fix: pkcs12 signing

TODO: add PEM support and use page number
This commit is contained in:
sbplat
2024-01-03 15:49:08 -05:00
parent 6a9ef7d538
commit f433e8032f
6 changed files with 697 additions and 218 deletions

View File

@@ -1,47 +1,21 @@
package stirling.software.SPDF.controller.api.security;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.security.KeyFactory;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.Security;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.spec.PKCS8EncodedKeySpec;
import java.text.SimpleDateFormat;
import java.security.UnrecoverableKeyException;
import java.security.cert.CertificateException;
import java.util.Calendar;
import java.util.Collections;
import java.util.Date;
import org.apache.commons.io.IOUtils;
import org.apache.pdfbox.examples.signature.CreateSignatureBase;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.PDResources;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationWidget;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAppearanceDictionary;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAppearanceStream;
import org.apache.pdfbox.pdmodel.interactive.digitalsignature.ExternalSigningSupport;
import org.apache.pdfbox.pdmodel.interactive.digitalsignature.PDSignature;
import org.apache.pdfbox.pdmodel.interactive.digitalsignature.SignatureOptions;
import org.apache.pdfbox.pdmodel.interactive.form.PDAcroForm;
import org.apache.pdfbox.pdmodel.interactive.form.PDSignatureField;
import org.bouncycastle.cert.jcajce.JcaCertStore;
import org.bouncycastle.cms.CMSProcessableByteArray;
import org.bouncycastle.cms.CMSSignedData;
import org.bouncycastle.cms.CMSSignedDataGenerator;
import org.bouncycastle.cms.CMSTypedData;
import org.bouncycastle.cms.jcajce.JcaSignerInfoGeneratorBuilder;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.operator.ContentSigner;
import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
import org.bouncycastle.operator.jcajce.JcaDigestCalculatorProviderBuilder;
import org.bouncycastle.util.io.pem.PemReader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.ResponseEntity;
@@ -68,6 +42,17 @@ public class CertSignController {
Security.addProvider(new BouncyCastleProvider());
}
class CreateSignature extends CreateSignatureBase {
public CreateSignature(KeyStore keystore, char[] pin)
throws KeyStoreException,
UnrecoverableKeyException,
NoSuchAlgorithmException,
IOException,
CertificateException {
super(keystore, pin);
}
}
@PostMapping(consumes = "multipart/form-data", value = "/cert-sign")
@Operation(
summary = "Sign PDF with a Digital Certificate",
@@ -87,203 +72,71 @@ public class CertSignController {
String name = request.getName();
Integer pageNumber = request.getPageNumber();
PrivateKey privateKey = null;
X509Certificate cert = null;
if (certType != null) {
logger.info("Cert type provided: {}", certType);
switch (certType) {
case "PKCS12":
if (p12File != null) {
KeyStore ks = KeyStore.getInstance("PKCS12");
ks.load(
new ByteArrayInputStream(p12File.getBytes()),
password.toCharArray());
String alias = ks.aliases().nextElement();
if (!ks.isKeyEntry(alias)) {
throw new IllegalArgumentException(
"The provided PKCS12 file does not contain a private key.");
}
privateKey = (PrivateKey) ks.getKey(alias, password.toCharArray());
cert = (X509Certificate) ks.getCertificate(alias);
}
break;
case "PEM":
if (privateKeyFile != null && certFile != null) {
// Load private key
KeyFactory keyFactory =
KeyFactory.getInstance("RSA", BouncyCastleProvider.PROVIDER_NAME);
if (isPEM(privateKeyFile.getBytes())) {
privateKey =
keyFactory.generatePrivate(
new PKCS8EncodedKeySpec(
parsePEM(privateKeyFile.getBytes())));
} else {
privateKey =
keyFactory.generatePrivate(
new PKCS8EncodedKeySpec(privateKeyFile.getBytes()));
}
// Load certificate
CertificateFactory certFactory =
CertificateFactory.getInstance(
"X.509", BouncyCastleProvider.PROVIDER_NAME);
if (isPEM(certFile.getBytes())) {
cert =
(X509Certificate)
certFactory.generateCertificate(
new ByteArrayInputStream(
parsePEM(certFile.getBytes())));
} else {
cert =
(X509Certificate)
certFactory.generateCertificate(
new ByteArrayInputStream(certFile.getBytes()));
}
}
break;
}
if (certType == null) {
throw new IllegalArgumentException("Cert type must be provided");
}
PDSignature signature = new PDSignature();
signature.setFilter(PDSignature.FILTER_ADOBE_PPKLITE); // default filter
signature.setSubFilter(PDSignature.SUBFILTER_ADBE_PKCS7_SHA1);
signature.setName(name);
signature.setLocation(location);
signature.setReason(reason);
signature.setSignDate(Calendar.getInstance());
// Load the PDF
try (PDDocument document = PDDocument.load(pdf.getBytes())) {
logger.info("Successfully loaded the provided PDF");
SignatureOptions signatureOptions = new SignatureOptions();
InputStream ksInputStream = null;
// If you want to show the signature
switch (certType) {
case "PKCS12":
ksInputStream = p12File.getInputStream();
break;
case "PEM":
throw new IllegalArgumentException("TODO: PEM not supported yet");
// ksInputStream = privateKeyFile.getInputStream();
// break;
default:
throw new IllegalArgumentException("Invalid cert type: " + certType);
}
// ATTEMPT 2
if (showSignature != null && showSignature) {
PDPage page = document.getPage(pageNumber - 1);
// TODO: page number
PDAcroForm acroForm = document.getDocumentCatalog().getAcroForm();
if (acroForm == null) {
acroForm = new PDAcroForm(document);
document.getDocumentCatalog().setAcroForm(acroForm);
}
KeyStore ks = getKeyStore(ksInputStream, password);
CreateSignature createSignature = new CreateSignature(ks, password.toCharArray());
ByteArrayOutputStream baos = new ByteArrayOutputStream();
sign(pdf.getBytes(), baos, createSignature, name, location, reason);
return WebResponseUtils.boasToWebResponse(
baos, pdf.getOriginalFilename().replaceFirst("[.][^.]+$", "") + "_signed.pdf");
}
// Create a new signature field and widget
private static KeyStore getKeyStore(InputStream is, String password) throws Exception {
KeyStore ks = KeyStore.getInstance("PKCS12");
ks.load(is, password.toCharArray());
return ks;
}
PDSignatureField signatureField = new PDSignatureField(acroForm);
PDAnnotationWidget widget = signatureField.getWidgets().get(0);
PDRectangle rect =
new PDRectangle(100, 100, 200, 50); // Define the rectangle size here
widget.setRectangle(rect);
page.getAnnotations().add(widget);
private static void sign(
byte[] input,
OutputStream output,
CreateSignature instance,
String name,
String location,
String reason) {
try (PDDocument doc = PDDocument.load(input)) {
PDSignature signature = new PDSignature();
signature.setFilter(PDSignature.FILTER_ADOBE_PPKLITE);
signature.setSubFilter(PDSignature.SUBFILTER_ADBE_PKCS7_DETACHED);
signature.setName(name);
signature.setLocation(location);
signature.setReason(reason);
signature.setSignDate(Calendar.getInstance());
// Set the appearance for the signature field
PDAppearanceDictionary appearanceDict = new PDAppearanceDictionary();
PDAppearanceStream appearanceStream = new PDAppearanceStream(document);
appearanceStream.setResources(new PDResources());
appearanceStream.setBBox(rect);
appearanceDict.setNormalAppearance(appearanceStream);
widget.setAppearance(appearanceDict);
try (PDPageContentStream contentStream =
new PDPageContentStream(document, appearanceStream)) {
contentStream.beginText();
contentStream.setFont(PDType1Font.HELVETICA_BOLD, 12);
contentStream.newLineAtOffset(110, 130);
contentStream.showText(
"Digitally signed by: " + (name != null ? name : "Unknown"));
contentStream.newLineAtOffset(0, -15);
contentStream.showText(
"Date: "
+ new SimpleDateFormat("yyyy.MM.dd HH:mm:ss z")
.format(new Date()));
contentStream.newLineAtOffset(0, -15);
if (reason != null && !reason.isEmpty()) {
contentStream.showText("Reason: " + reason);
contentStream.newLineAtOffset(0, -15);
}
if (location != null && !location.isEmpty()) {
contentStream.showText("Location: " + location);
contentStream.newLineAtOffset(0, -15);
}
contentStream.endText();
}
// Add the widget annotation to the page
page.getAnnotations().add(widget);
// Add the signature field to the acroform
acroForm.getFields().add(signatureField);
// Handle multiple signatures by ensuring a unique field name
String baseFieldName = "Signature";
String signatureFieldName = baseFieldName;
int suffix = 1;
while (acroForm.getField(signatureFieldName) != null) {
suffix++;
signatureFieldName = baseFieldName + suffix;
}
signatureField.setPartialName(signatureFieldName);
}
document.addSignature(signature, signatureOptions);
logger.info("Signature added to the PDF document");
// External signing
ExternalSigningSupport externalSigning =
document.saveIncrementalForExternalSigning(new ByteArrayOutputStream());
byte[] content = IOUtils.toByteArray(externalSigning.getContent());
// Using BouncyCastle to sign
CMSTypedData cmsData = new CMSProcessableByteArray(content);
CMSSignedDataGenerator gen = new CMSSignedDataGenerator();
ContentSigner signer =
new JcaContentSignerBuilder("SHA256withRSA")
.setProvider(BouncyCastleProvider.PROVIDER_NAME)
.build(privateKey);
gen.addSignerInfoGenerator(
new JcaSignerInfoGeneratorBuilder(
new JcaDigestCalculatorProviderBuilder()
.setProvider(BouncyCastleProvider.PROVIDER_NAME)
.build())
.build(signer, cert));
gen.addCertificates(new JcaCertStore(Collections.singletonList(cert)));
CMSSignedData signedData = gen.generate(cmsData, false);
byte[] cmsSignature = signedData.getEncoded();
logger.info("About to sign content using BouncyCastle");
externalSigning.setSignature(cmsSignature);
logger.info("Signature set successfully");
// After setting the signature, return the resultant PDF
try (ByteArrayOutputStream signedPdfOutput = new ByteArrayOutputStream()) {
document.save(signedPdfOutput);
return WebResponseUtils.boasToWebResponse(
signedPdfOutput,
pdf.getOriginalFilename().replaceFirst("[.][^.]+$", "") + "_signed.pdf");
} catch (Exception e) {
e.printStackTrace();
}
doc.addSignature(signature, instance);
doc.saveIncremental(output);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
private byte[] parsePEM(byte[] content) throws IOException {
PemReader pemReader =
new PemReader(new InputStreamReader(new ByteArrayInputStream(content)));
return pemReader.readPemObject().getContent();
}
// private byte[] parsePEM(byte[] content) throws IOException {
// PemReader pemReader =
// new PemReader(new InputStreamReader(new ByteArrayInputStream(content)));
// return pemReader.readPemObject().getContent();
// }
private boolean isPEM(byte[] content) {
String contentStr = new String(content);
return contentStr.contains("-----BEGIN") && contentStr.contains("-----END");
}
// private boolean isPEM(byte[] content) {
// String contentStr = new String(content);
// return contentStr.contains("-----BEGIN") && contentStr.contains("-----END");
// }
}