#2 - Added test to test the cypto library

src/main/java/net/locusworks/crypto/AES.java

@@ -9,13 +9,14 @@ import javax.crypto.spec.SecretKeySpec;
 
 import org.apache.commons.lang3.StringUtils;
 
+import net.locusworks.crypto.utils.RandomString;
+
 import java.nio.charset.StandardCharsets;
 import java.security.InvalidAlgorithmParameterException;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 import java.util.Base64;
-import java.util.Random;
 
 
 /**
@@ -79,7 +80,7 @@ public class AES {
     try {
       this.cipher = Cipher.getInstance(ENCRYPTION_ALGORITH, PROVIDER);
       this.secretKeySpec = new SecretKeySpec(key, ENCRYPTION_TYPE);
-      this.ivParamSpec = new IvParameterSpec(getRandomString(16, sr).getBytes(StandardCharsets.UTF_8));
+      this.ivParamSpec = new IvParameterSpec(RandomString.getBytes(16, sr));
     } catch (Exception ex) {
       System.err.println(ex);
       throw new IllegalArgumentException("Unable to initalize encryption:", ex);
@@ -135,7 +136,7 @@ public class AES {
   }
 
   public static AES createInstance() {
-    return createInstance(getRandomString(16, null));
+    return createInstance(RandomString.getString(16));
   }
   
   public static AES createInstance(byte[] byteSeed) {
@@ -149,15 +150,6 @@ public class AES {
     return aes;
   }
   
-  private static String getRandomString(int size, Random randomizer) {
-    byte[] array = new byte[size];
-    if (randomizer == null) {
-      randomizer = new Random(System.currentTimeMillis());
-    }
-    randomizer.nextBytes(array);
-    return new String(array, StandardCharsets.UTF_8);
-  }
-
   public static void main(String[] args) throws NoSuchAlgorithmException {
     if (args == null || !(args.length > 0)) {
       throw new IllegalArgumentException("No args provided. Need password as argument");

src/main/java/net/locusworks/crypto/utils/HashUtils.java

@@ -0,0 +1,188 @@
+package net.locusworks.crypto.utils;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.security.MessageDigest;
+
+/**
+ * Wrapper class that leverages java's MessageDigest to hash files
+ * @author Isaac Parenteau
+ *
+ */
+public class HashUtils {
+  
+  private static final Charset UTF_8 = StandardCharsets.UTF_8;
+
+  /**
+   * Used to build output as Hex
+   */
+  private static final char[] DIGITS_LOWER = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+
+  /**
+   * Used to build output as Hex
+   */
+  private static final char[] DIGITS_UPPER = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+  
+  /**
+   * Size of the streaming buffer
+   */
+  public static final Integer STREAM_BUFFER_LENGTH = 1024;
+
+  /**
+   * Hash a string literal
+   * @param hashType Hash types supported by MessageDigest (i.e MD5, SHA-1, SHA-512)
+   * @param data String to hash
+   * @return hash value of the string literal
+   */
+  public static String hash(String hashType, String data) {
+    return hash(hashType, data, true);
+  }
+  
+  /**
+   * Hash a string literal
+   * @param hashType Hash types supported by MessageDigest (i.e MD5, SHA-1, SHA-512)
+   * @param data String to hash
+   * @param toLower True to output the hash in lower case. False to output in upper case
+   * @return hash value of the string literal
+   */
+  public static String hash(String hashType, String data, boolean toLower) {
+    byte[] stringData = data.getBytes(UTF_8);
+    return hash(hashType, stringData, toLower);
+  }
+  
+  @Deprecated
+  public static String hash(String hashType, File data) {
+    return hash(hashType, data.toPath());
+  }
+
+  /**
+   * Hash a file
+   * @param hashType Hash types supported by MessageDigest (i.e MD5, SHA-1, SHA-512)
+   * @param data File to hash
+   * @return hash value of the file
+   */
+  public static String hash(String hashType, Path data) {
+    return hash(hashType, data, true);
+  }
+  
+  @Deprecated
+  public static String hash(String hashType, File data, boolean toLower) {
+    return hash(hashType, data.toPath(), toLower);
+  }
+
+  /**
+   * Hash a file
+   * @param hashType Hash types supported by MessageDigest (i.e MD5, SHA-1, SHA-512)
+   * @param data File to hash
+   * @param toLower True to output the hash in lower case. False to output in upper case
+   * @return hash value of the file
+   */
+  public static String hash(String hashType, Path data, boolean toLower) {
+    try (InputStream stream = Files.newInputStream(data)) {
+      return hash(stream, hashType, toLower);
+    } catch (IOException ex) {
+      throw new IllegalArgumentException(ex.getMessage());
+    }
+  }
+  
+  /**
+   * Hash a byte array
+   * @param hashType Hash types supported by MessageDigest (i.e MD5, SHA-1, SHA-512)
+   * @param data data to hash
+   * @return hash value of the data
+   */
+  public static String hash(String hashType, byte[] data) {
+    return hash(hashType, data, true);
+  }
+  
+  /**
+   * Hash a byte array
+   * @param hashType Hash types supported by MessageDigest (i.e MD5, SHA-1, SHA-512)
+   * @param data data to hash
+   * @param toLower True to output the hash in lower case. False to output in upper case
+   * @return hash value of the data
+   */
+  public static String hash(String hashType, byte[] data, boolean toLower) {
+    return hash(new BufferedInputStream(new ByteArrayInputStream(data)), hashType, toLower);
+  }
+  
+  /**
+   * Hash an input stream
+   * @param stream Stream with the data to hash
+   * @param hashType Hash types supported by MessageDigest (i.e MD5, SHA-1, SHA-512)
+   * @return Hash value of the input stream
+   */
+  public static String hash(InputStream stream, String hashType) {
+    return hash(stream, hashType, true);
+  }
+  
+  /**
+   * Hash an input stream
+   * @param stream Stream with the data to hash
+   * @param hashType Hash types supported by MessageDigest (i.e MD5, SHA-1, SHA-512)
+   * @param toLower True to output the hash in lower case. False to output in upper case
+   * @return Hash value of the input stream
+   */
+  public static String hash(InputStream stream, String hashType, boolean toLower) {
+    MessageDigest digest = null;
+    try(InputStream is = stream) {
+      digest = MessageDigest.getInstance(hashType);
+      
+      byte[] buffer = new byte[STREAM_BUFFER_LENGTH];
+      int read = is.read(buffer, 0, STREAM_BUFFER_LENGTH);
+
+      while (read > -1) {
+          digest.update(buffer, 0, read);
+          read = is.read(buffer, 0, STREAM_BUFFER_LENGTH);
+      }
+      
+      return encodeHexString(digest.digest(), toLower);
+    } catch (Exception ex) {
+      throw new IllegalArgumentException(ex.getMessage());
+    } 
+  }
+
+  /**
+   * Encode the hash data back to a string
+   * @param data Data to encode
+   * @param toLower output to lower case
+   * @return
+   */
+  private static String encodeHexString(byte[] data, boolean toLower) {
+    return new String(encodeHex(data, toLower));
+  }
+
+  /**
+   * Encode the hash data to a character array
+   * @param data Data to encode
+   * @param toLower output to lower case
+   * @return
+   */
+  private static char[] encodeHex(byte[] data, boolean toLower) {
+    return encodeHex(data, toLower ? DIGITS_LOWER : DIGITS_UPPER);
+  }
+
+  /**
+   * Encode the hex to a character array
+   * @param data Data to encode
+   * @param toDigits digits to use
+   * @return
+   */
+  private static char[] encodeHex(byte[] data, char[] toDigits) {
+    int l = data.length;
+    char[] out = new char[l << 1];
+    // two characters form the hex value.
+    for (int i = 0, j = 0; i < l; i++) {
+      out[j++] = toDigits[(0xF0 & data[i]) >>> 4];
+      out[j++] = toDigits[0x0F & data[i]];
+    }
+    return out;
+  }
+}

src/main/java/net/locusworks/crypto/utils/RandomString.java

@@ -0,0 +1,78 @@
+package net.locusworks.crypto.utils;
+
+import java.nio.charset.StandardCharsets;
+import java.security.SecureRandom;
+import java.util.Objects;
+import java.util.Random;
+
+public class RandomString {
+
+  public static final String LOWER = "abcdefghijklmnopqrstuvwxyz";
+  public static final String UPPER = LOWER.toUpperCase();
+  public static final String DIGITS = "0123456789";
+  
+  public static final String ALPHA_NUMERIC = LOWER + UPPER + DIGITS;
+  
+  private Random random;
+  
+  private char[] symbols;
+  private int length;
+  
+  private static RandomString instance;
+  
+  private RandomString(Integer length) {
+    this(length, new SecureRandom());
+  }
+  
+  private RandomString(Integer length, Random random) {
+    this(length, random, ALPHA_NUMERIC);
+  }
+  
+  private RandomString(Integer length, Random random, String symbols) {
+    if (length < 1) throw new IllegalArgumentException("Length has to be greater than 1");
+    if (symbols.length() < 2) throw new IllegalArgumentException("Symbols need to be greater than 2");
+    this.random = Objects.requireNonNull(random);
+    this.symbols = symbols.toCharArray();
+  }
+  
+  private synchronized final void setRandom(Random random) {
+    this.random = random;
+  }
+
+  private synchronized final void setLength(int length) {
+    this.length = length;
+  }
+
+  public String nextString() {
+    char[] buffer = new char[length];
+    for (int index = 0; index < buffer.length; index++) {
+     buffer[index] = symbols[random.nextInt(symbols.length)]; 
+    }
+    return new String(buffer);
+  }
+  
+  public static String getString(Integer length) {
+    if (instance == null) {
+      instance = new RandomString(length);
+    }
+    instance.setLength(length);
+    return instance.nextString();
+  }
+  
+  public static String getString(Integer length, Random random) {
+    if (instance == null) {
+      instance = new RandomString(length);
+    }
+    instance.setLength(length);
+    instance.setRandom(random);
+    return instance.nextString();
+  }
+  
+  public static byte[] getBytes(Integer length) {
+    return getString(length).getBytes(StandardCharsets.UTF_8);
+  }
+  
+  public static byte[] getBytes(Integer length, Random random) {
+    return getString(length, random).getBytes(StandardCharsets.UTF_8);
+  }
+}