/*
* @(#)SignatureFileVerifier.java 1.29 06/10/10
*
* Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* 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
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*
*/
package sun.security.util;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.security.cert.CertificateException;
import java.security.*;
import java.io.*;
import java.util.*;
import java.util.jar.*;
import sun.security.pkcs.*;
import sun.misc.BASE64Decoder;
public class SignatureFileVerifier {
/* Are we debugging ? */
private static final Debug debug = Debug.getInstance("jar");
/* cache of Certificate[] objects */
private ArrayList certCache;
/** the PKCS7 block for this .DSA/.RSA file */
private PKCS7 block;
/** the raw bytes of the .SF file */
private byte sfBytes[];
/** the name of the signature block file, uppercased and without
* the extension (.DSA/.RSA)
*/
private String name;
/** the ManifestDigester */
private ManifestDigester md;
/** cache of created MessageDigest objects */
private HashMap createdDigests;
/* workaround for parsing Netscape jars */
private boolean workaround = false;
/**
* Create the named SignatureFileVerifier.
*
* @param name the name of the signature block file (.DSA/.RSA)
*
* @param rawBytes the raw bytes of the signature block file
*/
public SignatureFileVerifier(ArrayList certCache,
ManifestDigester md,
String name,
byte rawBytes[])
throws IOException
{
block = new PKCS7(rawBytes);
sfBytes = block.getContentInfo().getData();
this.name = name.substring(0, name.lastIndexOf("."))
.toUpperCase(Locale.ENGLISH);
this.md = md;
this.certCache = certCache;
}
/**
* returns true if we need the .SF file
*/
public boolean needSignatureFileBytes()
{
return sfBytes == null;
}
/**
* returns true if we need this .SF file.
*
* @param name the name of the .SF file without the extension
*
*/
public boolean needSignatureFile(String name)
{
return this.name.equalsIgnoreCase(name);
}
/**
* used to set the raw bytes of the .SF file when it
* is external to the signature block file.
*/
public void setSignatureFile(byte sfBytes[])
{
this.sfBytes = sfBytes;
}
/** get digest from cache */
private MessageDigest getDigest(String algorithm)
{
if (createdDigests == null)
createdDigests = new HashMap();
MessageDigest digest =
(MessageDigest) createdDigests.get(algorithm);
if (digest == null) {
try {
digest = MessageDigest.getInstance(algorithm);
createdDigests.put(algorithm, digest);
} catch (NoSuchAlgorithmException nsae) {
// ignore
}
}
return digest;
}
/**
* process the signature block file. Goes through the .SF file
* and adds certificates for each section where the .SF section
* hash was verified against the Manifest section.
*
*
*/
public void process(Hashtable certificates)
throws IOException, SignatureException, NoSuchAlgorithmException,
JarException
{
Manifest sf = new Manifest();
sf.read(new ByteArrayInputStream(sfBytes));
String version =
sf.getMainAttributes().getValue(Attributes.Name.SIGNATURE_VERSION);
if ((version == null) || !(version.equalsIgnoreCase("1.0"))) {
// TODO: should this be an exception?
// for now we just ignore this signature file
return;
}
SignerInfo[] infos = block.verify(sfBytes);
if (infos == null) {
throw new SecurityException("cannot verify signature block file " +
name);
}
BASE64Decoder decoder = new BASE64Decoder();
Certificate[] newCerts = getCertificates(infos, block);
// make sure we have something to do all this work for...
if (newCerts == null)
return;
Iterator entries = sf.getEntries().entrySet().iterator();
// see if we can verify the whole manifest first
boolean manifestSigned = verifyManifestHash(sf, md, decoder);
// go through each section in the signature file
while(entries.hasNext()) {
Map.Entry e = (Map.Entry)entries.next();
String name = (String) e.getKey();
if (manifestSigned ||
(verifySection((Attributes) e.getValue(), name, md, decoder))) {
if (name.startsWith("./"))
name = name.substring(2);
if (name.startsWith("/"))
name = name.substring(1);
updateCerts(newCerts, certificates, name);
if (debug != null) {
debug.println("processSignature signed name = "+name);
}
} else if (debug != null) {
debug.println("processSignature unsigned name = "+name);
}
}
}
/**
* See if the whole manifest was signed.
*/
private boolean verifyManifestHash(Manifest sf,
ManifestDigester md,
BASE64Decoder decoder)
throws IOException
{
Attributes mattr = sf.getMainAttributes();
boolean manifestSigned = false;
Iterator mit = mattr.entrySet().iterator();
// go through all the attributes and process *-Digest-Manifest entries
while(mit.hasNext()) {
Map.Entry se = (Map.Entry)mit.next();
String key = se.getKey().toString();
if (key.toUpperCase(Locale.ENGLISH).endsWith("-DIGEST-MANIFEST")) {
// 16 is length of "-Digest-Manifest"
String algorithm = key.substring(0, key.length()-16);
MessageDigest digest = getDigest(algorithm);
if (digest != null) {
byte[] computedHash = md.manifestDigest(digest);
byte[] expectedHash =
decoder.decodeBuffer((String)se.getValue());
if (debug != null) {
debug.println("Signature File: Manifest digest " +
digest.getAlgorithm());
debug.println( " sigfile " + toHex(expectedHash));
debug.println( " computed " + toHex(computedHash));
debug.println();
}
if (MessageDigest.isEqual(computedHash,
expectedHash)) {
manifestSigned = true;
} else {
//we will continue and verify each section
}
}
}
}
return manifestSigned;
}
/**
* given the .SF digest header, and the data from the
* section in the manifest, see if the hashes match.
* if not, throw a SecurityException.
*
* @return true if all the -Digest headers verified
* @exception SecurityException if the hash was not equal
*/
private boolean verifySection(Attributes sfAttr,
String name,
ManifestDigester md,
BASE64Decoder decoder)
throws IOException
{
boolean oneDigestVerified = false;
ManifestDigester.Entry mde = md.get(name,block.isOldStyle());
if (mde == null) {
throw new SecurityException(
"no manifiest section for signature file entry "+name);
}
if (sfAttr != null) {
//sun.misc.HexDumpEncoder hex = new sun.misc.HexDumpEncoder();
//hex.encodeBuffer(data, System.out);
Iterator it = sfAttr.entrySet().iterator();
// go through all the attributes and process *-Digest entries
while(it.hasNext()) {
Map.Entry se = (Map.Entry)it.next();
String key = se.getKey().toString();
if (key.toUpperCase(Locale.ENGLISH).endsWith("-DIGEST")) {
// 7 is length of "-Digest"
String algorithm = key.substring(0, key.length()-7);
MessageDigest digest = getDigest(algorithm);
if (digest != null) {
boolean ok = false;
byte[] expected =
decoder.decodeBuffer((String)se.getValue());
byte[] computed;
if (workaround) {
computed = mde.digestWorkaround(digest);
} else {
computed = mde.digest(digest);
}
if (debug != null) {
debug.println("Signature Block File: " +
name + " digest=" + digest.getAlgorithm());
debug.println(" expected " + toHex(expected));
debug.println(" computed " + toHex(computed));
debug.println();
}
if (MessageDigest.isEqual(computed, expected)) {
oneDigestVerified = true;
ok = true;
} else {
// attempt to fallback to the workaround
if (!workaround) {
computed = mde.digestWorkaround(digest);
if (MessageDigest.isEqual(computed, expected)) {
if (debug != null) {
debug.println(" re-computed " + toHex(computed));
debug.println();
}
workaround = true;
oneDigestVerified = true;
ok = true;
}
}
}
if (!ok){
throw new SecurityException("invalid " +
digest.getAlgorithm() +
" signature file digest for " + name);
}
}
}
}
}
return oneDigestVerified;
}
/**
* Given the PKCS7 blocks and SignerInfo[], create a Vector
* of certificate objects. We do this only *once* for a given
* signature block file.
*/
private Certificate[] getCertificates(SignerInfo infos[], PKCS7 block) {
ArrayList certs = null;
for (int i = 0; i < infos.length; i++) {
SignerInfo info = infos[i];
try {
ArrayList certChain = info.getCertificateChain(block);
if (certs == null)
certs = new ArrayList();
certs.addAll(certChain);
if (debug != null) {
debug.println("Signature Block Certificate: " +
(X509Certificate)certChain.get(0));
}
} catch (IOException e) {
}
}
if (certs != null) {
Certificate[] certificates = new Certificate[certs.size()];
System.arraycopy(certs.toArray(), 0,
certificates, 0,
certs.size());
return certificates;
} else {
return null;
}
}
// for the toHex function
private static final char[] hexc =
{'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
/**
* convert a byte array to a hex string for debugging purposes
* @param data the binary data to be converted to a hex string
* @return an ASCII hex string
*/
static String toHex(byte[] data) {
StringBuffer sb = new StringBuffer(data.length*2);
for (int i=0; i<data.length; i++) {
sb.append(hexc[(data[i] >>4) & 0x0f]);
sb.append(hexc[data[i] & 0x0f]);
}
return sb.toString();
}
// returns true if set contains cert
static boolean contains(Certificate[] set, Certificate cert)
{
for (int i=0; i < set.length; i++) {
if (set[i].equals(cert))
return true;
}
return false;
}
// returns true if subset is a subset of set
static boolean isSubSet(Certificate[] subset, Certificate[] set)
{
// check for the same object
if (set == subset)
return true;
for (int i = 0; i < subset.length; i++) {
if (!contains(set, subset[i]))
return false;
}
return true;
}
/**
* returns true if certs contains exactly the same certs as
* oldCerts and newCerts, false otherwise. oldCerts
* is allowed to be null.
*/
static boolean matches(Certificate[] certs,
Certificate[] oldCerts, Certificate[] newCerts)
{
// special case
if ((oldCerts == null) && (certs == newCerts))
return true;
// make sure all oldCerts are in certs
if ((oldCerts != null) && !isSubSet(oldCerts, certs))
return false;
// make sure all newCerts are in certs
if (!isSubSet(newCerts, certs)) {
return false;
}
// now make sure all the certificates in certs are
// also in oldCerts or newCerts
for (int i = 0; i < certs.length; i++) {
boolean found =
((oldCerts != null) && contains(oldCerts, certs[i])) ||
contains(newCerts, certs[i]);
if (!found)
return false;
}
return true;
}
void updateCerts(Certificate[] newCerts, Hashtable certHash, String name)
{
Certificate[] oldCerts =
(Certificate[])certHash.get(name);
// search through the cache for a match, go in reverse order
// as we are more likely to find a match with the last one
// added to the cache
Certificate[] certs;
for (int i = certCache.size()-1; i != -1; i--) {
certs = (Certificate[]) certCache.get(i);
if (matches(certs, oldCerts, newCerts)) {
certHash.put(name, certs);
return;
}
}
if (oldCerts == null) {
certs = newCerts;
} else {
certs =
new Certificate[oldCerts.length + newCerts.length];
System.arraycopy(oldCerts, 0, certs, 0, oldCerts.length);
System.arraycopy(newCerts, 0, certs, oldCerts.length,
newCerts.length);
}
certCache.add(certs);
certHash.put(name, certs);
}
}