/*
* Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code 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. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code 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 in the LICENSE file that
* accompanied this code).
*
* 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 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package sun.security.util;
import java.security.CodeSigner;
import java.security.cert.CertPath;
import java.security.cert.X509Certificate;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.*;
import java.io.*;
import java.util.*;
import java.util.jar.*;
import java.io.ByteArrayOutputStream;
import sun.security.pkcs.*;
import sun.security.timestamp.TimestampToken;
import sun.misc.BASE64Decoder;
import sun.security.jca.Providers;
public class SignatureFileVerifier {
/* Are we debugging ? */
private static final Debug debug = Debug.getInstance("jar");
/* cache of CodeSigner objects */
private ArrayList<CodeSigner[]> signerCache;
private static final String ATTR_DIGEST =
("-DIGEST-" + ManifestDigester.MF_MAIN_ATTRS).toUpperCase
(Locale.ENGLISH);
/** 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<String, MessageDigest> createdDigests;
/* workaround for parsing Netscape jars */
private boolean workaround = false;
/* for generating certpath objects */
private CertificateFactory certificateFactory = null;
/**
* 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<CodeSigner[]> signerCache,
ManifestDigester md,
String name,
byte rawBytes[])
throws IOException, CertificateException
{
// new PKCS7() calls CertificateFactory.getInstance()
// need to use local providers here, see Providers class
Object obj = null;
try {
obj = Providers.startJarVerification();
block = new PKCS7(rawBytes);
sfBytes = block.getContentInfo().getData();
certificateFactory = CertificateFactory.getInstance("X509");
} finally {
Providers.stopJarVerification(obj);
}
this.name = name.substring(0, name.lastIndexOf("."))
.toUpperCase(Locale.ENGLISH);
this.md = md;
this.signerCache = signerCache;
}
/**
* 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;
}
/**
* Utility method used by JarVerifier and JarSigner
* to determine the signature file names and PKCS7 block
* files names that are supported
*
* @param s file name
* @return true if the input file name is a supported
* Signature File or PKCS7 block file name
*/
public static boolean isBlockOrSF(String s) {
// we currently only support DSA and RSA PKCS7 blocks
if (s.endsWith(".SF") || s.endsWith(".DSA") || s.endsWith(".RSA")) {
return true;
}
return false;
}
/** get digest from cache */
private MessageDigest getDigest(String algorithm)
{
if (createdDigests == null)
createdDigests = new HashMap<String, MessageDigest>();
MessageDigest digest = 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 code signers for each section where the .SF section
* hash was verified against the Manifest section.
*
*
*/
public void process(Hashtable<String, CodeSigner[]> signers)
throws IOException, SignatureException, NoSuchAlgorithmException,
JarException, CertificateException
{
// calls Signature.getInstance() and MessageDigest.getInstance()
// need to use local providers here, see Providers class
Object obj = null;
try {
obj = Providers.startJarVerification();
processImpl(signers);
} finally {
Providers.stopJarVerification(obj);
}
}
private void processImpl(Hashtable<String, CodeSigner[]> signers)
throws IOException, SignatureException, NoSuchAlgorithmException,
JarException, CertificateException
{
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"))) {
// XXX: 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();
CodeSigner[] newSigners = getSigners(infos, block);
// make sure we have something to do all this work for...
if (newSigners == null)
return;
Iterator<Map.Entry<String,Attributes>> entries =
sf.getEntries().entrySet().iterator();
// see if we can verify the whole manifest first
boolean manifestSigned = verifyManifestHash(sf, md, decoder);
// verify manifest main attributes
if (!manifestSigned && !verifyManifestMainAttrs(sf, md, decoder)) {
throw new SecurityException
("Invalid signature file digest for Manifest main attributes");
}
// go through each section in the signature file
while(entries.hasNext()) {
Map.Entry<String,Attributes> e = entries.next();
String name = e.getKey();
if (manifestSigned ||
(verifySection(e.getValue(), name, md, decoder))) {
if (name.startsWith("./"))
name = name.substring(2);
if (name.startsWith("/"))
name = name.substring(1);
updateSigners(newSigners, signers, 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;
// go through all the attributes and process *-Digest-Manifest entries
for (Map.Entry<Object,Object> se : mattr.entrySet()) {
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 {
//XXX: we will continue and verify each section
}
}
}
}
return manifestSigned;
}
private boolean verifyManifestMainAttrs(Manifest sf,
ManifestDigester md,
BASE64Decoder decoder)
throws IOException
{
Attributes mattr = sf.getMainAttributes();
boolean attrsVerified = true;
// go through all the attributes and process
// digest entries for the manifest main attributes
for (Map.Entry<Object,Object> se : mattr.entrySet()) {
String key = se.getKey().toString();
if (key.toUpperCase(Locale.ENGLISH).endsWith(ATTR_DIGEST)) {
String algorithm =
key.substring(0, key.length() - ATTR_DIGEST.length());
MessageDigest digest = getDigest(algorithm);
if (digest != null) {
ManifestDigester.Entry mde =
md.get(ManifestDigester.MF_MAIN_ATTRS, false);
byte[] computedHash = mde.digest(digest);
byte[] expectedHash =
decoder.decodeBuffer((String)se.getValue());
if (debug != null) {
debug.println("Signature File: " +
"Manifest Main Attributes digest " +
digest.getAlgorithm());
debug.println( " sigfile " + toHex(expectedHash));
debug.println( " computed " + toHex(computedHash));
debug.println();
}
if (MessageDigest.isEqual(computedHash,
expectedHash)) {
// good
} else {
// we will *not* continue and verify each section
attrsVerified = false;
if (debug != null) {
debug.println("Verification of " +
"Manifest main attributes failed");
debug.println();
}
break;
}
}
}
}
// this method returns 'true' if either:
// . manifest main attributes were not signed, or
// . manifest main attributes were signed and verified
return attrsVerified;
}
/**
* 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);
// go through all the attributes and process *-Digest entries
for (Map.Entry<Object,Object> se : sfAttr.entrySet()) {
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 block and SignerInfo[], create an array of
* CodeSigner objects. We do this only *once* for a given
* signature block file.
*/
private CodeSigner[] getSigners(SignerInfo infos[], PKCS7 block)
throws IOException, NoSuchAlgorithmException, SignatureException,
CertificateException {
ArrayList<CodeSigner> signers = null;
for (int i = 0; i < infos.length; i++) {
SignerInfo info = infos[i];
ArrayList<X509Certificate> chain = info.getCertificateChain(block);
CertPath certChain = certificateFactory.generateCertPath(chain);
if (signers == null) {
signers = new ArrayList<CodeSigner>();
}
// Append the new code signer
signers.add(new CodeSigner(certChain, getTimestamp(info)));
if (debug != null) {
debug.println("Signature Block Certificate: " +
chain.get(0));
}
}
if (signers != null) {
return signers.toArray(new CodeSigner[signers.size()]);
} else {
return null;
}
}
/*
* Examines a signature timestamp token to generate a timestamp object.
*
* Examines the signer's unsigned attributes for a
* <tt>signatureTimestampToken</tt> attribute. If present,
* then it is parsed to extract the date and time at which the
* timestamp was generated.
*
* @param info A signer information element of a PKCS 7 block.
*
* @return A timestamp token or null if none is present.
* @throws IOException if an error is encountered while parsing the
* PKCS7 data.
* @throws NoSuchAlgorithmException if an error is encountered while
* verifying the PKCS7 object.
* @throws SignatureException if an error is encountered while
* verifying the PKCS7 object.
* @throws CertificateException if an error is encountered while generating
* the TSA's certpath.
*/
private Timestamp getTimestamp(SignerInfo info)
throws IOException, NoSuchAlgorithmException, SignatureException,
CertificateException {
Timestamp timestamp = null;
// Extract the signer's unsigned attributes
PKCS9Attributes unsignedAttrs = info.getUnauthenticatedAttributes();
if (unsignedAttrs != null) {
PKCS9Attribute timestampTokenAttr =
unsignedAttrs.getAttribute("signatureTimestampToken");
if (timestampTokenAttr != null) {
PKCS7 timestampToken =
new PKCS7((byte[])timestampTokenAttr.getValue());
// Extract the content (an encoded timestamp token info)
byte[] encodedTimestampTokenInfo =
timestampToken.getContentInfo().getData();
// Extract the signer (the Timestamping Authority)
// while verifying the content
SignerInfo[] tsa =
timestampToken.verify(encodedTimestampTokenInfo);
// Expect only one signer
ArrayList<X509Certificate> chain =
tsa[0].getCertificateChain(timestampToken);
CertPath tsaChain = certificateFactory.generateCertPath(chain);
// Create a timestamp token info object
TimestampToken timestampTokenInfo =
new TimestampToken(encodedTimestampTokenInfo);
// Create a timestamp object
timestamp =
new Timestamp(timestampTokenInfo.getDate(), tsaChain);
}
}
return timestamp;
}
// 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 signer
static boolean contains(CodeSigner[] set, CodeSigner signer)
{
for (int i = 0; i < set.length; i++) {
if (set[i].equals(signer))
return true;
}
return false;
}
// returns true if subset is a subset of set
static boolean isSubSet(CodeSigner[] subset, CodeSigner[] set)
{
// check for the same object
if (set == subset)
return true;
boolean match;
for (int i = 0; i < subset.length; i++) {
if (!contains(set, subset[i]))
return false;
}
return true;
}
/**
* returns true if signer contains exactly the same code signers as
* oldSigner and newSigner, false otherwise. oldSigner
* is allowed to be null.
*/
static boolean matches(CodeSigner[] signers, CodeSigner[] oldSigners,
CodeSigner[] newSigners) {
// special case
if ((oldSigners == null) && (signers == newSigners))
return true;
boolean match;
// make sure all oldSigners are in signers
if ((oldSigners != null) && !isSubSet(oldSigners, signers))
return false;
// make sure all newSigners are in signers
if (!isSubSet(newSigners, signers)) {
return false;
}
// now make sure all the code signers in signers are
// also in oldSigners or newSigners
for (int i = 0; i < signers.length; i++) {
boolean found =
((oldSigners != null) && contains(oldSigners, signers[i])) ||
contains(newSigners, signers[i]);
if (!found)
return false;
}
return true;
}
void updateSigners(CodeSigner[] newSigners,
Hashtable<String, CodeSigner[]> signers, String name) {
CodeSigner[] oldSigners = signers.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
CodeSigner[] cachedSigners;
for (int i = signerCache.size() - 1; i != -1; i--) {
cachedSigners = signerCache.get(i);
if (matches(cachedSigners, oldSigners, newSigners)) {
signers.put(name, cachedSigners);
return;
}
}
if (oldSigners == null) {
cachedSigners = newSigners;
} else {
cachedSigners =
new CodeSigner[oldSigners.length + newSigners.length];
System.arraycopy(oldSigners, 0, cachedSigners, 0,
oldSigners.length);
System.arraycopy(newSigners, 0, cachedSigners, oldSigners.length,
newSigners.length);
}
signerCache.add(cachedSigners);
signers.put(name, cachedSigners);
}
}