CheckedHashAlgorithm (PF-All 7.4.0 API)

java.lang.Object
- org.pfsw.security.crypto.CheckedHashAlgorithm

All Implemented Interfaces:

java.io.Serializable
```
public class CheckedHashAlgorithm
extends java.lang.Object
implements java.io.Serializable
```
This is a helper class that represents a hash algorithm that has already been checked if it is supported by the platform.
It helps to avoid the annoying try-catch code-pollution every time you use a valid algorithm, but the API requires the handling of NoSuchAlgorithmException even if it cannot occur at all.

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static CheckedHashAlgorithm`	`MD5` The pre-defined constant for the MD hash algorithm.
`static CheckedHashAlgorithm`	`SHA_1` The pre-defined constant for the SHA-1 hash algorithm.
`static CheckedHashAlgorithm`	`SHA_2_256` The pre-defined constant for the SHA-256 hash algorithm.
`static CheckedHashAlgorithm`	`SHA_2_384` The pre-defined constant for the SHA-384 hash algorithm.
`static CheckedHashAlgorithm`	`SHA_2_512` The pre-defined constant for the SHA-512 hash algorithm.
`static int`	`UNKNOWN_LENGTH`

Constructor Summary

Constructors
Modifier Constructor and Description

protected CheckedHashAlgorithm(java.lang.String algorithmName)
Creates successfully a checked algorithm object or throws an exception.

Constructors
Modifier	Constructor and Description
`protected`	`CheckedHashAlgorithm(java.lang.String algorithmName)` Creates successfully a checked algorithm object or throws an exception.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`checkAlgorithm(java.lang.String algorithmName)` Checks whether or not the given algorithm is supported.
`byte[]`	`computeHash(byte[] content)` Computes a hash value for the given input data using the this hashing algorithm.
`byte[]`	`computeHash(java.lang.String text, CheckedCharsetName encoding)` Computes a hash value for the given text using the this hashing algorithm.
`byte[]`	`computeUTF8Hash(java.lang.String text)` Computes a hash value for the given text using the this hashing algorithm and UTF-8 encoding for the text conversion to bytes.
`static CheckedHashAlgorithm`	`create(java.lang.String algorithmName)` Creates a new instance based on the given algorithm name.
`protected int`	`detectBitLength()` Tries to derive the bit length from the algorithm's name.
`static int`	`detectBitLength(java.lang.String algorithmName)` Tries to extract the bit length part of the given algorithm name and return it as an integer.
`boolean`	`equals(java.lang.Object obj)`
`static CheckedHashAlgorithm`	`find(java.lang.String algorithmName)` Looks for a predefined CheckedHashAlgorithm constant with the given algorithm name and returns it.
`static CheckedHashAlgorithm`	`findOrCreate(java.lang.String algorithmName)` Looks for a predefined CheckedHashAlgorithm constant with the given algorithm name and returns it.
`int`	`getBitLength()` Returns the bit length of this algorithm.
`int`	`getByteLength()` Returns the byte length of this algorithm.
`java.security.MessageDigest`	`getMessageDigest()` Returns a MessageDigest for the specified algorithm name.
`java.lang.String`	`getName()` Returns the uppercase name of the hashing algorithm.
`static CheckedHashAlgorithm[]`	`getPredefinedAlgorithms()` Returns an array of all CheckedHashAlgorithm constants defined by this class.
`java.lang.String`	`getPrefix()` Returns the algorithm as prefix (i.e.
`int`	`hashCode()`
`static boolean`	`isSupportedAlgorithm(java.lang.String algorithmName)` Returns whether or not the given algorithm is supported.
`protected void`	`setAlgorithmName(java.lang.String algorithmName)`
`protected void`	`setByteLength(int byteLength)`
`java.lang.String`	`toString()`

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - MD5
```
public static final CheckedHashAlgorithm MD5
```
    The pre-defined constant for the MD hash algorithm.
  - SHA_1
```
public static final CheckedHashAlgorithm SHA_1
```
    The pre-defined constant for the SHA-1 hash algorithm.
  - SHA_2_256
```
public static final CheckedHashAlgorithm SHA_2_256
```
    The pre-defined constant for the SHA-256 hash algorithm.
  - SHA_2_384
```
public static final CheckedHashAlgorithm SHA_2_384
```
    The pre-defined constant for the SHA-384 hash algorithm.
  - SHA_2_512
```
public static final CheckedHashAlgorithm SHA_2_512
```
    The pre-defined constant for the SHA-512 hash algorithm.
  - UNKNOWN_LENGTH
```
public static final int UNKNOWN_LENGTH
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - CheckedHashAlgorithm
```
protected CheckedHashAlgorithm(java.lang.String algorithmName)
                        throws java.security.NoSuchAlgorithmException
```
    Creates successfully a checked algorithm object or throws an exception.
    
    Parameters:
    
    algorithmName - The name of the algorithm (e.g. @see CryptoConstants.ALGORITHM_NAME_SHA_2_512).
    
    Throws:
    
    java.security.NoSuchAlgorithmException - If the specified algorithm is not supported.
- Method Detail
  - checkAlgorithm
```
public static void checkAlgorithm(java.lang.String algorithmName)
                           throws java.security.NoSuchAlgorithmException
```
    Checks whether or not the given algorithm is supported.
    
    Parameters:
    
    algorithmName - The name of the algorithm to check (e.g. "SHA-1")
    
    Throws:
    
    java.security.NoSuchAlgorithmException - Will be thrown if the algorithm is not supported.
  - isSupportedAlgorithm
```
public static boolean isSupportedAlgorithm(java.lang.String algorithmName)
```
    Returns whether or not the given algorithm is supported.
    
    Parameters:
    
    algorithmName - The name of the algorithm to check (e.g. "SHA-256")
  - create
```
public static CheckedHashAlgorithm create(java.lang.String algorithmName)
                                   throws java.security.NoSuchAlgorithmException
```
    Creates a new instance based on the given algorithm name.
    
    Parameters:
    
    algorithmName - The name of the algorithm to create (e.g. "UTF-16")
    
    Returns:
    
    Returns a new instance of CheckedHashAlgorithm after checking the given algorithm name
    
    Throws:
    
    java.security.NoSuchAlgorithmException - Will be thrown if the algorithm is not supported.
  - find
```
public static CheckedHashAlgorithm find(java.lang.String algorithmName)
```
    Looks for a predefined CheckedHashAlgorithm constant with the given algorithm name and returns it. Returns null if not found.
    
    Parameters:
    
    algorithmName - The name of the hash algorithm.
  - findOrCreate
```
public static CheckedHashAlgorithm findOrCreate(java.lang.String algorithmName)
                                         throws java.security.NoSuchAlgorithmException
```
    Looks for a predefined CheckedHashAlgorithm constant with the given algorithm name and returns it. Tries to create a new instance if not found.
    
    Parameters:
    
    algorithmName - The name of the hash algorithm.
    
    Throws:
    
    java.security.NoSuchAlgorithmException - If the specified algorithm is not supported.
  - getPredefinedAlgorithms
```
public static CheckedHashAlgorithm[] getPredefinedAlgorithms()
```
    Returns an array of all CheckedHashAlgorithm constants defined by this class.
  - detectBitLength
```
public static int detectBitLength(java.lang.String algorithmName)
```
    Tries to extract the bit length part of the given algorithm name and return it as an integer.
    
    Parameters:
    
    algorithmName - The algorithm name (e.g. "SHA-256").
    
    Returns:
    
    The bit length derived from the name or UNKNOWN_LENGTH.
  - getName
```
public java.lang.String getName()
```
    Returns the uppercase name of the hashing algorithm.
  - getPrefix
```
public java.lang.String getPrefix()
```
    Returns the algorithm as prefix (i.e. surrounded by curly braces).
    Example: algorithm "SHA-512" returns prefix "{SHA512}"
  - getByteLength
```
public int getByteLength()
```
    Returns the byte length of this algorithm.
    
    Returns:
    
    The hash length in bytes of this algorithm or UNKNOWN_LENGTH if it is unknown.
  - getBitLength
```
public int getBitLength()
```
    Returns the bit length of this algorithm.
    
    Returns:
    
    The hash length in bits of this algorithm or UNKNOWN_LENGTH if it is unknown.
  - computeUTF8Hash
```
public byte[] computeUTF8Hash(java.lang.String text)
```
    Computes a hash value for the given text using the this hashing algorithm and UTF-8 encoding for the text conversion to bytes. The returned byte array contains the hash. Its length depends on the algorithm.
    
    Parameters:
    
    text - The text to be hashed (must not be null).
    
    Throws:
    
    CryptoRuntimeExcption - If the anything goes wrong.
  - computeHash
```
public byte[] computeHash(java.lang.String text,
                          CheckedCharsetName encoding)
```
    Computes a hash value for the given text using the this hashing algorithm. The returned byte array contains the hash. Its length depends on the algorithm.
    
    Parameters:
    
    text - The text to be hashed (must not be null).
    
    encoding - Specifies the character encoding to use for the string when it gets converted to bytes.
    
    Throws:
    
    CryptoRuntimeExcption - If the anything goes wrong.
  - computeHash
```
public byte[] computeHash(byte[] content)
```
    Computes a hash value for the given input data using the this hashing algorithm. The returned byte array contains the hash. Its length depends on the algorithm.
    
    Parameters:
    
    content - The content to be hashed (must not be null).
    
    Throws:
    
    CryptoRuntimeExcption - If the anything goes wrong.
  - getMessageDigest
```
public java.security.MessageDigest getMessageDigest()
```
    Returns a MessageDigest for the specified algorithm name. Since this is an already checked algorithm no exception is expected. If still an exception occurs it will be caught and a CryptoRuntimeException thrown instead (should never happen).
  - equals
```
public boolean equals(java.lang.Object obj)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - setAlgorithmName
```
protected void setAlgorithmName(java.lang.String algorithmName)
```
  - setByteLength
```
protected void setByteLength(int byteLength)
```
  - detectBitLength
```
protected int detectBitLength()
```
    Tries to derive the bit length from the algorithm's name.
    
    Returns:
    
    The bit length or UNKNOWN_LENGTH if not detectable.

Class CheckedHashAlgorithm

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MD5

SHA_1

SHA_2_256

SHA_2_384

SHA_2_512

UNKNOWN_LENGTH

Constructor Detail

CheckedHashAlgorithm

Method Detail

checkAlgorithm

isSupportedAlgorithm

create

find

findOrCreate

getPredefinedAlgorithms

detectBitLength

getName

getPrefix

getByteLength

getBitLength

computeUTF8Hash

computeHash

computeHash

getMessageDigest

equals

hashCode

toString

setAlgorithmName

setByteLength

detectBitLength