* For SRP, there are three (3) files: *
* This implementation assumes the following message digest algorithm codes: *
* IMPORTANT: This method computes the verifiers as described in * RFC-2945, which differs from the description given on the web page for SRP-6. *
* Reference: *
index.
*
* @param index a string representing 1-digit identification of an <N, g>
* pair used.
* @return true if the designated index is that
* of a known <N, g> pair, and false otherwise.
* @throws IOException if an exception occurs during the process.
* @see SRPRegistry#N_2048_BITS
* @see SRPRegistry#N_1536_BITS
* @see SRPRegistry#N_1280_BITS
* @see SRPRegistry#N_1024_BITS
* @see SRPRegistry#N_768_BITS
* @see SRPRegistry#N_640_BITS
* @see SRPRegistry#N_512_BITS
*/
public synchronized boolean containsConfig(final String index)
throws IOException
{
checkCurrent();
return configurations.containsKey(index);
}
/**
* Returns a pair of strings representing the pair of N and
* g MPIs for the designated index.
*
* @param index a string representing 1-digit identification of an <N, g>
* pair to look up.
* @return a pair of strings, arranged in an array, where the first (at index
* position #0) is the repesentation of the MPI N, and
* the second (at index position #1) is the representation of the MPI
* g. If the index refers to an unknown
* pair, then an empty string array is returned.
* @throws IOException if an exception occurs during the process.
*/
public synchronized String[] lookupConfig(final String index)
throws IOException
{
checkCurrent();
String[] result = null;
if (configurations.containsKey(index))
result = (String[]) configurations.get(index);
return result;
}
public synchronized boolean contains(final String user) throws IOException
{
checkCurrent();
return entries.containsKey(user);
}
public synchronized void add(final String user, final String passwd,
final byte[] salt, final String index)
throws IOException
{
checkCurrent();
if (entries.containsKey(user))
throw new UserAlreadyExistsException(user);
final HashMap fields = new HashMap(4);
fields.put(USER_FIELD, user); // 0
fields.put(VERIFIERS_FIELD, newVerifiers(user, salt, passwd, index)); // 1
fields.put(SALT_FIELD, Util.toBase64(salt)); // 2
fields.put(CONFIG_FIELD, index); // 3
entries.put(user, fields);
savePasswd();
}
public synchronized void changePasswd(final String user, final String passwd)
throws IOException
{
checkCurrent();
if (! entries.containsKey(user))
throw new NoSuchUserException(user);
final HashMap fields = (HashMap) entries.get(user);
final byte[] salt;
try
{
salt = Util.fromBase64((String) fields.get(SALT_FIELD));
}
catch (NumberFormatException x)
{
throw new IOException("Password file corrupt");
}
final String index = (String) fields.get(CONFIG_FIELD);
fields.put(VERIFIERS_FIELD, newVerifiers(user, salt, passwd, index));
entries.put(user, fields);
savePasswd();
}
public synchronized void savePasswd() throws IOException
{
final FileOutputStream f1 = new FileOutputStream(passwdFile);
final FileOutputStream f2 = new FileOutputStream(passwd2File);
PrintWriter pw1 = null;
PrintWriter pw2 = null;
try
{
pw1 = new PrintWriter(f1, true);
pw2 = new PrintWriter(f2, true);
this.writePasswd(pw1, pw2);
}
finally
{
if (pw1 != null)
try
{
pw1.flush();
}
finally
{
pw1.close();
}
if (pw2 != null)
try
{
pw2.flush();
}
finally
{
pw2.close();
}
try
{
f1.close();
}
catch (IOException ignored)
{
}
try
{
f2.close();
}
catch (IOException ignored)
{
}
}
lastmodPasswdFile = passwdFile.lastModified();
lastmodPasswd2File = passwd2File.lastModified();
}
/**
* Returns the triplet: verifier, salt and configuration file index, of a
* designated user, and a designated message digest algorithm name, as an
* array of strings.
*
* @param user the username.
* @param mdName the canonical name of the SRP's message digest algorithm.
* @return a string array containing, in this order, the BASE-64 encodings of
* the verifier, the salt and the index in the password configuration
* file of the MPIs N and g of the designated user.
*/
public synchronized String[] lookup(final String user, final String mdName)
throws IOException
{
checkCurrent();
if (! entries.containsKey(user))
throw new NoSuchUserException(user);
final HashMap fields = (HashMap) entries.get(user);
final HashMap verifiers = (HashMap) fields.get(VERIFIERS_FIELD);
final String salt = (String) fields.get(SALT_FIELD);
final String index = (String) fields.get(CONFIG_FIELD);
final String verifier = (String) verifiers.get(nameToID(mdName));
return new String[] { verifier, salt, index };
}
private synchronized void readOrCreateConf() throws IOException
{
configurations.clear();
final FileInputStream fis;
configFile = new File(confName);
try
{
fis = new FileInputStream(configFile);
readConf(fis);
}
catch (FileNotFoundException x)
{ // create a default one
final String g = Util.toBase64(Util.trim(new BigInteger("2")));
String index, N;
for (int i = 0; i < Nsrp.length; i++)
{
index = String.valueOf(i + 1);
N = Util.toBase64(Util.trim(Nsrp[i]));
configurations.put(index, new String[] { N, g });
}
FileOutputStream f0 = null;
PrintWriter pw0 = null;
try
{
f0 = new FileOutputStream(configFile);
pw0 = new PrintWriter(f0, true);
this.writeConf(pw0);
}
finally
{
if (pw0 != null)
pw0.close();
else if (f0 != null)
f0.close();
}
}
}
private void readConf(final InputStream in) throws IOException
{
final BufferedReader din = new BufferedReader(new InputStreamReader(in));
String line, index, N, g;
StringTokenizer st;
while ((line = din.readLine()) != null)
{
st = new StringTokenizer(line, ":");
try
{
index = st.nextToken();
N = st.nextToken();
g = st.nextToken();
}
catch (NoSuchElementException x)
{
throw new IOException("SRP password configuration file corrupt");
}
configurations.put(index, new String[] { N, g });
}
}
private void writeConf(final PrintWriter pw)
{
String ndx;
String[] mpi;
CPStringBuilder sb;
for (Iterator it = configurations.keySet().iterator(); it.hasNext();)
{
ndx = (String) it.next();
mpi = (String[]) configurations.get(ndx);
sb = new CPStringBuilder(ndx)
.append(":").append(mpi[0])
.append(":").append(mpi[1]);
pw.println(sb.toString());
}
}
/**
* Compute the new verifiers for the designated username and password.
* * IMPORTANT: This method computes the verifiers as described in * RFC-2945, which differs from the description given on the web page for * SRP-6. * * @param user the user's name. * @param s the user's salt. * @param password the user's password * @param index the index of the <N, g> pair to use for this user. * @return a {@link java.util.Map} of user verifiers. * @throws UnsupportedEncodingException if the US-ASCII decoder is not * available on this platform. */ private HashMap newVerifiers(final String user, final byte[] s, final String password, final String index) throws UnsupportedEncodingException { // to ensure inter-operability with non-java tools final String[] mpi = (String[]) configurations.get(index); final BigInteger N = new BigInteger(1, Util.fromBase64(mpi[0])); final BigInteger g = new BigInteger(1, Util.fromBase64(mpi[1])); final HashMap result = new HashMap(srps.size()); BigInteger x, v; SRP srp; for (int i = 0; i < srps.size(); i++) { final String digestID = String.valueOf(i); srp = (SRP) srps.get(digestID); x = new BigInteger(1, srp.computeX(s, user, password)); v = g.modPow(x, N); final String verifier = Util.toBase64(v.toByteArray()); result.put(digestID, verifier); } return result; } private synchronized void update() throws IOException { entries.clear(); FileInputStream fis; passwdFile = new File(pwName); lastmodPasswdFile = passwdFile.lastModified(); try { fis = new FileInputStream(passwdFile); readPasswd(fis); } catch (FileNotFoundException ignored) { } passwd2File = new File(pw2Name); lastmodPasswd2File = passwd2File.lastModified(); try { fis = new FileInputStream(passwd2File); readPasswd2(fis); } catch (FileNotFoundException ignored) { } } private void checkCurrent() throws IOException { if (passwdFile.lastModified() > lastmodPasswdFile || passwd2File.lastModified() > lastmodPasswd2File) update(); } private void readPasswd(final InputStream in) throws IOException { final BufferedReader din = new BufferedReader(new InputStreamReader(in)); String line, user, verifier, salt, index; StringTokenizer st; while ((line = din.readLine()) != null) { st = new StringTokenizer(line, ":"); try { user = st.nextToken(); verifier = st.nextToken(); salt = st.nextToken(); index = st.nextToken(); } catch (NoSuchElementException x) { throw new IOException("SRP base password file corrupt"); } final HashMap verifiers = new HashMap(6); verifiers.put("0", verifier); final HashMap fields = new HashMap(4); fields.put(USER_FIELD, user); fields.put(VERIFIERS_FIELD, verifiers); fields.put(SALT_FIELD, salt); fields.put(CONFIG_FIELD, index); entries.put(user, fields); } } private void readPasswd2(final InputStream in) throws IOException { final BufferedReader din = new BufferedReader(new InputStreamReader(in)); String line, digestID, user, verifier; StringTokenizer st; HashMap fields, verifiers; while ((line = din.readLine()) != null) { st = new StringTokenizer(line, ":"); try { digestID = st.nextToken(); user = st.nextToken(); verifier = st.nextToken(); } catch (NoSuchElementException x) { throw new IOException("SRP extended password file corrupt"); } fields = (HashMap) entries.get(user); if (fields != null) { verifiers = (HashMap) fields.get(VERIFIERS_FIELD); verifiers.put(digestID, verifier); } } } private void writePasswd(final PrintWriter pw1, final PrintWriter pw2) throws IOException { String user, digestID; HashMap fields, verifiers; CPStringBuilder sb1, sb2; Iterator j; final Iterator i = entries.keySet().iterator(); while (i.hasNext()) { user = (String) i.next(); fields = (HashMap) entries.get(user); if (! user.equals(fields.get(USER_FIELD))) throw new IOException("Inconsistent SRP password data"); verifiers = (HashMap) fields.get(VERIFIERS_FIELD); sb1 = new CPStringBuilder(user) .append(":").append((String) verifiers.get("0")) .append(":").append((String) fields.get(SALT_FIELD)) .append(":").append((String) fields.get(CONFIG_FIELD)); pw1.println(sb1.toString()); // write extended information j = verifiers.keySet().iterator(); while (j.hasNext()) { digestID = (String) j.next(); if (! "0".equals(digestID)) { // #0 is the default digest, already present in tpasswd! sb2 = new CPStringBuilder(digestID) .append(":").append(user) .append(":").append((String) verifiers.get(digestID)); pw2.println(sb2.toString()); } } } } }