From 3c3421afd8f74a3aa8d1011de07a8c18f9549210 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Parm=C3=A9nides=20GV?= Date: Tue, 8 Apr 2014 12:04:17 +0200 Subject: Rename app->bitmask_android This way, gradle commands generate apks correctly named. --- .../java/se/leap/bitmaskclient/LeapSRPSession.java | 341 +++++++++++++++++++++ 1 file changed, 341 insertions(+) create mode 100644 bitmask_android/src/main/java/se/leap/bitmaskclient/LeapSRPSession.java (limited to 'bitmask_android/src/main/java/se/leap/bitmaskclient/LeapSRPSession.java') diff --git a/bitmask_android/src/main/java/se/leap/bitmaskclient/LeapSRPSession.java b/bitmask_android/src/main/java/se/leap/bitmaskclient/LeapSRPSession.java new file mode 100644 index 00000000..a317d95e --- /dev/null +++ b/bitmask_android/src/main/java/se/leap/bitmaskclient/LeapSRPSession.java @@ -0,0 +1,341 @@ +/** + * Copyright (c) 2013 LEAP Encryption Access Project and contributers + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + package se.leap.bitmaskclient; + +import java.io.UnsupportedEncodingException; +import java.math.BigInteger; +import java.security.MessageDigest; +import java.security.NoSuchAlgorithmException; +import java.security.SecureRandom; +import java.util.Arrays; + +import org.jboss.security.srp.SRPParameters; + +/** + * Implements all SRP algorithm logic. + * + * It's derived from JBoss implementation, with adjustments to make it work with LEAP platform. + * + * @author parmegv + * + */ +public class LeapSRPSession { + + private static String token = ""; + + final public static String SALT = "salt"; + final public static String M1 = "M1"; + final public static String M2 = "M2"; + final public static String TOKEN = "token"; + final public static String AUTHORIZATION_HEADER= "Authorization"; + + private SRPParameters params; + private String username; + private String password; + private BigInteger N; + private byte[] N_bytes; + private BigInteger g; + private BigInteger x; + private BigInteger v; + private BigInteger a; + private BigInteger A; + private byte[] K; + private SecureRandom pseudoRng; + /** The M1 = H(H(N) xor H(g) | H(U) | s | A | B | K) hash */ + private MessageDigest clientHash; + /** The M2 = H(A | M | K) hash */ + private MessageDigest serverHash; + + private static int A_LEN; + + /** Creates a new SRP server session object from the username, password + verifier, + @param username, the user ID + @param password, the user clear text password + @param params, the SRP parameters for the session + */ + public LeapSRPSession(String username, String password, SRPParameters params) + { + this(username, password, params, null); + } + + /** Creates a new SRP server session object from the username, password + verifier, + @param username, the user ID + @param password, the user clear text password + @param params, the SRP parameters for the session + @param abytes, the random exponent used in the A public key + */ + public LeapSRPSession(String username, String password, SRPParameters params, + byte[] abytes) { + this.params = params; + this.g = new BigInteger(1, params.g); + N_bytes = ConfigHelper.trim(params.N); + this.N = new BigInteger(1, N_bytes); + this.username = username; + this.password = password; + + try { + pseudoRng = SecureRandom.getInstance("SHA1PRNG"); + } catch (NoSuchAlgorithmException e) { + // TODO Auto-generated catch block + e.printStackTrace(); + } + + if( abytes != null ) { + A_LEN = 8*abytes.length; + /* TODO Why did they put this condition? + if( 8*abytes.length != A_LEN ) + throw new IllegalArgumentException("The abytes param must be " + +(A_LEN/8)+" in length, abytes.length="+abytes.length); + */ + this.a = new BigInteger(abytes); + } + else + A_LEN = 64; + + serverHash = newDigest(); + clientHash = newDigest(); + } + + /** + * Calculates the parameter x of the SRP-6a algorithm. + * @param username + * @param password + * @param salt the salt of the user + * @return x + */ + public byte[] calculatePasswordHash(String username, String password, byte[] salt) + { + //password = password.replaceAll("\\\\", "\\\\\\\\"); + // Calculate x = H(s | H(U | ':' | password)) + MessageDigest x_digest = newDigest(); + // Try to convert the username to a byte[] using ISO-8859-1 + byte[] user = null; + byte[] password_bytes = null; + byte[] colon = {}; + String encoding = "ISO-8859-1"; + try { + user = ConfigHelper.trim(username.getBytes(encoding)); + colon = ConfigHelper.trim(":".getBytes(encoding)); + password_bytes = ConfigHelper.trim(password.getBytes(encoding)); + } + catch(UnsupportedEncodingException e) { + // Use the default platform encoding + user = ConfigHelper.trim(username.getBytes()); + colon = ConfigHelper.trim(":".getBytes()); + password_bytes = ConfigHelper.trim(password.getBytes()); + } + + // Build the hash + x_digest.update(user); + x_digest.update(colon); + x_digest.update(password_bytes); + byte[] h = x_digest.digest(); + + x_digest.reset(); + x_digest.update(salt); + x_digest.update(h); + byte[] x_digest_bytes = x_digest.digest(); + + return x_digest_bytes; + } + + /** + * Calculates the parameter V of the SRP-6a algorithm. + * @param k_string constant k predefined by the SRP server implementation. + * @return the value of V + */ + private BigInteger calculateV(String k_string) { + BigInteger k = new BigInteger(k_string, 16); + BigInteger v = k.multiply(g.modPow(x, N)); // g^x % N + return v; + } + + /** + * Calculates the trimmed xor from two BigInteger numbers + * @param b1 the positive source to build first BigInteger + * @param b2 the positive source to build second BigInteger + * @param length + * @return + */ + public byte[] xor(byte[] b1, byte[] b2) + { + //TODO Check if length matters in the order, when b2 is smaller than b1 or viceversa + byte[] xor_digest = new BigInteger(1, b1).xor(new BigInteger(1, b2)).toByteArray(); + return ConfigHelper.trim(xor_digest); + } + + /** + * @returns The exponential residue (parameter A) to be sent to the server. + */ + public byte[] exponential() { + byte[] Abytes = null; + if(A == null) { + /* If the random component of A has not been specified use a random + number */ + if( a == null ) { + BigInteger one = BigInteger.ONE; + do { + a = new BigInteger(A_LEN, pseudoRng); + } while(a.compareTo(one) <= 0); + } + A = g.modPow(a, N); + Abytes = ConfigHelper.trim(A.toByteArray()); + } + return Abytes; + } + + /** + * Calculates the parameter M1, to be sent to the SRP server. + * It also updates hashes of client and server for further calculations in other methods. + * It uses a predefined k. + * @param salt_bytes + * @param Bbytes the parameter received from the server, in bytes + * @return the parameter M1 + * @throws NoSuchAlgorithmException + */ + public byte[] response(byte[] salt_bytes, byte[] Bbytes) throws NoSuchAlgorithmException { + // Calculate x = H(s | H(U | ':' | password)) + byte[] M1 = null; + if(new BigInteger(1, Bbytes).mod(new BigInteger(1, N_bytes)) != BigInteger.ZERO) { + byte[] xb = calculatePasswordHash(username, password, ConfigHelper.trim(salt_bytes)); + this.x = new BigInteger(1, xb); + + // Calculate v = kg^x mod N + String k_string = "bf66c44a428916cad64aa7c679f3fd897ad4c375e9bbb4cbf2f5de241d618ef0"; + this.v = calculateV(k_string); + + // H(N) + byte[] digest_of_n = newDigest().digest(N_bytes); + + // H(g) + byte[] digest_of_g = newDigest().digest(params.g); + + // clientHash = H(N) xor H(g) + byte[] xor_digest = xor(digest_of_n, digest_of_g); + clientHash.update(xor_digest); + + // clientHash = H(N) xor H(g) | H(U) + byte[] username_digest = newDigest().digest(ConfigHelper.trim(username.getBytes())); + username_digest = ConfigHelper.trim(username_digest); + clientHash.update(username_digest); + + // clientHash = H(N) xor H(g) | H(U) | s + clientHash.update(ConfigHelper.trim(salt_bytes)); + + K = null; + + // clientHash = H(N) xor H(g) | H(U) | A + byte[] Abytes = ConfigHelper.trim(A.toByteArray()); + clientHash.update(Abytes); + + // clientHash = H(N) xor H(g) | H(U) | s | A | B + Bbytes = ConfigHelper.trim(Bbytes); + clientHash.update(Bbytes); + + // Calculate S = (B - kg^x) ^ (a + u * x) % N + BigInteger S = calculateS(Bbytes); + byte[] S_bytes = ConfigHelper.trim(S.toByteArray()); + + // K = SessionHash(S) + String hash_algorithm = params.hashAlgorithm; + MessageDigest sessionDigest = MessageDigest.getInstance(hash_algorithm); + K = ConfigHelper.trim(sessionDigest.digest(S_bytes)); + + // clientHash = H(N) xor H(g) | H(U) | A | B | K + clientHash.update(K); + + M1 = ConfigHelper.trim(clientHash.digest()); + + // serverHash = Astr + M + K + serverHash.update(Abytes); + serverHash.update(M1); + serverHash.update(K); + + } + return M1; + } + + /** + * It calculates the parameter S used by response() to obtain session hash K. + * @param Bbytes the parameter received from the server, in bytes + * @return the parameter S + */ + private BigInteger calculateS(byte[] Bbytes) { + byte[] Abytes = ConfigHelper.trim(A.toByteArray()); + Bbytes = ConfigHelper.trim(Bbytes); + byte[] u_bytes = getU(Abytes, Bbytes); + + BigInteger B = new BigInteger(1, Bbytes); + BigInteger u = new BigInteger(1, u_bytes); + + BigInteger B_minus_v = B.subtract(v); + BigInteger a_ux = a.add(u.multiply(x)); + BigInteger S = B_minus_v.modPow(a_ux, N); + return S; + } + + /** + * It calculates the parameter u used by calculateS to obtain S. + * @param Abytes the exponential residue sent to the server + * @param Bbytes the parameter received from the server, in bytes + * @return + */ + public byte[] getU(byte[] Abytes, byte[] Bbytes) { + MessageDigest u_digest = newDigest(); + u_digest.update(ConfigHelper.trim(Abytes)); + u_digest.update(ConfigHelper.trim(Bbytes)); + byte[] u_digest_bytes = u_digest.digest(); + return ConfigHelper.trim(new BigInteger(1, u_digest_bytes).toByteArray()); + } + + /** + * @param M2 The server's response to the client's challenge + * @returns True if and only if the server's response was correct. + */ + public boolean verify(byte[] M2) + { + // M2 = H(A | M1 | K) + M2 = ConfigHelper.trim(M2); + byte[] myM2 = ConfigHelper.trim(serverHash.digest()); + boolean valid = Arrays.equals(M2, myM2); + return valid; + } + + protected static void setToken(String token) { + LeapSRPSession.token = token; + } + + protected static String getToken() { + return token; + } + + /** + * @return a new SHA-256 digest. + */ + public MessageDigest newDigest() + { + MessageDigest md = null; + try { + md = MessageDigest.getInstance("SHA-256"); + } catch (NoSuchAlgorithmException e) { + e.printStackTrace(); + } + return md; + } +} -- cgit v1.2.3