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Commit b6310846 authored by Geremy Condra's avatar Geremy Condra
Browse files

DO NOT MERGE Add components for the Android Config Updater to system server. 

This adds the necessary bits to verify and install configuration
updates using system server. It also includes the cert pinning
updater as the first user.

Change-Id: I42307f58074157b33b6e01216aab10022340d449
parent 4f8da32f

core/res/AndroidManifest.xml

+6 −0
Original line number Diff line number Diff line
@@ -1843,6 +1843,12 @@ 
            </intent-filter>

        </receiver>



        <receiver android:name="com.android.server.updates.CertPinInstallReceiver" >

            <intent-filter>

                <action android:name="android.intent.action.UPDATE_PINS" />

            </intent-filter>

        </receiver>



        <receiver android:name="com.android.server.MasterClearReceiver"

            android:permission="android.permission.MASTER_CLEAR"

            android:priority="100" >

services/java/com/android/server/updatable/CertPinInstallReceiver.java

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Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */



package com.android.server.updates;



public class CertPinInstallReceiver extends ConfigUpdateInstallReceiver {



    public CertPinInstallReceiver() {

        super("/data/misc/keychain/", "pins", "metadata/", "version");

    }

}

services/java/com/android/server/updatable/ConfigUpdateInstallReceiver.java

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Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */



package com.android.server.updates;



import android.content.BroadcastReceiver;

import android.content.ContentResolver;

import android.content.Context;

import android.content.Intent;

import android.provider.Settings;

import android.os.FileUtils;

import android.util.Base64;

import android.util.Slog;



import java.io.ByteArrayInputStream;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.io.IOException;

import java.security.cert.Certificate;

import java.security.cert.CertificateException;

import java.security.cert.CertificateFactory;

import java.security.cert.X509Certificate;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.security.Signature;

import java.security.SignatureException;



import libcore.io.IoUtils;



public class ConfigUpdateInstallReceiver extends BroadcastReceiver {



    private static final String TAG = "ConfigUpdateInstallReceiver";



    private static final String EXTRA_CONTENT_PATH = "CONTENT_PATH";

    private static final String EXTRA_REQUIRED_HASH = "REQUIRED_HASH";

    private static final String EXTRA_SIGNATURE = "SIGNATURE";

    private static final String EXTRA_VERSION_NUMBER = "VERSION";



    private static final String UPDATE_CERTIFICATE_KEY = "config_update_certificate";



    private final File updateDir;

    private final File updateContent;

    private final File updateVersion;



    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);

    }



    @Override

    public void onReceive(final Context context, final 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

                    String altContent = getAltContent(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.e(TAG, "New version is not greater than current version, aborting!");

                    } else if (!verifyPreviousHash(currentHash, altRequiredHash)) {

                        Slog.e(TAG, "Current hash did not match required value, aborting!");

                    } else if (!verifySignature(altContent, altVersion, altRequiredHash, altSig,

                               cert)) {

                        Slog.e(TAG, "Signature did not verify, aborting!");

                    } else {

                        // install the new content

                        Slog.i(TAG, "Found new update, installing...");

                        install(altContent, altVersion);

                        Slog.i(TAG, "Installation successful");

                    }

                } catch (Exception e) {

                    Slog.e(TAG, "Could not update content!", e);

                }

            }

        }.start();

    }



    private X509Certificate getCert(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", e);

        }

    }



    private String getContentFromIntent(Intent i) {

        String extraValue = i.getStringExtra(EXTRA_CONTENT_PATH);

        if (extraValue == null) {

            throw new IllegalStateException("Missing required content path, ignoring.");

        }

        return extraValue;

    }



    private int getVersionFromIntent(Intent i) throws NumberFormatException {

        String extraValue = i.getStringExtra(EXTRA_VERSION_NUMBER);

        if (extraValue == null) {

            throw new IllegalStateException("Missing required version number, ignoring.");

        }

        return Integer.parseInt(extraValue.trim());

    }



    private String getRequiredHashFromIntent(Intent i) {

        String extraValue = i.getStringExtra(EXTRA_REQUIRED_HASH);

        if (extraValue == null) {

            throw new IllegalStateException("Missing required previous hash, ignoring.");

        }

        return extraValue.trim();

    }



    private String getSignatureFromIntent(Intent i) {

        String extraValue = i.getStringExtra(EXTRA_SIGNATURE);

        if (extraValue == null) {

            throw new IllegalStateException("Missing required signature, ignoring.");

        }

        return extraValue.trim();

    }



    private int getCurrentVersion() throws NumberFormatException {

        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", e);

            return 0;

        }

    }



    private String getAltContent(Intent i) throws IOException {

        String contents = IoUtils.readFileAsString(getContentFromIntent(i));

        return contents.trim();

    }



    private String getCurrentContent() {

        try {

            return IoUtils.readFileAsString(updateContent.getCanonicalPath()).trim();

        } catch (IOException e) {

            Slog.i(TAG, "Failed to read current content, assuming first update!", e);

            return null;

        }

    }



    private static String getCurrentHash(String content) {

        if (content == null) {

            return "0";

        }

        try {

            MessageDigest dgst = MessageDigest.getInstance("SHA512");

            byte[] encoded = content.getBytes();

            byte[] fingerprint = dgst.digest(encoded);

            return IntegralToString.bytesToHexString(fingerprint, false);

        } catch (NoSuchAlgorithmException e) {

            throw new AssertionError(e);

        }

    }



    private boolean verifyVersion(int current, int alternative) {

        return (current < alternative);

    }



    private boolean verifyPreviousHash(String current, 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(String content, int version, String requiredPrevious,

                                   String signature, X509Certificate cert) throws Exception {

        Signature signer = Signature.getInstance("SHA512withRSA");

        signer.initVerify(cert);

        signer.update(content.getBytes());

        signer.update(Long.toString(version).getBytes());

        signer.update(requiredPrevious.getBytes());

        return signer.verify(Base64.decode(signature.getBytes(), Base64.DEFAULT));

    }



    private void writeUpdate(File dir, File file, String content) {

        FileOutputStream out = null;

        File tmp = null;

        try {

            // 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.getBytes());

            // sync to disk

            FileUtils.sync(out);

            // atomic rename

            tmp.renameTo(file);

        } catch (IOException e) {

            Slog.e(TAG, "Failed to write update", e);

        } finally {

            if (tmp != null) {

                tmp.delete();

            }

            IoUtils.closeQuietly(out);

        }

    }



    private void install(String content, int version) {

        writeUpdate(updateDir, updateContent, content);

        writeUpdate(updateDir, updateVersion, Long.toString(version));

    }

}

services/tests/servicestests/src/com/android/server/updatable/CertPinInstallReceiverTest.java

0 → 100644
+243 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */



package com.android.server.updates;



import android.content.Context;

import android.content.Intent;

import android.test.AndroidTestCase;

import android.provider.Settings;

import android.util.Base64;

import android.util.Log;



import java.io.ByteArrayInputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.FileWriter;

import java.io.IOException;

import java.io.InputStream;

import java.security.cert.CertificateFactory;

import java.security.cert.Certificate;

import java.security.cert.X509Certificate;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.security.PrivateKey;

import java.security.Signature;

import java.security.spec.PKCS8EncodedKeySpec;

import java.security.KeyFactory;

import java.util.HashSet;

import java.io.*;

import libcore.io.IoUtils;



/**

 * Tests for {@link com.android.server.CertPinInstallReceiver}

 */

public class CertPinInstallReceiverTest extends AndroidTestCase {



    private static final String TAG = "CertPinInstallReceiverTest";



    private static final String PINLIST_ROOT = System.getenv("ANDROID_DATA") + "/misc/keychain/";



    public static final String PINLIST_CONTENT_PATH = PINLIST_ROOT + "pins";

    public static final String PINLIST_METADATA_PATH = PINLIST_CONTENT_PATH + "metadata";



    public static final String PINLIST_CONTENT_URL_KEY = "pinlist_content_url";

    public static final String PINLIST_METADATA_URL_KEY = "pinlist_metadata_url";

    public static final String PINLIST_CERTIFICATE_KEY = "config_update_certificate";

    public static final String PINLIST_VERSION_KEY = "pinlist_version";



    private static final String EXTRA_CONTENT_PATH = "CONTENT_PATH";

    private static final String EXTRA_REQUIRED_HASH = "REQUIRED_HASH";

    private static final String EXTRA_SIGNATURE = "SIGNATURE";

    private static final String EXTRA_VERSION_NUMBER = "VERSION";



    public static final String TEST_CERT = "" +

                    "MIIDsjCCAxugAwIBAgIJAPLf2gS0zYGUMA0GCSqGSIb3DQEBBQUAMIGYMQswCQYDVQQGEwJVUzET" +

                    "MBEGA1UECBMKQ2FsaWZvcm5pYTEWMBQGA1UEBxMNTW91bnRhaW4gVmlldzEPMA0GA1UEChMGR29v" +

                    "Z2xlMRAwDgYDVQQLEwd0ZXN0aW5nMRYwFAYDVQQDEw1HZXJlbXkgQ29uZHJhMSEwHwYJKoZIhvcN" +

                    "AQkBFhJnY29uZHJhQGdvb2dsZS5jb20wHhcNMTIwNzE0MTc1MjIxWhcNMTIwODEzMTc1MjIxWjCB" +

                    "mDELMAkGA1UEBhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExFjAUBgNVBAcTDU1vdW50YWluIFZp" +

                    "ZXcxDzANBgNVBAoTBkdvb2dsZTEQMA4GA1UECxMHdGVzdGluZzEWMBQGA1UEAxMNR2VyZW15IENv" +

                    "bmRyYTEhMB8GCSqGSIb3DQEJARYSZ2NvbmRyYUBnb29nbGUuY29tMIGfMA0GCSqGSIb3DQEBAQUA" +

                    "A4GNADCBiQKBgQCjGGHATBYlmas+0sEECkno8LZ1KPglb/mfe6VpCT3GhSr+7br7NG/ZwGZnEhLq" +

                    "E7YIH4fxltHmQC3Tz+jM1YN+kMaQgRRjo/LBCJdOKaMwUbkVynAH6OYsKevjrOPk8lfM5SFQzJMG" +

                    "sA9+Tfopr5xg0BwZ1vA/+E3mE7Tr3M2UvwIDAQABo4IBADCB/TAdBgNVHQ4EFgQUhzkS9E6G+x8W" +

                    "L4EsmRjDxu28tHUwgc0GA1UdIwSBxTCBwoAUhzkS9E6G+x8WL4EsmRjDxu28tHWhgZ6kgZswgZgx" +

                    "CzAJBgNVBAYTAlVTMRMwEQYDVQQIEwpDYWxpZm9ybmlhMRYwFAYDVQQHEw1Nb3VudGFpbiBWaWV3" +

                    "MQ8wDQYDVQQKEwZHb29nbGUxEDAOBgNVBAsTB3Rlc3RpbmcxFjAUBgNVBAMTDUdlcmVteSBDb25k" +

                    "cmExITAfBgkqhkiG9w0BCQEWEmdjb25kcmFAZ29vZ2xlLmNvbYIJAPLf2gS0zYGUMAwGA1UdEwQF" +

                    "MAMBAf8wDQYJKoZIhvcNAQEFBQADgYEAYiugFDmbDOQ2U/+mqNt7o8ftlEo9SJrns6O8uTtK6AvR" +

                    "orDrR1AXTXkuxwLSbmVfedMGOZy7Awh7iZa8hw5x9XmUudfNxvmrKVEwGQY2DZ9PXbrnta/dwbhK" +

                    "mWfoepESVbo7CKIhJp8gRW0h1Z55ETXD57aGJRvQS4pxkP8ANhM=";





    public static final String TEST_KEY = "" +

                    "MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBAKMYYcBMFiWZqz7SwQQKSejwtnUo" +

                    "+CVv+Z97pWkJPcaFKv7tuvs0b9nAZmcSEuoTtggfh/GW0eZALdPP6MzVg36QxpCBFGOj8sEIl04p" +

                    "ozBRuRXKcAfo5iwp6+Os4+TyV8zlIVDMkwawD35N+imvnGDQHBnW8D/4TeYTtOvczZS/AgMBAAEC" +

                    "gYBxwFalNSwZK3WJipq+g6KLCiBn1JxGGDQlLKrweFaSuFyFky9fd3IvkIabirqQchD612sMb+GT" +

                    "0t1jptW6z4w2w6++IW0A3apDOCwoD+uvDBXrbFqI0VbyAWUNqHVdaFFIRk2IHGEE6463mGRdmILX" +

                    "IlCd/85RTHReg4rl/GFqWQJBANgLAIR4pWbl5Gm+DtY18wp6Q3pJAAMkmP/lISCBIidu1zcqYIKt" +

                    "PoDW4Knq9xnhxPbXrXKv4YzZWHBK8GkKhQ0CQQDBQnXufQcMew+PwiS0oJvS+eQ6YJwynuqG2ejg" +

                    "WE+T7489jKtscRATpUXpZUYmDLGg9bLt7L62hFvFSj2LO2X7AkBcdrD9AWnBFWlh/G77LVHczSEu" +

                    "KCoyLiqxcs5vy/TjLaQ8vw1ZQG580/qJnr+tOxyCjSJ18GK3VppsTRaBznfNAkB3nuCKNp9HTWCL" +

                    "dfrsRsFMrFpk++mSt6SoxXaMbn0LL2u1CD4PCEiQMGt+lK3/3TmRTKNs+23sYS7Ahjxj0udDAkEA" +

                    "p57Nj65WNaWeYiOfTwKXkLj8l29H5NbaGWxPT0XkWr4PvBOFZVH/wj0/qc3CMVGnv11+DyO+QUCN" +

                    "SqBB5aRe8g==";



    private void overrideSettings(String key, String value) throws Exception {

        assertTrue(Settings.Secure.putString(mContext.getContentResolver(), key, value));

        Thread.sleep(1000);

    }



    private void overrideCert(String value) throws Exception {

        overrideSettings(PINLIST_CERTIFICATE_KEY, value);

    }



    private String readPins() throws Exception {

        return IoUtils.readFileAsString(PINLIST_CONTENT_PATH);

    }



    private String readCurrentVersion() throws Exception {

        return IoUtils.readFileAsString("/data/misc/keychain/metadata/version");

    }



    private String getNextVersion() throws Exception {

        int currentVersion = Integer.parseInt(readCurrentVersion());

        return Integer.toString(currentVersion + 1);

    }



    private static String getCurrentHash(String content) throws Exception {

        if (content == null) {

            return "0";

        }

        MessageDigest dgst = MessageDigest.getInstance("SHA512");

        byte[] encoded = content.getBytes();

        byte[] fingerprint = dgst.digest(encoded);

        return IntegralToString.bytesToHexString(fingerprint, false);

    }



    private static String getHashOfCurrentContent() throws Exception {

        String content = IoUtils.readFileAsString("/data/misc/keychain/pins");

        return getCurrentHash(content);

    }



    private PrivateKey createKey() throws Exception {

        byte[] derKey = Base64.decode(TEST_KEY.getBytes(), Base64.DEFAULT);

        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(derKey);

        KeyFactory keyFactory = KeyFactory.getInstance("RSA");

        return (PrivateKey) keyFactory.generatePrivate(keySpec);

    }



    private X509Certificate createCertificate() throws Exception {

        byte[] derCert = Base64.decode(TEST_CERT.getBytes(), Base64.DEFAULT);

        InputStream istream = new ByteArrayInputStream(derCert);

        CertificateFactory cf = CertificateFactory.getInstance("X.509");

        return (X509Certificate) cf.generateCertificate(istream);

    }



    private String makeTemporaryContentFile(String content) throws Exception {

        FileOutputStream fw = mContext.openFileOutput("content.txt", mContext.MODE_WORLD_READABLE);

        fw.write(content.getBytes(), 0, content.length());

        fw.close();

        return mContext.getFilesDir() + "/content.txt";

    }



    private String createSignature(String content, String version, String requiredHash)

                                   throws Exception {

        Signature signer = Signature.getInstance("SHA512withRSA");

        signer.initSign(createKey());

        signer.update(content.trim().getBytes());

        signer.update(version.trim().getBytes());

        signer.update(requiredHash.getBytes());

        String sig = new String(Base64.encode(signer.sign(), Base64.DEFAULT));

        assertEquals(true,

                     verifySignature(content, version, requiredHash, sig, createCertificate()));

        return sig;

    }



    public boolean verifySignature(String content, String version, String requiredPrevious,

                                   String signature, X509Certificate cert) throws Exception {

        Signature signer = Signature.getInstance("SHA512withRSA");

        signer.initVerify(cert);

        signer.update(content.trim().getBytes());

        signer.update(version.trim().getBytes());

        signer.update(requiredPrevious.trim().getBytes());

        return signer.verify(Base64.decode(signature.getBytes(), Base64.DEFAULT));

    }



    private void sendIntent(String contentPath, String version, String required, String sig) {

        Intent i = new Intent();

        i.setAction("android.intent.action.UPDATE_PINS");

        i.putExtra(EXTRA_CONTENT_PATH, contentPath);

        i.putExtra(EXTRA_VERSION_NUMBER, version);

        i.putExtra(EXTRA_REQUIRED_HASH, required);

        i.putExtra(EXTRA_SIGNATURE, sig);

        mContext.sendBroadcast(i);

    }



    private String runTest(String cert, String content, String version, String required, String sig)

                           throws Exception {

        Log.e(TAG, "started test");

        overrideCert(cert);

        String contentPath = makeTemporaryContentFile(content);

        sendIntent(contentPath, version, required, sig);

        Thread.sleep(1000);

        return readPins();

    }



    private String runTestWithoutSig(String cert, String content, String version, String required)

                                     throws Exception {

        String sig = createSignature(content, version, required);

        return runTest(cert, content, version, required, sig);

    }



    public void testOverwritePinlist() throws Exception {

        Log.e(TAG, "started testOverwritePinList");

        assertEquals("abcde", runTestWithoutSig(TEST_CERT, "abcde", getNextVersion(), getHashOfCurrentContent()));

        Log.e(TAG, "started testOverwritePinList");

    }



   public void testBadSignatureFails() throws Exception {

        Log.e(TAG, "started testOverwritePinList");

        String text = "blahblah";

        runTestWithoutSig(TEST_CERT, text, getNextVersion(), getHashOfCurrentContent());

        assertEquals(text, runTest(TEST_CERT, "bcdef", getNextVersion(), getCurrentHash(text), ""));

        Log.e(TAG, "started testOverwritePinList");

    }



    public void testBadRequiredHashFails() throws Exception {

        runTestWithoutSig(TEST_CERT, "blahblahblah", getNextVersion(), getHashOfCurrentContent());

        assertEquals("blahblahblah", runTestWithoutSig(TEST_CERT, "cdefg", getNextVersion(), "0"));

        Log.e(TAG, "started testOverwritePinList");

    }



    public void testBadVersionFails() throws Exception {

        String text = "blahblahblahblah";

        String version = getNextVersion();

        runTestWithoutSig(TEST_CERT, text, version, getHashOfCurrentContent());

        assertEquals(text, runTestWithoutSig(TEST_CERT, "defgh", version, getCurrentHash(text)));

        Log.e(TAG, "started testOverwritePinList");

    }



    public void testOverrideRequiredHash() throws Exception {

        runTestWithoutSig(TEST_CERT, "blahblahblah", getNextVersion(), getHashOfCurrentContent());

        assertEquals("blahblahblah", runTestWithoutSig(TEST_CERT, "cdefg", "NONE", "0"));

        Log.e(TAG, "started testOverwritePinList");

    }



}