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javax.crypto.spec
public class: PBEKeySpec [javadoc | source]
java.lang.Object
   javax.crypto.spec.PBEKeySpec

All Implemented Interfaces:
    KeySpec

A user-chosen password that can be used with password-based encryption (PBE).

The password can be viewed as some kind of raw key material, from which the encryption mechanism that uses it derives a cryptographic key.

Different PBE mechanisms may consume different bits of each password character. For example, the PBE mechanism defined in PKCS #5 looks at only the low order 8 bits of each character, whereas PKCS #12 looks at all 16 bits of each character.

You convert the password characters to a PBE key by creating an instance of the appropriate secret-key factory. For example, a secret-key factory for PKCS #5 will construct a PBE key from only the low order 8 bits of each password character, whereas a secret-key factory for PKCS #12 will take all 16 bits of each character.

Also note that this class stores passwords as char arrays instead of String objects (which would seem more logical), because the String class is immutable and there is no way to overwrite its internal value when the password stored in it is no longer needed. Hence, this class requests the password as a char array, so it can be overwritten when done.

Constructor:
 public PBEKeySpec(char[] password) 
 public PBEKeySpec(char[] password,
    byte[] salt,
    int iterationCount) 
 public PBEKeySpec(char[] password,
    byte[] salt,
    int iterationCount,
    int keyLength) 
Method from javax.crypto.spec.PBEKeySpec Summary:
clearPassword,   getIterationCount,   getKeyLength,   getPassword,   getSalt
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from javax.crypto.spec.PBEKeySpec Detail:
 public final  void clearPassword() 
    Clears the internal copy of the password.
 public final int getIterationCount() 
    Returns the iteration count or 0 if not specified.
 public final int getKeyLength() 
    Returns the to-be-derived key length or 0 if not specified.

    Note: this is used to indicate the preference on key length for variable-key-size ciphers. The actual key size depends on each provider's implementation.

 public final char[] getPassword() 
    Returns a copy of the password.

    Note: this method returns a copy of the password. It is the caller's responsibility to zero out the password information after it is no longer needed.

 public final byte[] getSalt() 
    Returns a copy of the salt or null if not specified.

    Note: this method should return a copy of the salt. It is the caller's responsibility to zero out the salt information after it is no longer needed.