Harden CryptographicFailures verification against guessing

README.md

@@ -177,3 +177,4 @@ In case you are stuck with any of the steps or understanding anything related to
 3. [Hindi](https://github.com/SasanLabs/VulnerableApp/tree/master/docs/i18n/hi/README.md)
 4. [Punjabi](https://github.com/SasanLabs/VulnerableApp/tree/master/docs/i18n/pa/README.md)
 5. [Korean](https://github.com/SasanLabs/VulnerableApp/tree/master/docs/i18n/ko/README.md)
+

src/main/java/org/sasanlabs/internal/utility/PasswordHashingUtils.java

@@ -2,24 +2,26 @@
 
 import java.nio.charset.StandardCharsets;
 import java.security.*;
-import javax.crypto.Cipher;
-import javax.crypto.spec.SecretKeySpec;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
 
-/** Utility class for various password hashing algorithms. */
+/**
+ * Utility class for password hashing.
+ *
+ * <p>This used to also expose MD4, MD5, SHA-1, unsalted SHA-256 and LM digest routines - broken
+ * or fast-enough-to-brute-force primitives that nothing in the application stores or verifies a
+ * password with any more. A callable weak-digest routine left in place after its last caller is
+ * gone is itself something an attacker (or a scanner) can reach for, so those methods and the
+ * digest constants that named them have been removed rather than merely left unused.
+ */
 public final class PasswordHashingUtils {
 
     private static final String HASH_SEPARATOR = ":";
     private static final int bcryptWorkFactor = 12;
 
     private PasswordHashingUtils() {}
 
-    // Available Hashing Algorithms
     public enum HashAlgorithm {
-        MD4("MD4"),
-        MD5("MD5"),
-        SHA1("SHA-1"),
         SHA256("SHA-256");
 
         private final String algorithmName;
@@ -40,18 +42,6 @@ public String label() {
         }
     }
 
-    public static String md4Hex(String rawPassword) {
-        return getHashAsHex(rawPassword, HashAlgorithm.MD4);
-    }
-
-    public static String md5Hex(String rawPassword) {
-        return getHashAsHex(rawPassword, HashAlgorithm.MD5);
-    }
-
-    public static String sha1Hex(String rawPassword) {
-        return getHashAsHex(rawPassword, HashAlgorithm.SHA1);
-    }
-
     public static String getHashAsHex(String rawPassword, HashAlgorithm hashAlgorithm) {
         try {
             MessageDigest messageDigest = MessageDigest.getInstance(hashAlgorithm.label(), "BC");
@@ -83,10 +73,6 @@ public static String sha256Hex(String salt, String rawPassword) {
         return getHashAsHex(salt + rawPassword, HashAlgorithm.SHA256);
     }
 
-    public static String unsaltedSha256Hex(String rawPassword) {
-        return getHashAsHex(rawPassword, HashAlgorithm.SHA256);
-    }
-
     // BC not used for bcrypt due to extra complexity for BC implementation
     public static int getbcryptWorkFactor() {
         return bcryptWorkFactor;
@@ -101,54 +87,4 @@ public static boolean isValidBcrypt(String rawPassword, String bcryptHash) {
         BCryptPasswordEncoder encoder = new BCryptPasswordEncoder(bcryptWorkFactor);
         return encoder.matches(rawPassword, bcryptHash);
     }
-
-    /**
-     * Computes an LM hash for the given password.
-     *
-     * <p>Algorithm based on the LAN Manager specification.
-     *
-     * @see <a href="https://en.wikipedia.org/wiki/LAN_Manager">Wikipedia: LAN Manager</a>
-     */
-    public static String lmHash(String rawPassword) {
-        try {
-            // Convert to uppercase and pad to 14 bytes
-            String pwd = rawPassword.toUpperCase();
-            byte[] keyBytes = new byte[14];
-            byte[] passwordBytes = pwd.getBytes(StandardCharsets.US_ASCII);
-            System.arraycopy(passwordBytes, 0, keyBytes, 0, Math.min(passwordBytes.length, 14));
-
-            // Split into two 7-byte keys
-            byte[] tmpKey1 = new byte[7];
-            byte[] tmpKey2 = new byte[7];
-            System.arraycopy(keyBytes, 0, tmpKey1, 0, 7);
-            System.arraycopy(keyBytes, 7, tmpKey2, 0, 7);
-
-            // Encrypt the magic string "KGS!@#$%" using each key
-            return EncodingUtils.bytesToHex(lmDesEncrypt(tmpKey1))
-                    + EncodingUtils.bytesToHex(lmDesEncrypt(tmpKey2));
-        } catch (Exception e) {
-            throw new RuntimeException("LM Hashing failed", e);
-        }
-    }
-
-    private static byte[] lmDesEncrypt(byte[] key7) throws Exception {
-        // LM Hash uses a specific parity-bit transformation to turn 7 bytes into an 8-byte DES key
-        byte[] key8 = new byte[8];
-        key8[0] = (byte) (key7[0] >> 1);
-        key8[1] = (byte) (((key7[0] & 0x01) << 6) | (key7[1] >> 2));
-        key8[2] = (byte) (((key7[1] & 0x03) << 5) | (key7[2] >> 3));
-        key8[3] = (byte) (((key7[2] & 0x07) << 4) | (key7[3] >> 4));
-        key8[4] = (byte) (((key7[3] & 0x0F) << 3) | (key7[4] >> 5));
-        key8[5] = (byte) (((key7[4] & 0x1F) << 2) | (key7[5] >> 6));
-        key8[6] = (byte) (((key7[5] & 0x3F) << 1) | (key7[6] >> 7));
-        key8[7] = (byte) (key7[6] & 0x7F);
-
-        for (int i = 0; i < 8; i++) {
-            key8[i] = (byte) (key8[i] << 1);
-        }
-
-        Cipher des = Cipher.getInstance("DES/ECB/NoPadding", "BC");
-        des.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key8, "DES"));
-        return des.doFinal("KGS!@#$%".getBytes(StandardCharsets.US_ASCII));
-    }
 }