2D9C4420013"); tlvs.add("710A0102030405060708090A"); tlvs.add("720A0102030405060708090A"); tlvs.add("8C209F02069F03069F1A0295055F2A029A039C019F37049F35019F45029F34039B028D08910A8A0295059B028E1000000000000000005F0341035E030203"); tlvs.forEach(x-> { try { parseBERTLVTag(x); } catch (DecoderException e) { // TODO Auto-generated catch block e.printStackTrace(); } }); } //B1 Coding of the Tag Field of BER-TLV Data Objects public static void parseBERTLVTag(String tlv) throws DecoderException { if(tlv==null || "".equalsIgnoreCase(tlv)) return; System.out.println("============= START ["+tlv+"]=================="); boolean inTagRead= true; Map<String,String> tags= new HashMap<>(); StringBuilder _tmp = new StringBuilder(); String lastTag = null; int old_index = 0; boolean isFirstTagByte = true; boolean more=true; while (more) { String hByte = tlv.substring(old_index,(old_index = old_index+2)); if(inTagRead) { if(isLastTagByte(hByte, isFirstTagByte)) { inTagRead=false; _tmp.append(hByte); lastTag = _tmp.toString(); System.out.println("Tag["+lastTag+"]"); tags.put(lastTag, null); _tmp= new StringBuilder(); }else { _tmp.append(hByte); } isFirstTagByte = false; }else//Length { isFirstTagByte = true; if(!isSpecialTag(lastTag)) { if(isLastLengthByte(hByte)) { inTagRead=true; _tmp.append(hByte); int len = Integer.parseInt(_tmp.toString(), 16 ); //read len*2 System.out.println(" Length ["+len+"]"); String data = tlv.substring(old_index, (old_index = old_index+len*2)); String tmpData= lastTag+":"+_tmp.toString()+":h"+data; System.out.println(" Data ["+tmpData+"]"); _tmp = new StringBuilder(); tags.put(lastTag, tmpData); }else { _tmp.append(hByte); } }else { //Special tag not TLV format int len=10; String data = "";//tlv.substring(old_index, (old_index = old_index+len*2)); String tmpData= lastTag+":0A:h"+data; System.out.println(" Data ["+tmpData+"]"); _tmp = new StringBuilder(); tags.put(lastTag, tmpData); } } more= tlv.length()<=old_index?false:true; // if(tlv.length()<=old_index) more=false; }//END OF WHILE System.out.println("------------ as MAP ---------------------"); tags.forEach((x,y)->{System.out.println("Tag["+x+"] Value["+y+"]");}); System.out.println("==============================="); } public static boolean isLastTagByte(String onehexByte, boolean firstByte) throws DecoderException { byte tagByte = Hex.decodeHex(onehexByte.toCharArray())[0]; if(firstByte && (tagByte & 0x1f) == 0x1f) { return false; } else if (!firstByte && (tagByte & 0x80) == 0x80) { return false; } else { return true; } } public static boolean isLastLengthByte(String onehexByte) { String binVal = new BigInteger(onehexByte, 16).toString(2); binVal= fillChars(false, binVal, 8, "0"); if(binVal.startsWith("0")) return true; return true; } public static String fillChars(String fillChar,int times) { StringBuffer builder=new StringBuffer(); if(fillChar==null) return ""; for (int i = 0; i < times; i++) { builder.append(fillChar); } return builder.toString(); } public static String fillChars(boolean isLeftJustified,String data,int length,String fillChar) { StringBuffer ret=new StringBuffer(); String fill=null; if(data!=null && !data.equalsIgnoreCase("")) { int datLength=data.length(); int diff=-1; if(datLength<length) { diff=length-datLength; fill=fillChars(fillChar, diff); if(isLeftJustified) { ret.append(data); ret.append(fill); }else { ret.append(fill); ret.append(data); } }else if(datLength==length) { ret.append(data); } }else { ret.append(fillChars(fillChar, length)); } return ret.toString(); } private static boolean isSpecialTag(String tagName) { return specialtags.contains(tagName); } } |
