Added Mnemonic{Length,Word,Checksum}Exception and tests for each case.

core/src/main/java/com/google/bitcoin/crypto/MnemonicChecksumException.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2013 Ken Sedgwick
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.bitcoin.crypto;
+
+/**
+ * Thrown when a list of MnemonicCode words fails the checksum check.
+ */
+@SuppressWarnings("serial")
+public class MnemonicChecksumException extends Exception {
+    public MnemonicChecksumException(String msg) {
+        super(msg);
+    }
+
+    public MnemonicChecksumException(Exception e) {
+        super(e);
+    }
+
+    public MnemonicChecksumException(String msg, Exception e) {
+        super(msg, e);
+    }
+}

core/src/main/java/com/google/bitcoin/crypto/MnemonicCode.java

@@ -86,12 +86,12 @@ public class MnemonicCode {
     /**
      * Encodes a 128, 192 or 256 bit seed into a list of words.
      */
-    public List<String> encode(byte[] seed) throws IllegalArgumentException {
+    public List<String> encode(byte[] seed) throws MnemonicLengthException {
         
         // 2. Make sure its length (L) is 128, 192 or 256 bits.
         int len = seed.length * 8;
         if (len != 128 && len != 192 && len != 256)
-            throw new IllegalArgumentException("seed not 128, 192 or 256 bits");
+            throw new MnemonicLengthException("seed not 128, 192 or 256 bits");
 
         // 3. Encrypt input data 10000x with Rijndael (ECB mode).
         //    Set key to SHA256 hash of string ("mnemonic" + user_password).
@@ -134,12 +134,12 @@ public class MnemonicCode {
     /**
      * Decodes a list of words into a seed value.
      */
-    public byte[] decode(List<String> words) throws IllegalArgumentException {
+    public byte[] decode(List<String> words) throws MnemonicLengthException, MnemonicWordException, MnemonicChecksumException {
         int nwords = words.size();
 
         // 2. Make sure the number of words is 12, 18 or 24.
         if (nwords != 12 && nwords != 18 && nwords != 24)
-            throw new IllegalArgumentException("Mnemonic code not 12, 18 or 24 words");
+            throw new MnemonicLengthException("Mnemonic code not 12, 18 or 24 words");
 
         // 3. Figure out word indexes in a dictionary and output them as binary stream E.
         int len = nwords * 11;
@@ -149,7 +149,7 @@ public class MnemonicCode {
             // Find the words index in the wordlist.
             int ndx = Collections.binarySearch(this.wordList, word);
             if (ndx < 0)
-                throw new IllegalArgumentException("\"" + word + "\" invalid");
+                throw new MnemonicWordException("\"" + word + "\" invalid", word);
 
             // Set the next 11 bits to the value of the index.
             for (int ii = 0; ii < 11; ++ii)
@@ -172,7 +172,7 @@ public class MnemonicCode {
         // 6. Make sure C is the checksum of B (using the step 5 from the above paragraph).
         boolean[] chksum = checksum(bb);
         if (!Arrays.equals(chksum, cc))
-            throw new IllegalArgumentException("checksum error");
+            throw new MnemonicChecksumException("checksum error");
 
         // 8. Treat B as binary data.
         byte[] outdata = new byte[bblen / 8];

core/src/main/java/com/google/bitcoin/crypto/MnemonicLengthException.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2013 Ken Sedgwick
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.bitcoin.crypto;
+
+/**
+ * Thrown when an argument to MnemonicCode is the wrong length.
+ */
+@SuppressWarnings("serial")
+public class MnemonicLengthException extends Exception {
+    public MnemonicLengthException(String msg) {
+        super(msg);
+    }
+
+    public MnemonicLengthException(Exception e) {
+        super(e);
+    }
+
+    public MnemonicLengthException(String msg, Exception e) {
+        super(msg, e);
+    }
+}

core/src/main/java/com/google/bitcoin/crypto/MnemonicWordException.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2013 Ken Sedgwick
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.bitcoin.crypto;
+
+/**
+ * Thrown when a word is encountered which is not in the MnemonicCode's word list.
+ */
+@SuppressWarnings("serial")
+public class MnemonicWordException extends Exception {
+    /** Contains the word that was not found in the word list. */
+    public String badWord;
+
+    public MnemonicWordException(String msg, String badWord) {
+        super(msg);
+        this.badWord = badWord;
+    }
+
+    public MnemonicWordException(String badWord, Exception e) {
+        super(e);
+        this.badWord = badWord;
+    }
+
+    public MnemonicWordException(String msg, String badWord, Exception e) {
+        super(msg, e);
+        this.badWord = badWord;
+    }
+
+    public String getBadWord() {
+        return badWord;
+    }
+}

core/src/test/java/com/google/bitcoin/crypto/MnemonicCodeTest.java

@@ -127,18 +127,30 @@ public class MnemonicCodeTest {
         }
     }
 
-    @Test(expected = IllegalArgumentException.class)
+    @Test(expected = MnemonicLengthException.class)
     public void testBadSeedLength() throws Exception {
         byte[] seed = Hex.decode("7f7f7f7f7f7f7f7f7f7f7f7f7f7f");
         mc.encode(seed);
     }    
 
-    @Test(expected = IllegalArgumentException.class)
+    @Test(expected = MnemonicLengthException.class)
-    public void testBadWordsLength() throws Exception {
+    public void testBadLength() throws Exception {
         List<String> words = split("risk tiger venture dinner age assume float denial penalty");
         mc.decode(words);
     }
 
+    @Test(expected = MnemonicWordException.class)
+    public void testBadWord() throws Exception {
+        List<String> words = split("risk tiger venture dinner xyzzy assume float denial penalty hello game wing");
+        mc.decode(words);
+    }
+
+    @Test(expected = MnemonicChecksumException.class)
+    public void testBadChecksum() throws Exception {
+        List<String> words = split("risk tiger venture dinner age assume float denial penalty hello game game");
+        mc.decode(words);
+    }
+
     static public List<String> split(String words) {
         return new ArrayList<String>(Arrays.asList(words.split("\\s+")));
     }