#358 Add future interface methods, remove exception throwing

- Create Utils class for a common implementation of md5/sha1
- Create "foolproof" way of getting the MessageDigest for md5 etc. (MessageDigestAlgorithm enum)
- Create description annotations to annotate algorithms with usage recommendation and salt type

src/main/java/fr/xephi/authme/security/crypts/BCRYPT.java

@@ -13,8 +13,12 @@
 // OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 package fr.xephi.authme.security.crypts;
 
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Usage;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+
 import java.io.UnsupportedEncodingException;
-import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 
 /**
@@ -59,11 +63,13 @@ import java.security.SecureRandom;
  * @author Damien Miller
  * @version 0.2
  */
+@Recommendation(Usage.RECOMMENDED)
+@HasSalt(value = SaltType.TEXT, length = BCRYPT.BCRYPT_SALT_LEN)
 public class BCRYPT implements EncryptionMethod {
 
     // BCrypt parameters
     private static final int GENSALT_DEFAULT_LOG2_ROUNDS = 10;
-    private static final int BCRYPT_SALT_LEN = 16;
+    protected static final int BCRYPT_SALT_LEN = 16;
 
     // Blowfish parameters
     private static final int BLOWFISH_NUM_ROUNDS = 16;
@@ -508,14 +514,20 @@ public class BCRYPT implements EncryptionMethod {
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
+    public String computeHash(String password, String salt, String name) {
         return hashpw(password, salt);
     }
 
+    public String computeHash(String password, String name) {
+        return hashpw(password, generateSalt());
+    }
+
     @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
+    public boolean comparePassword(String hash, String password, String playerName) {
         return checkpw(password, hash);
     }
+
+    public String generateSalt() {
+        return BCRYPT.gensalt();
+    }
 }

src/main/java/fr/xephi/authme/security/crypts/BCRYPT2Y.java

@@ -1,26 +1,22 @@
 package fr.xephi.authme.security.crypts;
 
-import java.security.NoSuchAlgorithmException;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.Usage;
 
-/**
- */
+@Recommendation(Usage.DOES_NOT_WORK)
 public class BCRYPT2Y implements EncryptionMethod {
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
+    public String computeHash(String password, String salt, String name) {
         if (salt.length() == 22)
             salt = "$2y$10$" + salt;
         return (BCRYPT.hashpw(password, salt));
     }
 
     @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
+    public boolean comparePassword(String hash, String password, String playerName) {
         String ok = hash.substring(0, 29);
-        if (ok.length() != 29)
-            return false;
-        return hash.equals(computeHash(password, ok, playerName));
+        return ok.length() == 29 && hash.equals(computeHash(password, ok, playerName));
     }
 
 }

src/main/java/fr/xephi/authme/security/crypts/CRAZYCRYPT1.java

@@ -1,18 +1,24 @@
 package fr.xephi.authme.security.crypts;
 
+import fr.xephi.authme.security.HashUtils;
+import fr.xephi.authme.security.MessageDigestAlgorithm;
+import fr.xephi.authme.security.crypts.description.Usage;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+
 import java.nio.charset.Charset;
 import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 
-/**
- */
+@Recommendation(Usage.DO_NOT_USE)
+@HasSalt(SaltType.USERNAME)
 public class CRAZYCRYPT1 implements EncryptionMethod {
 
-    private static final char[] CRYPTCHARS = new char[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
-    protected final Charset charset = Charset.forName("UTF-8");
+    private static final char[] CRYPTCHARS =
+        {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+    private final Charset charset = Charset.forName("UTF-8");
 
-
-    public static String byteArrayToHexString(final byte... args) {
+    private static String byteArrayToHexString(final byte... args) {
         final char[] chars = new char[args.length * 2];
         for (int i = 0; i < args.length; i++) {
             chars[i * 2] = CRYPTCHARS[(args[i] >> 4) & 0xF];
@@ -22,21 +28,23 @@ public class CRAZYCRYPT1 implements EncryptionMethod {
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
+    public String computeHash(String password, String salt, String name) {
+        return computeHash(password, name);
+    }
+
+    public String computeHash(String password, String name) {
         final String text = "ÜÄaeut//&/=I " + password + "7421€547" + name + "__+IÄIH§%NK " + password;
-        try {
-            final MessageDigest md = MessageDigest.getInstance("SHA-512");
-            md.update(text.getBytes(charset), 0, text.length());
-            return byteArrayToHexString(md.digest());
-        } catch (final NoSuchAlgorithmException e) {
-            return null;
-        }
+        final MessageDigest md = HashUtils.getDigest(MessageDigestAlgorithm.SHA512);
+        md.update(text.getBytes(charset), 0, text.length());
+        return byteArrayToHexString(md.digest());
     }
 
     @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
-        return hash.equals(computeHash(password, null, playerName));
+    public boolean comparePassword(String hash, String password, String playerName) {
+        return hash.equals(computeHash(password, playerName));
+    }
+
+    public String generateSalt() {
+        return null;
     }
 }

src/main/java/fr/xephi/authme/security/crypts/CryptPBKDF2.java

@@ -1,13 +1,14 @@
 package fr.xephi.authme.security.crypts;
 
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.Usage;
 import fr.xephi.authme.security.pbkdf2.PBKDF2Engine;
 import fr.xephi.authme.security.pbkdf2.PBKDF2Parameters;
 
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
 
-/**
- */
+@Recommendation(Usage.DOES_NOT_WORK)
 public class CryptPBKDF2 implements EncryptionMethod {
 
     @Override

src/main/java/fr/xephi/authme/security/crypts/CryptPBKDF2Django.java

@@ -1,18 +1,21 @@
 package fr.xephi.authme.security.crypts;
 
+import fr.xephi.authme.security.HashUtils;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
 import fr.xephi.authme.security.pbkdf2.PBKDF2Engine;
 import fr.xephi.authme.security.pbkdf2.PBKDF2Parameters;
 
 import javax.xml.bind.DatatypeConverter;
-import java.security.NoSuchAlgorithmException;
 
-/**
- */
+@Recommendation(Usage.OK)
+@HasSalt(value = SaltType.TEXT, length = 12)
 public class CryptPBKDF2Django implements EncryptionMethod {
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
+    public String computeHash(String password, String salt, String name) {
         String result = "pbkdf2_sha256$15000$" + salt + "$";
         PBKDF2Parameters params = new PBKDF2Parameters("HmacSHA256", "ASCII", salt.getBytes(), 15000);
         PBKDF2Engine engine = new PBKDF2Engine(params);
@@ -20,9 +23,12 @@ public class CryptPBKDF2Django implements EncryptionMethod {
         return result + String.valueOf(DatatypeConverter.printBase64Binary(engine.deriveKey(password, 32)));
     }
 
+    public String computeHash(String password, String name) {
+        return computeHash(password, generateSalt(), null);
+    }
+
     @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
+    public boolean comparePassword(String hash, String password, String playerName) {
         String[] line = hash.split("\\$");
         String salt = line[2];
         byte[] derivedKey = DatatypeConverter.parseBase64Binary(line[3]);
@@ -31,4 +37,8 @@ public class CryptPBKDF2Django implements EncryptionMethod {
         return engine.verifyKey(password);
     }
 
+    public String generateSalt() {
+        return HashUtils.generateSalt(12);
+    }
+
 }

src/main/java/fr/xephi/authme/security/crypts/DOUBLEMD5.java

@@ -1,32 +1,31 @@
 package fr.xephi.authme.security.crypts;
 
-import java.math.BigInteger;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
+import fr.xephi.authme.security.HashUtils;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
 
-/**
- */
+@Recommendation(Usage.DO_NOT_USE)
+@HasSalt(SaltType.NONE)
 public class DOUBLEMD5 implements EncryptionMethod {
 
-    private static String getMD5(String message)
-        throws NoSuchAlgorithmException {
-        MessageDigest md5 = MessageDigest.getInstance("MD5");
-        md5.reset();
-        md5.update(message.getBytes());
-        byte[] digest = md5.digest();
-        return String.format("%0" + (digest.length << 1) + "x", new BigInteger(1, digest));
+    @Override
+    public String computeHash(String password, String salt, String name) {
+        return computeHash(password, null);
+    }
+
+    public String computeHash(String password, String name) {
+        return HashUtils.md5(HashUtils.md5(password));
+    }
+
+    public String generateSalt() {
+        return null;
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
-        return getMD5(getMD5(password));
-    }
-
-    @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
-        return hash.equals(computeHash(password, "", ""));
+    public boolean comparePassword(String hash, String password, String playerName) {
+        return hash.equals(computeHash(password, null, null));
     }
 
 }

src/main/java/fr/xephi/authme/security/crypts/EncryptionMethod.java

@@ -32,4 +32,8 @@ public interface EncryptionMethod {
     boolean comparePassword(String hash, String password, String playerName)
         throws NoSuchAlgorithmException;
 
+    // String generateSalt();
+
+    // String computeHash(String password, String name);
+
 }

src/main/java/fr/xephi/authme/security/crypts/JOOMLA.java

@@ -1,32 +1,35 @@
 package fr.xephi.authme.security.crypts;
 
-import java.math.BigInteger;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
+import fr.xephi.authme.security.HashUtils;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
 
-/**
- */
+@Recommendation(Usage.OK)
+@HasSalt(value = SaltType.TEXT, length = 32)
 public class JOOMLA implements EncryptionMethod {
 
-    private static String getMD5(String message)
-        throws NoSuchAlgorithmException {
-        MessageDigest md5 = MessageDigest.getInstance("MD5");
-        md5.reset();
-        md5.update(message.getBytes());
-        byte[] digest = md5.digest();
-        return String.format("%0" + (digest.length << 1) + "x", new BigInteger(1, digest));
+    @Override
+    public String computeHash(String password, String salt, String name) {
+        return HashUtils.md5(password + salt) + ":" + salt;
+    }
+
+    public String computeHash(String password, String name) {
+        return computeHash(password, generateSalt(), null);
+    }
+
+    public String generateSalt() {
+        return HashUtils.generateSalt(32);
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
-        return getMD5(password + salt) + ":" + salt;
-    }
-
-    @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
-        String salt = hash.split(":")[1];
-        return hash.equals(getMD5(password + salt) + ":" + salt);
+    public boolean comparePassword(String hash, String password, String playerName) {
+        String[] hashParts = hash.split(":");
+        if (hashParts.length != 2) {
+            return false;
+        }
+        String salt = hashParts[1];
+        return hash.equals(computeHash(password, salt, null));
     }
 }

src/main/java/fr/xephi/authme/security/crypts/MD5.java

@@ -1,31 +1,26 @@
 package fr.xephi.authme.security.crypts;
 
-import java.math.BigInteger;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
+import fr.xephi.authme.security.HashUtils;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
 
-/**
- */
+@Recommendation(Usage.DO_NOT_USE)
+@HasSalt(SaltType.NONE)
 public class MD5 implements EncryptionMethod {
 
-    private static String getMD5(String message)
-        throws NoSuchAlgorithmException {
-        MessageDigest md5 = MessageDigest.getInstance("MD5");
-        md5.reset();
-        md5.update(message.getBytes());
-        byte[] digest = md5.digest();
-        return String.format("%0" + (digest.length << 1) + "x", new BigInteger(1, digest));
+    @Override
+    public String computeHash(String password, String salt, String name) {
+        return computeHash(password, null);
+    }
+
+    public String computeHash(String password, String name) {
+        return HashUtils.md5(password);
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
-        return getMD5(password);
-    }
-
-    @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
-        return hash.equals(computeHash(password, "", ""));
+    public boolean comparePassword(String hash, String password, String playerName) {
+        return hash.equals(computeHash(password, null));
     }
 }

src/main/java/fr/xephi/authme/security/crypts/MD5VB.java

@@ -1,33 +1,34 @@
 package fr.xephi.authme.security.crypts;
 
-import java.math.BigInteger;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
+import fr.xephi.authme.security.HashUtils;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
 
-/**
- */
+import static fr.xephi.authme.security.HashUtils.md5;
+
+@Recommendation(Usage.OK)
+@HasSalt(value = SaltType.TEXT, length = 16)
 public class MD5VB implements EncryptionMethod {
 
-    private static String getMD5(String message)
-        throws NoSuchAlgorithmException {
-        MessageDigest md5 = MessageDigest.getInstance("MD5");
-        md5.reset();
-        md5.update(message.getBytes());
-        byte[] digest = md5.digest();
-        return String.format("%0" + (digest.length << 1) + "x", new BigInteger(1, digest));
+    @Override
+    public String computeHash(String password, String salt, String name) {
+        return "$MD5vb$" + salt + "$" + md5(md5(password) + salt);
+    }
+
+    public String computeHash(String password, String name) {
+        return computeHash(password, generateSalt(), null);
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
-        return "$MD5vb$" + salt + "$" + getMD5(getMD5(password) + salt);
-    }
-
-    @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
+    public boolean comparePassword(String hash, String password, String playerName) {
         String[] line = hash.split("\\$");
-        return hash.equals(computeHash(password, line[2], ""));
+        return line.length == 4 && hash.equals(computeHash(password, line[2], ""));
+    }
+
+    public String generateSalt() {
+        return HashUtils.generateSalt(16);
     }
 
 }

src/main/java/fr/xephi/authme/security/crypts/SHA1.java

@@ -1,32 +1,31 @@
 package fr.xephi.authme.security.crypts;
 
-import java.math.BigInteger;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
+import fr.xephi.authme.security.HashUtils;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
 
-/**
- */
+@Recommendation(Usage.DO_NOT_USE)
+@HasSalt(SaltType.NONE)
 public class SHA1 implements EncryptionMethod {
 
-    private static String getSHA1(String message)
-        throws NoSuchAlgorithmException {
-        MessageDigest sha1 = MessageDigest.getInstance("SHA1");
-        sha1.reset();
-        sha1.update(message.getBytes());
-        byte[] digest = sha1.digest();
-        return String.format("%0" + (digest.length << 1) + "x", new BigInteger(1, digest));
+    @Override
+    public String computeHash(String password, String salt, String name) {
+        return computeHash(password, null);
+    }
+
+    public String computeHash(String password, String name) {
+        return HashUtils.sha1(password);
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
-        return getSHA1(password);
+    public boolean comparePassword(String hash, String password, String playerName) {
+        return hash.equals(computeHash(password, null));
     }
 
-    @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
-        return hash.equals(computeHash(password, "", ""));
+    public String generateSalt() {
+        return null;
     }
 
 }

src/main/java/fr/xephi/authme/security/crypts/WHIRLPOOL.java

@@ -59,11 +59,15 @@ package fr.xephi.authme.security.crypts;
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import java.security.NoSuchAlgorithmException;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
+
 import java.util.Arrays;
 
-/**
- */
+@Recommendation(Usage.DO_NOT_USE)
+@HasSalt(SaltType.NONE)
 public class WHIRLPOOL implements EncryptionMethod {
 
     /**
@@ -383,8 +387,11 @@ public class WHIRLPOOL implements EncryptionMethod {
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
+    public String computeHash(String password, String salt, String name) {
+        return computeHash(password, null);
+    }
+
+    public String computeHash(String password, String name) {
         byte[] digest = new byte[DIGESTBYTES];
         NESSIEinit();
         NESSIEadd(password);
@@ -393,8 +400,8 @@ public class WHIRLPOOL implements EncryptionMethod {
     }
 
     @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
-        return hash.equals(computeHash(password, "", ""));
+    public boolean comparePassword(String hash, String password, String playerName) {
+        return hash.equals(computeHash(password, null, null));
     }
+
 }

src/main/java/fr/xephi/authme/security/crypts/WORDPRESS.java

@@ -1,13 +1,18 @@
 package fr.xephi.authme.security.crypts;
 
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
+
 import java.io.UnsupportedEncodingException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 import java.util.Arrays;
 
-/**
- */
+@Recommendation(Usage.OK)
+@HasSalt(value = SaltType.TEXT, length = 9)
 public class WORDPRESS implements EncryptionMethod {
 
     private static final String itoa64 = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
@@ -102,18 +107,25 @@ public class WORDPRESS implements EncryptionMethod {
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
+    public String computeHash(String password, String salt, String name) {
         byte random[] = new byte[6];
-        this.randomGen.nextBytes(random);
+        randomGen.nextBytes(random);
         return crypt(password, gensaltPrivate(stringToUtf8(new String(random))));
     }
 
+    public String computeHash(String password, String name) {
+        return computeHash(password, null, null);
+    }
+
     @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
+    public boolean comparePassword(String hash, String password, String playerName) {
         String comparedHash = crypt(password, hash);
         return comparedHash.equals(hash);
     }
 
+    public String generateSalt() {
+        // This hash uses a salt, but it is not exposed to the outside
+        return null;
+    }
+
 }

src/main/java/fr/xephi/authme/security/crypts/XAUTH.java

@@ -1,9 +1,13 @@
 package fr.xephi.authme.security.crypts;
 
-import java.security.NoSuchAlgorithmException;
+import fr.xephi.authme.security.HashUtils;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
 
-/**
- */
+@Recommendation(Usage.RECOMMENDED)
+@HasSalt(value = SaltType.TEXT, length = 12)
 public class XAUTH implements EncryptionMethod {
 
     public static String getWhirlpool(String message) {
@@ -16,19 +20,25 @@ public class XAUTH implements EncryptionMethod {
     }
 
     @Override
-    public String computeHash(String password, String salt, String name)
-        throws NoSuchAlgorithmException {
+    public String computeHash(String password, String salt, String name) {
         String hash = getWhirlpool(salt + password).toLowerCase();
         int saltPos = (password.length() >= hash.length() ? hash.length() - 1 : password.length());
         return hash.substring(0, saltPos) + salt + hash.substring(saltPos);
     }
 
+    public String computeHash(String password, String name) {
+        return computeHash(password, generateSalt(), null);
+    }
+
     @Override
-    public boolean comparePassword(String hash, String password,
-                                   String playerName) throws NoSuchAlgorithmException {
+    public boolean comparePassword(String hash, String password, String playerName) {
         int saltPos = (password.length() >= hash.length() ? hash.length() - 1 : password.length());
         String salt = hash.substring(saltPos, saltPos + 12);
         return hash.equals(computeHash(password, salt, ""));
     }
 
+    public String generateSalt() {
+        return HashUtils.generateSalt(12);
+    }
+
 }

src/main/java/fr/xephi/authme/security/crypts/description/HasSalt.java

@@ -0,0 +1,13 @@
+package fr.xephi.authme.security.crypts.description;
+
+/**
+ * Describes the type of salt the encryption algorithm uses. This is purely for documentation
+ * purposes and is ignored by the code.
+ */
+public @interface HasSalt {
+
+    SaltType value();
+
+    int length() default 0;
+
+}

src/main/java/fr/xephi/authme/security/crypts/description/Recommendation.java

@@ -0,0 +1,10 @@
+package fr.xephi.authme.security.crypts.description;
+
+/**
+ * Annotation to mark a hash algorithm with the usage recommendation, see {@link Usage}.
+ */
+public @interface Recommendation {
+
+    Usage value();
+
+}

src/main/java/fr/xephi/authme/security/crypts/description/SaltType.java

@@ -0,0 +1,17 @@
+package fr.xephi.authme.security.crypts.description;
+
+/**
+ * The type of salt used by an encryption algorithms.
+ */
+public enum SaltType {
+
+    /** Random, newly generated text. */
+    TEXT,
+
+    /** The username, including variations or repetitions. */
+    USERNAME,
+
+    /** No salt. */
+    NONE
+
+}

src/main/java/fr/xephi/authme/security/crypts/description/Usage.java

@@ -0,0 +1,20 @@
+package fr.xephi.authme.security.crypts.description;
+
+/**
+ * Usage recommendation that can be provided for a hash algorithm.
+ */
+public enum Usage {
+
+    /** The hash algorithm appears to be cryptographically secure and is one of the algorithms recommended by AuthMe. */
+    RECOMMENDED,
+
+    /** There are safer algorithms that can be chosen but using the algorithm is generally OK. */
+    OK,
+
+    /** Hash algorithm is not recommended to be used. Use only if required by another system. */
+    DO_NOT_USE,
+
+    /** The algorithm does not work properly; do not use. */
+    DOES_NOT_WORK
+
+}