信頼できるタイムスタンプを使用して、Bouncy Castle で有効な CMS 署名を作成する際に問題があります。署名の作成はうまく機能し (署名を PDF ファイルに含めたい)、署名は有効です。しかし、信頼できるタイムスタンプを署名の unsigned 属性テーブルに含めた後も、署名は引き続き有効ですが、リーダーはThe signature includes an embedded timestamp but it is invalid と報告します。これにより、ハッシュIタイムスタンプは正しいものではないと信じるようになりますが、何が問題なのかわかりません。
署名コード:
Store store = new JcaCertStore(Arrays.asList(certContainer.getChain()));
CMSSignedDataGenerator signedDataGenerator = new CMSSignedDataGenerator();
JcaSignerInfoGeneratorBuilder infoGeneratorBuilder = new JcaSignerInfoGeneratorBuilder(new JcaDigestCalculatorProviderBuilder().setProvider("BC").build());
JcaContentSignerBuilder contentSignerBuilder = new JcaContentSignerBuilder("SHA1withRSA");
signedDataGenerator.addSignerInfoGenerator(
infoGeneratorBuilder.build(contentSignerBuilder.build(certContainer.getPrivateKey()), (X509Certificate)certContainer.getSignatureCertificate()));
signedDataGenerator.addCertificates(store);
CMSTypedData cmsData = new CMSProcessableByteArray(data);
signedData = signedDataGenerator.generate(cmsData, false);
Collection<SignerInformation> ss = signedData.getSignerInfos().getSigners();
SignerInformation si = ss.iterator().next(); // get first signer (should be only one)
ASN1EncodableVector timestampVector = new ASN1EncodableVector();
Attribute token = createTSToken(si.getSignature());
timestampVector.add(token);
AttributeTable at = new AttributeTable(timestampVector);
si = SignerInformation.replaceUnsignedAttributes(si, at);
ss.clear();
ss.add(si);
SignerInformationStore newSignerStore = new SignerInformationStore(ss);
CMSSignedData newSignedData = CMSSignedData.replaceSigners(signedData, newSignerStore);
createTSTokenコード:
public Attribute createTSToken(byte[] data) throws NoSuchProviderException, NoSuchAlgorithmException, IOException {
// Generate timestamp
MessageDigest digest = MessageDigest.getInstance("SHA1", "BC");
TimeStampResponse response = timestampData(digest.digest(data));
TimeStampToken timestampToken = response.getTimeStampToken();
// Create timestamp attribute
Attribute a = new Attribute(PKCSObjectIdentifiers.id_aa_signatureTimeStampToken, new DERSet(ASN1Primitive.fromByteArray(timestampToken.getEncoded())));
return a;
}
timestampData:
TimeStampRequestGenerator reqgen = new TimeStampRequestGenerator();
TimeStampRequest req = reqgen.generate(TSPAlgorithms.SHA1, data);
byte request[] = req.getEncoded();
URL url = new URL("http://time.certum.pl");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setDoOutput(true);
con.setDoInput(true);
con.setRequestMethod("POST");
con.setRequestProperty("Content-type", "application/timestamp-query");
con.setRequestProperty("Content-length", String.valueOf(request.length));
OutputStream out = con.getOutputStream();
out.write(request);
out.flush();
if (con.getResponseCode() != HttpURLConnection.HTTP_OK) {
throw new IOException("Received HTTP error: " + con.getResponseCode() + " - " + con.getResponseMessage());
}
InputStream in = con.getInputStream();
TimeStampResp resp = TimeStampResp.getInstance(new ASN1InputStream(in).readObject());
response = new TimeStampResponse(resp);
response.validate(req);
if(response.getStatus() != 0) {
System.out.println(response.getStatusString());
return null;
}
return response;
ご協力いただきありがとうございます！
サンプル ファイル:
LTV 付きの署名済み PDF - 編集済み