/** Get the "issuer" from the TBSCertificate bytes that are passed in */
private DERObject getIssuer(byte[] enc) {
try {
ASN1InputStream in = new ASN1InputStream(new ByteArrayInputStream(enc));
ASN1Sequence seq = (ASN1Sequence) in.readObject();
return (DERObject) seq.getObjectAt(seq.getObjectAt(0) instanceof DERTaggedObject ? 3 : 2);
} catch (IOException e) {
throw new Error("IOException reading from ByteArray: " + e);
}
}
/** Read an existing PKCS#7 object from a DER encoded byte array */
public PKCS7SignedData(byte[] in, String provider)
throws SecurityException, CRLException, InvalidKeyException, NoSuchProviderException,
NoSuchAlgorithmException {
ASN1InputStream din = new ASN1InputStream(new ByteArrayInputStream(in));
//
// Basic checks to make sure it's a PKCS#7 SignedData Object
//
DERObject pkcs;
try {
pkcs = din.readObject();
} catch (IOException e) {
throw new SecurityException("can't decode PKCS7SignedData object");
}
if (!(pkcs instanceof ASN1Sequence)) {
throw new SecurityException("Not a valid PKCS#7 object - not a sequence");
}
ContentInfo content = ContentInfo.getInstance(pkcs);
if (!content.getContentType().equals(signedData)) {
throw new SecurityException(
"Not a valid PKCS#7 signed-data object - wrong header "
+ content.getContentType().getId());
}
SignedData data = SignedData.getInstance(content.getContent());
certs = new ArrayList();
if (data.getCertificates() != null) {
Enumeration ec = ASN1Set.getInstance(data.getCertificates()).getObjects();
while (ec.hasMoreElements()) {
try {
certs.add(
new X509CertificateObject(X509CertificateStructure.getInstance(ec.nextElement())));
} catch (CertificateParsingException e) {
throw new SecurityException(e.toString());
}
}
}
crls = new ArrayList();
if (data.getCRLs() != null) {
Enumeration ec = ASN1Set.getInstance(data.getCRLs()).getObjects();
while (ec.hasMoreElements()) {
crls.add(new X509CRLObject(CertificateList.getInstance(ec.nextElement())));
}
}
version = data.getVersion().getValue().intValue();
//
// Get the digest algorithm
//
digestalgos = new HashSet();
Enumeration e = data.getDigestAlgorithms().getObjects();
while (e.hasMoreElements()) {
ASN1Sequence s = (ASN1Sequence) e.nextElement();
DERObjectIdentifier o = (DERObjectIdentifier) s.getObjectAt(0);
digestalgos.add(o.getId());
}
//
// Get the SignerInfo
//
ASN1Set signerinfos = data.getSignerInfos();
if (signerinfos.size() != 1) {
throw new SecurityException(
"This PKCS#7 object has multiple SignerInfos - only one is supported at this time");
}
SignerInfo signerInfo = SignerInfo.getInstance(signerinfos.getObjectAt(0));
signerversion = signerInfo.getVersion().getValue().intValue();
IssuerAndSerialNumber isAnds = signerInfo.getIssuerAndSerialNumber();
//
// Get the signing certificate
//
BigInteger serialNumber = isAnds.getCertificateSerialNumber().getValue();
X509Principal issuer = new X509Principal(isAnds.getName());
for (Iterator i = certs.iterator(); i.hasNext(); ) {
X509Certificate cert = (X509Certificate) i.next();
if (serialNumber.equals(cert.getSerialNumber()) && issuer.equals(cert.getIssuerDN())) {
signCert = cert;
break;
}
}
if (signCert == null) {
throw new SecurityException(
"Can't find signing certificate with serial " + serialNumber.toString(16));
}
digestAlgorithm = signerInfo.getDigestAlgorithm().getObjectId().getId();
digest = signerInfo.getEncryptedDigest().getOctets();
digestEncryptionAlgorithm = signerInfo.getDigestEncryptionAlgorithm().getObjectId().getId();
sig = Signature.getInstance(getDigestAlgorithm(), provider);
sig.initVerify(signCert.getPublicKey());
}
/** return the bytes for the PKCS7SignedData object. */
public byte[] getEncoded() {
try {
digest = sig.sign();
// Create the set of Hash algorithms. I've assumed this is the
// set of all hash agorithms used to created the digest in the
// "signerInfo" structure. I may be wrong.
//
ASN1EncodableVector v = new ASN1EncodableVector();
for (Iterator i = digestalgos.iterator(); i.hasNext(); ) {
AlgorithmIdentifier a =
new AlgorithmIdentifier(new DERObjectIdentifier((String) i.next()), null);
v.add(a);
}
DERSet algos = new DERSet(v);
// Create the contentInfo. Empty, I didn't implement this bit
//
DERSequence contentinfo = new DERSequence(new DERObjectIdentifier(ID_PKCS7_DATA));
// Get all the certificates
//
v = new ASN1EncodableVector();
for (Iterator i = certs.iterator(); i.hasNext(); ) {
ASN1InputStream tempstream =
new ASN1InputStream(
new ByteArrayInputStream(((X509Certificate) i.next()).getEncoded()));
v.add(tempstream.readObject());
}
DERSet dercertificates = new DERSet(v);
// Create signerinfo structure.
//
ASN1EncodableVector signerinfo = new ASN1EncodableVector();
// Add the signerInfo version
//
signerinfo.add(new DERInteger(signerversion));
IssuerAndSerialNumber isAnds =
new IssuerAndSerialNumber(
new X509Name((ASN1Sequence) getIssuer(signCert.getTBSCertificate())),
new DERInteger(signCert.getSerialNumber()));
signerinfo.add(isAnds);
// Add the digestAlgorithm
//
signerinfo.add(
new AlgorithmIdentifier(new DERObjectIdentifier(digestAlgorithm), new DERNull()));
//
// Add the digestEncryptionAlgorithm
//
signerinfo.add(
new AlgorithmIdentifier(
new DERObjectIdentifier(digestEncryptionAlgorithm), new DERNull()));
//
// Add the digest
//
signerinfo.add(new DEROctetString(digest));
//
// Finally build the body out of all the components above
//
ASN1EncodableVector body = new ASN1EncodableVector();
body.add(new DERInteger(version));
body.add(algos);
body.add(contentinfo);
body.add(new DERTaggedObject(false, 0, dercertificates));
if (crls.size() > 0) {
v = new ASN1EncodableVector();
for (Iterator i = crls.iterator(); i.hasNext(); ) {
ASN1InputStream t =
new ASN1InputStream(new ByteArrayInputStream(((X509CRL) i.next()).getEncoded()));
v.add(t.readObject());
}
DERSet dercrls = new DERSet(v);
body.add(new DERTaggedObject(false, 1, dercrls));
}
// Only allow one signerInfo
//
body.add(new DERSet(new DERSequence(signerinfo)));
// Now we have the body, wrap it in it's PKCS7Signed shell
// and return it
//
ASN1EncodableVector whole = new ASN1EncodableVector();
whole.add(new DERObjectIdentifier(ID_PKCS7_SIGNED_DATA));
whole.add(new DERTaggedObject(0, new DERSequence(body)));
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
DEROutputStream dout = new DEROutputStream(bOut);
dout.writeObject(new DERSequence(whole));
dout.close();
return bOut.toByteArray();
} catch (Exception e) {
throw new RuntimeException(e.toString());
}
}