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authorJason A. Donenfeld <Jason@zx2c4.com>2020-03-09 09:06:28 -0600
committerJason A. Donenfeld <Jason@zx2c4.com>2020-03-09 09:07:48 -0600
commit056cf472d98a135c9300b8e4ebe4cca109529cf2 (patch)
tree76c8550b3fd53af81d3490e8fb3ea2074f4e210e /tunnel
parentAsyncWorker: move back to original location (diff)
downloadwireguard-android-056cf472d98a135c9300b8e4ebe4cca109529cf2.tar.xz
wireguard-android-056cf472d98a135c9300b8e4ebe4cca109529cf2.zip
ModuleLoader: move to right project
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'tunnel')
-rw-r--r--tunnel/build.gradle1
-rw-r--r--tunnel/src/main/java/com/wireguard/android/util/ModuleLoader.java186
2 files changed, 187 insertions, 0 deletions
diff --git a/tunnel/build.gradle b/tunnel/build.gradle
index 9c7d43f6..10494823 100644
--- a/tunnel/build.gradle
+++ b/tunnel/build.gradle
@@ -28,4 +28,5 @@ dependencies {
implementation "androidx.collection:collection:$collectionVersion"
implementation "com.google.code.findbugs:jsr305:$jsr305Version"
implementation "com.jakewharton.threetenabp:threetenabp:$threetenabpVersion"
+ implementation "net.i2p.crypto:eddsa:$eddsaVersion"
}
diff --git a/tunnel/src/main/java/com/wireguard/android/util/ModuleLoader.java b/tunnel/src/main/java/com/wireguard/android/util/ModuleLoader.java
new file mode 100644
index 00000000..f09d9a87
--- /dev/null
+++ b/tunnel/src/main/java/com/wireguard/android/util/ModuleLoader.java
@@ -0,0 +1,186 @@
+/*
+ * Copyright © 2019-2020 WireGuard LLC. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.wireguard.android.util;
+
+import android.content.Context;
+import android.system.OsConstants;
+import android.util.Base64;
+
+import com.wireguard.android.util.RootShell.RootShellException;
+
+import net.i2p.crypto.eddsa.EdDSAEngine;
+import net.i2p.crypto.eddsa.EdDSAPublicKey;
+import net.i2p.crypto.eddsa.spec.EdDSANamedCurveTable;
+import net.i2p.crypto.eddsa.spec.EdDSAParameterSpec;
+import net.i2p.crypto.eddsa.spec.EdDSAPublicKeySpec;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.security.InvalidParameterException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.security.Signature;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import androidx.annotation.Nullable;
+
+public class ModuleLoader {
+ private static final String MODULE_PUBLIC_KEY_BASE64 = "RWRmHuT9PSqtwfsLtEx+QS06BJtLgFYteL9WCNjH7yuyu5Y1DieSN7If";
+ private static final String MODULE_LIST_URL = "https://download.wireguard.com/android-module/modules.txt.sig";
+ private static final String MODULE_URL = "https://download.wireguard.com/android-module/%s";
+ private static final String MODULE_NAME = "wireguard-%s.ko";
+
+ private final RootShell rootShell;
+ private final String userAgent;
+ private final File moduleDir;
+ private final File tmpDir;
+
+ public ModuleLoader(final Context context, final RootShell rootShell, final String userAgent) {
+ moduleDir = new File(context.getCacheDir(), "kmod");
+ tmpDir = new File(context.getCacheDir(), "tmp");
+ this.rootShell = rootShell;
+ this.userAgent = userAgent;
+ }
+
+ public boolean moduleMightExist() {
+ return moduleDir.exists() && moduleDir.isDirectory();
+ }
+
+ public void loadModule() throws IOException, RootShellException {
+ rootShell.run(null, String.format("insmod \"%s/wireguard-$(sha256sum /proc/version|cut -d ' ' -f 1).ko\"", moduleDir.getAbsolutePath()));
+ }
+
+ public static boolean isModuleLoaded() {
+ return new File("/sys/module/wireguard").exists();
+ }
+
+ private static final class Sha256Digest {
+ private byte[] bytes;
+ private Sha256Digest(final String hex) {
+ if (hex.length() != 64)
+ throw new InvalidParameterException("SHA256 hashes must be 32 bytes long");
+ bytes = new byte[32];
+ for (int i = 0; i < 32; ++i)
+ bytes[i] = (byte)Integer.parseInt(hex.substring(i * 2, i * 2 + 2), 16);
+ }
+ }
+
+ @Nullable
+ private Map<String, Sha256Digest> verifySignedHashes(final String signifyDigest) {
+ final byte[] publicKeyBytes = Base64.decode(MODULE_PUBLIC_KEY_BASE64, Base64.DEFAULT);
+
+ if (publicKeyBytes == null || publicKeyBytes.length != 32 + 10 || publicKeyBytes[0] != 'E' || publicKeyBytes[1] != 'd')
+ return null;
+
+ final String[] lines = signifyDigest.split("\n", 3);
+ if (lines.length != 3)
+ return null;
+ if (!lines[0].startsWith("untrusted comment: "))
+ return null;
+
+ final byte[] signatureBytes = Base64.decode(lines[1], Base64.DEFAULT);
+ if (signatureBytes == null || signatureBytes.length != 64 + 10)
+ return null;
+ for (int i = 0; i < 10; ++i) {
+ if (signatureBytes[i] != publicKeyBytes[i])
+ return null;
+ }
+
+ try {
+ EdDSAParameterSpec parameterSpec = EdDSANamedCurveTable.getByName(EdDSANamedCurveTable.ED_25519);
+ Signature signature = new EdDSAEngine(MessageDigest.getInstance(parameterSpec.getHashAlgorithm()));
+ byte[] rawPublicKeyBytes = new byte[32];
+ System.arraycopy(publicKeyBytes, 10, rawPublicKeyBytes, 0, 32);
+ signature.initVerify(new EdDSAPublicKey(new EdDSAPublicKeySpec(rawPublicKeyBytes, parameterSpec)));
+ signature.update(lines[2].getBytes(StandardCharsets.UTF_8));
+ if (!signature.verify(signatureBytes, 10, 64))
+ return null;
+ } catch (final Exception ignored) {
+ return null;
+ }
+
+ Map<String, Sha256Digest> hashes = new HashMap<>();
+ for (final String line : lines[2].split("\n")) {
+ final String[] components = line.split(" ", 2);
+ if (components.length != 2)
+ return null;
+ try {
+ hashes.put(components[1], new Sha256Digest(components[0]));
+ } catch (final Exception ignored) {
+ return null;
+ }
+ }
+ return hashes;
+ }
+
+ public Integer download() throws IOException, RootShellException, NoSuchAlgorithmException {
+ final List<String> output = new ArrayList<>();
+ rootShell.run(output, "sha256sum /proc/version|cut -d ' ' -f 1");
+ if (output.size() != 1 || output.get(0).length() != 64)
+ throw new InvalidParameterException("Invalid sha256 of /proc/version");
+ final String moduleName = String.format(MODULE_NAME, output.get(0));
+ HttpURLConnection connection = (HttpURLConnection)new URL(MODULE_LIST_URL).openConnection();
+ connection.setRequestProperty("User-Agent", userAgent);
+ connection.connect();
+ if (connection.getResponseCode() != HttpURLConnection.HTTP_OK)
+ throw new IOException("Hash list could not be found");
+ byte[] input = new byte[1024 * 1024 * 3 /* 3MiB */];
+ int len;
+ try (final InputStream inputStream = connection.getInputStream()) {
+ len = inputStream.read(input);
+ }
+ if (len <= 0)
+ throw new IOException("Hash list was empty");
+ final Map<String, Sha256Digest> modules = verifySignedHashes(new String(input, 0, len, StandardCharsets.UTF_8));
+ if (modules == null)
+ throw new InvalidParameterException("The signature did not verify or invalid hash list format");
+ if (!modules.containsKey(moduleName))
+ return OsConstants.ENOENT;
+ connection = (HttpURLConnection)new URL(String.format(MODULE_URL, moduleName)).openConnection();
+ connection.setRequestProperty("User-Agent", userAgent);
+ connection.connect();
+ if (connection.getResponseCode() != HttpURLConnection.HTTP_OK)
+ throw new IOException("Module file could not be found, despite being on hash list");
+
+ tmpDir.mkdirs();
+ moduleDir.mkdir();
+ File tempFile = null;
+ try {
+ tempFile = File.createTempFile("UNVERIFIED-", null, tmpDir);
+ MessageDigest digest = MessageDigest.getInstance("SHA-256");
+ try (final InputStream inputStream = connection.getInputStream();
+ final FileOutputStream outputStream = new FileOutputStream(tempFile)) {
+ int total = 0;
+ while ((len = inputStream.read(input)) > 0) {
+ total += len;
+ if (total > 1024 * 1024 * 15 /* 15 MiB */)
+ throw new IOException("File too big");
+ outputStream.write(input, 0, len);
+ digest.update(input, 0, len);
+ }
+ outputStream.getFD().sync();
+ }
+ if (!Arrays.equals(digest.digest(), modules.get(moduleName).bytes))
+ throw new IOException("Incorrect file hash");
+
+ if (!tempFile.renameTo(new File(moduleDir, moduleName)))
+ throw new IOException("Unable to rename to final destination");
+ } finally {
+ if (tempFile != null)
+ tempFile.delete();
+ }
+ return OsConstants.EXIT_SUCCESS;
+ }
+}