ConfigUpdateInstallReceiverpublic class ConfigUpdateInstallReceiver extends android.content.BroadcastReceiver
| Fields Summary |
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| private static final String | TAG | | private static final String | EXTRA_CONTENT_PATH | | private static final String | EXTRA_REQUIRED_HASH | | private static final String | EXTRA_SIGNATURE | | private static final String | EXTRA_VERSION_NUMBER | | private static final String | UPDATE_CERTIFICATE_KEY | | protected final File | updateDir | | protected final File | updateContent | | protected final File | updateVersion |
| Constructors Summary |
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public ConfigUpdateInstallReceiver(String updateDir, String updateContentPath, String updateMetadataPath, String updateVersionPath)
this.updateDir = new File(updateDir);
this.updateContent = new File(updateDir, updateContentPath);
File updateMetadataDir = new File(updateDir, updateMetadataPath);
this.updateVersion = new File(updateMetadataDir, updateVersionPath);
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| Methods Summary |
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| private byte[] | getAltContent(android.content.Context c, android.content.Intent i)
Uri content = getContentFromIntent(i);
InputStream is = c.getContentResolver().openInputStream(content);
try {
return Streams.readFullyNoClose(is);
} finally {
is.close();
}
| | private java.security.cert.X509Certificate | getCert(android.content.ContentResolver cr)
// get the cert from settings
String cert = Settings.Secure.getString(cr, UPDATE_CERTIFICATE_KEY);
// convert it into a real certificate
try {
byte[] derCert = Base64.decode(cert.getBytes(), Base64.DEFAULT);
InputStream istream = new ByteArrayInputStream(derCert);
CertificateFactory cf = CertificateFactory.getInstance("X.509");
return (X509Certificate) cf.generateCertificate(istream);
} catch (CertificateException e) {
throw new IllegalStateException("Got malformed certificate from settings, ignoring");
}
| | private android.net.Uri | getContentFromIntent(android.content.Intent i)
Uri data = i.getData();
if (data == null) {
throw new IllegalStateException("Missing required content path, ignoring.");
}
return data;
| | private byte[] | getCurrentContent()
try {
return IoUtils.readFileAsByteArray(updateContent.getCanonicalPath());
} catch (IOException e) {
Slog.i(TAG, "Failed to read current content, assuming first update!");
return null;
}
| | private static java.lang.String | getCurrentHash(byte[] content)
if (content == null) {
return "0";
}
try {
MessageDigest dgst = MessageDigest.getInstance("SHA512");
byte[] fingerprint = dgst.digest(content);
return IntegralToString.bytesToHexString(fingerprint, false);
} catch (NoSuchAlgorithmException e) {
throw new AssertionError(e);
}
| | private int | getCurrentVersion()
try {
String strVersion = IoUtils.readFileAsString(updateVersion.getCanonicalPath()).trim();
return Integer.parseInt(strVersion);
} catch (IOException e) {
Slog.i(TAG, "Couldn't find current metadata, assuming first update");
return 0;
}
| | private java.lang.String | getRequiredHashFromIntent(android.content.Intent i)
String extraValue = i.getStringExtra(EXTRA_REQUIRED_HASH);
if (extraValue == null) {
throw new IllegalStateException("Missing required previous hash, ignoring.");
}
return extraValue.trim();
| | private java.lang.String | getSignatureFromIntent(android.content.Intent i)
String extraValue = i.getStringExtra(EXTRA_SIGNATURE);
if (extraValue == null) {
throw new IllegalStateException("Missing required signature, ignoring.");
}
return extraValue.trim();
| | private int | getVersionFromIntent(android.content.Intent i)
String extraValue = i.getStringExtra(EXTRA_VERSION_NUMBER);
if (extraValue == null) {
throw new IllegalStateException("Missing required version number, ignoring.");
}
return Integer.parseInt(extraValue.trim());
| | protected void | install(byte[] content, int version)
writeUpdate(updateDir, updateContent, content);
writeUpdate(updateDir, updateVersion, Long.toString(version).getBytes());
| | public void | onReceive(android.content.Context context, android.content.Intent intent)
new Thread() {
@Override
public void run() {
try {
// get the certificate from Settings.Secure
X509Certificate cert = getCert(context.getContentResolver());
// get the content path from the extras
byte[] altContent = getAltContent(context, intent);
// get the version from the extras
int altVersion = getVersionFromIntent(intent);
// get the previous value from the extras
String altRequiredHash = getRequiredHashFromIntent(intent);
// get the signature from the extras
String altSig = getSignatureFromIntent(intent);
// get the version currently being used
int currentVersion = getCurrentVersion();
// get the hash of the currently used value
String currentHash = getCurrentHash(getCurrentContent());
if (!verifyVersion(currentVersion, altVersion)) {
Slog.i(TAG, "Not installing, new version is <= current version");
} else if (!verifyPreviousHash(currentHash, altRequiredHash)) {
EventLog.writeEvent(EventLogTags.CONFIG_INSTALL_FAILED,
"Current hash did not match required value");
} else if (!verifySignature(altContent, altVersion, altRequiredHash, altSig,
cert)) {
EventLog.writeEvent(EventLogTags.CONFIG_INSTALL_FAILED,
"Signature did not verify");
} else {
// install the new content
Slog.i(TAG, "Found new update, installing...");
install(altContent, altVersion);
Slog.i(TAG, "Installation successful");
postInstall(context, intent);
}
} catch (Exception e) {
Slog.e(TAG, "Could not update content!", e);
// keep the error message <= 100 chars
String errMsg = e.toString();
if (errMsg.length() > 100) {
errMsg = errMsg.substring(0, 99);
}
EventLog.writeEvent(EventLogTags.CONFIG_INSTALL_FAILED, errMsg);
}
}
}.start();
| | protected void | postInstall(android.content.Context context, android.content.Intent intent)
| | private boolean | verifyPreviousHash(java.lang.String current, java.lang.String required)
// this is an optional value- if the required field is NONE then we ignore it
if (required.equals("NONE")) {
return true;
}
// otherwise, verify that we match correctly
return current.equals(required);
| | private boolean | verifySignature(byte[] content, int version, java.lang.String requiredPrevious, java.lang.String signature, java.security.cert.X509Certificate cert)
Signature signer = Signature.getInstance("SHA512withRSA");
signer.initVerify(cert);
signer.update(content);
signer.update(Long.toString(version).getBytes());
signer.update(requiredPrevious.getBytes());
return signer.verify(Base64.decode(signature.getBytes(), Base64.DEFAULT));
| | private boolean | verifyVersion(int current, int alternative)
return (current < alternative);
| | protected void | writeUpdate(java.io.File dir, java.io.File file, byte[] content)
FileOutputStream out = null;
File tmp = null;
try {
// create the parents for the destination file
File parent = file.getParentFile();
parent.mkdirs();
// check that they were created correctly
if (!parent.exists()) {
throw new IOException("Failed to create directory " + parent.getCanonicalPath());
}
// create the temporary file
tmp = File.createTempFile("journal", "", dir);
// mark tmp -rw-r--r--
tmp.setReadable(true, false);
// write to it
out = new FileOutputStream(tmp);
out.write(content);
// sync to disk
out.getFD().sync();
// atomic rename
if (!tmp.renameTo(file)) {
throw new IOException("Failed to atomically rename " + file.getCanonicalPath());
}
} finally {
if (tmp != null) {
tmp.delete();
}
IoUtils.closeQuietly(out);
}
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