chore: Add back removed CiphertextHeaders.deserialize method (#382)

Author: farleyb-amazon

src/main/java/com/amazonaws/encryptionsdk/model/CiphertextHeaders.java

@@ -503,11 +503,27 @@ private int parseComplete(final byte[] b, final int off) throws ParseException {
     return 0;
   }
 
+  /**
+   * Deserialize the provided bytes starting at the specified offset to construct an instance of
+   * this class. Uses the default value for maxEncryptedDataKeys, which results in no limit.
+   *
+   * <p>This method parses the provided bytes for the individual fields in this class. This method
+   * also supports partial parsing where not all the bytes required for parsing the fields
+   * successfully are available.
+   *
+   * @param b the byte array to deserialize.
+   * @param off the offset in the byte array to use for deserialization.
+   * @return the number of bytes consumed in deserialization.
+   */
+  public int deserialize(final byte[] b, final int off) throws ParseException {
+    return deserialize(b, off, NO_MAX_ENCRYPTED_DATA_KEYS);
+  }
+
   /**
    * Deserialize the provided bytes starting at the specified offset to construct an instance of
    * this class.
    *
-   * <p>This method parses the provided bytes for the individual fields in this class. This methods
+   * <p>This method parses the provided bytes for the individual fields in this class. This method
    * also supports partial parsing where not all the bytes required for parsing the fields
    * successfully are available.
    *
@@ -835,6 +851,15 @@ public void setSuiteData(byte[] suiteData) {
     suiteData_ = suiteData.clone();
   }
 
+  /**
+   * Return max encrypted data keys. Package scope for unit testing.
+   *
+   * @return int
+   */
+  int getMaxEncryptedDataKeys() {
+    return maxEncryptedDataKeys_;
+  }
+
   private static class PartialParseException extends Exception {
     private static final long serialVersionUID = 1L;
     final int bytesParsed_;

src/test/java/com/amazonaws/encryptionsdk/model/CiphertextHeadersTest.java

@@ -51,6 +51,8 @@ public class CiphertextHeadersTest {
 
   @Test
   public void serializeDeserialize() {
+    int maxEncryptedDataKeys = 42;
+
     Map<String, String> encryptionContext = new HashMap<String, String>(1);
     encryptionContext.put("ENC", "CiphertextHeader Test");
 
@@ -59,10 +61,30 @@ public void serializeDeserialize() {
 
       final byte[] headerBytes = ciphertextHeaders.toByteArray();
       final CiphertextHeaders reconstructedHeaders = new CiphertextHeaders();
-      reconstructedHeaders.deserialize(
-          headerBytes, 0, CiphertextHeaders.NO_MAX_ENCRYPTED_DATA_KEYS);
+      reconstructedHeaders.deserialize(headerBytes, 0, maxEncryptedDataKeys);
+      final byte[] reconstructedHeaderBytes = reconstructedHeaders.toByteArray();
+
+      assertEquals(reconstructedHeaders.getMaxEncryptedDataKeys(), maxEncryptedDataKeys);
+      assertArrayEquals(headerBytes, reconstructedHeaderBytes);
+    }
+  }
+
+  @Test
+  public void serializeDeserializeDefaultMaxEncryptedDataKeys() {
+    Map<String, String> encryptionContext = new HashMap<String, String>(1);
+    encryptionContext.put("ENC", "CiphertextHeader Test");
+
+    for (CryptoAlgorithm alg : testAlgs) {
+      final CiphertextHeaders ciphertextHeaders = createCiphertextHeaders(encryptionContext, alg);
+
+      final byte[] headerBytes = ciphertextHeaders.toByteArray();
+      final CiphertextHeaders reconstructedHeaders = new CiphertextHeaders();
+      reconstructedHeaders.deserialize(headerBytes, 0);
       final byte[] reconstructedHeaderBytes = reconstructedHeaders.toByteArray();
 
+      assertEquals(
+          reconstructedHeaders.getMaxEncryptedDataKeys(),
+          CiphertextHeaders.NO_MAX_ENCRYPTED_DATA_KEYS);
       assertArrayEquals(headerBytes, reconstructedHeaderBytes);
     }
   }