org.apache.pdfbox.examples.signature.validation

Class CertInformationHelper

java.lang.Object

org.apache.pdfbox.examples.signature.validation.CertInformationHelper

public class CertInformationHelper
extends Object

Method Summary

Modifier and Type	Method and Description
protected static void	getAuthorityInfoExtensionValue(byte[] extensionValue, CertInformationCollector.CertSignatureInformation certInfo) Extracts authority information access extension values from the given data.
protected static String	getCrlUrlFromExtensionValue(byte[] extensionValue) Gets the first CRL Url from given extension value.
protected static String	getSha1Hash(byte[] content) Gets the SHA-1-Hash has of given byte[]-content.
static boolean	isSelfSigned(X509Certificate cert) Checks whether the given certificate is self-signed (root).
static boolean	verify(X509Certificate cert, PublicKey key) Verifies whether the certificate is signed by the given public key.

Methods inherited from class java.lang.Object

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

Method Detail

getSha1Hash

protected static String getSha1Hash(byte[] content)

Gets the SHA-1-Hash has of given byte[]-content.

Parameters:

content - to be hashed

Returns:

SHA-1 hash String

isSelfSigned

public static boolean isSelfSigned(X509Certificate cert)
                            throws CertificateProccessingException

Checks whether the given certificate is self-signed (root).

Parameters:

cert - to be checked

Returns:

true when it is a self-signed certificate

Throws:

CertificateProccessingException - containing the cause, on multiple exception with the given data

verify

public static boolean verify(X509Certificate cert,
                             PublicKey key)
                      throws CertificateProccessingException

Verifies whether the certificate is signed by the given public key. Can be done to check signature chain. Idea and code are from Julius Musseau at: https://stackoverflow.com/a/10822177/2497581

Parameters:

cert - Child certificate to check

key - Fathers public key to check

Returns:

true when the certificate is signed by the public key

Throws:

CertificateProccessingException - containing the cause, on multiple exception with the given data

getAuthorityInfoExtensionValue

protected static void getAuthorityInfoExtensionValue(byte[] extensionValue,
                                                     CertInformationCollector.CertSignatureInformation certInfo)
                                              throws IOException

Extracts authority information access extension values from the given data. The Data structure has to be implemented as described in RFC 2459, 4.2.2.1.

Parameters:

extensionValue - byte[] of the extension value.

certInfo - where to put the found values

Throws:

IOException - when there is a problem with the extensionValue

getCrlUrlFromExtensionValue

protected static String getCrlUrlFromExtensionValue(byte[] extensionValue)
                                             throws IOException

Gets the first CRL Url from given extension value. Structure has to be build as in 4.2.1.14 CRL Distribution Points of RFC 2459.

Parameters:

extensionValue - to get the extension value from

Returns:

first CRL- URL or null

Throws:

IOException - when there is a problem with the extensionValue