Package org.apache.shiro.crypto.hash

Class SimpleHash

    • Constructor Detail

      • SimpleHash

        public SimpleHash​(String algorithmName)
        Creates an new instance with only its algorithmName set - no hashing is performed.

        Because all other constructors in this class hash the source constructor argument, this constructor is useful in scenarios when you have a byte array that you know is already hashed and just want to set the bytes in their raw form directly on an instance. After using this constructor, you can then immediately call setBytes to have a fully-initialized instance.

        N.B.The algorithm identified by the algorithmName parameter must be available on the JVM. If it is not, a UnknownAlgorithmException will be thrown when the hash is performed (not at instantiation).

        Parameters:
        algorithmName - the MessageDigest algorithm name to use when performing the hash.
        See Also:
        UnknownAlgorithmException

      • SimpleHash

        public SimpleHash​(String algorithmName,
                  Object source,
                  Object salt)
           throws CodecException,
                  UnknownAlgorithmException
        Creates an algorithmName-specific hash of the specified source using the given salt using a single hash iteration.

        It is a convenience constructor that merely executes this( algorithmName, source, salt, 1);.

        Please see the SimpleHashHash(algorithmName, Object,Object,int) constructor for the types of Objects that may be passed into this constructor, as well as how to support further types.

        Parameters:
        algorithmName - the MessageDigest algorithm name to use when performing the hash.
        source - the source object to be hashed.
        salt - the salt to use for the hash
        Throws:
        CodecException - if either constructor argument cannot be converted into a byte array.
        UnknownAlgorithmException - if the algorithmName is not available.

      • SimpleHash

        public SimpleHash​(String algorithmName,
                  Object source,
                  Object salt,
                  int hashIterations)
           throws CodecException,
                  UnknownAlgorithmException
        Creates an algorithmName-specific hash of the specified source using the given salt a total of hashIterations times.

        By default, this class only supports Object method arguments of type byte[], char[], String, File, InputStream or ByteSource. If either argument is anything other than these types a CodecException will be thrown.

        If you want to be able to hash other object types, or use other salt types, you need to override the toBytes(Object) method to support those specific types. Your other option is to convert your arguments to one of the default supported types first before passing them in to this constructor}.

        Parameters:
        algorithmName - the MessageDigest algorithm name to use when performing the hash.
        source - the source object to be hashed.
        salt - the salt to use for the hash
        hashIterations - the number of times the source argument hashed for attack resiliency.
        Throws:
        CodecException - if either Object constructor argument cannot be converted into a byte array.
        UnknownAlgorithmException - if the algorithmName is not available.

    • Method Detail

      • convertSourceToBytes

        protected ByteSource convertSourceToBytes​(Object source)
        Acquires the specified source argument's bytes and returns them in the form of a ByteSource instance.

        This implementation merely delegates to the convenience toByteSource(Object) method for generic conversion. Can be overridden by subclasses for source-specific conversion.

        Parameters:
        source - the source object to be hashed.
        Returns:
        the source's bytes in the form of a ByteSource instance.
        Since:
        1.2

      • convertSaltToBytes

        protected ByteSource convertSaltToBytes​(Object salt)
        Acquires the specified salt argument's bytes and returns them in the form of a ByteSource instance.

        This implementation merely delegates to the convenience toByteSource(Object) method for generic conversion. Can be overridden by subclasses for salt-specific conversion.

        Parameters:
        salt - the salt to be use for the hash.
        Returns:
        the salt's bytes in the form of a ByteSource instance.
        Since:
        1.2

      • toByteSource

        protected ByteSource toByteSource​(Object o)
        Converts a given object into a ByteSource instance. Assumes the object can be converted to bytes.
        Parameters:
        o - the Object to convert into a ByteSource instance.
        Returns:
        the ByteSource representation of the specified object's bytes.
        Since:
        1.2

      • getSalt

        public ByteSource getSalt()
        Description copied from interface: Hash
        Returns a salt used to compute the hash or null if no salt was used.
        Returns:
        a salt used to compute the hash or null if no salt was used.

      • getIterations

        public int getIterations()
        Description copied from interface: Hash
        Returns the number of hash iterations used to compute the hash.
        Returns:
        the number of hash iterations used to compute the hash.

      • setBytes

        public void setBytes​(byte[] alreadyHashedBytes)
        Sets the raw bytes stored by this hash instance.

        The bytes are kept in raw form - they will not be hashed/changed. This is primarily a utility method for constructing a Hash instance when the hashed value is already known.

        Overrides:
        setBytes in class AbstractHash
        Parameters:
        alreadyHashedBytes - the raw already-hashed bytes to store in this instance.

      • setIterations

        public void setIterations​(int iterations)
        Sets the iterations used to previously compute AN ALREADY GENERATED HASH.

        This is provided ONLY to reconstitute an already-created Hash instance. It should ONLY ever be invoked when re-constructing a hash instance from an already-hashed value.

        Parameters:
        iterations - the number of hash iterations used to previously create the hash/digest.
        Since:
        1.2

      • setSalt

        public void setSalt​(ByteSource salt)
        Sets the salt used to previously compute AN ALREADY GENERATED HASH.

        This is provided ONLY to reconstitute a Hash instance that has already been computed. It should ONLY ever be invoked when re-constructing a hash instance from an already-hashed value.

        Parameters:
        salt - the salt used to previously create the hash/digest.
        Since:
        1.2

      • hash

        protected byte[] hash​(byte[] bytes,
                      byte[] salt,
                      int hashIterations)
               throws UnknownAlgorithmException
        Hashes the specified byte array using the given salt for the specified number of iterations.
        Overrides:
        hash in class AbstractHash
        Parameters:
        bytes - the bytes to hash
        salt - the salt to use for the initial hash
        hashIterations - the number of times the the bytes will be hashed (for attack resiliency).
        Returns:
        the hashed bytes.
        Throws:
        UnknownAlgorithmException - if the algorithmName is not available.

      • isEmpty

        public boolean isEmpty()
        Description copied from interface: ByteSource
        Returns true if the underlying wrapped byte array is null or empty (zero length), false otherwise.
        Returns:
        true if the underlying wrapped byte array is null or empty (zero length), false otherwise.

      • toHex

        public String toHex()
        Returns a hex-encoded string of the underlying byte array.

        This implementation caches the resulting hex string so multiple calls to this method remain efficient. However, calling setBytes will null the cached value, forcing it to be recalculated the next time this method is called.

        Specified by:
        toHex in interface ByteSource
        Overrides:
        toHex in class AbstractHash
        Returns:
        a hex-encoded string of the underlying byte array.

      • toBase64

        public String toBase64()
        Returns a Base64-encoded string of the underlying byte array.

        This implementation caches the resulting Base64 string so multiple calls to this method remain efficient. However, calling setBytes will null the cached value, forcing it to be recalculated the next time this method is called.

        Specified by:
        toBase64 in interface ByteSource
        Overrides:
        toBase64 in class AbstractHash
        Returns:
        a Base64-encoded string of the underlying byte array.

      • equals

        public boolean equals​(Object o)
        Returns true if the specified object is a Hash and its byte array is identical to this Hash's byte array, false otherwise.
        Overrides:
        equals in class AbstractHash
        Parameters:
        o - the object (Hash) to check for equality.
        Returns:
        true if the specified object is a Hash and its byte array is identical to this Hash's byte array, false otherwise.

      • hashCode

        public int hashCode()
        Simply returns toHex().hashCode();
        Overrides:
        hashCode in class AbstractHash
        Returns:
        toHex().hashCode()