--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/com/trilead/ssh2/KnownHosts.java	Thu May 22 10:41:19 2014 -0700
@@ -0,0 +1,759 @@
+
+package com.trilead.ssh2;
+
+import java.io.BufferedReader;
+import java.io.CharArrayReader;
+import java.io.CharArrayWriter;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.io.UnsupportedEncodingException;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.security.InvalidKeyException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.security.PublicKey;
+import java.security.SecureRandom;
+import java.security.interfaces.DSAPublicKey;
+import java.security.interfaces.ECPublicKey;
+import java.security.interfaces.RSAPublicKey;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.Locale;
+import java.util.Vector;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+import com.trilead.ssh2.crypto.Base64;
+import com.trilead.ssh2.signature.DSASHA1Verify;
+import com.trilead.ssh2.signature.ECDSASHA2Verify;
+import com.trilead.ssh2.signature.RSASHA1Verify;
+
+
+/**
+ * The <code>KnownHosts</code> class is a handy tool to verify received server hostkeys
+ * based on the information in <code>known_hosts</code> files (the ones used by OpenSSH).
+ * <p>
+ * It offers basically an in-memory database for known_hosts entries, as well as some
+ * helper functions. Entries from a <code>known_hosts</code> file can be loaded at construction time.
+ * It is also possible to add more keys later (e.g., one can parse different
+ * <code>known_hosts<code> files).
+ * <p>
+ * It is a thread safe implementation, therefore, you need only to instantiate one
+ * <code>KnownHosts</code> for your whole application.
+ *
+ * @author Christian Plattner, plattner@trilead.com
+ * @version $Id: KnownHosts.java,v 1.2 2008/04/01 12:38:09 cplattne Exp $
+ */
+
+public class KnownHosts {
+    public static final int HOSTKEY_IS_OK = 0;
+    public static final int HOSTKEY_IS_NEW = 1;
+    public static final int HOSTKEY_HAS_CHANGED = 2;
+
+    private class KnownHostsEntry {
+        String[] patterns;
+        PublicKey key;
+
+        KnownHostsEntry(String[] patterns, PublicKey key) {
+            this.patterns = patterns;
+            this.key = key;
+        }
+    }
+
+    private LinkedList<KnownHostsEntry> publicKeys = new LinkedList<KnownHostsEntry>();
+
+    public KnownHosts() {
+    }
+
+    public KnownHosts(char[] knownHostsData) throws IOException {
+        initialize(knownHostsData);
+    }
+
+    public KnownHosts(File knownHosts) throws IOException {
+        initialize(knownHosts);
+    }
+
+    /**
+     * Adds a single public key entry to the database. Note: this will NOT add the public key
+     * to any physical file (e.g., "~/.ssh/known_hosts") - use <code>addHostkeyToFile()</code> for that purpose.
+     * This method is designed to be used in a {@link ServerHostKeyVerifier}.
+     *
+     * @param hostnames a list of hostname patterns - at least one most be specified. Check out the
+     *        OpenSSH sshd man page for a description of the pattern matching algorithm.
+     * @param serverHostKeyAlgorithm as passed to the {@link ServerHostKeyVerifier}.
+     * @param serverHostKey as passed to the {@link ServerHostKeyVerifier}.
+     * @throws IOException
+     */
+    public void addHostkey(String hostnames[], String serverHostKeyAlgorithm, byte[] serverHostKey) throws IOException {
+        if (hostnames == null)
+            throw new IllegalArgumentException("hostnames may not be null");
+
+        if ("ssh-rsa".equals(serverHostKeyAlgorithm)) {
+            RSAPublicKey rpk = RSASHA1Verify.decodeSSHRSAPublicKey(serverHostKey);
+
+            synchronized (publicKeys) {
+                publicKeys.add(new KnownHostsEntry(hostnames, rpk));
+            }
+        }
+        else if ("ssh-dss".equals(serverHostKeyAlgorithm)) {
+            DSAPublicKey dpk = DSASHA1Verify.decodeSSHDSAPublicKey(serverHostKey);
+
+            synchronized (publicKeys) {
+                publicKeys.add(new KnownHostsEntry(hostnames, dpk));
+            }
+        }
+        else if (serverHostKeyAlgorithm.startsWith(ECDSASHA2Verify.ECDSA_SHA2_PREFIX)) {
+            ECPublicKey epk = ECDSASHA2Verify.decodeSSHECDSAPublicKey(serverHostKey);
+
+            synchronized (publicKeys) {
+                publicKeys.add(new KnownHostsEntry(hostnames, epk));
+            }
+        }
+        else
+            throw new IOException("Unknwon host key type (" + serverHostKeyAlgorithm + ")");
+    }
+
+    /**
+     * Parses the given known_hosts data and adds entries to the database.
+     *
+     * @param knownHostsData
+     * @throws IOException
+     */
+    public void addHostkeys(char[] knownHostsData) throws IOException {
+        initialize(knownHostsData);
+    }
+
+    /**
+     * Parses the given known_hosts file and adds entries to the database.
+     *
+     * @param knownHosts
+     * @throws IOException
+     */
+    public void addHostkeys(File knownHosts) throws IOException {
+        initialize(knownHosts);
+    }
+
+    /**
+     * Generate the hashed representation of the given hostname. Useful for adding entries
+     * with hashed hostnames to a known_hosts file. (see -H option of OpenSSH key-gen).
+     *
+     * @param hostname
+     * @return the hashed representation, e.g., "|1|cDhrv7zwEUV3k71CEPHnhHZezhA=|Xo+2y6rUXo2OIWRAYhBOIijbJMA="
+     */
+    public static final String createHashedHostname(String hostname) {
+        MessageDigest sha1;
+
+        try {
+            sha1 = MessageDigest.getInstance("SHA1");
+        }
+        catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException("VM doesn't support SHA1", e);
+        }
+
+        byte[] salt = new byte[sha1.getDigestLength()];
+        new SecureRandom().nextBytes(salt);
+        byte[] hash = hmacSha1Hash(salt, hostname);
+        String base64_salt = new String(Base64.encode(salt));
+        String base64_hash = new String(Base64.encode(hash));
+        return new String("|1|" + base64_salt + "|" + base64_hash);
+    }
+
+    private static final byte[] hmacSha1Hash(byte[] salt, String hostname) {
+        Mac hmac;
+
+        try {
+            hmac = Mac.getInstance("HmacSHA1");
+
+            if (salt.length != hmac.getMacLength())
+                throw new IllegalArgumentException("Salt has wrong length (" + salt.length + ")");
+
+            hmac.init(new SecretKeySpec(salt, "HmacSHA1"));
+        }
+        catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException("Unable to HMAC-SHA1", e);
+        }
+        catch (InvalidKeyException e) {
+            throw new RuntimeException("Unable to create SecretKey", e);
+        }
+
+        try {
+            hmac.update(hostname.getBytes("ISO-8859-1"));
+        }
+        catch (UnsupportedEncodingException ignore) {
+            /* Actually, ISO-8859-1 is supported by all correct
+             * Java implementations. But... you never know. */
+            hmac.update(hostname.getBytes());
+        }
+
+        return hmac.doFinal();
+    }
+
+    private final boolean checkHashed(String entry, String hostname) {
+        if (entry.startsWith("|1|") == false)
+            return false;
+
+        int delim_idx = entry.indexOf('|', 3);
+
+        if (delim_idx == -1)
+            return false;
+
+        String salt_base64 = entry.substring(3, delim_idx);
+        String hash_base64 = entry.substring(delim_idx + 1);
+        byte[] salt = null;
+        byte[] hash = null;
+
+        try {
+            salt = Base64.decode(salt_base64.toCharArray());
+            hash = Base64.decode(hash_base64.toCharArray());
+        }
+        catch (IOException e) {
+            return false;
+        }
+
+        try {
+            MessageDigest sha1 = MessageDigest.getInstance("SHA1");
+
+            if (salt.length != sha1.getDigestLength())
+                return false;
+        }
+        catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException("VM does not support SHA1", e);
+        }
+
+        byte[] dig = hmacSha1Hash(salt, hostname);
+
+        for (int i = 0; i < dig.length; i++)
+            if (dig[i] != hash[i])
+                return false;
+
+        return true;
+    }
+
+    private int checkKey(String remoteHostname, PublicKey remoteKey) {
+        int result = HOSTKEY_IS_NEW;
+
+        synchronized (publicKeys) {
+            Iterator<KnownHostsEntry> i = publicKeys.iterator();
+
+            while (i.hasNext()) {
+                KnownHostsEntry ke = i.next();
+
+                if (hostnameMatches(ke.patterns, remoteHostname) == false)
+                    continue;
+
+                boolean res = matchKeys(ke.key, remoteKey);
+
+                if (res == true)
+                    return HOSTKEY_IS_OK;
+
+                result = HOSTKEY_HAS_CHANGED;
+            }
+        }
+
+        return result;
+    }
+
+    private Vector<PublicKey> getAllKeys(String hostname) {
+        Vector<PublicKey> keys = new Vector<PublicKey>();
+
+        synchronized (publicKeys) {
+            Iterator<KnownHostsEntry> i = publicKeys.iterator();
+
+            while (i.hasNext()) {
+                KnownHostsEntry ke = i.next();
+
+                if (hostnameMatches(ke.patterns, hostname) == false)
+                    continue;
+
+                keys.addElement(ke.key);
+            }
+        }
+
+        return keys;
+    }
+
+    /**
+     * Try to find the preferred order of hostkey algorithms for the given hostname.
+     * Based on the type of hostkey that is present in the internal database
+     * (i.e., either <code>ssh-rsa</code> or <code>ssh-dss</code>)
+     * an ordered list of hostkey algorithms is returned which can be passed
+     * to <code>Connection.setServerHostKeyAlgorithms</code>.
+     *
+     * @param hostname
+     * @return <code>null</code> if no key for the given hostname is present or
+     * there are keys of multiple types present for the given hostname. Otherwise,
+     * an array with hostkey algorithms is returned (i.e., an array of length 2).
+     */
+    public String[] getPreferredServerHostkeyAlgorithmOrder(String hostname) {
+        String[] algos = recommendHostkeyAlgorithms(hostname);
+
+        if (algos != null)
+            return algos;
+
+        InetAddress[] ipAdresses = null;
+
+        try {
+            ipAdresses = InetAddress.getAllByName(hostname);
+        }
+        catch (UnknownHostException e) {
+            return null;
+        }
+
+        for (int i = 0; i < ipAdresses.length; i++) {
+            algos = recommendHostkeyAlgorithms(ipAdresses[i].getHostAddress());
+
+            if (algos != null)
+                return algos;
+        }
+
+        return null;
+    }
+
+    private final boolean hostnameMatches(String[] hostpatterns, String hostname) {
+        boolean isMatch = false;
+        boolean negate = false;
+        hostname = hostname.toLowerCase(Locale.US);
+
+        for (int k = 0; k < hostpatterns.length; k++) {
+            if (hostpatterns[k] == null)
+                continue;
+
+            String pattern = null;
+
+            /* In contrast to OpenSSH we also allow negated hash entries (as well as hashed
+             * entries in lines with multiple entries).
+             */
+
+            if ((hostpatterns[k].length() > 0) && (hostpatterns[k].charAt(0) == '!')) {
+                pattern = hostpatterns[k].substring(1);
+                negate = true;
+            }
+            else {
+                pattern = hostpatterns[k];
+                negate = false;
+            }
+
+            /* Optimize, no need to check this entry */
+
+            if ((isMatch) && (negate == false))
+                continue;
+
+            /* Now compare */
+
+            if (pattern.charAt(0) == '|') {
+                if (checkHashed(pattern, hostname)) {
+                    if (negate)
+                        return false;
+
+                    isMatch = true;
+                }
+            }
+            else {
+                pattern = pattern.toLowerCase(Locale.US);
+
+                if ((pattern.indexOf('?') != -1) || (pattern.indexOf('*') != -1)) {
+                    if (pseudoRegex(pattern.toCharArray(), 0, hostname.toCharArray(), 0)) {
+                        if (negate)
+                            return false;
+
+                        isMatch = true;
+                    }
+                }
+                else if (pattern.compareTo(hostname) == 0) {
+                    if (negate)
+                        return false;
+
+                    isMatch = true;
+                }
+            }
+        }
+
+        return isMatch;
+    }
+
+    private void initialize(char[] knownHostsData) throws IOException {
+        BufferedReader br = new BufferedReader(new CharArrayReader(knownHostsData));
+
+        while (true) {
+            String line = br.readLine();
+
+            if (line == null)
+                break;
+
+            line = line.trim();
+
+            if (line.startsWith("#"))
+                continue;
+
+            String[] arr = line.split(" ");
+
+            if (arr.length >= 3) {
+                if ((arr[1].compareTo("ssh-rsa") == 0) || (arr[1].compareTo("ssh-dss") == 0)) {
+                    String[] hostnames = arr[0].split(",");
+                    byte[] msg = Base64.decode(arr[2].toCharArray());
+                    addHostkey(hostnames, arr[1], msg);
+                }
+            }
+        }
+    }
+
+    private void initialize(File knownHosts) throws IOException {
+        char[] buff = new char[512];
+        CharArrayWriter cw = new CharArrayWriter();
+        knownHosts.createNewFile();
+        FileReader fr = new FileReader(knownHosts);
+
+        while (true) {
+            int len = fr.read(buff);
+
+            if (len < 0)
+                break;
+
+            cw.write(buff, 0, len);
+        }
+
+        fr.close();
+        initialize(cw.toCharArray());
+    }
+
+    private final boolean matchKeys(PublicKey key1, PublicKey key2) {
+        return key1.equals(key2);
+    }
+
+    private final boolean pseudoRegex(char[] pattern, int i, char[] match, int j) {
+        /* This matching logic is equivalent to the one present in OpenSSH 4.1 */
+        while (true) {
+            /* Are we at the end of the pattern? */
+            if (pattern.length == i)
+                return (match.length == j);
+
+            if (pattern[i] == '*') {
+                i++;
+
+                if (pattern.length == i)
+                    return true;
+
+                if ((pattern[i] != '*') && (pattern[i] != '?')) {
+                    while (true) {
+                        if ((pattern[i] == match[j]) && pseudoRegex(pattern, i + 1, match, j + 1))
+                            return true;
+
+                        j++;
+
+                        if (match.length == j)
+                            return false;
+                    }
+                }
+
+                while (true) {
+                    if (pseudoRegex(pattern, i, match, j))
+                        return true;
+
+                    j++;
+
+                    if (match.length == j)
+                        return false;
+                }
+            }
+
+            if (match.length == j)
+                return false;
+
+            if ((pattern[i] != '?') && (pattern[i] != match[j]))
+                return false;
+
+            i++;
+            j++;
+        }
+    }
+
+    private String[] recommendHostkeyAlgorithms(String hostname) {
+        String preferredAlgo = null;
+        Vector<PublicKey> keys = getAllKeys(hostname);
+
+        for (int i = 0; i < keys.size(); i++) {
+            String thisAlgo = null;
+
+            if (keys.elementAt(i) instanceof RSAPublicKey)
+                thisAlgo = "ssh-rsa";
+            else if (keys.elementAt(i) instanceof DSAPublicKey)
+                thisAlgo = "ssh-dss";
+            else
+                continue;
+
+            if (preferredAlgo != null) {
+                /* If we find different key types, then return null */
+                if (preferredAlgo.compareTo(thisAlgo) != 0)
+                    return null;
+
+                /* OK, we found the same algo again, optimize */
+                continue;
+            }
+        }
+
+        /* If we did not find anything that we know of, return null */
+
+        if (preferredAlgo == null)
+            return null;
+
+        /* Now put the preferred algo to the start of the array.
+         * You may ask yourself why we do it that way - basically, we could just
+         * return only the preferred algorithm: since we have a saved key of that
+         * type (sent earlier from the remote host), then that should work out.
+         * However, imagine that the server is (for whatever reasons) not offering
+         * that type of hostkey anymore (e.g., "ssh-rsa" was disabled and
+         * now "ssh-dss" is being used). If we then do not let the server send us
+         * a fresh key of the new type, then we shoot ourself into the foot:
+         * the connection cannot be established and hence the user cannot decide
+         * if he/she wants to accept the new key.
+         */
+
+        if (preferredAlgo.equals("ssh-rsa"))
+            return new String[] { "ssh-rsa", "ssh-dss" };
+
+        return new String[] { "ssh-dss", "ssh-rsa" };
+    }
+
+    /**
+     * Checks the internal hostkey database for the given hostkey.
+     * If no matching key can be found, then the hostname is resolved to an IP address
+     * and the search is repeated using that IP address.
+     *
+     * @param hostname the server's hostname, will be matched with all hostname patterns
+     * @param serverHostKeyAlgorithm type of hostkey, either <code>ssh-rsa</code> or <code>ssh-dss</code>
+     * @param serverHostKey the key blob
+     * @return <ul>
+     *         <li><code>HOSTKEY_IS_OK</code>: the given hostkey matches an entry for the given hostname</li>
+     *         <li><code>HOSTKEY_IS_NEW</code>: no entries found for this hostname and this type of hostkey</li>
+     *         <li><code>HOSTKEY_HAS_CHANGED</code>: hostname is known, but with another key of the same type
+     *         (man-in-the-middle attack?)</li>
+     *         </ul>
+     * @throws IOException if the supplied key blob cannot be parsed or does not match the given hostkey type.
+     */
+    public int verifyHostkey(String hostname, String serverHostKeyAlgorithm, byte[] serverHostKey) throws IOException {
+        PublicKey remoteKey = null;
+
+        if ("ssh-rsa".equals(serverHostKeyAlgorithm)) {
+            remoteKey = RSASHA1Verify.decodeSSHRSAPublicKey(serverHostKey);
+        }
+        else if ("ssh-dss".equals(serverHostKeyAlgorithm)) {
+            remoteKey = DSASHA1Verify.decodeSSHDSAPublicKey(serverHostKey);
+        }
+        else if (serverHostKeyAlgorithm.startsWith("ecdsa-sha2-")) {
+            remoteKey = ECDSASHA2Verify.decodeSSHECDSAPublicKey(serverHostKey);
+        }
+        else
+            throw new IllegalArgumentException("Unknown hostkey type " + serverHostKeyAlgorithm);
+
+        int result = checkKey(hostname, remoteKey);
+
+        if (result == HOSTKEY_IS_OK)
+            return result;
+
+        InetAddress[] ipAdresses = null;
+
+        try {
+            ipAdresses = InetAddress.getAllByName(hostname);
+        }
+        catch (UnknownHostException e) {
+            return result;
+        }
+
+        for (int i = 0; i < ipAdresses.length; i++) {
+            int newresult = checkKey(ipAdresses[i].getHostAddress(), remoteKey);
+
+            if (newresult == HOSTKEY_IS_OK)
+                return newresult;
+
+            if (newresult == HOSTKEY_HAS_CHANGED)
+                result = HOSTKEY_HAS_CHANGED;
+        }
+
+        return result;
+    }
+
+    /**
+     * Adds a single public key entry to the a known_hosts file.
+     * This method is designed to be used in a {@link ServerHostKeyVerifier}.
+     *
+     * @param knownHosts the file where the publickey entry will be appended.
+     * @param hostnames a list of hostname patterns - at least one most be specified. Check out the
+     *        OpenSSH sshd man page for a description of the pattern matching algorithm.
+     * @param serverHostKeyAlgorithm as passed to the {@link ServerHostKeyVerifier}.
+     * @param serverHostKey as passed to the {@link ServerHostKeyVerifier}.
+     * @throws IOException
+     */
+    public final static void addHostkeyToFile(File knownHosts, String[] hostnames, String serverHostKeyAlgorithm,
+            byte[] serverHostKey) throws IOException {
+        if ((hostnames == null) || (hostnames.length == 0))
+            throw new IllegalArgumentException("Need at least one hostname specification");
+
+        if ((serverHostKeyAlgorithm == null) || (serverHostKey == null))
+            throw new IllegalArgumentException();
+
+        CharArrayWriter writer = new CharArrayWriter();
+
+        for (int i = 0; i < hostnames.length; i++) {
+            if (i != 0)
+                writer.write(',');
+
+            writer.write(hostnames[i]);
+        }
+
+        writer.write(' ');
+        writer.write(serverHostKeyAlgorithm);
+        writer.write(' ');
+        writer.write(Base64.encode(serverHostKey));
+        writer.write("\n");
+        char[] entry = writer.toCharArray();
+        RandomAccessFile raf = new RandomAccessFile(knownHosts, "rw");
+        long len = raf.length();
+
+        if (len > 0) {
+            raf.seek(len - 1);
+            int last = raf.read();
+
+            if (last != '\n')
+                raf.write('\n');
+        }
+
+        raf.write(new String(entry).getBytes("ISO-8859-1"));
+        raf.close();
+    }
+
+    /**
+     * Generates a "raw" fingerprint of a hostkey.
+     *
+     * @param type either "md5" or "sha1"
+     * @param keyType either "ssh-rsa" or "ssh-dss"
+     * @param hostkey the hostkey
+     * @return the raw fingerprint
+     */
+    static final private byte[] rawFingerPrint(String type, String keyType, byte[] hostkey) {
+        MessageDigest dig = null;
+
+        try {
+            if ("md5".equals(type)) {
+                dig = MessageDigest.getInstance("MD5");
+            }
+            else if ("sha1".equals(type)) {
+                dig = MessageDigest.getInstance("SHA1");
+            }
+            else {
+                throw new IllegalArgumentException("Unknown hash type " + type);
+            }
+        }
+        catch (NoSuchAlgorithmException e) {
+            throw new IllegalArgumentException("Unknown hash type " + type);
+        }
+
+        if (keyType.startsWith("ecdsa-sha2-")) {
+        }
+        else if ("ssh-rsa".equals(keyType)) {
+        }
+        else if ("ssh-dss".equals(keyType)) {
+        }
+        else
+            throw new IllegalArgumentException("Unknown key type " + keyType);
+
+        if (hostkey == null)
+            throw new IllegalArgumentException("hostkey is null");
+
+        dig.update(hostkey);
+        return dig.digest();
+    }
+
+    /**
+     * Convert a raw fingerprint to hex representation (XX:YY:ZZ...).
+     * @param fingerprint raw fingerprint
+     * @return the hex representation
+     */
+    static final private String rawToHexFingerprint(byte[] fingerprint) {
+        final char[] alpha = "0123456789abcdef".toCharArray();
+        StringBuffer sb = new StringBuffer();
+
+        for (int i = 0; i < fingerprint.length; i++) {
+            if (i != 0)
+                sb.append(':');
+
+            int b = fingerprint[i] & 0xff;
+            sb.append(alpha[b >> 4]);
+            sb.append(alpha[b & 15]);
+        }
+
+        return sb.toString();
+    }
+
+    /**
+     * Convert a raw fingerprint to bubblebabble representation.
+     * @param raw raw fingerprint
+     * @return the bubblebabble representation
+     */
+    static final private String rawToBubblebabbleFingerprint(byte[] raw) {
+        final char[] v = "aeiouy".toCharArray();
+        final char[] c = "bcdfghklmnprstvzx".toCharArray();
+        StringBuffer sb = new StringBuffer();
+        int seed = 1;
+        int rounds = (raw.length / 2) + 1;
+        sb.append('x');
+
+        for (int i = 0; i < rounds; i++) {
+            if (((i + 1) < rounds) || ((raw.length) % 2 != 0)) {
+                sb.append(v[(((raw[2 * i] >> 6) & 3) + seed) % 6]);
+                sb.append(c[(raw[2 * i] >> 2) & 15]);
+                sb.append(v[((raw[2 * i] & 3) + (seed / 6)) % 6]);
+
+                if ((i + 1) < rounds) {
+                    sb.append(c[(((raw[(2 * i) + 1])) >> 4) & 15]);
+                    sb.append('-');
+                    sb.append(c[(((raw[(2 * i) + 1]))) & 15]);
+                    // As long as seed >= 0, seed will be >= 0 afterwards
+                    seed = ((seed * 5) + (((raw[2 * i] & 0xff) * 7) + (raw[(2 * i) + 1] & 0xff))) % 36;
+                }
+            }
+            else {
+                sb.append(v[seed % 6]); // seed >= 0, therefore index positive
+                sb.append('x');
+                sb.append(v[seed / 6]);
+            }
+        }
+
+        sb.append('x');
+        return sb.toString();
+    }
+
+    /**
+     * Convert a ssh2 key-blob into a human readable hex fingerprint.
+     * Generated fingerprints are identical to those generated by OpenSSH.
+     * <p>
+     * Example fingerprint: d0:cb:76:19:99:5a:03:fc:73:10:70:93:f2:44:63:47.
+
+     * @param keytype either "ssh-rsa" or "ssh-dss"
+     * @param publickey key blob
+     * @return Hex fingerprint
+     */
+    public final static String createHexFingerprint(String keytype, byte[] publickey) {
+        byte[] raw = rawFingerPrint("md5", keytype, publickey);
+        return rawToHexFingerprint(raw);
+    }
+
+    /**
+     * Convert a ssh2 key-blob into a human readable bubblebabble fingerprint.
+     * The used bubblebabble algorithm (taken from OpenSSH) generates fingerprints
+     * that are easier to remember for humans.
+     * <p>
+     * Example fingerprint: xofoc-bubuz-cazin-zufyl-pivuk-biduk-tacib-pybur-gonar-hotat-lyxux.
+     *
+     * @param keytype either "ssh-rsa" or "ssh-dss"
+     * @param publickey key data
+     * @return Bubblebabble fingerprint
+     */
+    public final static String createBubblebabbleFingerprint(String keytype, byte[] publickey) {
+        byte[] raw = rawFingerPrint("sha1", keytype, publickey);
+        return rawToBubblebabbleFingerprint(raw);
+    }
+}