Merge "Augment SELinuxMMAC functionality." (f7422885) · Commits · e / os / android_frameworks_base

services/java/com/android/server/pm/SELinuxMMAC.java

+174 −74

Original line number	Diff line number	Diff line
		@@ -48,12 +48,11 @@ public final class SELinuxMMAC {
		private static final boolean DEBUG_POLICY_INSTALL = DEBUG_POLICY \|\| false;

		// Signature seinfo values read from policy.
		private static final HashMap<Signature, String> sSigSeinfo =
		new HashMap<Signature, String>();
		private static HashMap<Signature, Policy> sSigSeinfo =
		new HashMap<Signature, Policy>();

		// Package name seinfo values read from policy.
		private static final HashMap<String, String> sPackageSeinfo =
		new HashMap<String, String>();
		// Default seinfo read from policy.
		private static String sDefaultSeinfo = null;

		// Locations of potential install policy files.
		private static final File[] INSTALL_POLICY_FILE = {
		@@ -61,9 +60,45 @@ public final class SELinuxMMAC {
		new File(Environment.getRootDirectory(), "etc/security/mac_permissions.xml"),
		null};

		// Signature policy stanzas
		static class Policy {
		private String seinfo;
		private final HashMap<String, String> pkgMap;

		Policy() {
		seinfo = null;
		pkgMap = new HashMap<String, String>();
		}

		void putSeinfo(String seinfoValue) {
		seinfo = seinfoValue;
		}

		void putPkg(String pkg, String seinfoValue) {
		pkgMap.put(pkg, seinfoValue);
		}

		// Valid policy stanza means there exists a global
		// seinfo value or at least one package policy.
		boolean isValid() {
		return (seinfo != null) \|\| (!pkgMap.isEmpty());
		}

		String checkPolicy(String pkgName) {
		// Check for package name seinfo value first.
		String seinfoValue = pkgMap.get(pkgName);
		if (seinfoValue != null) {
		return seinfoValue;
		}

		// Return the global seinfo value.
		return seinfo;
		}
		}

		private static void flushInstallPolicy() {
		sSigSeinfo.clear();
		sPackageSeinfo.clear();
		sDefaultSeinfo = null;
		}

		/**
		@@ -87,6 +122,10 @@ public final class SELinuxMMAC {
		}

		private static boolean readInstallPolicy(File[] policyFiles) {
		// Temp structures to hold the rules while we parse the xml file.
		// We add all the rules together once we know there's no structural problems.
		HashMap<Signature, Policy> sigSeinfo = new HashMap<Signature, Policy>();
		String defaultSeinfo = null;

		FileReader policyFile = null;
		int i = 0;
		@@ -107,8 +146,6 @@ public final class SELinuxMMAC {

		Slog.d(TAG, "Using install policy file " + policyFiles[i].getPath());

		flushInstallPolicy();

		try {
		XmlPullParser parser = Xml.newPullParser();
		parser.setInput(policyFile);
		@@ -138,55 +175,82 @@ public final class SELinuxMMAC {
		XmlUtils.skipCurrentTag(parser);
		continue;
		}
		String seinfo = readSeinfoTag(parser);
		if (seinfo != null) {
		if (DEBUG_POLICY_INSTALL)
		Slog.i(TAG, "<signer> tag: (" + cert + ") assigned seinfo="
		+ seinfo);

		sSigSeinfo.put(signature, seinfo);
		Policy policy = readPolicyTags(parser);
		if (policy.isValid()) {
		sigSeinfo.put(signature, policy);
		}
		} else if ("default".equals(tagName)) {
		String seinfo = readSeinfoTag(parser);
		if (seinfo != null) {
		// Value is null if default tag is absent or seinfo tag is malformed.
		defaultSeinfo = readSeinfoTag(parser);
		if (DEBUG_POLICY_INSTALL)
		Slog.i(TAG, "<default> tag assigned seinfo=" + seinfo);
		Slog.i(TAG, "<default> tag assigned seinfo=" + defaultSeinfo);

		} else {
		XmlUtils.skipCurrentTag(parser);
		}
		}
		} catch (XmlPullParserException e) {
		// An error outside of a stanza means a structural problem
		// with the xml file. So ignore it.
		Slog.w(TAG, "Got exception parsing ", e);
		return false;
		} catch (IOException e) {
		Slog.w(TAG, "Got exception parsing ", e);
		return false;
		} finally {
		try {
		policyFile.close();
		} catch (IOException e) {
		//omit
		}
		}

		flushInstallPolicy();
		sSigSeinfo = sigSeinfo;
		sDefaultSeinfo = defaultSeinfo;

		return true;
		}

		private static Policy readPolicyTags(XmlPullParser parser) throws
		IOException, XmlPullParserException {

		int type;
		int outerDepth = parser.getDepth();
		Policy policy = new Policy();
		while ((type=parser.next()) != XmlPullParser.END_DOCUMENT
		&& (type != XmlPullParser.END_TAG
		\|\| parser.getDepth() > outerDepth)) {
		if (type == XmlPullParser.END_TAG
		\|\| type == XmlPullParser.TEXT) {
		continue;
		}

		// The 'null' signature is the default seinfo value
		sSigSeinfo.put(null, seinfo);
		String tagName = parser.getName();
		if ("seinfo".equals(tagName)) {
		String seinfo = parseSeinfo(parser);
		if (seinfo != null) {
		policy.putSeinfo(seinfo);
		}
		XmlUtils.skipCurrentTag(parser);
		} else if ("package".equals(tagName)) {
		String pkgName = parser.getAttributeValue(null, "name");
		if (pkgName == null) {
		Slog.w(TAG, "<package> without name at "
		String pkg = parser.getAttributeValue(null, "name");
		if (!validatePackageName(pkg)) {
		Slog.w(TAG, "<package> without valid name at "
		+ parser.getPositionDescription());
		XmlUtils.skipCurrentTag(parser);
		continue;
		}

		String seinfo = readSeinfoTag(parser);
		if (seinfo != null) {
		if (DEBUG_POLICY_INSTALL)
		Slog.i(TAG, "<package> tag: (" + pkgName +
		") assigned seinfo=" + seinfo);

		sPackageSeinfo.put(pkgName, seinfo);
		policy.putPkg(pkg, seinfo);
		}
		} else {
		XmlUtils.skipCurrentTag(parser);
		continue;
		}
		}
		} catch (XmlPullParserException e) {
		Slog.w(TAG, "Got execption parsing ", e);
		} catch (IOException e) {
		Slog.w(TAG, "Got execption parsing ", e);
		}
		try {
		policyFile.close();
		} catch (IOException e) {
		//omit
		}
		return true;
		return policy;
		}

		private static String readSeinfoTag(XmlPullParser parser) throws
		@@ -205,17 +269,55 @@ public final class SELinuxMMAC {

		String tagName = parser.getName();
		if ("seinfo".equals(tagName)) {
		seinfo = parseSeinfo(parser);
		}
		XmlUtils.skipCurrentTag(parser);
		}
		return seinfo;
		}

		private static String parseSeinfo(XmlPullParser parser) {

		String seinfoValue = parser.getAttributeValue(null, "value");
		if (validateValue(seinfoValue)) {
		seinfo = seinfoValue;
		} else {
		if (!validateValue(seinfoValue)) {
		Slog.w(TAG, "<seinfo> without valid value at "
		+ parser.getPositionDescription());
		seinfoValue = null;
		}
		return seinfoValue;
		}
		XmlUtils.skipCurrentTag(parser);

		/**
		* General validation routine for package names.
		* Returns a boolean indicating if the passed string
		* is a valid android package name.
		*/
		private static boolean validatePackageName(String name) {
		if (name == null)
		return false;

		final int N = name.length();
		boolean hasSep = false;
		boolean front = true;
		for (int i=0; i<N; i++) {
		final char c = name.charAt(i);
		if ((c >= 'a' && c <= 'z') \|\| (c >= 'A' && c <= 'Z')) {
		front = false;
		continue;
		}
		if (!front) {
		if ((c >= '0' && c <= '9') \|\| c == '_') {
		continue;
		}
		return seinfo;
		}
		if (c == '.') {
		hasSep = true;
		front = true;
		continue;
		}
		return false;
		}
		return hasSep;
		}

		/**
		@@ -245,10 +347,11 @@ public final class SELinuxMMAC {
		* The label is attached to the ApplicationInfo instance of the package.
		* @param PackageParser.Package object representing the package
		* to labeled.
		* @return String holding the value of the seinfo label that was assigned.
		* Value may be null which indicates no seinfo label was assigned.
		* @return boolean which determines whether a non null seinfo label
		* was assigned to the package. A null value simply meaning that
		* no policy matched.
		*/
		public static void assignSeinfoValue(PackageParser.Package pkg) {
		public static boolean assignSeinfoValue(PackageParser.Package pkg) {

		/*
		* Non system installed apps should be treated the same. This
		@@ -264,31 +367,28 @@ public final class SELinuxMMAC {
		if (s == null)
		continue;

		if (sSigSeinfo.containsKey(s)) {
		String seinfo = pkg.applicationInfo.seinfo = sSigSeinfo.get(s);
		Policy policy = sSigSeinfo.get(s);
		if (policy != null) {
		String seinfo = policy.checkPolicy(pkg.packageName);
		if (seinfo != null) {
		pkg.applicationInfo.seinfo = seinfo;
		if (DEBUG_POLICY_INSTALL)
		Slog.i(TAG, "package (" + pkg.packageName +
		") labeled with seinfo=" + seinfo);

		return;
		return true;
		}
		}

		// Check for seinfo labeled by package.
		if (sPackageSeinfo.containsKey(pkg.packageName)) {
		String seinfo = pkg.applicationInfo.seinfo = sPackageSeinfo.get(pkg.packageName);
		if (DEBUG_POLICY_INSTALL)
		Slog.i(TAG, "package (" + pkg.packageName +
		") labeled with seinfo=" + seinfo);
		return;
		}
		}

		// If we have a default seinfo value then great, otherwise
		// we set a null object and that is what we started with.
		String seinfo = pkg.applicationInfo.seinfo = sSigSeinfo.get(null);
		pkg.applicationInfo.seinfo = sDefaultSeinfo;
		if (DEBUG_POLICY_INSTALL)
		Slog.i(TAG, "package (" + pkg.packageName +
		") labeled with seinfo=" + (seinfo == null ? "null" : seinfo));
		Slog.i(TAG, "package (" + pkg.packageName + ") labeled with seinfo="
		+ (sDefaultSeinfo == null ? "null" : sDefaultSeinfo));

		return (sDefaultSeinfo != null);
		}
		}