Refactoring in Argon2

Author: peterdettman

core/src/main/java/org/bouncycastle/crypto/generators/Argon2BytesGenerator.java

@@ -24,7 +24,7 @@ public class Argon2BytesGenerator
 
     /* Minimum and maximum number of lanes (degree of parallelism) */
     private static final int MIN_PARALLELISM = 1;
-    private static final int MAX_PARALLELISM = 16777216;
+    private static final int MAX_PARALLELISM = (1 << 24) - 1;
 
     /* Minimum and maximum digest size in bytes */
     private static final int MIN_OUTLEN = 4;
@@ -52,26 +52,49 @@ public Argon2BytesGenerator()
      */
     public void init(Argon2Parameters parameters)
     {
-        this.parameters = parameters;
-
-        if (parameters.getLanes() < Argon2BytesGenerator.MIN_PARALLELISM)
+        if (parameters.getVersion() != Argon2Parameters.ARGON2_VERSION_10 &&
+            parameters.getVersion() != Argon2Parameters.ARGON2_VERSION_13)
         {
-            throw new IllegalStateException("lanes must be greater than " + Argon2BytesGenerator.MIN_PARALLELISM);
+            throw new UnsupportedOperationException("unknown Argon2 version");
         }
-        else if (parameters.getLanes() > Argon2BytesGenerator.MAX_PARALLELISM)
+        if (parameters.getType() != Argon2Parameters.ARGON2_d &&
+            parameters.getType() != Argon2Parameters.ARGON2_i &&
+            parameters.getType() != Argon2Parameters.ARGON2_id)
+        {
+            throw new UnsupportedOperationException("unknown Argon2 type");
+        }
+
+        if (parameters.getLanes() < MIN_PARALLELISM)
         {
-            throw new IllegalStateException("lanes must be less than " + Argon2BytesGenerator.MAX_PARALLELISM);
+            throw new IllegalStateException("lanes must be at least " + MIN_PARALLELISM);
         }
-        else if (parameters.getMemory() < 2 * parameters.getLanes())
+        else if (parameters.getLanes() > MAX_PARALLELISM)
         {
-            throw new IllegalStateException("memory is less than: " + (2 * parameters.getLanes()) + " expected " + (2 * parameters.getLanes()));
+            throw new IllegalStateException("lanes must be at most " + MAX_PARALLELISM);
         }
-        else if (parameters.getIterations() < Argon2BytesGenerator.MIN_ITERATIONS)
+        else if (parameters.getIterations() < MIN_ITERATIONS)
         {
-            throw new IllegalStateException("iterations is less than: " + Argon2BytesGenerator.MIN_ITERATIONS);
+            throw new IllegalStateException("iterations is less than: " + MIN_ITERATIONS);
         }
 
-        doInit(parameters);
+        this.parameters = parameters;
+
+        // 2. Align memory size
+        // Minimum memoryBlocks = 8L blocks, where L is the number of lanes
+        int memoryBlocks = Math.max(parameters.getMemory(), 2 * ARGON2_SYNC_POINTS * parameters.getLanes());
+
+        this.segmentLength = memoryBlocks / (ARGON2_SYNC_POINTS * parameters.getLanes());
+        this.laneLength = segmentLength * ARGON2_SYNC_POINTS;
+
+        // Ensure that all segments have equal length
+        memoryBlocks = parameters.getLanes() * laneLength;
+
+        this.memory = new Block[memoryBlocks];
+
+        for (int i = 0; i < memory.length; i++)
+        {
+            memory[i] = new Block();
+        }
     }
 
     public int generateBytes(char[] password, byte[] out)
@@ -91,9 +114,9 @@ public int generateBytes(byte[] password, byte[] out)
 
     public int generateBytes(byte[] password, byte[] out, int outOff, int outLen)
     {
-        if (outLen < Argon2BytesGenerator.MIN_OUTLEN)
+        if (outLen < MIN_OUTLEN)
         {
-            throw new IllegalStateException("output length less than " + Argon2BytesGenerator.MIN_OUTLEN);
+            throw new IllegalStateException("output length less than " + MIN_OUTLEN);
         }
 
         byte[] tmpBlockBytes = new byte[ARGON2_BLOCK_SIZE];
@@ -124,36 +147,6 @@ private void reset()
         }
     }
 
-    private void doInit(Argon2Parameters parameters)
-    {
-        /* 2. Align memory size */
-        /* Minimum memoryBlocks = 8L blocks, where L is the number of lanes */
-        int memoryBlocks = parameters.getMemory();
-
-        if (memoryBlocks < 2 * Argon2BytesGenerator.ARGON2_SYNC_POINTS * parameters.getLanes())
-        {
-            memoryBlocks = 2 * Argon2BytesGenerator.ARGON2_SYNC_POINTS * parameters.getLanes();
-        }
-
-        this.segmentLength = memoryBlocks / (parameters.getLanes() * Argon2BytesGenerator.ARGON2_SYNC_POINTS);
-        this.laneLength = segmentLength * Argon2BytesGenerator.ARGON2_SYNC_POINTS;
-
-        /* Ensure that all segments have equal length */
-        memoryBlocks = segmentLength * (parameters.getLanes() * Argon2BytesGenerator.ARGON2_SYNC_POINTS);
-
-        initMemory(memoryBlocks);
-    }
-
-    private void initMemory(int memoryBlocks)
-    {
-        this.memory = new Block[memoryBlocks];
-
-        for (int i = 0; i < memory.length; i++)
-        {
-            memory[i] = new Block();
-        }
-    }
-
     private void fillMemoryBlocks()
     {
         FillBlock filler = new FillBlock();