001 package edu.harvard.deas.hyperenc;
002
003 import java.util.ArrayList;
004 import java.util.List;
005
006 import edu.harvard.deas.hyperenc.util.HexCoder;
007 import edu.harvard.deas.hyperenc.util.Pair;
008
009 /**
010 * Parses plain-text representations of hyper-encryption protocol messages
011 * according to the following specification:
012 * <p>
013 * <b>Master reconciliation message</b>: Each line contains one ID-hash pair.
014 * The integer ID comes first, followed by a single space, followed by the hash,
015 * encoded as a hexadecimal number using digits 0-9 and a-f (case-insensitive).
016 * <p>
017 * <b>Slave reconciliation message</b>: Each line contains one ID-code pair. The
018 * integer ID comes first, followed by a single space, followed by a result
019 * code, which must be one of the following single-character strings:
020 * <ul>
021 * <li>"<b>+</b>" for SlaveRecResult.SUCCESS</li>
022 * <li>"<b>0</b>" for SlaveRecResult.NO_RESULT</li>
023 * <li>"<b>-</b>" for SlaveRecResult.FAILURE</li>
024 * </ul>
025 * @see SlaveRecResult
026 */
027 public class PlainTextMessageParser extends MessageParser {
028
029 @Override
030 public List<Pair<Integer, byte[]>> parseMRec(String message)
031 throws MessageParseException {
032 List<Pair<Integer,byte[]>> result = new ArrayList<Pair<Integer,byte[]>>();
033
034 String lines[] = message.split("\\r?\\n");
035 for (String line : lines) {
036 String tokens[] = line.split(" ", 2);
037 int id;
038 byte[] hash;
039
040 try {
041 id = Integer.parseInt(tokens[0]);
042 } catch (NumberFormatException e) {
043 throw new MessageParseException(
044 "Illegal ID: " + tokens[0], message, e);
045 }
046
047 try {
048 hash = HexCoder.decode(tokens[1].toLowerCase());
049 } catch (IllegalArgumentException e) {
050 throw new MessageParseException(
051 "Illegal hash string: " + tokens[1], message, e);
052 }
053
054 result.add(new Pair<Integer,byte[]>(id, hash));
055 }
056
057 return result;
058 }
059
060 @Override
061 public List<Pair<Integer, SlaveRecResult>> parseSRec(String message)
062 throws MessageParseException {
063 List<Pair<Integer,SlaveRecResult>> result =
064 new ArrayList<Pair<Integer,SlaveRecResult>>();
065
066 String lines[] = message.split("\\r?\\n");
067 for (String line : lines) {
068 String tokens[] = line.split(" ", 2);
069 int id;
070 SlaveRecResult res;
071
072 try {
073 id = Integer.parseInt(tokens[0]);
074 } catch (NumberFormatException e) {
075 throw new MessageParseException(
076 "Illegal ID: " + tokens[0], message, e);
077 }
078
079 if (tokens[1].equals("+"))
080 res = SlaveRecResult.SUCCESS;
081 else if (tokens[1].equals("0"))
082 res = SlaveRecResult.NO_RESULT;
083 else if (tokens[1].equals("-"))
084 res = SlaveRecResult.FAILURE;
085 else
086 throw new MessageParseException(
087 "Illegal result code: " + tokens[1], message);
088
089 result.add(new Pair<Integer,SlaveRecResult>(id, res));
090 }
091
092 return result;
093 }
094
095 @Override
096 public String mrecToString(List<Pair<Integer, byte[]>> lst) {
097 String result = "";
098
099 for (Pair<Integer,byte[]> p : lst) {
100 int id = p.first();
101 byte[] hash = p.second();
102
103 String line = id + " " + HexCoder.encode(hash) + "\n";
104 result += line;
105 }
106
107 return result;
108 }
109
110 /**
111 * {@inheritDoc}
112 * @throws IllegalArgumentException
113 * if a result in <code>lst</code> is not supported by this parser
114 */
115 @Override
116 public String srecToString(List<Pair<Integer, SlaveRecResult>> lst) {
117 String result = "";
118
119 for (Pair<Integer,SlaveRecResult> p : lst) {
120 int id = p.first();
121 SlaveRecResult res = p.second();
122 String code;
123
124 switch (res) {
125 case SUCCESS:
126 code = "+"; break;
127 case NO_RESULT:
128 code = "0"; break;
129 case FAILURE:
130 code = "-"; break;
131 default:
132 throw new IllegalArgumentException(
133 "Invalid result code " + res.toString());
134 }
135
136 String line = id + " " + code + "\n";
137 result += line;
138 }
139
140 return result;
141 }
142
143 }