Merge "Use all certs for computing package signing sha256" into oc-mr1-dev (ee580764) · Commits · e / os / android_frameworks_base

core/java/android/content/pm/PackageInfo.java

+11 −2

Original line number	Diff line number	Diff line
		@@ -188,7 +188,16 @@ public class PackageInfo implements Parcelable {

		/**
		* Array of all signatures read from the package file. This is only filled
		* in if the flag {@link PackageManager#GET_SIGNATURES} was set.
		* in if the flag {@link PackageManager#GET_SIGNATURES} was set. A package
		* must be singed with at least one certificate which is at position zero.
		* The package can be signed with additional certificates which appear as
		* subsequent entries.
		*
		* <strong>Note:</strong> Signature ordering is not guaranteed to be
		* stable which means that a package signed with certificates A and B is
		* equivalent to being signed with certificates B and A. This means that
		* in case multiple signatures are reported you cannot assume the one at
		* the first position to be the same across updates.
		*/
		public Signature[] signatures;

core/java/android/content/pm/PackageParser.java

+74 −12

Original line number	Diff line number	Diff line
		@@ -97,6 +97,7 @@ import com.android.internal.util.XmlUtils;

		import libcore.io.IoUtils;

		import libcore.util.EmptyArray;
		import org.xmlpull.v1.XmlPullParser;
		import org.xmlpull.v1.XmlPullParserException;

		@@ -2824,14 +2825,14 @@ public class PackageParser {
		com.android.internal.R.styleable.AndroidManifestUsesLibrary_name);
		final int version = sa.getInt(
		com.android.internal.R.styleable.AndroidManifestUsesStaticLibrary_version, -1);
		String certSha256 = sa.getNonResourceString(com.android.internal.R.styleable
		String certSha256Digest = sa.getNonResourceString(com.android.internal.R.styleable
		.AndroidManifestUsesStaticLibrary_certDigest);
		sa.recycle();

		// Since an APK providing a static shared lib can only provide the lib - fail if malformed
		if (lname == null \|\| version < 0 \|\| certSha256 == null) {
		if (lname == null \|\| version < 0 \|\| certSha256Digest == null) {
		outError[0] = "Bad uses-static-library declaration name: " + lname + " version: "
		+ version + " certDigest" + certSha256;
		+ version + " certDigest" + certSha256Digest;
		mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
		XmlUtils.skipCurrentTag(parser);
		return false;
		@@ -2848,16 +2849,73 @@ public class PackageParser {
		lname = lname.intern();
		// We allow ":" delimiters in the SHA declaration as this is the format
		// emitted by the certtool making it easy for developers to copy/paste.
		certSha256 = certSha256.replace(":", "").toLowerCase();
		certSha256Digest = certSha256Digest.replace(":", "").toLowerCase();

		// Fot apps targeting O-MR1 we require explicit enumeration of all certs.
		String[] additionalCertSha256Digests = EmptyArray.STRING;
		if (pkg.applicationInfo.targetSdkVersion > Build.VERSION_CODES.O) {
		additionalCertSha256Digests = parseAdditionalCertificates(res, parser, outError);
		if (additionalCertSha256Digests == null) {
		return false;
		}
		} else {
		XmlUtils.skipCurrentTag(parser);
		}

		final String[] certSha256Digests = new String[additionalCertSha256Digests.length + 1];
		certSha256Digests[0] = certSha256Digest;
		System.arraycopy(additionalCertSha256Digests, 0, certSha256Digests,
		1, additionalCertSha256Digests.length);

		pkg.usesStaticLibraries = ArrayUtils.add(pkg.usesStaticLibraries, lname);
		pkg.usesStaticLibrariesVersions = ArrayUtils.appendInt(
		pkg.usesStaticLibrariesVersions, version, true);
		pkg.usesStaticLibrariesCertDigests = ArrayUtils.appendElement(String.class,
		pkg.usesStaticLibrariesCertDigests, certSha256, true);
		pkg.usesStaticLibrariesCertDigests = ArrayUtils.appendElement(String[].class,
		pkg.usesStaticLibrariesCertDigests, certSha256Digests, true);

		return true;
		}

		private String[] parseAdditionalCertificates(Resources resources, XmlResourceParser parser,
		String[] outError) throws XmlPullParserException, IOException {
		String[] certSha256Digests = EmptyArray.STRING;

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

		final String nodeName = parser.getName();
		if (nodeName.equals("additional-certificate")) {
		final TypedArray sa = resources.obtainAttributes(parser, com.android.internal.
		R.styleable.AndroidManifestAdditionalCertificate);
		String certSha256Digest = sa.getNonResourceString(com.android.internal.
		R.styleable.AndroidManifestAdditionalCertificate_certDigest);
		sa.recycle();

		if (TextUtils.isEmpty(certSha256Digest)) {
		outError[0] = "Bad additional-certificate declaration with empty"
		+ " certDigest:" + certSha256Digest;
		mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
		XmlUtils.skipCurrentTag(parser);
		sa.recycle();
		return null;
		}

		return true;
		// We allow ":" delimiters in the SHA declaration as this is the format
		// emitted by the certtool making it easy for developers to copy/paste.
		certSha256Digest = certSha256Digest.replace(":", "").toLowerCase();
		certSha256Digests = ArrayUtils.appendElement(String.class,
		certSha256Digests, certSha256Digest);
		} else {
		XmlUtils.skipCurrentTag(parser);
		}
		}

		return certSha256Digests;
		}

		private boolean parseUsesPermission(Package pkg, Resources res, XmlResourceParser parser)
		@@ -5820,7 +5878,7 @@ public class PackageParser {
		public ArrayList<String> usesLibraries = null;
		public ArrayList<String> usesStaticLibraries = null;
		public int[] usesStaticLibrariesVersions = null;
		public String[] usesStaticLibrariesCertDigests = null;
		public String[][] usesStaticLibrariesCertDigests = null;
		public ArrayList<String> usesOptionalLibraries = null;
		public String[] usesLibraryFiles = null;

		@@ -6318,8 +6376,10 @@ public class PackageParser {
		internStringArrayList(usesStaticLibraries);
		usesStaticLibrariesVersions = new int[libCount];
		dest.readIntArray(usesStaticLibrariesVersions);
		usesStaticLibrariesCertDigests = new String[libCount];
		dest.readStringArray(usesStaticLibrariesCertDigests);
		usesStaticLibrariesCertDigests = new String[libCount][];
		for (int i = 0; i < libCount; i++) {
		usesStaticLibrariesCertDigests[i] = dest.createStringArray();
		}
		}

		preferredActivityFilters = new ArrayList<>();
		@@ -6465,7 +6525,9 @@ public class PackageParser {
		dest.writeInt(usesStaticLibraries.size());
		dest.writeStringList(usesStaticLibraries);
		dest.writeIntArray(usesStaticLibrariesVersions);
		dest.writeStringArray(usesStaticLibrariesCertDigests);
		for (String[] usesStaticLibrariesCertDigest : usesStaticLibrariesCertDigests) {
		dest.writeStringArray(usesStaticLibrariesCertDigest);
		}
		}

		dest.writeParcelableList(preferredActivityFilters, flags);

core/java/android/util/PackageUtils.java

+58 −22

Original line number	Diff line number	Diff line
		@@ -18,12 +18,13 @@ package android.util;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.content.pm.PackageInfo;
		import android.content.pm.PackageManager;
		import android.content.pm.Signature;

		import java.io.ByteArrayOutputStream;
		import java.io.IOException;
		import java.security.MessageDigest;
		import java.security.NoSuchAlgorithmException;
		import java.util.Arrays;

		/**
		* Helper functions applicable to packages.
		@@ -36,32 +37,67 @@ public final class PackageUtils {
		}

		/**
		* Computes the SHA256 digest of the signing cert for a package.
		* @param packageManager The package manager.
		* @param packageName The package for which to generate the digest.
		* @param userId The user for which to generate the digest.
		* @return The digest or null if the package does not exist for this user.
		* Computes the SHA256 digests of a list of signatures. Items in the
		* resulting array of hashes correspond to the signatures in the
		* input array.
		* @param signatures The signatures.
		* @return The digest array.
		*/
		public static @Nullable String computePackageCertSha256Digest(
		@NonNull PackageManager packageManager,
		@NonNull String packageName, int userId) {
		final PackageInfo packageInfo;
		try {
		packageInfo = packageManager.getPackageInfoAsUser(packageName,
		PackageManager.GET_SIGNATURES, userId);
		} catch (PackageManager.NameNotFoundException e) {
		return null;
		public static @NonNull String[] computeSignaturesSha256Digests(
		@NonNull Signature[] signatures) {
		final int signatureCount = signatures.length;
		final String[] digests = new String[signatureCount];
		for (int i = 0; i < signatureCount; i++) {
		digests[i] = computeSha256Digest(signatures[i].toByteArray());
		}
		return computeCertSha256Digest(packageInfo.signatures[0]);
		return digests;
		}
		/**
		* Computes a SHA256 digest of the signatures' SHA256 digests. First,
		* individual hashes for each signature is derived in a hexademical
		* form, then these strings are sorted based the natural ordering, and
		* finally a hash is derived from these strings' bytes.
		* @param signatures The signatures.
		* @return The digest.
		*/
		public static @NonNull String computeSignaturesSha256Digest(
		@NonNull Signature[] signatures) {
		// Shortcut for optimization - most apps singed by a single cert
		if (signatures.length == 1) {
		return computeSha256Digest(signatures[0].toByteArray());
		}

		// Make sure these are sorted to handle reversed certificates
		final String[] sha256Digests = computeSignaturesSha256Digests(signatures);
		return computeSignaturesSha256Digest(sha256Digests);
		}

		/**
		* Computes the SHA256 digest of a cert.
		* @param signature The signature.
		* @return The digest or null if an error occurs.
		* Computes a SHA256 digest in of the signatures SHA256 digests. First,
		* the strings are sorted based the natural ordering, and then a hash is
		* derived from these strings' bytes.
		* @param sha256Digests Signature SHA256 hashes in hexademical form.
		* @return The digest.
		*/
		public static @Nullable String computeCertSha256Digest(@NonNull Signature signature) {
		return computeSha256Digest(signature.toByteArray());
		public static @NonNull String computeSignaturesSha256Digest(
		@NonNull String[] sha256Digests) {
		// Shortcut for optimization - most apps singed by a single cert
		if (sha256Digests.length == 1) {
		return sha256Digests[0];
		}

		// Make sure these are sorted to handle reversed certificates
		Arrays.sort(sha256Digests);

		final ByteArrayOutputStream bytes = new ByteArrayOutputStream();
		for (String sha256Digest : sha256Digests) {
		try {
		bytes.write(sha256Digest.getBytes());
		} catch (IOException e) {
		/* ignore - can't happen */
		}
		}
		return computeSha256Digest(bytes.toByteArray());
		}

		/**

core/res/res/values/attrs_manifest.xml

+16 −0

Original line number	Diff line number	Diff line
		@@ -1779,6 +1779,11 @@
		the library at build time while it offers apps to share code defined in such
		libraries. Hence, static libraries are strictly required.

		<p>On devices running O MR1 or higher, if the library is singed with multiple
		signing certificates you must to specify the SHA-256 hashes of the additional
		certificates via adding
		{@link #AndroidManifestAdditionalCertificate additional-certificate} tags.

		<p>This appears as a child tag of the
		{@link #AndroidManifestApplication application} tag. -->
		<declare-styleable name="AndroidManifestUsesStaticLibrary" parent="AndroidManifestApplication">
		@@ -1790,6 +1795,17 @@
		<attr name="certDigest" format="string" />
		</declare-styleable>

		<!-- The <code>additional-certificate</code> specifies the SHA-256 digest of a static
		shared library's additional signing certificate. You need to use this tag if the
		library is singed with more than one certificate.

		<p>This appears as a child tag of the
		{@link #AndroidManifestUsesStaticLibrary uses-static-library} tag. -->
		<declare-styleable name="AndroidManifestAdditionalCertificate" parent="AndroidManifestUsesStaticLibrary">
		<!-- The SHA-256 digest of the library signing certificate. -->
		<attr name="certDigest" />
		</declare-styleable>

		<!-- The <code>supports-screens</code> specifies the screen dimensions an
		application supports. By default a modern application supports all
		screen sizes and must explicitly disable certain screen sizes here;

services/core/java/com/android/server/accounts/AccountManagerBackupHelper.java

+25 −5

Original line number	Diff line number	Diff line
		@@ -23,6 +23,7 @@ import android.annotation.IntRange;
		import android.annotation.NonNull;
		import android.content.pm.PackageInfo;
		import android.content.pm.PackageManager;
		import android.content.pm.Signature;
		import android.database.Cursor;
		import android.database.sqlite.SQLiteDatabase;
		import android.os.UserHandle;
		@@ -30,6 +31,7 @@ import android.text.TextUtils;
		import android.util.Log;
		import android.util.PackageUtils;
		import android.util.Pair;
		import android.util.Slog;
		import android.util.Xml;
		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.content.PackageMonitor;
		@@ -126,9 +128,18 @@ public final class AccountManagerBackupHelper {
		} catch (PackageManager.NameNotFoundException e) {
		return false;
		}
		String currentCertDigest = PackageUtils.computeCertSha256Digest(
		packageInfo.signatures[0]);
		if (!certDigest.equals(currentCertDigest)) {

		// Before we used only the first signature to compute the SHA 256 but some
		// apps could be singed by multiple certs and the cert order is undefined.
		// We prefer the modern computation procedure where all certs are taken
		// into account but also allow the value from the old computation to allow
		// restoring backed up grants on an older platform version.
		final String[] signaturesSha256Digests = PackageUtils.computeSignaturesSha256Digests(
		packageInfo.signatures);
		final String signaturesSha256Digest = PackageUtils.computeSignaturesSha256Digest(
		signaturesSha256Digests);
		if (!certDigest.equals(signaturesSha256Digest) && (packageInfo.signatures.length <= 1
		\|\| !certDigest.equals(signaturesSha256Digests[0]))) {
		return false;
		}
		final int uid = packageInfo.applicationInfo.uid;
		@@ -169,8 +180,17 @@ public final class AccountManagerBackupHelper {
		}

		for (String packageName : packageNames) {
		String digest = PackageUtils.computePackageCertSha256Digest(
		packageManager, packageName, userId);
		final PackageInfo packageInfo;
		try {
		packageInfo = packageManager.getPackageInfoAsUser(packageName,
		PackageManager.GET_SIGNATURES, userId);
		} catch (PackageManager.NameNotFoundException e) {
		Slog.i(TAG, "Skipping backup of account access grant for"
		+ " non-existing package: " + packageName);
		continue;
		}
		final String digest = PackageUtils.computeSignaturesSha256Digest(
		packageInfo.signatures);
		if (digest != null) {
		serializer.startTag(null, TAG_PERMISSION);
		serializer.attribute(null, ATTR_ACCOUNT_SHA_256,