Package gov.usgs.earthquake.product

Class ProductDigest

java.lang.Object

gov.usgs.earthquake.product.ProductDigest

All Implemented Interfaces:

ProductHandler

public class ProductDigest
extends java.lang.Object
implements ProductHandler

Used to generate product digests. All product attributes and content are used when generating a digest, except any existing signature, since the digest is used to generate or verify signatures. Calls to ProductOutput methods on this class must occur in identical order to generate consistent signatures. Therefore it is almost required to use the ObjectProductInput, which fulfills this requirement.

Field Summary

Fields

Modifier and Type	Field	Description
static java.nio.charset.Charset	CHARSET	Character set used when computing digests.
static java.lang.String	MESSAGE_DIGEST_ALGORITHM	Algorithm used when generating product digest.
static java.lang.String	MESSAGE_DIGEST_V2_ALGORITHM	v2 digest algorithm

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ProductDigest(CryptoUtils.Version version)	Construct a new ProductDigest.

Method Summary

Modifier and Type	Method	Description
void	close()	Free any resources associated with this handler.
static byte[]	digestProduct(Product product)	A convenience method that generates a product digest.
static byte[]	digestProduct(Product product, CryptoUtils.Version version)
byte[]	getDigest()
static void	main(java.lang.String[] args)	CLI access into ProductDigest
void	onBeginProduct(ProductId id, java.lang.String status, java.net.URL trackerURL)	Digest the id, update time, status, and URL.
void	onContent(ProductId id, java.lang.String path, Content content)	Digest the path, content attributes, and content bytes.
void	onEndProduct(ProductId id)	Finish computing digest.
void	onLink(ProductId id, java.lang.String relation, java.net.URI href)	Digest the link relation and href.
void	onProperty(ProductId id, java.lang.String name, java.lang.String value)	Digest the property name and value.
void	onSignature(ProductId id, java.lang.String signature)	Don't digest the signature.
void	onSignatureVersion(ProductId id, CryptoUtils.Version version)	Don't digest signature version.

Methods inherited from class java.lang.Object

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

Field Detail

CHARSET

public static final java.nio.charset.Charset CHARSET

Character set used when computing digests.

MESSAGE_DIGEST_ALGORITHM

public static final java.lang.String MESSAGE_DIGEST_ALGORITHM

Algorithm used when generating product digest.

See Also:

Constant Field Values

MESSAGE_DIGEST_V2_ALGORITHM

public static final java.lang.String MESSAGE_DIGEST_V2_ALGORITHM

v2 digest algorithm

See Also:

Constant Field Values

Constructor Detail

ProductDigest

protected ProductDigest(CryptoUtils.Version version)
                 throws java.security.NoSuchAlgorithmException

Construct a new ProductDigest.

Parameters:

version - signature version

Throws:

java.security.NoSuchAlgorithmException - if not SHA1 or SHA-256

Method Detail

digestProduct

public static byte[] digestProduct(Product product)
                            throws java.lang.Exception

A convenience method that generates a product digest.

Parameters:

product - the product to digest

Returns:

the computed digest.

Throws:

java.lang.Exception - if errors occur while digesting product.

digestProduct

public static byte[] digestProduct(Product product,
                                   CryptoUtils.Version version)
                            throws java.lang.Exception

Parameters:

product - A product

version - What version of product digest

Returns:

A byte array of the product digest

Throws:

java.lang.Exception - if error occurs

getDigest

public byte[] getDigest()

Returns:

the computed digest, or null if not finished yet.

onBeginProduct

public void onBeginProduct(ProductId id,
                           java.lang.String status,
                           java.net.URL trackerURL)
                    throws java.lang.Exception

Digest the id, update time, status, and URL.

Specified by:

onBeginProduct in interface ProductHandler

Parameters:

id - which product.

status - the product's status.

trackerURL - a location to send status updates.

Throws:

java.lang.Exception - if error occurs

onContent

public void onContent(ProductId id,
                      java.lang.String path,
                      Content content)
               throws java.lang.Exception

Digest the path, content attributes, and content bytes.

Specified by:

onContent in interface ProductHandler

Parameters:

id - which product.

path - path to content within product.

content - the product content.

Throws:

java.lang.Exception - if error occurs

onEndProduct

public void onEndProduct(ProductId id)
                  throws java.lang.Exception

Finish computing digest.

Specified by:

onEndProduct in interface ProductHandler

Parameters:

id - which product.

Throws:

java.lang.Exception - if error occurs

onLink

public void onLink(ProductId id,
                   java.lang.String relation,
                   java.net.URI href)
            throws java.lang.Exception

Digest the link relation and href.

Specified by:

onLink in interface ProductHandler

Parameters:

id - which product.

relation - how the URI is related to this product.

href - the URI that is related to this product.

Throws:

java.lang.Exception - if error occurs

onProperty

public void onProperty(ProductId id,
                       java.lang.String name,
                       java.lang.String value)
                throws java.lang.Exception

Digest the property name and value.

Specified by:

onProperty in interface ProductHandler

Parameters:

id - which product.

name - the property name.

value - the property value.

Throws:

java.lang.Exception - if error occurs

onSignatureVersion

public void onSignatureVersion(ProductId id,
                               CryptoUtils.Version version)
                        throws java.lang.Exception

Don't digest signature version.

Specified by:

onSignatureVersion in interface ProductHandler

Parameters:

id - which product.

version - product version

Throws:

java.lang.Exception - if error occurs

onSignature

public void onSignature(ProductId id,
                        java.lang.String signature)
                 throws java.lang.Exception

Don't digest the signature.

Specified by:

onSignature in interface ProductHandler

Parameters:

id - which product.

signature - the product signature, which can be verified using the ProductSigner class.

Throws:

java.lang.Exception - if error occurs

close

public void close()

Free any resources associated with this handler.

Specified by:

close in interface ProductHandler

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception

CLI access into ProductDigest

Parameters:

args - CLI Args

Throws:

java.lang.Exception - if error occurs