org.modeshape.common.util

Class SecureHash

java.lang.Object

org.modeshape.common.util.SecureHash

@Immutable
public class SecureHash
extends Object

A simple utility to generate various kinds of secure hashes.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SecureHash.Algorithm Commonly-used hashing algorithms.
static class	SecureHash.HashingInputStream
static class	SecureHash.HashingReader

Method Summary

Modifier and Type	Method and Description
static String	asHexString(byte[] hash) Get the string representation of the supplied binary hash.
static SecureHash.HashingReader	createHashingReader(SecureHash.Algorithm algorithm, Reader reader, Charset charset) Create an Reader instance that wraps another reader and that computes the secure hash (using the algorithm with the supplied name) as the returned Reader is used.
static SecureHash.HashingReader	createHashingReader(String digestName, Reader reader, Charset charset) Create an Reader instance that wraps another reader and that computes the secure hash (using the algorithm with the supplied name) as the returned Reader is used.
static SecureHash.HashingInputStream	createHashingStream(SecureHash.Algorithm algorithm, InputStream inputStream) Create an InputStream instance that wraps another stream and that computes the secure hash (using the algorithm with the supplied name) as the returned stream is used.
static SecureHash.HashingInputStream	createHashingStream(String digestName, InputStream inputStream) Create an InputStream instance that wraps another stream and that computes the secure hash (using the algorithm with the supplied name) as the returned stream is used.
static byte[]	getHash(SecureHash.Algorithm algorithm, byte[] content) Get the hash of the supplied content, using the supplied digest algorithm.
static byte[]	getHash(SecureHash.Algorithm algorithm, File file) Get the hash of the supplied content, using the supplied digest algorithm.
static byte[]	getHash(SecureHash.Algorithm algorithm, InputStream stream) Get the hash of the supplied content, using the supplied digest algorithm.
static byte[]	getHash(String digestName, byte[] content) Get the hash of the supplied content, using the digest identified by the supplied name.
static byte[]	getHash(String digestName, File file) Get the hash of the supplied content, using the digest identified by the supplied name.
static byte[]	getHash(String digestName, InputStream stream) Get the hash of the supplied content, using the digest identified by the supplied name.
static String	sha1(String string) Computes the sha1 value for the given string.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getHash

public static byte[] getHash(SecureHash.Algorithm algorithm,
                             byte[] content)
                      throws NoSuchAlgorithmException

Get the hash of the supplied content, using the supplied digest algorithm.

Parameters:

algorithm - the hashing function algorithm that should be used

content - the content to be hashed; may not be null

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException - if the supplied algorithm could not be found

IllegalArgumentException - if the algorithm is null

getHash

public static byte[] getHash(SecureHash.Algorithm algorithm,
                             File file)
                      throws NoSuchAlgorithmException,
                             IOException

Get the hash of the supplied content, using the supplied digest algorithm.

Parameters:

algorithm - the hashing function algorithm that should be used

file - the file containing the content to be hashed; may not be null

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException - if the supplied algorithm could not be found

IllegalArgumentException - if the algorithm is null

IOException - if there is an error reading the file

getHash

public static byte[] getHash(SecureHash.Algorithm algorithm,
                             InputStream stream)
                      throws NoSuchAlgorithmException,
                             IOException

Get the hash of the supplied content, using the supplied digest algorithm.

Parameters:

algorithm - the hashing function algorithm that should be used

stream - the stream containing the content to be hashed; may not be null

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException - if the supplied algorithm could not be found

IllegalArgumentException - if the algorithm is null

IOException - if there is an error reading the stream

getHash

public static byte[] getHash(String digestName,
                             byte[] content)
                      throws NoSuchAlgorithmException

Get the hash of the supplied content, using the digest identified by the supplied name.

Parameters:

digestName - the name of the hashing function (or message digest) that should be used

content - the content to be hashed; may not be null

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException - if the supplied algorithm could not be found

getHash

public static byte[] getHash(String digestName,
                             File file)
                      throws NoSuchAlgorithmException,
                             IOException

Get the hash of the supplied content, using the digest identified by the supplied name.

Parameters:

digestName - the name of the hashing function (or message digest) that should be used

file - the file whose content is to be hashed; may not be null

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException - if the supplied algorithm could not be found

IOException - if there is an error reading the file

getHash

public static byte[] getHash(String digestName,
                             InputStream stream)
                      throws NoSuchAlgorithmException,
                             IOException

Get the hash of the supplied content, using the digest identified by the supplied name. Note that this method never closes the supplied stream.

Parameters:

digestName - the name of the hashing function (or message digest) that should be used

stream - the stream containing the content to be hashed; may not be null

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException - if the supplied algorithm could not be found

IOException - if there is an error reading the stream

createHashingStream

public static SecureHash.HashingInputStream createHashingStream(SecureHash.Algorithm algorithm,
                                                                InputStream inputStream)
                                                         throws NoSuchAlgorithmException

Create an InputStream instance that wraps another stream and that computes the secure hash (using the algorithm with the supplied name) as the returned stream is used. This can be used to compute the hash of a stream while the stream is being processed by another reader, and saves from having to process the same stream twice.

Parameters:

algorithm - the hashing function algorithm that should be used

inputStream - the stream containing the content that is to be hashed

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException

createHashingStream

public static SecureHash.HashingInputStream createHashingStream(String digestName,
                                                                InputStream inputStream)
                                                         throws NoSuchAlgorithmException

Create an InputStream instance that wraps another stream and that computes the secure hash (using the algorithm with the supplied name) as the returned stream is used. This can be used to compute the hash of a stream while the stream is being processed by another reader, and saves from having to process the same stream twice.

Parameters:

digestName - the name of the hashing function (or message digest) that should be used

inputStream - the stream containing the content that is to be hashed

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException

createHashingReader

public static SecureHash.HashingReader createHashingReader(SecureHash.Algorithm algorithm,
                                                           Reader reader,
                                                           Charset charset)
                                                    throws NoSuchAlgorithmException

Create an Reader instance that wraps another reader and that computes the secure hash (using the algorithm with the supplied name) as the returned Reader is used. This can be used to compute the hash while the content is being processed, and saves from having to process the same content twice.

Parameters:

algorithm - the hashing function algorithm that should be used

reader - the reader containing the content that is to be hashed

charset - the character set used within the supplied reader; may not be null

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException

createHashingReader

public static SecureHash.HashingReader createHashingReader(String digestName,
                                                           Reader reader,
                                                           Charset charset)
                                                    throws NoSuchAlgorithmException

Create an Reader instance that wraps another reader and that computes the secure hash (using the algorithm with the supplied name) as the returned Reader is used. This can be used to compute the hash while the content is being processed, and saves from having to process the same content twice.

Parameters:

digestName - the name of the hashing function (or message digest) that should be used

reader - the reader containing the content that is to be hashed

charset - the character set used within the supplied reader; may not be null

Returns:

the hash of the contents as a byte array

Throws:

NoSuchAlgorithmException

asHexString

public static String asHexString(byte[] hash)

Get the string representation of the supplied binary hash.

Parameters:

hash - the binary hash

Returns:

the hex-encoded representation of the binary hash, or null if the hash is null

sha1

public static String sha1(String string)

Computes the sha1 value for the given string.

Parameters:

string - a non-null string

Returns:

the SHA1 value for the given string.