--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/src/main/java/ch/ethz/ssh2/KnownHosts.java	Thu Dec 03 11:23:55 2015 -0800
@@ -0,0 +1,814 @@
+/*
+ * Copyright (c) 2006-2011 Christian Plattner. All rights reserved.
+ * Please refer to the LICENSE.txt for licensing details.
+ */
+
+package ch.ethz.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.net.InetAddress;
+import java.net.UnknownHostException;
+import java.security.DigestException;
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+
+import ch.ethz.ssh2.crypto.Base64;
+import ch.ethz.ssh2.crypto.SecureRandomFix;
+import ch.ethz.ssh2.crypto.digest.Digest;
+import ch.ethz.ssh2.crypto.digest.HMAC;
+import ch.ethz.ssh2.crypto.digest.MD5;
+import ch.ethz.ssh2.crypto.digest.SHA1;
+
+import java.security.KeyPair;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+import java.security.interfaces.DSAPublicKey;
+import java.security.interfaces.ECPublicKey;
+import java.security.interfaces.RSAPublicKey;
+import ch.ethz.ssh2.signature.DSASHA1Verify;
+import ch.ethz.ssh2.signature.ECDSASHA2Verify;
+import ch.ethz.ssh2.signature.RSASHA1Verify;
+import ch.ethz.ssh2.util.StringEncoder;
+
+/**
+ * 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
+ * @version $Id: KnownHosts.java 152 2014-04-28 11:02:23Z dkocher@sudo.ch $
+ */
+
+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 final LinkedList<KnownHostsEntry> publicKeys = new LinkedList<KnownHosts.KnownHostsEntry>();
+
+    public KnownHosts() {
+    }
+
+    public KnownHosts(char[] knownHostsData) throws IOException {
+        initialize(knownHostsData);
+    }
+
+    public KnownHosts(String knownHosts) throws IOException {
+        initialize(new File(knownHosts));
+    }
+
+    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("ecdsa-sha2-")) {
+            ECPublicKey epk = ECDSASHA2Verify.decodeSSHECDSAPublicKey(serverHostKey);
+
+            synchronized (publicKeys) {
+                publicKeys.add(new KnownHostsEntry(hostnames, epk));
+            }
+        }
+        else {
+            throw new IOException(String.format("Unknown host key type %s", 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 String createHashedHostname(String hostname) throws IOException {
+        SHA1 sha1 = new SHA1();
+        byte[] salt = new byte[sha1.getDigestLength()];
+        new SecureRandomFix().nextBytes(salt);
+        byte[] hash;
+
+        try {
+            hash = hmacSha1Hash(salt, hostname);
+        }
+        catch (IOException e) {
+            throw new IOException(e);
+        }
+
+        String base64_salt = new String(Base64.encode(salt));
+        String base64_hash = new String(Base64.encode(hash));
+        return String.format("|1|%s|%s", base64_salt, base64_hash);
+    }
+
+    private static byte[] hmacSha1Hash(byte[] salt, String hostname) throws IOException {
+        SHA1 sha1 = new SHA1();
+
+        if (salt.length != sha1.getDigestLength()) {
+            throw new IllegalArgumentException("Salt has wrong length (" + salt.length + ")");
+        }
+
+        try {
+            HMAC hmac = new HMAC(sha1, salt, salt.length);
+            hmac.update(StringEncoder.GetBytes(hostname));
+            byte[] dig = new byte[hmac.getDigestLength()];
+            hmac.digest(dig);
+            return dig;
+        }
+        catch (DigestException e) {
+            throw new IOException(e);
+        }
+    }
+
+    private 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;
+        byte[] hash;
+
+        try {
+            salt = Base64.decode(salt_base64.toCharArray());
+            hash = Base64.decode(hash_base64.toCharArray());
+        }
+        catch (IOException e) {
+            return false;
+        }
+
+        SHA1 sha1 = new SHA1();
+
+        if (salt.length != sha1.getDigestLength()) {
+            return false;
+        }
+
+        byte[] dig = new byte[0];
+
+        try {
+            dig = hmacSha1Hash(salt, hostname);
+        }
+        catch (IOException e) {
+            return false;
+        }
+
+        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) {
+            for (KnownHostsEntry ke : publicKeys) {
+                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 List<Object> getAllKeys(String hostname) {
+        List<Object> keys = new ArrayList<Object>();
+
+        synchronized (publicKeys) {
+            for (KnownHostsEntry ke : publicKeys) {
+                if (hostnameMatches(ke.patterns, hostname) == false) {
+                    continue;
+                }
+
+                keys.add(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;
+
+        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 boolean hostnameMatches(String[] hostpatterns, String hostname) {
+        boolean isMatch = false;
+        boolean negate;
+        hostname = hostname.toLowerCase();
+
+        for (int k = 0; k < hostpatterns.length; k++) {
+            if (hostpatterns[k] == null) {
+                continue;
+            }
+
+            String pattern;
+
+            /* 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();
+
+                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) ||
+                        (arr[1].startsWith("ecdsa-sha2-"))) {
+                    String[] hostnames = arr[0].split(",");
+                    byte[] msg = Base64.decode(arr[2].toCharArray());
+
+                    try {
+                        addHostkey(hostnames, arr[1], msg);
+                    }
+                    catch (IOException e) {
+                        continue;
+                    }
+                }
+            }
+        }
+    }
+
+    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 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;
+        List<Object> keys = getAllKeys(hostname);
+
+        for (Object key : keys) {
+            String thisAlgo;
+
+            if (key instanceof RSAPublicKey) {
+                thisAlgo = "ssh-rsa";
+            }
+            else if (key instanceof DSAPublicKey) {
+                thisAlgo = "ssh-dss";
+            }
+            else if (key instanceof ECPublicKey) {
+                ECPublicKey ecPub = (ECPublicKey) key;
+                String keyType = ECDSASHA2Verify.getCurveName(ecPub.getParams().getCurve().getField().getFieldSize());
+                thisAlgo = ECDSASHA2Verify.ECDSA_SHA2_PREFIX + keyType;
+            }
+            else {
+                continue;
+            }
+
+            if (preferredAlgo != null) {
+                /* If we find different key types, then return null */
+                if (preferredAlgo.compareTo(thisAlgo) != 0) {
+                    return null;
+                }
+            }
+            else {
+                preferredAlgo = thisAlgo;
+            }
+        }
+
+        /* 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", "ecdsa-sha2-nistp256"};
+        }
+
+        return new String[] {"ssh-dss", "ssh-rsa", "ecdsa-sha2-nistp256"};
+    }
+
+    /**
+     * 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;
+
+        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;
+
+        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 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(StringEncoder.GetBytes(new String(entry)));
+        raf.close();
+    }
+
+    /**
+     * Generates a "raw" fingerprint of a hostkey.
+     *
+     * @param type    either "md5" or "sha1"
+     * @param keyType either "ssh-rsa" or "ssh-dss" or "ecdsa-sha2..."
+     * @param hostkey the hostkey
+     * @return the raw fingerprint
+     */
+    static private byte[] rawFingerPrint(String type, String keyType, byte[] hostkey) throws IOException {
+        Digest dig;
+
+        if ("md5".equals(type)) {
+            dig = new MD5();
+        }
+        else if ("sha1".equals(type)) {
+            dig = new SHA1();
+        }
+        else {
+            throw new IllegalArgumentException("Unknown hash type " + type);
+        }
+
+        if ("ssh-rsa".equals(keyType)) {
+        }
+        else if ("ssh-dss".equals(keyType)) {
+        }
+        else if (keyType.startsWith("ecdsa-sha2-")) {
+        }
+        else {
+            throw new IllegalArgumentException("Unknown key type " + keyType);
+        }
+
+        if (hostkey == null) {
+            throw new IllegalArgumentException("hostkey is null");
+        }
+
+        dig.update(hostkey);
+        byte[] res = new byte[dig.getDigestLength()];
+
+        try {
+            dig.digest(res);
+        }
+        catch (DigestException e) {
+            throw new IOException(e);
+        }
+
+        return res;
+    }
+
+    /**
+     * Convert a raw fingerprint to hex representation (XX:YY:ZZ...).
+     *
+     * @param fingerprint raw fingerprint
+     * @return the hex representation
+     */
+    static private String rawToHexFingerprint(byte[] fingerprint) {
+        final char[] alpha = "0123456789abcdef".toCharArray();
+        StringBuilder sb = new StringBuilder();
+
+        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 private String rawToBubblebabbleFingerprint(byte[] raw) {
+        final char[] v = "aeiouy".toCharArray();
+        final char[] c = "bcdfghklmnprstvzx".toCharArray();
+        StringBuilder sb = new StringBuilder();
+        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" or "ecdsa-sha2..."
+     * @param publickey key blob
+     * @return Hex fingerprint
+     */
+    public static String createHexFingerprint(String keytype, byte[] publickey) throws IOException {
+        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 static String createBubblebabbleFingerprint(String keytype, byte[] publickey) throws IOException {
+        byte[] raw = rawFingerPrint("sha1", keytype, publickey);
+        return rawToBubblebabbleFingerprint(raw);
+    }
+}