/*******************************************************************************
* Copyright (c) 2007, 2011 IBM Corporation and others. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*
* Contributors: IBM Corporation - initial API and implementation
******************************************************************************/
package org.eclipse.osgi.internal.signedcontent;
import java.io.IOException;
import java.io.InputStream;
import java.security.*;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.util.*;
import org.eclipse.osgi.baseadaptor.bundlefile.BundleEntry;
import org.eclipse.osgi.baseadaptor.bundlefile.BundleFile;
import org.eclipse.osgi.framework.log.FrameworkLogEntry;
import org.eclipse.osgi.signedcontent.SignerInfo;
import org.eclipse.osgi.util.NLS;
public class SignatureBlockProcessor implements SignedContentConstants {
private final SignedBundleFile signedBundle;
private List<SignerInfo> signerInfos = new ArrayList<SignerInfo>();
private Map<String, Object> contentMDResults = new HashMap<String, Object>();
// map of tsa singers keyed by SignerInfo -> {tsa_SignerInfo, signingTime}
private Map<SignerInfo, Object[]> tsaSignerInfos;
private final int supportFlags;
public SignatureBlockProcessor(SignedBundleFile signedContent, int supportFlags) {
this.signedBundle = signedContent;
this.supportFlags = supportFlags;
}
public SignedContentImpl process() throws IOException, InvalidKeyException, SignatureException, CertificateException, NoSuchAlgorithmException, NoSuchProviderException {
BundleFile wrappedBundleFile = signedBundle.getWrappedBundleFile();
BundleEntry be = wrappedBundleFile.getEntry(META_INF_MANIFEST_MF);
if (be == null)
return createUnsignedContent();
// read all the signature block file names into a list
Enumeration<String> en = wrappedBundleFile.getEntryPaths(META_INF);
List<String> signers = new ArrayList<String>(2);
while (en.hasMoreElements()) {
String name = en.nextElement();
if ((name.endsWith(DOT_DSA) || name.endsWith(DOT_RSA)) && name.indexOf('/') == name.lastIndexOf('/'))
signers.add(name);
}
// this means the jar is not signed
if (signers.size() == 0)
return createUnsignedContent();
byte manifestBytes[] = readIntoArray(be);
// process the signers
for (Iterator<String> iSigners = signers.iterator(); iSigners.hasNext();)
processSigner(wrappedBundleFile, manifestBytes, iSigners.next());
// done processing now create a SingedContent to return
SignerInfo[] allSigners = signerInfos.toArray(new SignerInfo[signerInfos.size()]);
for (Iterator<Map.Entry<String, Object>> iResults = contentMDResults.entrySet().iterator(); iResults.hasNext();) {
Map.Entry<String, Object> entry = iResults.next();
@SuppressWarnings("unchecked")
List<Object>[] value = (List<Object>[]) entry.getValue();
SignerInfo[] entrySigners = value[0].toArray(new SignerInfo[value[0].size()]);
byte[][] entryResults = value[1].toArray(new byte[value[1].size()][]);
entry.setValue(new Object[] {entrySigners, entryResults});
}
SignedContentImpl result = new SignedContentImpl(allSigners, (supportFlags & SignedBundleHook.VERIFY_RUNTIME) != 0 ? contentMDResults : null);
result.setContent(signedBundle);
result.setTSASignerInfos(tsaSignerInfos);
return result;
}
private SignedContentImpl createUnsignedContent() {
SignedContentImpl result = new SignedContentImpl(new SignerInfo[0], contentMDResults);
result.setContent(signedBundle);
return result;
}
private void processSigner(BundleFile bf, byte[] manifestBytes, String signer) throws IOException, SignatureException, InvalidKeyException, CertificateException, NoSuchAlgorithmException, NoSuchProviderException {
BundleEntry be = bf.getEntry(signer);
byte pkcs7Bytes[] = readIntoArray(be);
int dotIndex = signer.lastIndexOf('.');
be = bf.getEntry(signer.substring(0, dotIndex) + DOT_SF);
byte sfBytes[] = readIntoArray(be);
// Step 1, verify the .SF file is signed by the private key that corresponds to the public key
// in the .RSA/.DSA file
String baseFile = bf.getBaseFile() != null ? bf.getBaseFile().toString() : null;
PKCS7Processor processor = new PKCS7Processor(pkcs7Bytes, 0, pkcs7Bytes.length, signer, baseFile);
// call the Step 1 in the Jar File Verification algorithm
processor.verifySFSignature(sfBytes, 0, sfBytes.length);
// algorithm used
String digAlg = getDigAlgFromSF(sfBytes);
if (digAlg == null)
throw new SignatureException(NLS.bind(SignedContentMessages.SF_File_Parsing_Error, new String[] {bf.toString()}));
// get the digest results
// Process the Step 2 in the Jar File Verification algorithm
// Get the manifest out of the signature file and make sure
// it matches MANIFEST.MF
verifyManifestAndSignatureFile(manifestBytes, sfBytes);
// create a SignerInfo with the processed information
SignerInfoImpl signerInfo = new SignerInfoImpl(processor.getCertificates(), null, digAlg);
if ((supportFlags & SignedBundleHook.VERIFY_RUNTIME) != 0)
// only populate the manifests digest information for verifying content at runtime
populateMDResults(manifestBytes, signerInfo);
signerInfos.add(signerInfo);
// check for tsa signers
Certificate[] tsaCerts = processor.getTSACertificates();
Date signingTime = processor.getSigningTime();
if (tsaCerts != null && signingTime != null) {
SignerInfoImpl tsaSignerInfo = new SignerInfoImpl(tsaCerts, null, digAlg);
if (tsaSignerInfos == null)
tsaSignerInfos = new HashMap<SignerInfo, Object[]>(2);
tsaSignerInfos.put(signerInfo, new Object[] {tsaSignerInfo, signingTime});
}
}
/**
* Verify the digest listed in each entry in the .SF file with corresponding section in the manifest
* @throws SignatureException
*/
private void verifyManifestAndSignatureFile(byte[] manifestBytes, byte[] sfBytes) throws SignatureException {
String sf = new String(sfBytes);
sf = stripContinuations(sf);
// check if there -Digest-Manfiest: header in the file
int off = sf.indexOf(digestManifestSearch);
if (off != -1) {
int start = sf.lastIndexOf('\n', off);
String manifestDigest = null;
if (start != -1) {
// Signature-Version has to start the file, so there
// should always be a newline at the start of
// Digest-Manifest
String digestName = sf.substring(start + 1, off);
if (digestName.equalsIgnoreCase(MD5_STR))
manifestDigest = calculateDigest(getMessageDigest(MD5_STR), manifestBytes);
else if (digestName.equalsIgnoreCase(SHA1_STR))
manifestDigest = calculateDigest(getMessageDigest(SHA1_STR), manifestBytes);
off += digestManifestSearchLen;
// find out the index of first '\n' after the -Digest-Manifest:
int nIndex = sf.indexOf('\n', off);
String digestValue = sf.substring(off, nIndex - 1);
// check if the the computed digest value of manifest file equals to the digest value in the .sf file
if (!digestValue.equals(manifestDigest)) {
SignatureException se = new SignatureException(NLS.bind(SignedContentMessages.Security_File_Is_Tampered, new String[] {signedBundle.getBaseFile().toString()}));
SignedBundleHook.log(se.getMessage(), FrameworkLogEntry.ERROR, se);
throw se;
}
}
}
}
private void populateMDResults(byte mfBuf[], SignerInfo signerInfo) throws NoSuchAlgorithmException {
// need to make a string from the MF file data bytes
String mfStr = new String(mfBuf);
// start parsing each entry in the MF String
int entryStartOffset = mfStr.indexOf(MF_ENTRY_NEWLN_NAME);
int length = mfStr.length();
while ((entryStartOffset != -1) && (entryStartOffset < length)) {
// get the start of the next 'entry', i.e. the end of this entry
int entryEndOffset = mfStr.indexOf(MF_ENTRY_NEWLN_NAME, entryStartOffset + 1);
if (entryEndOffset == -1) {
// if there is no next entry, then the end of the string
// is the end of this entry
entryEndOffset = mfStr.length();
}
// get the string for this entry only, since the entryStartOffset
// points to the '\n' befor the 'Name: ' we increase it by 1
// this is guaranteed to not go past end-of-string and be less
// then entryEndOffset.
String entryStr = mfStr.substring(entryStartOffset + 1, entryEndOffset);
entryStr = stripContinuations(entryStr);
// entry points to the start of the next 'entry'
String entryName = getEntryFileName(entryStr);
// if we could retrieve an entry name, then we will extract
// digest type list, and the digest value list
if (entryName != null) {
String aDigestLine = getDigestLine(entryStr, signerInfo.getMessageDigestAlgorithm());
if (aDigestLine != null) {
String msgDigestAlgorithm = getDigestAlgorithmFromString(aDigestLine);
if (!msgDigestAlgorithm.equalsIgnoreCase(signerInfo.getMessageDigestAlgorithm()))
continue; // TODO log error?
byte digestResult[] = getDigestResultsList(aDigestLine);
//
// only insert this entry into the table if its
// "well-formed",
// i.e. only if we could extract its name, digest types, and
// digest-results
//
// sanity check, if the 2 lists are non-null, then their
// counts must match
//
// if ((msgDigestObj != null) && (digestResultsList != null)
// && (1 != digestResultsList.length)) {
// throw new RuntimeException(
// "Errors occurs when parsing the manifest file stream!"); //$NON-NLS-1$
// }
@SuppressWarnings("unchecked")
List<Object>[] mdResult = (List<Object>[]) contentMDResults.get(entryName);
if (mdResult == null) {
@SuppressWarnings("unchecked")
List<Object>[] arrayLists = new ArrayList[2];
mdResult = arrayLists;
mdResult[0] = new ArrayList<Object>();
mdResult[1] = new ArrayList<Object>();
contentMDResults.put(entryName, mdResult);
}
mdResult[0].add(signerInfo);
mdResult[1].add(digestResult);
} // could get lines of digest entries in this MF file entry
} // could retrieve entry name
// increment the offset to the ending entry...
entryStartOffset = entryEndOffset;
}
}
private static byte[] getDigestResultsList(String digestLines) {
byte resultsList[] = null;
if (digestLines != null) {
// for each digest-line retrieve the digest result
// for (int i = 0; i < digestLines.length; i++) {
String sDigestLine = digestLines;
int indexDigest = sDigestLine.indexOf(MF_DIGEST_PART);
indexDigest += MF_DIGEST_PART.length();
// if there is no data to extract for this digest value
// then we will fail...
if (indexDigest >= sDigestLine.length()) {
resultsList = null;
// break;
}
// now attempt to base64 decode the result
String sResult = sDigestLine.substring(indexDigest);
try {
resultsList = Base64.decode(sResult.getBytes());
} catch (Throwable t) {
// malformed digest result, no longer processing this entry
resultsList = null;
}
}
return resultsList;
}
private static String getDigestAlgorithmFromString(String digestLines) throws NoSuchAlgorithmException {
if (digestLines != null) {
// String sDigestLine = digestLines[i];
int indexDigest = digestLines.indexOf(MF_DIGEST_PART);
String sDigestAlgType = digestLines.substring(0, indexDigest);
if (sDigestAlgType.equalsIgnoreCase(MD5_STR)) {
// remember the "algorithm type"
return MD5_STR;
} else if (sDigestAlgType.equalsIgnoreCase(SHA1_STR)) {
// remember the "algorithm type" object
return SHA1_STR;
} else {
// unknown algorithm type, we will stop processing this entry
// break;
throw new NoSuchAlgorithmException(NLS.bind(SignedContentMessages.Algorithm_Not_Supported, sDigestAlgType));
}
}
return null;
}
private static String getEntryFileName(String manifestEntry) {
// get the beginning of the name
int nameStart = manifestEntry.indexOf(MF_ENTRY_NAME);
if (nameStart == -1) {
return null;
}
// check where the name ends
int nameEnd = manifestEntry.indexOf('\n', nameStart);
if (nameEnd == -1) {
return null;
}
// if there is a '\r' before the '\n', then we'll strip it
if (manifestEntry.charAt(nameEnd - 1) == '\r') {
nameEnd--;
}
// get to the beginning of the actual name...
nameStart += MF_ENTRY_NAME.length();
if (nameStart >= nameEnd) {
return null;
}
return manifestEntry.substring(nameStart, nameEnd);
}
/**
* Returns the Base64 encoded digest of the passed set of bytes.
*/
private static String calculateDigest(MessageDigest digest, byte[] bytes) {
return new String(Base64.encode(digest.digest(bytes)));
}
static synchronized MessageDigest getMessageDigest(String algorithm) {
try {
return MessageDigest.getInstance(algorithm);
} catch (NoSuchAlgorithmException e) {
SignedBundleHook.log(e.getMessage(), FrameworkLogEntry.ERROR, e);
}
return null;
}
/**
* Read the .SF file abd assuming that same digest algorithm will be used through out the whole
* .SF file. That digest algorithm name in the last entry will be returned.
*
* @param SFBuf a .SF file in bytes
* @return the digest algorithm name used in the .SF file
*/
private static String getDigAlgFromSF(byte SFBuf[]) {
// need to make a string from the MF file data bytes
String mfStr = new String(SFBuf);
String entryStr = null;
// start parsing each entry in the MF String
int entryStartOffset = mfStr.indexOf(MF_ENTRY_NEWLN_NAME);
int length = mfStr.length();
while ((entryStartOffset != -1) && (entryStartOffset < length)) {
// get the start of the next 'entry', i.e. the end of this entry
int entryEndOffset = mfStr.indexOf(MF_ENTRY_NEWLN_NAME, entryStartOffset + 1);
if (entryEndOffset == -1) {
// if there is no next entry, then the end of the string
// is the end of this entry
entryEndOffset = mfStr.length();
}
// get the string for this entry only, since the entryStartOffset
// points to the '\n' befor the 'Name: ' we increase it by 1
// this is guaranteed to not go past end-of-string and be less
// then entryEndOffset.
entryStr = mfStr.substring(entryStartOffset + 1, entryEndOffset);
entryStr = stripContinuations(entryStr);
break;
}
if (entryStr != null) {
// process the entry to retrieve the digest algorith name
String digestLine = getDigestLine(entryStr, null);
// throw parsing
return getMessageDigestName(digestLine);
}
return null;
}
/**
*
* @param manifestEntry contains a single MF file entry of the format
* "Name: foo"
* "MD5-Digest: [base64 encoded MD5 digest data]"
* "SHA1-Digest: [base64 encoded SHA1 digest dat]"
*
* @param desireDigestAlg a string representing the desire digest value to be returned if there are
* multiple digest lines.
* If this value is null, return whatever digest value is in the entry.
*
* @return this function returns a digest line based on the desire digest algorithm value
* (since only MD5 and SHA1 are recognized here),
* or a 'null' will be returned if none of the digest algorithms
* were recognized.
*/
private static String getDigestLine(String manifestEntry, String desireDigestAlg) {
String result = null;
// find the first digest line
int indexDigest = manifestEntry.indexOf(MF_DIGEST_PART);
// if we didn't find any digests at all, then we are done
if (indexDigest == -1)
return null;
// while we continue to find digest entries
// note: in the following loop we bail if any of the lines
// look malformed...
while (indexDigest != -1) {
// see where this digest line begins (look to left)
int indexStart = manifestEntry.lastIndexOf('\n', indexDigest);
if (indexStart == -1)
return null;
// see where it ends (look to right)
int indexEnd = manifestEntry.indexOf('\n', indexDigest);
if (indexEnd == -1)
return null;
// strip off ending '\r', if any
int indexEndToUse = indexEnd;
if (manifestEntry.charAt(indexEndToUse - 1) == '\r')
indexEndToUse--;
// indexStart points to the '\n' before this digest line
int indexStartToUse = indexStart + 1;
if (indexStartToUse >= indexEndToUse)
return null;
// now this may be a valid digest line, parse it a bit more
// to see if this is a preferred digest algorithm
String digestLine = manifestEntry.substring(indexStartToUse, indexEndToUse);
String digAlg = getMessageDigestName(digestLine);
if (desireDigestAlg != null) {
if (desireDigestAlg.equalsIgnoreCase(digAlg))
return digestLine;
}
// desireDigestAlg is null, always return the digestLine
result = digestLine;
// iterate to next digest line in this entry
indexDigest = manifestEntry.indexOf(MF_DIGEST_PART, indexEnd);
}
// if we couldn't find any digest lines, then we are done
return result;
}
/**
* Return the Message Digest name
*
* @param digLine the message digest line is in the following format. That is in the
* following format:
* DIGEST_NAME-digest: digest value
* @return a string representing a message digest.
*/
private static String getMessageDigestName(String digLine) {
String rtvValue = null;
if (digLine != null) {
int indexDigest = digLine.indexOf(MF_DIGEST_PART);
if (indexDigest != -1) {
rtvValue = digLine.substring(0, indexDigest);
}
}
return rtvValue;
}
private static String stripContinuations(String entry) {
if (entry.indexOf("\n ") < 0) //$NON-NLS-1$
return entry;
StringBuffer buffer = new StringBuffer(entry.length());
int cont = entry.indexOf("\n "); //$NON-NLS-1$
int start = 0;
while (cont >= 0) {
buffer.append(entry.substring(start, cont - 1));
start = cont + 2;
cont = cont + 2 < entry.length() ? entry.indexOf("\n ", cont + 2) : -1; //$NON-NLS-1$
}
// get the last one continuation
if (start < entry.length())
buffer.append(entry.substring(start));
return buffer.toString();
}
private static byte[] readIntoArray(BundleEntry be) throws IOException {
int size = (int) be.getSize();
InputStream is = be.getInputStream();
try {
byte b[] = new byte[size];
int rc = readFully(is, b);
if (rc != size) {
throw new IOException("Couldn't read all of " + be.getName() + ": " + rc + " != " + size); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
}
return b;
} finally {
try {
is.close();
} catch (IOException e) {
// do nothing;
}
}
}
private static int readFully(InputStream is, byte b[]) throws IOException {
int count = b.length;
int offset = 0;
int rc;
while ((rc = is.read(b, offset, count)) > 0) {
count -= rc;
offset += rc;
}
return offset;
}
}