Merge "Automatically assign default seinfo labels using the string "default"." (9d586927) · Commits · e / os / android_frameworks_base

core/java/android/content/pm/ApplicationInfo.java

+5 −3

Original line number	Diff line number	Diff line
		@@ -492,12 +492,14 @@ public class ApplicationInfo extends PackageItemInfo implements Parcelable {

		/**
		* String retrieved from the seinfo tag found in selinux policy. This value
		* is useful in setting an SELinux security context on the process as well
		* as its data directory.
		* can be overridden with a value set through the mac_permissions.xml policy
		* construct. This value is useful in setting an SELinux security context on
		* the process as well as its data directory. The String default is being used
		* here to represent a catchall label when no policy matches.
		*
		* {@hide}
		*/
		public String seinfo;
		public String seinfo = "default";

		/**
		* Paths to all shared libraries this application is linked against. This

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

+48 −184

Original line number	Diff line number	Diff line
		@@ -139,9 +139,6 @@ public final class SELinuxMMAC {
		case "signer":
		policies.add(readSignerOrThrow(parser));
		break;
		case "default":
		policies.add(readDefaultOrThrow(parser));
		break;
		default:
		skip(parser);
		}
		@@ -235,45 +232,6 @@ public final class SELinuxMMAC {
		return pb.build();
		}

		/**
		* Loop over a default element looking for seinfo child tags. A {@link Policy}
		* instance will be created and returned in the process. All other tags encountered
		* will be skipped.
		*
		* @param parser an XmlPullParser object representing a default element.
		* @return the constructed {@link Policy} instance
		* @throws IOException
		* @throws XmlPullParserException
		* @throws IllegalArgumentException if any of the validation checks fail while
		* parsing tag values.
		* @throws IllegalStateException if any of the invariants fail when constructing
		* the {@link Policy} instance.
		*/
		private static Policy readDefaultOrThrow(XmlPullParser parser) throws IOException,
		XmlPullParserException {

		parser.require(XmlPullParser.START_TAG, null, "default");
		Policy.PolicyBuilder pb = new Policy.PolicyBuilder();
		pb.setAsDefaultPolicy();

		while (parser.next() != XmlPullParser.END_TAG) {
		if (parser.getEventType() != XmlPullParser.START_TAG) {
		continue;
		}

		String tagName = parser.getName();
		if ("seinfo".equals(tagName)) {
		String seinfo = parser.getAttributeValue(null, "value");
		pb.setGlobalSeinfoOrThrow(seinfo);
		readSeinfo(parser);
		} else {
		skip(parser);
		}
		}

		return pb.build();
		}

		/**
		* Loop over a package element looking for seinfo child tags. If found return the
		* value attribute of the seinfo tag, otherwise return null. All other tags encountered
		@@ -340,35 +298,28 @@ public final class SELinuxMMAC {

		/**
		* Applies a security label to a package based on an seinfo tag taken from a matched
		* policy. All signature based policy stanzas are consulted first and, if no match
		* is found, the default policy stanza is then consulted. The security label is
		* attached to the ApplicationInfo instance of the package in the event that a matching
		* policy was found.
		* policy. All signature based policy stanzas are consulted and, if no match is
		* found, the default seinfo label of 'default' (set in ApplicationInfo object) is
		* used. The security label is attached to the ApplicationInfo instance of the package
		* in the event that a matching policy was found.
		*
		* @param pkg object representing the package to be labeled.
		* @return boolean which determines whether a non null seinfo label was assigned
		* to the package. A null value simply represents that no policy matched.
		*/
		public static boolean assignSeinfoValue(PackageParser.Package pkg) {
		public static void assignSeinfoValue(PackageParser.Package pkg) {
		synchronized (sPolicies) {
		for (Policy policy : sPolicies) {
		String seinfo = policy.getMatchedSeinfo(pkg);
		if (seinfo != null) {
		pkg.applicationInfo.seinfo = seinfo;
		if (DEBUG_POLICY_INSTALL) {
		Slog.i(TAG, "package (" + pkg.packageName + ") labeled with " +
		"seinfo=" + seinfo);
		}
		return true;
		break;
		}
		}
		}

		if (DEBUG_POLICY_INSTALL) {
		Slog.i(TAG, "package (" + pkg.packageName + ") doesn't match any policy; " +
		"seinfo will remain null");
		Slog.i(TAG, "package (" + pkg.packageName + ") labeled with " +
		"seinfo=" + pkg.applicationInfo.seinfo);
		}
		return false;
		}

		/**
		@@ -509,30 +460,16 @@ public final class SELinuxMMAC {
		* .build();
		* }
		* </pre>
		* <p>
		* The following is an example of how to use {@link Policy.PolicyBuilder} to create a
		* default based Policy instance.
		* </p>
		* <pre>
		* {@code
		* Policy policy = new Policy.PolicyBuilder()
		* .setAsDefaultPolicy()
		* .setGlobalSeinfoOrThrow("default")
		* .build();
		* }
		* </pre>
		*/
		final class Policy {

		private final String mSeinfo;
		private final boolean mDefaultStanza;
		private final Set<Signature> mCerts;
		private final Map<String, String> mPkgMap;

		// Use the PolicyBuilder pattern to instantiate
		private Policy(PolicyBuilder builder) {
		mSeinfo = builder.mSeinfo;
		mDefaultStanza = builder.mDefaultStanza;
		mCerts = Collections.unmodifiableSet(builder.mCerts);
		mPkgMap = Collections.unmodifiableMap(builder.mPkgMap);
		}
		@@ -547,15 +484,6 @@ final class Policy {
		return mCerts;
		}

		/**
		* Return whether this policy object represents a default stanza.
		*
		* @return A boolean indicating if this object represents a default policy stanza.
		*/
		public boolean isDefaultStanza() {
		return mDefaultStanza;
		}

		/**
		* Return whether this policy object contains package name mapping refinements.
		*
		@@ -587,10 +515,6 @@ final class Policy {
		@Override
		public String toString() {
		StringBuilder sb = new StringBuilder();
		if (mDefaultStanza) {
		sb.append("defaultStanza=true ");
		}

		for (Signature cert : mCerts) {
		sb.append("cert=" + cert.toCharsString().substring(0, 11) + "... ");
		}
		@@ -612,11 +536,6 @@ final class Policy {
		* is determined using the following steps:
		* </p>
		* <ul>
		* <li> If this Policy instance is defined as a default stanza:
		* <ul><li>Return the global seinfo value</li></ul>
		* </li>
		* <li> If this Policy instance is defined as a signer stanza:
		* <ul>
		* <li> All certs used to sign the apk and all certs stored with this policy
		* instance are tested for set equality. If this fails then null is returned.
		* </li>
		@@ -628,8 +547,6 @@ final class Policy {
		* the global seinfo value. The returned value can be null in this case.
		* </li>
		* </ul>
		* </li>
		* </ul>
		* <p>
		* In all cases, a return value of null should be interpreted as the apk failing
		* to match this Policy instance; i.e. failing this policy stanza.
		@@ -639,7 +556,6 @@ final class Policy {
		* A value of null can also be returned if no match occured.
		*/
		public String getMatchedSeinfo(PackageParser.Package pkg) {
		if (!mDefaultStanza) {
		// Check for exact signature matches across all certs.
		Signature[] certs = mCerts.toArray(new Signature[0]);
		if (!Signature.areExactMatch(certs, pkg.mSignatures)) {
		@@ -652,24 +568,22 @@ final class Policy {
		if (seinfoValue != null) {
		return seinfoValue;
		}
		}

		// Return the global seinfo value (even if it's null).
		// Return the global seinfo value.
		return mSeinfo;
		}

		/**
		* A nested builder class to create {@link Policy} instances. A {@link Policy}
		* class instance represents one valid policy stanza found in a mac_permissions.xml
		* file. A valid policy stanza is defined to be either a signer or default stanza
		* which obeys the rules outlined in external/sepolicy/mac_permissions.xml. The
		* {@link #build} method ensures a set of invariants are upheld enforcing the correct
		* stanza structure before returning a valid Policy object.
		* file. A valid policy stanza is defined to be a signer stanza which obeys the rules
		* outlined in external/sepolicy/mac_permissions.xml. The {@link #build} method
		* ensures a set of invariants are upheld enforcing the correct stanza structure
		* before returning a valid Policy object.
		*/
		public static final class PolicyBuilder {

		private String mSeinfo;
		private boolean mDefaultStanza;
		private final Set<Signature> mCerts;
		private final Map<String, String> mPkgMap;

		@@ -678,19 +592,6 @@ final class Policy {
		mPkgMap = new HashMap<String, String>(2);
		}

		/**
		* Sets this stanza as a default stanza. All policy stanzas are assumed to
		* be signer stanzas unless this method is explicitly called. Default stanzas
		* are treated differently with respect to allowable child tags, ordering and
		* when and how policy decisions are enforced.
		*
		* @return The reference to this PolicyBuilder.
		*/
		public PolicyBuilder setAsDefaultPolicy() {
		mDefaultStanza = true;
		return this;
		}

		/**
		* Adds a signature to the set of certs used for validation checks. The purpose
		* being that all contained certs will need to be matched against all certs
		@@ -713,11 +614,8 @@ final class Policy {

		/**
		* Set the global seinfo tag for this policy stanza. The global seinfo tag
		* represents the seinfo element that is used in one of two ways depending on
		* its context. When attached to a signer tag the global seinfo represents an
		* assignment when there isn't a further inner package refinement in policy.
		* When used with a default tag, it represents the only allowable assignment
		* value.
		* when attached to a signer tag represents the assignment when there isn't a
		* further inner package refinement in policy.
		*
		* @param seinfo the seinfo value given as a String.
		* @return The reference to this PolicyBuilder.
		@@ -743,9 +641,7 @@ final class Policy {
		/**
		* Create a package name to seinfo value mapping. Each mapping represents
		* the seinfo value that will be assigned to the described package name.
		* These localized mappings allow the global seinfo to be overriden. This
		* mapping provides no value when used in conjunction with a default stanza;
		* enforced through the {@link #build} method.
		* These localized mappings allow the global seinfo to be overriden.
		*
		* @param pkgName the android package name given to the app
		* @param seinfo the seinfo value that will be assigned to the passed pkgName
		@@ -803,42 +699,17 @@ final class Policy {
		* Those invariants are:
		* </p>
		* <ul>
		* <li> If a default stanza
		* <ul>
		* <li> an attached global seinfo tag must be present </li>
		* <li> no signatures and no package names can be present </li>
		* </ul>
		* </li>
		* <li> If a signer stanza
		* <ul>
		* <li> at least one cert must be found </li>
		* <li> either a global seinfo value is present OR at least one
		* inner package mapping must be present BUT not both. </li>
		* </ul>
		* </li>
		* </ul>
		*
		* @return an instance of {@link Policy} with the options set from this builder
		* @throws IllegalStateException if an invariant is violated.
		*/
		public Policy build() {
		Policy p = new Policy(this);

		if (p.mDefaultStanza) {
		if (p.mSeinfo == null) {
		String err = "Missing global seinfo tag with default stanza.";
		throw new IllegalStateException(err);
		}
		if (p.mCerts.size() != 0) {
		String err = "Certs not allowed with default stanza.";
		throw new IllegalStateException(err);
		}
		if (!p.mPkgMap.isEmpty()) {
		String err = "Inner package mappings not allowed with default stanza.";
		throw new IllegalStateException(err);
		}
		} else {
		if (p.mCerts.size() == 0) {
		if (p.mCerts.isEmpty()) {
		String err = "Missing certs with signer tag. Expecting at least one.";
		throw new IllegalStateException(err);
		}
		@@ -847,7 +718,6 @@ final class Policy {
		"a signer stanza.";
		throw new IllegalStateException(err);
		}
		}

		return p;
		}
		@@ -861,7 +731,6 @@ final class Policy {
		* <ul>
		* <li> signer stanzas with inner package mappings </li>
		* <li> signer stanzas with global seinfo tags </li>
		* <li> default stanza </li>
		* </ul>
		* This comparison also checks for duplicate entries on the input selectors. Any
		* found duplicates will be flagged and can be checked with {@link #foundDuplicate}.
		@@ -878,11 +747,6 @@ final class PolicyComparator implements Comparator<Policy> {
		@Override
		public int compare(Policy p1, Policy p2) {

		// Give precedence to signature stanzas over default stanzas
		if (p1.isDefaultStanza() != p2.isDefaultStanza()) {
		return p1.isDefaultStanza() ? 1 : -1;
		}

		// Give precedence to stanzas with inner package mappings
		if (p1.hasInnerPackages() != p2.hasInnerPackages()) {
		return p1.hasInnerPackages() ? -1 : 1;
		@@ -890,7 +754,7 @@ final class PolicyComparator implements Comparator<Policy> {

		// Check for duplicate entries
		if (p1.getSignatures().equals(p2.getSignatures())) {
		// Checks if default stanza or a signer w/o inner package names
		// Checks if signer w/o inner package names
		if (p1.hasGlobalSeinfo()) {
		duplicateFound = true;
		Slog.e(SELinuxMMAC.TAG, "Duplicate policy entry: " + p1.toString());