/*
* JBoss, Home of Professional Open Source.
* Copyright 2015 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 org.wildfly.security.sasl.otp;
import static org.wildfly.security._private.ElytronMessages.log;
import static org.wildfly.security.password.interfaces.OneTimePassword.*;
import static org.wildfly.security.sasl.otp.OTP.*;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Locale;
import java.util.Random;
import javax.security.sasl.SaslException;
import org.wildfly.security.sasl.util.SaslMechanismInformation;
import org.wildfly.security.util.ByteIterator;
import org.wildfly.security.util.ByteStringBuilder;
import org.wildfly.security.util.CodePointIterator;
/**
* @author <a href="mailto:fjuma@redhat.com">Farah Juma</a>
*/
class OTPUtil {
public static final int[] DELIMS = new int[] {'\n', '\r', '\t', ' '};
public static final String[] RESPONSE_TYPES = new String[] { WORD_RESPONSE, INIT_WORD_RESPONSE, HEX_RESPONSE, INIT_HEX_RESPONSE };
public static final String[] PASSWORD_FORMAT_TYPES = new String[] { PASS_PHRASE, DIRECT_OTP };
private static final int FOUR_LETTER_WORDS_OFFSET = 571;
private static final byte[] randomCharDictionary;
static {
byte[] dict = new byte[36];
int i = 0;
for (byte c = 'a'; c <= 'z'; c ++) {
dict[i ++] = c;
}
for (byte c = '0'; c <= '9'; c ++) {
dict[i ++] = c;
}
assert i == dict.length;
randomCharDictionary = dict;
}
/**
* Generate a 64-bit OTP as specified in <a href="https://tools.ietf.org/html/rfc2289">RFC 2289</a>.
*
* @param algorithm the OTP algorithm, must be either "otp-md5" or "otp-sha1"
* @param passPhrase the pass phrase, as a byte array
* @param seed the seed, as a byte array
* @param sequenceNumber the number of times the hash function will be applied
* @return the 64-bit OTP hash
* @throws SaslException if the given OTP algorithm is invalid
*/
public static byte[] generateOTP(String algorithm, byte[] passPhrase, byte[] seed, int sequenceNumber) throws SaslException {
final MessageDigest messageDigest;
try {
messageDigest = getMessageDigest(algorithm);
} catch (NoSuchAlgorithmException e) {
throw log.mechInvalidOTPAlgorithm(algorithm).toSaslException();
}
// Initial step
final ByteStringBuilder seedAndPassPhrase = new ByteStringBuilder();
seedAndPassPhrase.append(seed);
seedAndPassPhrase.append(passPhrase);
byte[] hash = hashAndFold(algorithm, messageDigest, seedAndPassPhrase.toArray());
// Computation step
for (int i = 0; i < sequenceNumber; i++) {
messageDigest.reset();
hash = hashAndFold(algorithm, messageDigest, hash);
}
return hash;
}
/**
* Generate a 64-bit OTP as specified in <a href="https://tools.ietf.org/html/rfc2289">RFC 2289</a>.
*
* @param algorithm the OTP algorithm, must be either "otp-md5" or "otp-sha1"
* @param passPhrase the pass phrase
* @param seed the seed
* @param sequenceNumber the number of times the hash function will be applied
* @return the 64-bit OTP hash
* @throws SaslException if the given OTP algorithm is invalid
*/
public static byte[] generateOTP(String algorithm, String passPhrase, String seed, int sequenceNumber) throws SaslException {
return generateOTP(algorithm, passPhrase.getBytes(StandardCharsets.UTF_8), seed.toLowerCase(Locale.ENGLISH).getBytes(StandardCharsets.US_ASCII), sequenceNumber);
}
/**
* Pass the given input through a hash function and fold the result to 64 bits.
*
* @param algorithm the OTP algorithm, must be either "otp-md5" or "otp-sha1"
* @param messageDigest the {@code MessageDigest} to use when generating the hash
* @param input the data to hash
* @return the folded hash
*/
public static byte[] hashAndFold(String algorithm, MessageDigest messageDigest, byte[] input) {
messageDigest.update(input);
byte[] result = messageDigest.digest();
byte[] hash = new byte[OTP_HASH_SIZE];
// Fold the result (either 128 bits for MD5 or 160 bits for SHA-1) to 64 bits
for (int i = OTP_HASH_SIZE; i < result.length; i++) {
result[i % OTP_HASH_SIZE] ^= result[i];
}
System.arraycopy(result, 0, hash, 0, OTP_HASH_SIZE);
if (algorithm.equals(ALGORITHM_OTP_SHA1)) {
reverse(hash, 0, 4);
reverse(hash, 4, 4);
}
return hash;
}
/**
* Pass the given input through a hash function and fold the result to 64 bits.
*
* @param algorithm the OTP algorithm
* @param input the data to hash
* @return the folded hash
* @throws SaslException if the given OTP algorithm is invalid
*/
public static byte[] hashAndFold(String algorithm, byte[] input) throws SaslException {
final MessageDigest messageDigest;
try {
messageDigest = getMessageDigest(algorithm);
} catch (NoSuchAlgorithmException e) {
throw log.mechInvalidOTPAlgorithm(algorithm).toSaslException();
}
return hashAndFold(algorithm, messageDigest, input);
}
/**
* Convert the given OTP hash into hexadecimal format.
*
* @param otp the OTP hash
* @return the hexadecimal value that corresponds to the given OTP hash
*/
public static String convertToHex(byte[] otp) {
return ByteIterator.ofBytes(otp).hexEncode().drainToString();
}
/**
* Convert the given hexadecimal OTP value into a hash.
*
* @param otp the OTP in hexadecimal format
* @return the OTP hash that corresponds to the given hexadecimal value
* @throws SaslException if an error occurs while parsing the hexadecimal value
*/
public static byte[] convertFromHex(String otp) throws SaslException {
final CodePointIterator cpi = CodePointIterator.ofString(otp);
final CodePointIterator di = cpi.delimitedBy(DELIMS);
// Remove any white space
final StringBuilder sb = new StringBuilder();
while (di.hasNext()) {
di.drainTo(sb);
skipDelims(di, cpi);
}
return CodePointIterator.ofString(sb.toString()).hexDecode().drain();
}
/**
* Convert the given OTP hash into a sequence of six words.
*
* @param otp the OTP hash
* @param alternateDictionary the alternate dictionary to use (if {@code null}, the standard OTP dictionary will be used)
* @return the sequence of six words that corresponds to the given OTP hash
*/
public static String convertToWords(byte[] otp, String[] alternateDictionary) {
final StringBuilder words = new StringBuilder();
long otpValue = eightBytesToLong(otp);
for (int i = 0; i < 6; i++) {
words.append(getWord(otpValue, i, alternateDictionary));
if (i != 5) {
words.append(' ');
}
}
return words.toString();
}
/**
* Convert the given OTP hash into the specified format.
*
* @param otp the OTP hash
* @param responseType the response type
* @param alternateDictionary the alternate dictionary to use (if {@code null}, the standard OTP dictionary will be used)
* @return the formatted OTP
* @throws SaslException if the response type is invalid
*/
public static String formatOTP(byte[] otp, String responseType, String[] alternateDictionary) throws SaslException {
switch (responseType) {
case HEX_RESPONSE:
case INIT_HEX_RESPONSE: {
return convertToHex(otp);
}
case WORD_RESPONSE:
case INIT_WORD_RESPONSE: {
return convertToWords(otp, alternateDictionary);
}
default:
throw log.mechInvalidOTPResponseType().toSaslException();
}
}
/**
* Convert the given six words into an OTP hash.
*
* @param words the OTP formatted as a sequence of six words
* @param algorithm the OTP algorithm
* @return the OTP hash that corresponds to the given sequence of six words
* @throws SaslException if the given algorithm is invalid or if the parity encoded in the
* last two bits of the final word is incorrect or if an error occurs while parsing the words
*/
public static byte[] convertFromWords(String words, String algorithm) throws SaslException {
final CodePointIterator cpi = CodePointIterator.ofString(words);
final CodePointIterator di = cpi.delimitedBy(DELIMS);
final MessageDigest messageDigest;
int dictionaryIndex = -1;
long otpValue = 0L;
int parity;
String word;
byte[] result;
boolean useStandardDictionary = true;
try {
messageDigest = getMessageDigest(algorithm);
} catch (NoSuchAlgorithmException e) {
throw log.mechInvalidOTPAlgorithm(algorithm).toSaslException();
}
for (int i = 0; i < 6; i++) {
word = di.drainToString();
if (useStandardDictionary) {
dictionaryIndex = searchStandardDictionary(word);
if (dictionaryIndex < 0) {
if (i == 0) {
// The first word could not be found, switch to using an alternate dictionary instead
useStandardDictionary = false;
} else {
throw log.mechInvalidOTP().toSaslException();
}
}
}
if (! useStandardDictionary) {
// Alternate dictionaries must satisfy the following property:
// alg(word) % 2048 = N (where N is the position of the word in the dictionary)
result = hashAndFold(algorithm, messageDigest, word.getBytes(StandardCharsets.UTF_8));
dictionaryIndex = ((result[result.length - 2] & 0x7) << 8) | (result[result.length - 1] & 0xff);
messageDigest.reset();
}
skipDelims(di, cpi);
if (i < 5) {
otpValue |= (((long) dictionaryIndex) << (53 - (11 * i)));
} else {
otpValue |= ((((long) dictionaryIndex) & 0x7fc) >> 2);
parity = dictionaryIndex & 0x3;
if (parity != calculateParity(otpValue)) {
throw log.mechIncorrectParity(SaslMechanismInformation.Names.OTP).toSaslException();
}
}
}
return longToEightBytes(otpValue);
}
/**
* Search the standard OTP dictionary for the given word.
*
* @param word the word to search for
* @return the index of the word if it is found and a value less than 0 otherwise
*/
private static int searchStandardDictionary(String word) {
if (word.length() < 4) {
return Arrays.binarySearch(STANDARD_DICTIONARY, 0, FOUR_LETTER_WORDS_OFFSET, word.toUpperCase(Locale.ENGLISH));
} else {
return Arrays.binarySearch(STANDARD_DICTIONARY, FOUR_LETTER_WORDS_OFFSET, STANDARD_DICTIONARY.length, word.toUpperCase(Locale.ENGLISH));
}
}
/**
* Get the word from the dictionary that corresponds to the given index for
* the given OTP hash.
*
* @param otp the OTP hash
* @param index the index of the word to obtain, must be between 0 and 5 (inclusive)
* @param alternateDictionary the alternate dictionary to use (if {@code null}, the standard OTP dictionary will be used)
* @return the word that corresponds to the given index for the given OTP hash
*/
private static String getWord(long otp, int index, String[] alternateDictionary) {
int dictionaryIndex;
if ((index >= 0) && (index < 5)) {
dictionaryIndex = (int) ((otp >> (53 - (11 * index))) & 0x7ff);
} else if (index == 5) {
dictionaryIndex = (int) ((((otp << 2) & 0x7fc) | calculateParity(otp)) & 0x7ff);
} else {
throw new IllegalArgumentException();
}
if (alternateDictionary != null) {
return alternateDictionary[dictionaryIndex];
} else {
return STANDARD_DICTIONARY[dictionaryIndex];
}
}
/**
* Break down the given hash into pairs of bits and then calculate the sum of the pairs.
*
* @param hash the hash
* @return the two least significant bits of the sum of the pairs of bits from the given hash
*/
private static int calculateParity(long hash) {
int parity = 0;
for (int i = 0; i < 64; i += 2) {
parity += (hash & 0x3);
hash >>= 2;
}
return (parity & 0x3);
}
public static int getResponseTypeChoiceIndex(String responseType) throws SaslException {
switch (responseType) {
case WORD_RESPONSE:
return 0;
case INIT_WORD_RESPONSE:
return 1;
case HEX_RESPONSE:
return 2;
case INIT_HEX_RESPONSE:
return 3;
default:
throw log.mechInvalidOTPResponseType().toSaslException();
}
}
public static int getPasswordFormatTypeChoiceIndex(String passwordFormatType) throws SaslException {
switch (passwordFormatType) {
case PASS_PHRASE:
return 0;
case DIRECT_OTP:
return 1;
default:
throw log.mechInvalidOTPPasswordFormatType().toSaslException();
}
}
public static MessageDigest getMessageDigest(String algorithm) throws NoSuchAlgorithmException {
switch (algorithm) {
case ALGORITHM_OTP_MD5:
return MessageDigest.getInstance(MD5);
case ALGORITHM_OTP_SHA1:
return MessageDigest.getInstance(SHA1);
default:
throw new NoSuchAlgorithmException();
}
}
public static String messageDigestAlgorithm(String algorithm) throws NoSuchAlgorithmException {
switch (algorithm) {
case ALGORITHM_OTP_MD5:
return MD5;
case ALGORITHM_OTP_SHA1:
return SHA1;
default:
throw new NoSuchAlgorithmException();
}
}
public static void validateAlternateDictionary(String[] dictionary) throws SaslException {
if ((dictionary == null) || (dictionary.length != DICTIONARY_SIZE)) {
throw log.mechInvalidOTPAlternateDictionary().toSaslException();
}
for (int i = 0; i < dictionary.length; i++) {
if (searchStandardDictionary(dictionary[i]) >= 0) {
throw log.mechInvalidOTPAlternateDictionary().toSaslException();
}
}
}
public static void validateUserName(String userName) throws SaslException {
if (userName == null) {
throw log.mechNoLoginNameGiven(SaslMechanismInformation.Names.OTP).toSaslException();
} else if (userName.length() > MAX_AUTHENTICATION_ID_LENGTH) {
throw log.mechAuthenticationNameTooLong(SaslMechanismInformation.Names.OTP).toSaslException();
} else if (userName.isEmpty()) {
throw log.mechAuthenticationNameIsEmpty(SaslMechanismInformation.Names.OTP).toSaslException();
}
}
public static void validateAuthorizationId(String authorizationId) throws SaslException {
if ((authorizationId != null) && (authorizationId.length() > MAX_AUTHORIZATION_ID_LENGTH)) {
throw log.mechAuthorizationIdTooLong(SaslMechanismInformation.Names.OTP).toSaslException();
}
}
public static void validateAlgorithm(String algorithm) throws SaslException {
if ((! algorithm.equals(ALGORITHM_OTP_MD5)) && (! algorithm.equals(ALGORITHM_OTP_SHA1))) {
throw log.mechInvalidOTPAlgorithm(algorithm).toSaslException();
}
}
public static void validateSequenceNumber(int sequenceNumber) throws SaslException {
if (sequenceNumber < 1) {
throw log.mechInvalidOTPSequenceNumber().toSaslException();
}
}
public static void validateSeed(String seed) throws SaslException {
if ((seed.length() < MIN_SEED_LENGTH) || (seed.length() > MAX_SEED_LENGTH)) {
throw log.mechInvalidOTPSeed().toSaslException();
}
// Must only contain alphanumeric characters
for (int i = 0; i < seed.length(); i++) {
if (! Character.isLetterOrDigit(seed.charAt(i))) {
throw log.mechInvalidCharacterInSeed(SaslMechanismInformation.Names.OTP).toSaslException();
}
}
}
public static void validatePassPhrase(String passPhrase) throws SaslException {
if ((passPhrase == null) || (passPhrase.length() < MIN_PASS_PHRASE_LENGTH)
|| (passPhrase.length() > MAX_PASS_PHRASE_LENGTH)) {
throw log.mechInvalidOTPPassPhrase().toSaslException();
}
}
public static String generateRandomAlphanumericString(int length, Random random) {
final byte[] chars = new byte[length];
for (int i = 0; i < length; i ++) {
chars[i] = randomCharDictionary[random.nextInt(36)];
}
return new String(chars, StandardCharsets.US_ASCII);
}
public static void skipDelims(CodePointIterator di, CodePointIterator cpi, int...delims) throws SaslException {
while ((! di.hasNext()) && cpi.hasNext()) {
if (! isDelim(cpi.next(), delims)) {
throw log.mechInvalidMessageReceived(SaslMechanismInformation.Names.OTP).toSaslException();
}
}
}
public static void skipDelims(CodePointIterator di, CodePointIterator cpi) throws SaslException {
skipDelims(di, cpi, DELIMS);
}
private static boolean isDelim(int c, int... delims) {
for (int delim : delims) {
if (delim == c) {
return true;
}
}
return false;
}
private static boolean isDelim(int c) {
return isDelim(c, DELIMS);
}
private static void reverse(byte[] bytes, int offset, int length) {
byte tmp;
int mid = (length / 2) + offset;
for (int i = offset, j = offset + length - 1; i < mid; i++, j--) {
tmp = bytes[i];
bytes[i] = bytes[j];
bytes[j] = tmp;
}
}
private static long eightBytesToLong(final byte[] b) {
long value = 0L;
for (int i = 0; i < 8; i++) {
value = (value << 8) | (b[i] & 0xff);
}
return value;
}
private static byte[] longToEightBytes(final long value) {
byte[] b = new byte[8];
int shift = 56;
for (int i = 0; i < 8; i++) {
b[i] = (byte) ((value >>> shift) & 0xff);
shift -= 8;
}
return b;
}
// The standard OTP dictionary as defined in RFC 1760 (https://tools.ietf.org/html/rfc1760)
private static final String[] STANDARD_DICTIONARY =
new String[] {"A", "ABE", "ACE", "ACT", "AD", "ADA", "ADD",
"AGO", "AID", "AIM", "AIR", "ALL", "ALP", "AM", "AMY",
"AN", "ANA", "AND", "ANN", "ANT", "ANY", "APE", "APS",
"APT", "ARC", "ARE", "ARK", "ARM", "ART", "AS", "ASH",
"ASK", "AT", "ATE", "AUG", "AUK", "AVE", "AWE", "AWK",
"AWL", "AWN", "AX", "AYE", "BAD", "BAG", "BAH", "BAM",
"BAN", "BAR", "BAT", "BAY", "BE", "BED", "BEE", "BEG",
"BEN", "BET", "BEY", "BIB", "BID", "BIG", "BIN", "BIT",
"BOB", "BOG", "BON", "BOO", "BOP", "BOW", "BOY", "BUB",
"BUD", "BUG", "BUM", "BUN", "BUS", "BUT", "BUY", "BY",
"BYE", "CAB", "CAL", "CAM", "CAN", "CAP", "CAR", "CAT",
"CAW", "COD", "COG", "COL", "CON", "COO", "COP", "COT",
"COW", "COY", "CRY", "CUB", "CUE", "CUP", "CUR", "CUT",
"DAB", "DAD", "DAM", "DAN", "DAR", "DAY", "DEE", "DEL",
"DEN", "DES", "DEW", "DID", "DIE", "DIG", "DIN", "DIP",
"DO", "DOE", "DOG", "DON", "DOT", "DOW", "DRY", "DUB",
"DUD", "DUE", "DUG", "DUN", "EAR", "EAT", "ED", "EEL",
"EGG", "EGO", "ELI", "ELK", "ELM", "ELY", "EM", "END",
"EST", "ETC", "EVA", "EVE", "EWE", "EYE", "FAD", "FAN",
"FAR", "FAT", "FAY", "FED", "FEE", "FEW", "FIB", "FIG",
"FIN", "FIR", "FIT", "FLO", "FLY", "FOE", "FOG", "FOR",
"FRY", "FUM", "FUN", "FUR", "GAB", "GAD", "GAG", "GAL",
"GAM", "GAP", "GAS", "GAY", "GEE", "GEL", "GEM", "GET",
"GIG", "GIL", "GIN", "GO", "GOT", "GUM", "GUN", "GUS",
"GUT", "GUY", "GYM", "GYP", "HA", "HAD", "HAL", "HAM",
"HAN", "HAP", "HAS", "HAT", "HAW", "HAY", "HE", "HEM",
"HEN", "HER", "HEW", "HEY", "HI", "HID", "HIM", "HIP",
"HIS", "HIT", "HO", "HOB", "HOC", "HOE", "HOG", "HOP",
"HOT", "HOW", "HUB", "HUE", "HUG", "HUH", "HUM", "HUT",
"I", "ICY", "IDA", "IF", "IKE", "ILL", "INK", "INN",
"IO", "ION", "IQ", "IRA", "IRE", "IRK", "IS", "IT",
"ITS", "IVY", "JAB", "JAG", "JAM", "JAN", "JAR", "JAW",
"JAY", "JET", "JIG", "JIM", "JO", "JOB", "JOE", "JOG",
"JOT", "JOY", "JUG", "JUT", "KAY", "KEG", "KEN", "KEY",
"KID", "KIM", "KIN", "KIT", "LA", "LAB", "LAC", "LAD",
"LAG", "LAM", "LAP", "LAW", "LAY", "LEA", "LED", "LEE",
"LEG", "LEN", "LEO", "LET", "LEW", "LID", "LIE", "LIN",
"LIP", "LIT", "LO", "LOB", "LOG", "LOP", "LOS", "LOT",
"LOU", "LOW", "LOY", "LUG", "LYE", "MA", "MAC", "MAD",
"MAE", "MAN", "MAO", "MAP", "MAT", "MAW", "MAY", "ME",
"MEG", "MEL", "MEN", "MET", "MEW", "MID", "MIN", "MIT",
"MOB", "MOD", "MOE", "MOO", "MOP", "MOS", "MOT", "MOW",
"MUD", "MUG", "MUM", "MY", "NAB", "NAG", "NAN", "NAP",
"NAT", "NAY", "NE", "NED", "NEE", "NET", "NEW", "NIB",
"NIL", "NIP", "NIT", "NO", "NOB", "NOD", "NON", "NOR",
"NOT", "NOV", "NOW", "NU", "NUN", "NUT", "O", "OAF",
"OAK", "OAR", "OAT", "ODD", "ODE", "OF", "OFF", "OFT",
"OH", "OIL", "OK", "OLD", "ON", "ONE", "OR", "ORB",
"ORE", "ORR", "OS", "OTT", "OUR", "OUT", "OVA", "OW",
"OWE", "OWL", "OWN", "OX", "PA", "PAD", "PAL", "PAM",
"PAN", "PAP", "PAR", "PAT", "PAW", "PAY", "PEA", "PEG",
"PEN", "PEP", "PER", "PET", "PEW", "PHI", "PI", "PIE",
"PIN", "PIT", "PLY", "PO", "POD", "POE", "POP", "POT",
"POW", "PRO", "PRY", "PUB", "PUG", "PUN", "PUP", "PUT",
"QUO", "RAG", "RAM", "RAN", "RAP", "RAT", "RAW", "RAY",
"REB", "RED", "REP", "RET", "RIB", "RID", "RIG", "RIM",
"RIO", "RIP", "ROB", "ROD", "ROE", "RON", "ROT", "ROW",
"ROY", "RUB", "RUE", "RUG", "RUM", "RUN", "RYE", "SAC",
"SAD", "SAG", "SAL", "SAM", "SAN", "SAP", "SAT", "SAW",
"SAY", "SEA", "SEC", "SEE", "SEN", "SET", "SEW", "SHE",
"SHY", "SIN", "SIP", "SIR", "SIS", "SIT", "SKI", "SKY",
"SLY", "SO", "SOB", "SOD", "SON", "SOP", "SOW", "SOY",
"SPA", "SPY", "SUB", "SUD", "SUE", "SUM", "SUN", "SUP",
"TAB", "TAD", "TAG", "TAN", "TAP", "TAR", "TEA", "TED",
"TEE", "TEN", "THE", "THY", "TIC", "TIE", "TIM", "TIN",
"TIP", "TO", "TOE", "TOG", "TOM", "TON", "TOO", "TOP",
"TOW", "TOY", "TRY", "TUB", "TUG", "TUM", "TUN", "TWO",
"UN", "UP", "US", "USE", "VAN", "VAT", "VET", "VIE",
"WAD", "WAG", "WAR", "WAS", "WAY", "WE", "WEB", "WED",
"WEE", "WET", "WHO", "WHY", "WIN", "WIT", "WOK", "WON",
"WOO", "WOW", "WRY", "WU", "YAM", "YAP", "YAW", "YE",
"YEA", "YES", "YET", "YOU", "ABED", "ABEL", "ABET", "ABLE",
"ABUT", "ACHE", "ACID", "ACME", "ACRE", "ACTA", "ACTS", "ADAM",
"ADDS", "ADEN", "AFAR", "AFRO", "AGEE", "AHEM", "AHOY", "AIDA",
"AIDE", "AIDS", "AIRY", "AJAR", "AKIN", "ALAN", "ALEC", "ALGA",
"ALIA", "ALLY", "ALMA", "ALOE", "ALSO", "ALTO", "ALUM", "ALVA",
"AMEN", "AMES", "AMID", "AMMO", "AMOK", "AMOS", "AMRA", "ANDY",
"ANEW", "ANNA", "ANNE", "ANTE", "ANTI", "AQUA", "ARAB", "ARCH",
"AREA", "ARGO", "ARID", "ARMY", "ARTS", "ARTY", "ASIA", "ASKS",
"ATOM", "AUNT", "AURA", "AUTO", "AVER", "AVID", "AVIS", "AVON",
"AVOW", "AWAY", "AWRY", "BABE", "BABY", "BACH", "BACK", "BADE",
"BAIL", "BAIT", "BAKE", "BALD", "BALE", "BALI", "BALK", "BALL",
"BALM", "BAND", "BANE", "BANG", "BANK", "BARB", "BARD", "BARE",
"BARK", "BARN", "BARR", "BASE", "BASH", "BASK", "BASS", "BATE",
"BATH", "BAWD", "BAWL", "BEAD", "BEAK", "BEAM", "BEAN", "BEAR",
"BEAT", "BEAU", "BECK", "BEEF", "BEEN", "BEER", "BEET", "BELA",
"BELL", "BELT", "BEND", "BENT", "BERG", "BERN", "BERT", "BESS",
"BEST", "BETA", "BETH", "BHOY", "BIAS", "BIDE", "BIEN", "BILE",
"BILK", "BILL", "BIND", "BING", "BIRD", "BITE", "BITS", "BLAB",
"BLAT", "BLED", "BLEW", "BLOB", "BLOC", "BLOT", "BLOW", "BLUE",
"BLUM", "BLUR", "BOAR", "BOAT", "BOCA", "BOCK", "BODE", "BODY",
"BOGY", "BOHR", "BOIL", "BOLD", "BOLO", "BOLT", "BOMB", "BONA",
"BOND", "BONE", "BONG", "BONN", "BONY", "BOOK", "BOOM", "BOON",
"BOOT", "BORE", "BORG", "BORN", "BOSE", "BOSS", "BOTH", "BOUT",
"BOWL", "BOYD", "BRAD", "BRAE", "BRAG", "BRAN", "BRAY", "BRED",
"BREW", "BRIG", "BRIM", "BROW", "BUCK", "BUDD", "BUFF", "BULB",
"BULK", "BULL", "BUNK", "BUNT", "BUOY", "BURG", "BURL", "BURN",
"BURR", "BURT", "BURY", "BUSH", "BUSS", "BUST", "BUSY", "BYTE",
"CADY", "CAFE", "CAGE", "CAIN", "CAKE", "CALF", "CALL", "CALM",
"CAME", "CANE", "CANT", "CARD", "CARE", "CARL", "CARR", "CART",
"CASE", "CASH", "CASK", "CAST", "CAVE", "CEIL", "CELL", "CENT",
"CERN", "CHAD", "CHAR", "CHAT", "CHAW", "CHEF", "CHEN", "CHEW",
"CHIC", "CHIN", "CHOU", "CHOW", "CHUB", "CHUG", "CHUM", "CITE",
"CITY", "CLAD", "CLAM", "CLAN", "CLAW", "CLAY", "CLOD", "CLOG",
"CLOT", "CLUB", "CLUE", "COAL", "COAT", "COCA", "COCK", "COCO",
"CODA", "CODE", "CODY", "COED", "COIL", "COIN", "COKE", "COLA",
"COLD", "COLT", "COMA", "COMB", "COME", "COOK", "COOL", "COON",
"COOT", "CORD", "CORE", "CORK", "CORN", "COST", "COVE", "COWL",
"CRAB", "CRAG", "CRAM", "CRAY", "CREW", "CRIB", "CROW", "CRUD",
"CUBA", "CUBE", "CUFF", "CULL", "CULT", "CUNY", "CURB", "CURD",
"CURE", "CURL", "CURT", "CUTS", "DADE", "DALE", "DAME", "DANA",
"DANE", "DANG", "DANK", "DARE", "DARK", "DARN", "DART", "DASH",
"DATA", "DATE", "DAVE", "DAVY", "DAWN", "DAYS", "DEAD", "DEAF",
"DEAL", "DEAN", "DEAR", "DEBT", "DECK", "DEED", "DEEM", "DEER",
"DEFT", "DEFY", "DELL", "DENT", "DENY", "DESK", "DIAL", "DICE",
"DIED", "DIET", "DIME", "DINE", "DING", "DINT", "DIRE", "DIRT",
"DISC", "DISH", "DISK", "DIVE", "DOCK", "DOES", "DOLE", "DOLL",
"DOLT", "DOME", "DONE", "DOOM", "DOOR", "DORA", "DOSE", "DOTE",
"DOUG", "DOUR", "DOVE", "DOWN", "DRAB", "DRAG", "DRAM", "DRAW",
"DREW", "DRUB", "DRUG", "DRUM", "DUAL", "DUCK", "DUCT", "DUEL",
"DUET", "DUKE", "DULL", "DUMB", "DUNE", "DUNK", "DUSK", "DUST",
"DUTY", "EACH", "EARL", "EARN", "EASE", "EAST", "EASY", "EBEN",
"ECHO", "EDDY", "EDEN", "EDGE", "EDGY", "EDIT", "EDNA", "EGAN",
"ELAN", "ELBA", "ELLA", "ELSE", "EMIL", "EMIT", "EMMA", "ENDS",
"ERIC", "EROS", "EVEN", "EVER", "EVIL", "EYED", "FACE", "FACT",
"FADE", "FAIL", "FAIN", "FAIR", "FAKE", "FALL", "FAME", "FANG",
"FARM", "FAST", "FATE", "FAWN", "FEAR", "FEAT", "FEED", "FEEL",
"FEET", "FELL", "FELT", "FEND", "FERN", "FEST", "FEUD", "FIEF",
"FIGS", "FILE", "FILL", "FILM", "FIND", "FINE", "FINK", "FIRE",
"FIRM", "FISH", "FISK", "FIST", "FITS", "FIVE", "FLAG", "FLAK",
"FLAM", "FLAT", "FLAW", "FLEA", "FLED", "FLEW", "FLIT", "FLOC",
"FLOG", "FLOW", "FLUB", "FLUE", "FOAL", "FOAM", "FOGY", "FOIL",
"FOLD", "FOLK", "FOND", "FONT", "FOOD", "FOOL", "FOOT", "FORD",
"FORE", "FORK", "FORM", "FORT", "FOSS", "FOUL", "FOUR", "FOWL",
"FRAU", "FRAY", "FRED", "FREE", "FRET", "FREY", "FROG", "FROM",
"FUEL", "FULL", "FUME", "FUND", "FUNK", "FURY", "FUSE", "FUSS",
"GAFF", "GAGE", "GAIL", "GAIN", "GAIT", "GALA", "GALE", "GALL",
"GALT", "GAME", "GANG", "GARB", "GARY", "GASH", "GATE", "GAUL",
"GAUR", "GAVE", "GAWK", "GEAR", "GELD", "GENE", "GENT", "GERM",
"GETS", "GIBE", "GIFT", "GILD", "GILL", "GILT", "GINA", "GIRD",
"GIRL", "GIST", "GIVE", "GLAD", "GLEE", "GLEN", "GLIB", "GLOB",
"GLOM", "GLOW", "GLUE", "GLUM", "GLUT", "GOAD", "GOAL", "GOAT",
"GOER", "GOES", "GOLD", "GOLF", "GONE", "GONG", "GOOD", "GOOF",
"GORE", "GORY", "GOSH", "GOUT", "GOWN", "GRAB", "GRAD", "GRAY",
"GREG", "GREW", "GREY", "GRID", "GRIM", "GRIN", "GRIT", "GROW",
"GRUB", "GULF", "GULL", "GUNK", "GURU", "GUSH", "GUST", "GWEN",
"GWYN", "HAAG", "HAAS", "HACK", "HAIL", "HAIR", "HALE", "HALF",
"HALL", "HALO", "HALT", "HAND", "HANG", "HANK", "HANS", "HARD",
"HARK", "HARM", "HART", "HASH", "HAST", "HATE", "HATH", "HAUL",
"HAVE", "HAWK", "HAYS", "HEAD", "HEAL", "HEAR", "HEAT", "HEBE",
"HECK", "HEED", "HEEL", "HEFT", "HELD", "HELL", "HELM", "HERB",
"HERD", "HERE", "HERO", "HERS", "HESS", "HEWN", "HICK", "HIDE",
"HIGH", "HIKE", "HILL", "HILT", "HIND", "HINT", "HIRE", "HISS",
"HIVE", "HOBO", "HOCK", "HOFF", "HOLD", "HOLE", "HOLM", "HOLT",
"HOME", "HONE", "HONK", "HOOD", "HOOF", "HOOK", "HOOT", "HORN",
"HOSE", "HOST", "HOUR", "HOVE", "HOWE", "HOWL", "HOYT", "HUCK",
"HUED", "HUFF", "HUGE", "HUGH", "HUGO", "HULK", "HULL", "HUNK",
"HUNT", "HURD", "HURL", "HURT", "HUSH", "HYDE", "HYMN", "IBIS",
"ICON", "IDEA", "IDLE", "IFFY", "INCA", "INCH", "INTO", "IONS",
"IOTA", "IOWA", "IRIS", "IRMA", "IRON", "ISLE", "ITCH", "ITEM",
"IVAN", "JACK", "JADE", "JAIL", "JAKE", "JANE", "JAVA", "JEAN",
"JEFF", "JERK", "JESS", "JEST", "JIBE", "JILL", "JILT", "JIVE",
"JOAN", "JOBS", "JOCK", "JOEL", "JOEY", "JOHN", "JOIN", "JOKE",
"JOLT", "JOVE", "JUDD", "JUDE", "JUDO", "JUDY", "JUJU", "JUKE",
"JULY", "JUNE", "JUNK", "JUNO", "JURY", "JUST", "JUTE", "KAHN",
"KALE", "KANE", "KANT", "KARL", "KATE", "KEEL", "KEEN", "KENO",
"KENT", "KERN", "KERR", "KEYS", "KICK", "KILL", "KIND", "KING",
"KIRK", "KISS", "KITE", "KLAN", "KNEE", "KNEW", "KNIT", "KNOB",
"KNOT", "KNOW", "KOCH", "KONG", "KUDO", "KURD", "KURT", "KYLE",
"LACE", "LACK", "LACY", "LADY", "LAID", "LAIN", "LAIR", "LAKE",
"LAMB", "LAME", "LAND", "LANE", "LANG", "LARD", "LARK", "LASS",
"LAST", "LATE", "LAUD", "LAVA", "LAWN", "LAWS", "LAYS", "LEAD",
"LEAF", "LEAK", "LEAN", "LEAR", "LEEK", "LEER", "LEFT", "LEND",
"LENS", "LENT", "LEON", "LESK", "LESS", "LEST", "LETS", "LIAR",
"LICE", "LICK", "LIED", "LIEN", "LIES", "LIEU", "LIFE", "LIFT",
"LIKE", "LILA", "LILT", "LILY", "LIMA", "LIMB", "LIME", "LIND",
"LINE", "LINK", "LINT", "LION", "LISA", "LIST", "LIVE", "LOAD",
"LOAF", "LOAM", "LOAN", "LOCK", "LOFT", "LOGE", "LOIS", "LOLA",
"LONE", "LONG", "LOOK", "LOON", "LOOT", "LORD", "LORE", "LOSE",
"LOSS", "LOST", "LOUD", "LOVE", "LOWE", "LUCK", "LUCY", "LUGE",
"LUKE", "LULU", "LUND", "LUNG", "LURA", "LURE", "LURK", "LUSH",
"LUST", "LYLE", "LYNN", "LYON", "LYRA", "MACE", "MADE", "MAGI",
"MAID", "MAIL", "MAIN", "MAKE", "MALE", "MALI", "MALL", "MALT",
"MANA", "MANN", "MANY", "MARC", "MARE", "MARK", "MARS", "MART",
"MARY", "MASH", "MASK", "MASS", "MAST", "MATE", "MATH", "MAUL",
"MAYO", "MEAD", "MEAL", "MEAN", "MEAT", "MEEK", "MEET", "MELD",
"MELT", "MEMO", "MEND", "MENU", "MERT", "MESH", "MESS", "MICE",
"MIKE", "MILD", "MILE", "MILK", "MILL", "MILT", "MIMI", "MIND",
"MINE", "MINI", "MINK", "MINT", "MIRE", "MISS", "MIST", "MITE",
"MITT", "MOAN", "MOAT", "MOCK", "MODE", "MOLD", "MOLE", "MOLL",
"MOLT", "MONA", "MONK", "MONT", "MOOD", "MOON", "MOOR", "MOOT",
"MORE", "MORN", "MORT", "MOSS", "MOST", "MOTH", "MOVE", "MUCH",
"MUCK", "MUDD", "MUFF", "MULE", "MULL", "MURK", "MUSH", "MUST",
"MUTE", "MUTT", "MYRA", "MYTH", "NAGY", "NAIL", "NAIR", "NAME",
"NARY", "NASH", "NAVE", "NAVY", "NEAL", "NEAR", "NEAT", "NECK",
"NEED", "NEIL", "NELL", "NEON", "NERO", "NESS", "NEST", "NEWS",
"NEWT", "NIBS", "NICE", "NICK", "NILE", "NINA", "NINE", "NOAH",
"NODE", "NOEL", "NOLL", "NONE", "NOOK", "NOON", "NORM", "NOSE",
"NOTE", "NOUN", "NOVA", "NUDE", "NULL", "NUMB", "OATH", "OBEY",
"OBOE", "ODIN", "OHIO", "OILY", "OINT", "OKAY", "OLAF", "OLDY",
"OLGA", "OLIN", "OMAN", "OMEN", "OMIT", "ONCE", "ONES", "ONLY",
"ONTO", "ONUS", "ORAL", "ORGY", "OSLO", "OTIS", "OTTO", "OUCH",
"OUST", "OUTS", "OVAL", "OVEN", "OVER", "OWLY", "OWNS", "QUAD",
"QUIT", "QUOD", "RACE", "RACK", "RACY", "RAFT", "RAGE", "RAID",
"RAIL", "RAIN", "RAKE", "RANK", "RANT", "RARE", "RASH", "RATE",
"RAVE", "RAYS", "READ", "REAL", "REAM", "REAR", "RECK", "REED",
"REEF", "REEK", "REEL", "REID", "REIN", "RENA", "REND", "RENT",
"REST", "RICE", "RICH", "RICK", "RIDE", "RIFT", "RILL", "RIME",
"RING", "RINK", "RISE", "RISK", "RITE", "ROAD", "ROAM", "ROAR",
"ROBE", "ROCK", "RODE", "ROIL", "ROLL", "ROME", "ROOD", "ROOF",
"ROOK", "ROOM", "ROOT", "ROSA", "ROSE", "ROSS", "ROSY", "ROTH",
"ROUT", "ROVE", "ROWE", "ROWS", "RUBE", "RUBY", "RUDE", "RUDY",
"RUIN", "RULE", "RUNG", "RUNS", "RUNT", "RUSE", "RUSH", "RUSK",
"RUSS", "RUST", "RUTH", "SACK", "SAFE", "SAGE", "SAID", "SAIL",
"SALE", "SALK", "SALT", "SAME", "SAND", "SANE", "SANG", "SANK",
"SARA", "SAUL", "SAVE", "SAYS", "SCAN", "SCAR", "SCAT", "SCOT",
"SEAL", "SEAM", "SEAR", "SEAT", "SEED", "SEEK", "SEEM", "SEEN",
"SEES", "SELF", "SELL", "SEND", "SENT", "SETS", "SEWN", "SHAG",
"SHAM", "SHAW", "SHAY", "SHED", "SHIM", "SHIN", "SHOD", "SHOE",
"SHOT", "SHOW", "SHUN", "SHUT", "SICK", "SIDE", "SIFT", "SIGH",
"SIGN", "SILK", "SILL", "SILO", "SILT", "SINE", "SING", "SINK",
"SIRE", "SITE", "SITS", "SITU", "SKAT", "SKEW", "SKID", "SKIM",
"SKIN", "SKIT", "SLAB", "SLAM", "SLAT", "SLAY", "SLED", "SLEW",
"SLID", "SLIM", "SLIT", "SLOB", "SLOG", "SLOT", "SLOW", "SLUG",
"SLUM", "SLUR", "SMOG", "SMUG", "SNAG", "SNOB", "SNOW", "SNUB",
"SNUG", "SOAK", "SOAR", "SOCK", "SODA", "SOFA", "SOFT", "SOIL",
"SOLD", "SOME", "SONG", "SOON", "SOOT", "SORE", "SORT", "SOUL",
"SOUR", "SOWN", "STAB", "STAG", "STAN", "STAR", "STAY", "STEM",
"STEW", "STIR", "STOW", "STUB", "STUN", "SUCH", "SUDS", "SUIT",
"SULK", "SUMS", "SUNG", "SUNK", "SURE", "SURF", "SWAB", "SWAG",
"SWAM", "SWAN", "SWAT", "SWAY", "SWIM", "SWUM", "TACK", "TACT",
"TAIL", "TAKE", "TALE", "TALK", "TALL", "TANK", "TASK", "TATE",
"TAUT", "TEAL", "TEAM", "TEAR", "TECH", "TEEM", "TEEN", "TEET",
"TELL", "TEND", "TENT", "TERM", "TERN", "TESS", "TEST", "THAN",
"THAT", "THEE", "THEM", "THEN", "THEY", "THIN", "THIS", "THUD",
"THUG", "TICK", "TIDE", "TIDY", "TIED", "TIER", "TILE", "TILL",
"TILT", "TIME", "TINA", "TINE", "TINT", "TINY", "TIRE", "TOAD",
"TOGO", "TOIL", "TOLD", "TOLL", "TONE", "TONG", "TONY", "TOOK",
"TOOL", "TOOT", "TORE", "TORN", "TOTE", "TOUR", "TOUT", "TOWN",
"TRAG", "TRAM", "TRAY", "TREE", "TREK", "TRIG", "TRIM", "TRIO",
"TROD", "TROT", "TROY", "TRUE", "TUBA", "TUBE", "TUCK", "TUFT",
"TUNA", "TUNE", "TUNG", "TURF", "TURN", "TUSK", "TWIG", "TWIN",
"TWIT", "ULAN", "UNIT", "URGE", "USED", "USER", "USES", "UTAH",
"VAIL", "VAIN", "VALE", "VARY", "VASE", "VAST", "VEAL", "VEDA",
"VEIL", "VEIN", "VEND", "VENT", "VERB", "VERY", "VETO", "VICE",
"VIEW", "VINE", "VISE", "VOID", "VOLT", "VOTE", "WACK", "WADE",
"WAGE", "WAIL", "WAIT", "WAKE", "WALE", "WALK", "WALL", "WALT",
"WAND", "WANE", "WANG", "WANT", "WARD", "WARM", "WARN", "WART",
"WASH", "WAST", "WATS", "WATT", "WAVE", "WAVY", "WAYS", "WEAK",
"WEAL", "WEAN", "WEAR", "WEED", "WEEK", "WEIR", "WELD", "WELL",
"WELT", "WENT", "WERE", "WERT", "WEST", "WHAM", "WHAT", "WHEE",
"WHEN", "WHET", "WHOA", "WHOM", "WICK", "WIFE", "WILD", "WILL",
"WIND", "WINE", "WING", "WINK", "WINO", "WIRE", "WISE", "WISH",
"WITH", "WOLF", "WONT", "WOOD", "WOOL", "WORD", "WORE", "WORK",
"WORM", "WORN", "WOVE", "WRIT", "WYNN", "YALE", "YANG", "YANK",
"YARD", "YARN", "YAWL", "YAWN", "YEAH", "YEAR", "YELL", "YOGA",
"YOKE" };
}