com.itextpdf.signatures.PdfSigner Maven / Gradle / Ivy
/*
This file is part of the iText (R) project.
Copyright (c) 1998-2023 Apryse Group NV
Authors: Apryse Software.
This program is offered under a commercial and under the AGPL license.
For commercial licensing, contact us at https://itextpdf.com/sales. For AGPL licensing, see below.
AGPL licensing:
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see exclusionLocations;
/**
* Indicates if the pdf document has already been pre-closed.
*/
protected boolean preClosed = false;
/**
* Signature field lock dictionary.
*/
protected PdfSigFieldLock fieldLock;
/**
* The signature appearance.
*/
protected PdfSignatureAppearance appearance;
/**
* Holds value of property signDate.
*/
protected Calendar signDate;
/**
* Boolean to check if this PdfSigner instance has been closed already or not.
*/
protected boolean closed;
/**
* Creates a PdfSigner instance. Uses a {@link java.io.ByteArrayOutputStream} instead of a temporary file.
*
* @param reader PdfReader that reads the PDF file
* @param outputStream OutputStream to write the signed PDF file
* @param properties {@link StampingProperties} for the signing document. Note that encryption will be
* preserved regardless of what is set in properties.
* @throws IOException if some I/O problem occurs
*/
public PdfSigner(PdfReader reader, OutputStream outputStream, StampingProperties properties) throws IOException {
this(reader, outputStream, null, properties);
}
/**
* Creates a PdfSigner instance. Uses a {@link java.io.ByteArrayOutputStream} instead of a temporary file.
*
* @param reader PdfReader that reads the PDF file
* @param outputStream OutputStream to write the signed PDF file
* @param path File to which the output is temporarily written
* @param properties {@link StampingProperties} for the signing document. Note that encryption will be
* preserved regardless of what is set in properties.
* @throws IOException if some I/O problem occurs
*/
public PdfSigner(PdfReader reader, OutputStream outputStream, String path, StampingProperties properties)
throws IOException {
StampingProperties localProps = new StampingProperties(properties).preserveEncryption();
if (path == null) {
temporaryOS = new ByteArrayOutputStream();
document = initDocument(reader, new PdfWriter(temporaryOS), localProps);
} else {
this.tempFile = FileUtil.createTempFile(path);
document = initDocument(reader, new PdfWriter(FileUtil.getFileOutputStream(tempFile)), localProps);
}
originalOS = outputStream;
signDate = DateTimeUtil.getCurrentTimeCalendar();
fieldName = getNewSigFieldName();
appearance = new PdfSignatureAppearance(document, new Rectangle(0, 0), 1);
appearance.setSignDate(signDate);
closed = false;
}
protected PdfDocument initDocument(PdfReader reader, PdfWriter writer, StampingProperties properties) {
return new PdfAAgnosticPdfDocument(reader, writer, properties);
}
/**
* Gets the signature date.
*
* @return Calendar set to the signature date
*/
public java.util.Calendar getSignDate() {
return signDate;
}
/**
* Sets the signature date.
*
* @param signDate the signature date
*/
public void setSignDate(java.util.Calendar signDate) {
this.signDate = signDate;
this.appearance.setSignDate(signDate);
}
/**
* Provides access to a signature appearance object. Use it to
* customize the appearance of the signature.
*
* Be aware:
*
* - If you create new signature field (either use {@link #setFieldName} with
* the name that doesn't exist in the document or don't specify it at all) then
* the signature is invisible by default.
*
- If you sign already existing field, then the signature appearance object
* is modified to have all the properties (page num., rect etc.) consistent with
* the state of the field (if you customized the appearance object
* before the {@link #setFieldName} call you'll have to do it again)
*
*
*
* @return {@link PdfSignatureAppearance} object.
*/
public PdfSignatureAppearance getSignatureAppearance() {
return appearance;
}
/**
* Returns the document's certification level.
* For possible values see {@link #setCertificationLevel(int)}.
*
* @return The certified status.
*/
public int getCertificationLevel() {
return this.certificationLevel;
}
/**
* Sets the document's certification level.
*
* @param certificationLevel a new certification level for a document.
* Possible values are:
* - {@link #NOT_CERTIFIED}
*
- {@link #CERTIFIED_NO_CHANGES_ALLOWED}
*
- {@link #CERTIFIED_FORM_FILLING}
*
- {@link #CERTIFIED_FORM_FILLING_AND_ANNOTATIONS}
*
*/
public void setCertificationLevel(int certificationLevel) {
this.certificationLevel = certificationLevel;
}
/**
* Gets the field name.
*
* @return the field name
*/
public String getFieldName() {
return fieldName;
}
/**
* Returns the user made signature dictionary. This is the dictionary at the /V key
* of the signature field.
*
* @return The user made signature dictionary.
*/
public PdfSignature getSignatureDictionary() {
return cryptoDictionary;
}
/**
* Getter for property signatureEvent.
*
* @return Value of property signatureEvent.
*/
public ISignatureEvent getSignatureEvent() {
return this.signatureEvent;
}
/**
* Sets the signature event to allow modification of the signature dictionary.
*
* @param signatureEvent the signature event
*/
public void setSignatureEvent(ISignatureEvent signatureEvent) {
this.signatureEvent = signatureEvent;
}
/**
* Gets a new signature field name that doesn't clash with any existing name.
*
* @return A new signature field name.
*/
public String getNewSigFieldName() {
PdfAcroForm acroForm = PdfAcroForm.getAcroForm(document, true);
String name = "Signature";
int step = 1;
while (acroForm.getField(name + step) != null) {
++step;
}
return name + step;
}
/**
* Sets the name indicating the field to be signed. The field can already be presented in the
* document but shall not be signed. If the field is not presented in the document, it will be created.
*
* @param fieldName The name indicating the field to be signed.
*/
public void setFieldName(String fieldName) {
if (fieldName != null) {
PdfAcroForm acroForm = PdfAcroForm.getAcroForm(document, true);
PdfFormField field = acroForm.getField(fieldName);
if (field != null) {
if (!PdfName.Sig.equals(field.getFormType())) {
throw new IllegalArgumentException(
SignExceptionMessageConstant.FIELD_TYPE_IS_NOT_A_SIGNATURE_FIELD_TYPE);
}
if (field.getValue() != null) {
throw new IllegalArgumentException(SignExceptionMessageConstant.FIELD_ALREADY_SIGNED);
}
appearance.setFieldName(fieldName);
List widgets = field.getWidgets();
if (widgets.size() > 0) {
PdfWidgetAnnotation widget = widgets.get(0);
appearance.setPageRect(getWidgetRectangle(widget));
appearance.setPageNumber(getWidgetPageNumber(widget));
}
} else {
// Do not allow dots for new fields
// For existing fields dots are allowed because there it might be fully qualified name
if (fieldName.indexOf('.') >= 0) {
throw new IllegalArgumentException(SignExceptionMessageConstant.FIELD_NAMES_CANNOT_CONTAIN_A_DOT);
}
}
this.fieldName = fieldName;
}
}
/**
* Gets the PdfDocument associated with this instance.
*
* @return the PdfDocument associated with this instance
*/
public PdfDocument getDocument() {
return document;
}
/**
* Sets the PdfDocument.
*
* @param document The PdfDocument
*/
protected void setDocument(PdfDocument document) {
if (null == document.getReader()) {
throw new IllegalArgumentException(SignExceptionMessageConstant.DOCUMENT_MUST_HAVE_READER);
}
this.document = document;
}
/**
* Setter for the OutputStream.
*
* @param originalOS OutputStream for the bytes of the document
*/
public void setOriginalOutputStream(OutputStream originalOS) {
this.originalOS = originalOS;
}
/**
* Getter for the field lock dictionary.
*
* @return Field lock dictionary.
*/
public PdfSigFieldLock getFieldLockDict() {
return fieldLock;
}
/**
* Setter for the field lock dictionary.
*
* Be aware: if a signature is created on an existing signature field,
* then its /Lock dictionary takes the precedence (if it exists).
*
* @param fieldLock Field lock dictionary
*/
public void setFieldLockDict(PdfSigFieldLock fieldLock) {
this.fieldLock = fieldLock;
}
/**
* Signs the document using the detached mode, CMS or CAdES equivalent.
*
* NOTE: This method closes the underlying pdf document. This means, that current instance
* of PdfSigner cannot be used after this method call.
*
* @param externalSignature the interface providing the actual signing
* @param chain the certificate chain
* @param crlList the CRL list
* @param ocspClient the OCSP client
* @param tsaClient the Timestamp client
* @param externalDigest an implementation that provides the digest
* @param estimatedSize the reserved size for the signature. It will be estimated if 0
* @param sigtype Either Signature.CMS or Signature.CADES
* @throws IOException if some I/O problem occurs
* @throws GeneralSecurityException if some problem during apply security algorithms occurs
*/
public void signDetached(IExternalDigest externalDigest, IExternalSignature externalSignature, Certificate[] chain,
Collection crlList, IOcspClient ocspClient, ITSAClient tsaClient, int estimatedSize,
CryptoStandard sigtype) throws IOException, GeneralSecurityException {
signDetached(externalDigest, externalSignature, chain, crlList, ocspClient, tsaClient, estimatedSize, sigtype,
(ISignaturePolicyIdentifier) null);
}
/**
* Signs the document using the detached mode, CMS or CAdES equivalent.
*
* NOTE: This method closes the underlying pdf document. This means, that current instance
* of PdfSigner cannot be used after this method call.
*
* @param externalSignature the interface providing the actual signing
* @param chain the certificate chain
* @param crlList the CRL list
* @param ocspClient the OCSP client
* @param tsaClient the Timestamp client
* @param externalDigest an implementation that provides the digest
* @param estimatedSize the reserved size for the signature. It will be estimated if 0
* @param sigtype Either Signature.CMS or Signature.CADES
* @param signaturePolicy the signature policy (for EPES signatures)
* @throws IOException if some I/O problem occurs
* @throws GeneralSecurityException if some problem during apply security algorithms occurs
*/
public void signDetached(IExternalDigest externalDigest, IExternalSignature externalSignature, Certificate[] chain,
Collection crlList, IOcspClient ocspClient, ITSAClient tsaClient, int estimatedSize,
CryptoStandard sigtype, SignaturePolicyInfo signaturePolicy) throws IOException, GeneralSecurityException {
signDetached(externalDigest, externalSignature, chain, crlList, ocspClient, tsaClient, estimatedSize, sigtype,
signaturePolicy.toSignaturePolicyIdentifier());
}
/**
* Signs the document using the detached mode, CMS or CAdES equivalent.
*
* NOTE: This method closes the underlying pdf document. This means, that current instance
* of PdfSigner cannot be used after this method call.
*
* @param externalSignature the interface providing the actual signing
* @param chain the certificate chain
* @param crlList the CRL list
* @param ocspClient the OCSP client
* @param tsaClient the Timestamp client
* @param externalDigest an implementation that provides the digest
* @param estimatedSize the reserved size for the signature. It will be estimated if 0
* @param sigtype Either Signature.CMS or Signature.CADES
* @param signaturePolicy the signature policy (for EPES signatures)
* @throws IOException if some I/O problem occurs
* @throws GeneralSecurityException if some problem during apply security algorithms occurs
*/
public void signDetached(IExternalDigest externalDigest, IExternalSignature externalSignature, Certificate[] chain,
Collection crlList, IOcspClient ocspClient, ITSAClient tsaClient, int estimatedSize,
CryptoStandard sigtype, ISignaturePolicyIdentifier signaturePolicy)
throws IOException, GeneralSecurityException {
if (closed) {
throw new PdfException(SignExceptionMessageConstant.THIS_INSTANCE_OF_PDF_SIGNER_ALREADY_CLOSED);
}
if (certificationLevel > 0 && isDocumentPdf2()) {
if (documentContainsCertificationOrApprovalSignatures()) {
throw new PdfException(
SignExceptionMessageConstant.CERTIFICATION_SIGNATURE_CREATION_FAILED_DOC_SHALL_NOT_CONTAIN_SIGS);
}
}
Collection crlBytes = null;
int i = 0;
while (crlBytes == null && i < chain.length) {
crlBytes = processCrl(chain[i++], crlList);
}
if (estimatedSize == 0) {
estimatedSize = 8192;
if (crlBytes != null) {
for (byte[] element : crlBytes) {
estimatedSize += element.length + 10;
}
}
if (ocspClient != null) {
estimatedSize += 4192;
}
if (tsaClient != null) {
estimatedSize += 4192;
}
}
PdfSignatureAppearance appearance = getSignatureAppearance();
appearance.setCertificate(chain[0]);
if (sigtype == CryptoStandard.CADES && !isDocumentPdf2()) {
addDeveloperExtension(PdfDeveloperExtension.ESIC_1_7_EXTENSIONLEVEL2);
}
if (externalSignature.getSignatureAlgorithmName().startsWith("Ed")) {
addDeveloperExtension(PdfDeveloperExtension.ISO_32002);
// Note: at this level of abstraction, we have no easy way of determining whether we are signing using a
// specific ECDSA curve, so we can't auto-declare the extension safely, since we don't know whether
// the curve is on the ISO/TS 32002 allowed curves list. That responsibility is delegated to the user.
}
String hashAlgorithm = externalSignature.getDigestAlgorithmName();
if(hashAlgorithm.startsWith("SHA3-") || hashAlgorithm.equals(DigestAlgorithms.SHAKE256)) {
addDeveloperExtension(PdfDeveloperExtension.ISO_32001);
}
PdfSignature dic = new PdfSignature(PdfName.Adobe_PPKLite, sigtype == CryptoStandard.CADES
? PdfName.ETSI_CAdES_DETACHED
: PdfName.Adbe_pkcs7_detached);
dic.setReason(appearance.getReason());
dic.setLocation(appearance.getLocation());
dic.setSignatureCreator(appearance.getSignatureCreator());
dic.setContact(appearance.getContact());
dic.setDate(new PdfDate(getSignDate())); // time-stamp will over-rule this
cryptoDictionary = dic;
Map exc = new HashMap<>();
exc.put(PdfName.Contents, estimatedSize * 2 + 2);
preClose(exc);
PdfPKCS7 sgn = new PdfPKCS7((PrivateKey) null, chain, hashAlgorithm, null, externalDigest, false);
if (signaturePolicy != null) {
sgn.setSignaturePolicy(signaturePolicy);
}
InputStream data = getRangeStream();
byte[] hash = DigestAlgorithms.digest(data, SignUtils.getMessageDigest(hashAlgorithm, externalDigest));
List ocspList = new ArrayList<>();
if (chain.length > 1 && ocspClient != null) {
for (int j = 0; j < chain.length - 1; ++j) {
byte[] ocsp = ocspClient.getEncoded((X509Certificate) chain[j], (X509Certificate) chain[j + 1], null);
if (ocsp != null) {
ocspList.add(ocsp);
}
}
}
byte[] sh = sgn.getAuthenticatedAttributeBytes(hash, sigtype, ocspList, crlBytes);
byte[] extSignature = externalSignature.sign(sh);
sgn.setExternalSignatureValue(
extSignature,
null,
externalSignature.getSignatureAlgorithmName(),
externalSignature.getSignatureMechanismParameters()
);
byte[] encodedSig = sgn.getEncodedPKCS7(hash, sigtype, tsaClient, ocspList, crlBytes);
if (estimatedSize < encodedSig.length) {
throw new IOException("Not enough space");
}
byte[] paddedSig = new byte[estimatedSize];
System.arraycopy(encodedSig, 0, paddedSig, 0, encodedSig.length);
PdfDictionary dic2 = new PdfDictionary();
dic2.put(PdfName.Contents, new PdfString(paddedSig).setHexWriting(true));
close(dic2);
closed = true;
}
/**
* Sign the document using an external container, usually a PKCS7. The signature is fully composed
* externally, iText will just put the container inside the document.
*
* NOTE: This method closes the underlying pdf document. This means, that current instance
* of PdfSigner cannot be used after this method call.
*
* @param externalSignatureContainer the interface providing the actual signing
* @param estimatedSize the reserved size for the signature
* @throws GeneralSecurityException if some problem during apply security algorithms occurs
* @throws IOException if some I/O problem occurs
*/
public void signExternalContainer(IExternalSignatureContainer externalSignatureContainer, int estimatedSize) throws GeneralSecurityException, IOException {
if (closed) {
throw new PdfException(SignExceptionMessageConstant.THIS_INSTANCE_OF_PDF_SIGNER_ALREADY_CLOSED);
}
PdfSignature dic = new PdfSignature();
PdfSignatureAppearance appearance = getSignatureAppearance();
dic.setReason(appearance.getReason());
dic.setLocation(appearance.getLocation());
dic.setSignatureCreator(appearance.getSignatureCreator());
dic.setContact(appearance.getContact());
dic.setDate(new PdfDate(getSignDate())); // time-stamp will over-rule this
externalSignatureContainer.modifySigningDictionary(dic.getPdfObject());
cryptoDictionary = dic;
Map exc = new HashMap<>();
exc.put(PdfName.Contents, estimatedSize * 2 + 2);
preClose(exc);
InputStream data = getRangeStream();
byte[] encodedSig = externalSignatureContainer.sign(data);
if (estimatedSize < encodedSig.length) {
throw new IOException(SignExceptionMessageConstant.NOT_ENOUGH_SPACE);
}
byte[] paddedSig = new byte[estimatedSize];
System.arraycopy(encodedSig, 0, paddedSig, 0, encodedSig.length);
PdfDictionary dic2 = new PdfDictionary();
dic2.put(PdfName.Contents, new PdfString(paddedSig).setHexWriting(true));
close(dic2);
closed = true;
}
/**
* Signs a document with a PAdES-LTV Timestamp. The document is closed at the end.
*
* NOTE: This method closes the underlying pdf document. This means, that current instance
* of PdfSigner cannot be used after this method call.
*
* @param tsa the timestamp generator
* @param signatureName the signature name or null to have a name generated
* automatically
* @throws IOException if some I/O problem occurs
* @throws GeneralSecurityException if some problem during apply security algorithms occurs
*/
public void timestamp(ITSAClient tsa, String signatureName) throws IOException, GeneralSecurityException {
if (closed) {
throw new PdfException(SignExceptionMessageConstant.THIS_INSTANCE_OF_PDF_SIGNER_ALREADY_CLOSED);
}
int contentEstimated = tsa.getTokenSizeEstimate();
if (!isDocumentPdf2()) {
addDeveloperExtension(PdfDeveloperExtension.ESIC_1_7_EXTENSIONLEVEL5);
}
setFieldName(signatureName);
PdfSignature dic = new PdfSignature(PdfName.Adobe_PPKLite, PdfName.ETSI_RFC3161);
dic.put(PdfName.Type, PdfName.DocTimeStamp);
cryptoDictionary = dic;
Map exc = new HashMap<>();
exc.put(PdfName.Contents, contentEstimated * 2 + 2);
preClose(exc);
InputStream data = getRangeStream();
MessageDigest messageDigest = tsa.getMessageDigest();
byte[] buf = new byte[4096];
int n;
while ((n = data.read(buf)) > 0) {
messageDigest.update(buf, 0, n);
}
byte[] tsImprint = messageDigest.digest();
byte[] tsToken;
try {
tsToken = tsa.getTimeStampToken(tsImprint);
} catch (Exception e) {
throw new GeneralSecurityException(e.getMessage(), e);
}
if (contentEstimated + 2 < tsToken.length)
throw new IOException("Not enough space");
byte[] paddedSig = new byte[contentEstimated];
System.arraycopy(tsToken, 0, paddedSig, 0, tsToken.length);
PdfDictionary dic2 = new PdfDictionary();
dic2.put(PdfName.Contents, new PdfString(paddedSig).setHexWriting(true));
close(dic2);
closed = true;
}
/**
* Signs a PDF where space was already reserved.
*
* @param document the original PDF
* @param fieldName the field to sign. It must be the last field
* @param outs the output PDF
* @param externalSignatureContainer the signature container doing the actual signing. Only the
* method ExternalSignatureContainer.sign is used
* @throws IOException if some I/O problem occurs
* @throws GeneralSecurityException if some problem during apply security algorithms occurs
*/
public static void signDeferred(PdfDocument document, String fieldName, OutputStream outs, IExternalSignatureContainer externalSignatureContainer) throws IOException, GeneralSecurityException {
SignatureUtil signatureUtil = new SignatureUtil(document);
PdfSignature signature = signatureUtil.getSignature(fieldName);
if (signature == null) {
throw new PdfException(SignExceptionMessageConstant.THERE_IS_NO_FIELD_IN_THE_DOCUMENT_WITH_SUCH_NAME)
.setMessageParams(fieldName);
}
if (!signatureUtil.signatureCoversWholeDocument(fieldName)) {
throw new PdfException(
SignExceptionMessageConstant.SIGNATURE_WITH_THIS_NAME_IS_NOT_THE_LAST_IT_DOES_NOT_COVER_WHOLE_DOCUMENT
).setMessageParams(fieldName);
}
PdfArray b = signature.getByteRange();
long[] gaps = b.toLongArray();
if (b.size() != 4 || gaps[0] != 0) {
throw new IllegalArgumentException("Single exclusion space supported");
}
IRandomAccessSource readerSource = document.getReader().getSafeFile().createSourceView();
InputStream rg = new RASInputStream(new RandomAccessSourceFactory().createRanged(readerSource, gaps));
byte[] signedContent = externalSignatureContainer.sign(rg);
int spaceAvailable = (int) (gaps[2] - gaps[1]) - 2;
if ((spaceAvailable & 1) != 0) {
throw new IllegalArgumentException("Gap is not a multiple of 2");
}
spaceAvailable /= 2;
if (spaceAvailable < signedContent.length) {
throw new PdfException(SignExceptionMessageConstant.AVAILABLE_SPACE_IS_NOT_ENOUGH_FOR_SIGNATURE);
}
StreamUtil.copyBytes(readerSource, 0, gaps[1] + 1, outs);
ByteBuffer bb = new ByteBuffer(spaceAvailable * 2);
for (byte bi : signedContent) {
bb.appendHex(bi);
}
int remain = (spaceAvailable - signedContent.length) * 2;
for (int k = 0; k < remain; ++k) {
bb.append((byte) 48);
}
byte[] bbArr = bb.toByteArray();
outs.write(bbArr);
StreamUtil.copyBytes(readerSource, gaps[2] - 1, gaps[3] + 1, outs);
}
/**
* Processes a CRL list.
*
* @param cert a Certificate if one of the CrlList implementations needs to retrieve the CRL URL from it.
* @param crlList a list of CrlClient implementations
* @return a collection of CRL bytes that can be embedded in a PDF
* @throws CertificateEncodingException if an encoding error occurs in {@link Certificate}.
*/
protected Collection processCrl(Certificate cert, Collection crlList)
throws CertificateEncodingException {
if (crlList == null) {
return null;
}
List crlBytes = new ArrayList<>();
for (ICrlClient cc : crlList) {
if (cc == null) {
continue;
}
Collection b = cc.getEncoded((X509Certificate) cert, null);
if (b == null) {
continue;
}
crlBytes.addAll(b);
}
return crlBytes.size() == 0 ? null : crlBytes;
}
protected void addDeveloperExtension(PdfDeveloperExtension extension) {
document.getCatalog().addDeveloperExtension(extension);
}
/**
* Checks if the document is in the process of closing.
*
* @return true if the document is in the process of closing, false otherwise
*/
protected boolean isPreClosed() {
return preClosed;
}
/**
* This is the first method to be called when using external signatures. The general sequence is:
* preClose(), getDocumentBytes() and close().
*
* exclusionSizes must contain at least
* the PdfName.CONTENTS key with the size that it will take in the
* document. Note that due to the hex string coding this size should be byte_size*2+2.
*
* @param exclusionSizes Map with names and sizes to be excluded in the signature
* calculation. The key is a PdfName and the value an Integer. At least the /Contents must be present
* @throws IOException on error
*/
protected void preClose(Map exclusionSizes) throws IOException {
if (preClosed) {
throw new PdfException(SignExceptionMessageConstant.DOCUMENT_ALREADY_PRE_CLOSED);
}
preClosed = true;
PdfAcroForm acroForm = PdfAcroForm.getAcroForm(document, true);
SignatureUtil sgnUtil = new SignatureUtil(document);
String name = getFieldName();
boolean fieldExist = sgnUtil.doesSignatureFieldExist(name);
acroForm.setSignatureFlags(PdfAcroForm.SIGNATURE_EXIST | PdfAcroForm.APPEND_ONLY);
PdfSigFieldLock fieldLock = null;
if (cryptoDictionary == null) {
throw new PdfException(SignExceptionMessageConstant.NO_CRYPTO_DICTIONARY_DEFINED);
}
cryptoDictionary.getPdfObject().makeIndirect(document);
if (fieldExist) {
fieldLock = populateExistingSignatureFormField(acroForm);
} else {
fieldLock = createNewSignatureFormField(acroForm, name);
}
exclusionLocations = new HashMap<>();
PdfLiteral lit = new PdfLiteral(80);
exclusionLocations.put(PdfName.ByteRange, lit);
cryptoDictionary.put(PdfName.ByteRange, lit);
for (Map.Entry entry : exclusionSizes.entrySet()) {
PdfName key = entry.getKey();
lit = new PdfLiteral((int) entry.getValue());
exclusionLocations.put(key, lit);
cryptoDictionary.put(key, lit);
}
if (certificationLevel > 0) {
addDocMDP(cryptoDictionary);
}
if (fieldLock != null) {
addFieldMDP(cryptoDictionary, fieldLock);
}
if (signatureEvent != null) {
signatureEvent.getSignatureDictionary(cryptoDictionary);
}
if (certificationLevel > 0) {
// add DocMDP entry to root
PdfDictionary docmdp = new PdfDictionary();
docmdp.put(PdfName.DocMDP, cryptoDictionary.getPdfObject());
document.getCatalog().put(PdfName.Perms, docmdp);
document.getCatalog().setModified();
}
document.checkIsoConformance(cryptoDictionary.getPdfObject(), IsoKey.SIGNATURE);
cryptoDictionary.getPdfObject().flush(false);
document.close();
range = new long[exclusionLocations.size() * 2];
long byteRangePosition = exclusionLocations.get(PdfName.ByteRange).getPosition();
exclusionLocations.remove(PdfName.ByteRange);
int idx = 1;
for (PdfLiteral lit1 : exclusionLocations.values()) {
long n = lit1.getPosition();
range[idx++] = n;
range[idx++] = lit1.getBytesCount() + n;
}
Arrays.sort(range, 1, range.length - 1);
for (int k = 3; k < range.length - 2; k += 2)
range[k] -= range[k - 1];
if (tempFile == null) {
bout = temporaryOS.toByteArray();
range[range.length - 1] = bout.length - range[range.length - 2];
ByteArrayOutputStream bos = new ByteArrayOutputStream();
PdfOutputStream os = new PdfOutputStream(bos);
os.write('[');
for (int k = 0; k < range.length; ++k) {
os.writeLong(range[k]).write(' ');
}
os.write(']');
System.arraycopy(bos.toByteArray(), 0, bout, (int) byteRangePosition, (int) bos.size());
} else {
try {
raf = FileUtil.getRandomAccessFile(tempFile);
long len = raf.length();
range[range.length - 1] = len - range[range.length - 2];
ByteArrayOutputStream bos = new ByteArrayOutputStream();
PdfOutputStream os = new PdfOutputStream(bos);
os.write('[');
for (int k = 0; k < range.length; ++k) {
os.writeLong(range[k]).write(' ');
}
os.write(']');
raf.seek(byteRangePosition);
raf.write(bos.toByteArray(), 0, (int) bos.size());
} catch (IOException e) {
try {
raf.close();
} catch (Exception ignored) {
}
try {
tempFile.delete();
} catch (Exception ignored) {
}
throw e;
}
}
}
/**
* Populates already existing signature form field in the acroForm object.
* This method is called during the {@link PdfSigner#preClose(Map)} method if the signature field already exists.
*
* @param acroForm {@link PdfAcroForm} object in which the signature field will be populated
* @return signature field lock dictionary
* @throws IOException if font for the appearance dictionary cannot be created
*/
protected PdfSigFieldLock populateExistingSignatureFormField(PdfAcroForm acroForm) throws IOException {
PdfSignatureFormField sigField = (PdfSignatureFormField) acroForm.getField(fieldName);
sigField.put(PdfName.V, cryptoDictionary.getPdfObject());
PdfSigFieldLock sigFieldLock = sigField.getSigFieldLockDictionary();
if (sigFieldLock == null && this.fieldLock != null) {
this.fieldLock.getPdfObject().makeIndirect(document);
sigField.put(PdfName.Lock, this.fieldLock.getPdfObject());
sigFieldLock = this.fieldLock;
}
sigField.put(PdfName.P, document.getPage(appearance.getPageNumber()).getPdfObject());
sigField.put(PdfName.V, cryptoDictionary.getPdfObject());
PdfObject obj = sigField.getPdfObject().get(PdfName.F);
int flags = 0;
if (obj != null && obj.isNumber()) {
flags = ((PdfNumber) obj).intValue();
}
flags |= PdfAnnotation.LOCKED;
sigField.put(PdfName.F, new PdfNumber(flags));
if (appearance.isInvisible()) {
// According to the spec, appearance stream is not required if the width and height of the rectangle are 0
sigField.remove(PdfName.AP);
} else {
PdfDictionary ap = new PdfDictionary();
ap.put(PdfName.N, appearance.getAppearance().getPdfObject());
sigField.put(PdfName.AP, ap);
}
sigField.setModified();
return sigFieldLock;
}
/**
* Creates new signature form field and adds it to the acroForm object.
* This method is called during the {@link PdfSigner#preClose(Map)} method if the signature field doesn't exist.
*
* @param acroForm {@link PdfAcroForm} object in which new signature field will be added
* @param name the name of the field
* @return signature field lock dictionary
* @throws IOException if font for the appearance dictionary cannot be created
*/
protected PdfSigFieldLock createNewSignatureFormField(PdfAcroForm acroForm, String name) throws IOException {
PdfWidgetAnnotation widget = new PdfWidgetAnnotation(appearance.getPageRect());
widget.setFlags(PdfAnnotation.PRINT | PdfAnnotation.LOCKED);
PdfSignatureFormField sigField = new SignatureFormFieldBuilder(document, name).createSignature();
sigField.put(PdfName.V, cryptoDictionary.getPdfObject());
sigField.addKid(widget);
PdfSigFieldLock sigFieldLock = sigField.getSigFieldLockDictionary();
if (this.fieldLock != null) {
this.fieldLock.getPdfObject().makeIndirect(document);
sigField.put(PdfName.Lock, this.fieldLock.getPdfObject());
sigFieldLock = this.fieldLock;
}
int pagen = appearance.getPageNumber();
widget.setPage(document.getPage(pagen));
if (appearance.isInvisible()) {
// According to the spec, appearance stream is not required if the width and height of the rectangle are 0
widget.remove(PdfName.AP);
} else {
PdfDictionary ap = widget.getAppearanceDictionary();
if (ap == null) {
ap = new PdfDictionary();
widget.put(PdfName.AP, ap);
}
ap.put(PdfName.N, appearance.getAppearance().getPdfObject());
}
acroForm.addField(sigField, document.getPage(pagen));
if (acroForm.getPdfObject().isIndirect()) {
acroForm.setModified();
} else {
//Acroform dictionary is a Direct dictionary,
//for proper flushing, catalog needs to be marked as modified
document.getCatalog().setModified();
}
return sigFieldLock;
}
/**
* Gets the document bytes that are hashable when using external signatures.
* The general sequence is:
* {@link #preClose(Map)}, {@link #getRangeStream()} and {@link #close(PdfDictionary)}.
*
* @return The {@link InputStream} of bytes to be signed.
* @throws IOException if some I/O problem occurs
*/
protected InputStream getRangeStream() throws IOException {
RandomAccessSourceFactory fac = new RandomAccessSourceFactory();
IRandomAccessSource randomAccessSource = fac.createRanged(getUnderlyingSource(), range);
return new RASInputStream(randomAccessSource);
}
/**
* This is the last method to be called when using external signatures. The general sequence is:
* preClose(), getDocumentBytes() and close().
*
* update is a PdfDictionary that must have exactly the
* same keys as the ones provided in {@link #preClose(Map)}.
*
* @param update a PdfDictionary with the key/value that will fill the holes defined
* in {@link #preClose(Map)}
* @throws IOException on error
*/
protected void close(PdfDictionary update) throws IOException {
try {
if (!preClosed)
throw new PdfException(SignExceptionMessageConstant.DOCUMENT_MUST_BE_PRE_CLOSED);
ByteArrayOutputStream bous = new ByteArrayOutputStream();
PdfOutputStream os = new PdfOutputStream(bous);
for (PdfName key : update.keySet()) {
PdfObject obj = update.get(key);
PdfLiteral lit = exclusionLocations.get(key);
if (lit == null)
throw new IllegalArgumentException("The key didn't reserve space in preclose");
bous.reset();
os.write(obj);
if (bous.size() > lit.getBytesCount()) {
throw new IllegalArgumentException(SignExceptionMessageConstant.TOO_BIG_KEY);
}
if (tempFile == null) {
System.arraycopy(bous.toByteArray(), 0, bout, (int) lit.getPosition(), (int) bous.size());
} else {
raf.seek(lit.getPosition());
raf.write(bous.toByteArray(), 0, (int) bous.size());
}
}
if (update.size() != exclusionLocations.size())
throw new IllegalArgumentException("The update dictionary has less keys than required");
if (tempFile == null) {
originalOS.write(bout, 0, bout.length);
} else {
if (originalOS != null) {
raf.seek(0);
long length = raf.length();
byte[] buf = new byte[8192];
while (length > 0) {
int r = raf.read(buf, 0, (int) Math.min((long) buf.length, length));
if (r < 0)
throw new EOFException("unexpected eof");
originalOS.write(buf, 0, r);
length -= r;
}
}
}
} finally {
if (tempFile != null) {
raf.close();
if (originalOS != null) {
tempFile.delete();
}
}
if (originalOS != null) {
try {
originalOS.close();
} catch (Exception ignored) {
}
}
}
}
/**
* Returns the underlying source.
*
* @return the underlying source
* @throws IOException if some I/O problem occurs
*/
protected IRandomAccessSource getUnderlyingSource() throws IOException {
RandomAccessSourceFactory fac = new RandomAccessSourceFactory();
return raf == null ? fac.createSource(bout) : fac.createSource(raf);
}
/**
* Adds keys to the signature dictionary that define the certification level and the permissions.
* This method is only used for Certifying signatures.
*
* @param crypto the signature dictionary
*/
protected void addDocMDP(PdfSignature crypto) {
PdfDictionary reference = new PdfDictionary();
PdfDictionary transformParams = new PdfDictionary();
transformParams.put(PdfName.P, new PdfNumber(certificationLevel));
transformParams.put(PdfName.V, new PdfName("1.2"));
transformParams.put(PdfName.Type, PdfName.TransformParams);
reference.put(PdfName.TransformMethod, PdfName.DocMDP);
reference.put(PdfName.Type, PdfName.SigRef);
reference.put(PdfName.TransformParams, transformParams);
reference.put(PdfName.Data, document.getTrailer().get(PdfName.Root));
PdfArray types = new PdfArray();
types.add(reference);
crypto.put(PdfName.Reference, types);
}
/**
* Adds keys to the signature dictionary that define the field permissions.
* This method is only used for signatures that lock fields.
*
* @param crypto the signature dictionary
* @param fieldLock the {@link PdfSigFieldLock} instance specified the field lock to be set
*/
protected void addFieldMDP(PdfSignature crypto, PdfSigFieldLock fieldLock) {
PdfDictionary reference = new PdfDictionary();
PdfDictionary transformParams = new PdfDictionary();
transformParams.putAll(fieldLock.getPdfObject());
transformParams.put(PdfName.Type, PdfName.TransformParams);
transformParams.put(PdfName.V, new PdfName("1.2"));
reference.put(PdfName.TransformMethod, PdfName.FieldMDP);
reference.put(PdfName.Type, PdfName.SigRef);
reference.put(PdfName.TransformParams, transformParams);
reference.put(PdfName.Data, document.getTrailer().get(PdfName.Root));
PdfArray types = crypto.getPdfObject().getAsArray(PdfName.Reference);
if (types == null) {
types = new PdfArray();
crypto.put(PdfName.Reference, types);
}
types.add(reference);
}
protected boolean documentContainsCertificationOrApprovalSignatures() {
boolean containsCertificationOrApprovalSignature = false;
PdfDictionary urSignature = null;
PdfDictionary catalogPerms = document.getCatalog().getPdfObject().getAsDictionary(PdfName.Perms);
if (catalogPerms != null) {
urSignature = catalogPerms.getAsDictionary(PdfName.UR3);
}
PdfAcroForm acroForm = PdfAcroForm.getAcroForm(document, false);
if (acroForm != null) {
for (Map.Entry entry : acroForm.getAllFormFields().entrySet()) {
PdfDictionary fieldDict = entry.getValue().getPdfObject();
if (!PdfName.Sig.equals(fieldDict.get(PdfName.FT)))
continue;
PdfDictionary sigDict = fieldDict.getAsDictionary(PdfName.V);
if (sigDict == null)
continue;
PdfSignature pdfSignature = new PdfSignature(sigDict);
if (pdfSignature.getContents() == null || pdfSignature.getByteRange() == null) {
continue;
}
if (!pdfSignature.getType().equals(PdfName.DocTimeStamp) && sigDict != urSignature) {
containsCertificationOrApprovalSignature = true;
break;
}
}
}
return containsCertificationOrApprovalSignature;
}
/**
* Get the rectangle associated to the provided widget.
*
* @param widget PdfWidgetAnnotation to extract the rectangle from
* @return Rectangle
*/
protected Rectangle getWidgetRectangle(PdfWidgetAnnotation widget) {
return widget.getRectangle().toRectangle();
}
/**
* Get the page number associated to the provided widget.
*
* @param widget PdfWidgetAnnotation from which to extract the page number
* @return page number
*/
protected int getWidgetPageNumber(PdfWidgetAnnotation widget) {
int pageNumber = 0;
PdfDictionary pageDict = widget.getPdfObject().getAsDictionary(PdfName.P);
if (pageDict != null) {
pageNumber = document.getPageNumber(pageDict);
} else {
for (int i = 1; i <= document.getNumberOfPages(); i++) {
PdfPage page = document.getPage(i);
if (!page.isFlushed()) {
if (page.containsAnnotation(widget)) {
pageNumber = i;
break;
}
}
}
}
return pageNumber;
}
private boolean isDocumentPdf2() {
return document.getPdfVersion().compareTo(PdfVersion.PDF_2_0) >= 0;
}
/**
* An interface to retrieve the signature dictionary for modification.
*/
public interface ISignatureEvent {
/**
* Allows modification of the signature dictionary.
*
* @param sig The signature dictionary
*/
void getSignatureDictionary(PdfSignature sig);
}
}