Package com.bfo.box

Class C2PA_AssertionHashData

java.lang.Object

com.bfo.box.Box

com.bfo.box.JUMBox

com.bfo.box.CborContainerBox

com.bfo.box.C2PA_AssertionHashData

All Implemented Interfaces:

C2PA_Assertion

public class C2PA_AssertionHashData
extends CborContainerBox
implements C2PA_Assertion

A C2PA Assertion for the "c2pa.hash.data" type

Since:

5

Constructor Summary

Constructors

Constructor	Description
C2PA_AssertionHashData()	Create a new assertion

Method Summary

Modifier and Type	Method	Description
void	setExclusions(long[] exclusions)	Set the exclusion range, a sequence of [start, length] pairs determining which bytes from the InputStream read by verify() to read and which to skip.
void	setHashAlgorithm(String alg)	Set the hash algorithm.
List<C2PAStatus>	sign()	Calculate the digest during signing.
List<C2PAStatus>	verify()	Verify this assertion, returning a list of status codes describing why this assertion failed or an empty list if it succeeded.

Methods inherited from class com.bfo.box.CborContainerBox

cbor, getBox

Methods inherited from class com.bfo.box.JUMBox

find, find, label, subtype

Methods inherited from class com.bfo.box.Box

add, dump, duplicate, first, fullType, getEncoded, insertBefore, isSparse, length, next, parent, remove, toString, type

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.bfo.box.C2PA_Assertion

asBox, getManifest

Constructor Details

C2PA_AssertionHashData

public C2PA_AssertionHashData()

Create a new assertion

Method Details

setExclusions

public void setExclusions(long[] exclusions)

Set the exclusion range, a sequence of [start, length] pairs determining which bytes from the InputStream read by verify() to read and which to skip. The list must be in order and must not overlap.

Parameters:

exclusions - an even-numbered list of longs, which may be zero length or null

setHashAlgorithm

public void setHashAlgorithm(String alg)

Set the hash algorithm. If not set, defaults to the C2PAClaim.getHashAlgorithm()

Parameters:

alg - the algorithm

sign

public List<C2PAStatus> sign()
                      throws IOException

Calculate the digest during signing. This assertion retrieves the InputStream from C2PAManifest.getInputStream() and calculates the digest based on that, ignoring any ranges specified in the exclusions. This method is called by C2PASignature.sign() and there should be no need to call it manually.

Returns:

a list of failure codes, or an empty list on success

Throws:

IOException - if an exception was thrown while calculating the digest

verify

public List<C2PAStatus> verify()
                        throws IOException

Description copied from interface: C2PA_Assertion

Verify this assertion, returning a list of status codes describing why this assertion failed or an empty list if it succeeded. The default implementation succeeds, and returns an empty list.

Specified by:

verify in interface C2PA_Assertion

Returns:

a list of status codes, which may be empty on success

Throws:

IOException - if the assertion verification involved I/O and the IO layer threw an exception