src/java.base/share/classes/java/util/zip/ZipEntry.java

*** 55,64 ****
--- 55,67 ----
      long csize = -1;    // compressed size of entry data
      int method = -1;    // compression method
      int flag = 0;       // general purpose flag
      byte[] extra;       // optional extra field data for entry
      String comment;     // optional comment string for entry
+     ZipCryption zipCryption = null; // encryption / decryption engine
+     byte[] encryptionHeader; // ZIP encryption header
+     boolean passphraseValidated = false; // passphrase validation is not yet.
  
      /**
       * Compression method for uncompressed entries.
       */
      public static final int STORED = 0;
*** 129,138 ****
--- 132,143 ----
          csize = e.csize;
          method = e.method;
          flag = e.flag;
          extra = e.extra;
          comment = e.comment;
+         zipCryption = e.zipCryption;
+         encryptionHeader = e.encryptionHeader;
      }
  
      /**
       * Creates a new un-initialized zip entry
       */
*** 671,676 ****
--- 676,728 ----
          } catch (CloneNotSupportedException e) {
              // This should never happen, since we are Cloneable
              throw new InternalError(e);
          }
      }
+ 
+     /**
+      * Set passphrase for ZIP encryption and decryption.
+      * @param passphrase Passphrase for encryption and decryption.
+      */
+     public void setPassphrase(String passphrase) {
+         zipCryption = new TraditionalZipCryption(passphrase);
+     }
+ 
+     ZipCryption getZipCryption() {
+         return zipCryption;
+     }
+ 
+     /**
+      * Get the state whether encrypted entry or not.
+      * @return true if passphrase is required.
+      */
+     public boolean isPassphraseRequired() {
+         return (flag & 1) == 1;
+     }
+ 
+     /**
+      * Validate passphrase for this entry.
+      * @return true if passphrase is valid, or this entry is not encrypted.
+      * @throws ZipException Passphrase is not set or Encryption header is not set.
+      */
+     public boolean isValidPassphrase() throws ZipException{
+         if (!isPassphraseRequired()) {
+             return true;
+         }
+ 
+         if (zipCryption == null) {
+             throw new ZipException("Passphrase is not set.");
+         }
+         if (passphraseValidated) {
+             return true;
+         }
+         if (encryptionHeader == null) {
+             throw new ZipException("Encryption header is not set.");
+         }
+ 
+         zipCryption.reset();
+         byte[] tmp = encryptionHeader.clone();
+         zipCryption.decryptBytes(tmp);
+         passphraseValidated =  zipCryption.isValid(this, tmp);
+         return passphraseValidated;
+     }
  }