Merge "Verify the content length in the verity digest" into pi-dev (429a58d1) · Commits · e / os / android_frameworks_base

core/java/android/util/apk/ApkSignatureSchemeV2Verifier.java

+3 −1

Original line number	Diff line number	Diff line
		@@ -213,7 +213,9 @@ public class ApkSignatureSchemeV2Verifier {

		byte[] verityRootHash = null;
		if (contentDigests.containsKey(CONTENT_DIGEST_VERITY_CHUNKED_SHA256)) {
		verityRootHash = contentDigests.get(CONTENT_DIGEST_VERITY_CHUNKED_SHA256);
		byte[] verityDigest = contentDigests.get(CONTENT_DIGEST_VERITY_CHUNKED_SHA256);
		verityRootHash = ApkSigningBlockUtils.parseVerityDigestAndVerifySourceLength(
		verityDigest, apk.length(), signatureInfo);
		}

		return new VerifiedSigner(

core/java/android/util/apk/ApkSignatureSchemeV3Verifier.java

+4 −2

Original line number	Diff line number	Diff line
		@@ -165,7 +165,7 @@ public class ApkSignatureSchemeV3Verifier {
		private static VerifiedSigner verify(
		RandomAccessFile apk,
		SignatureInfo signatureInfo,
		boolean doVerifyIntegrity) throws SecurityException {
		boolean doVerifyIntegrity) throws SecurityException, IOException {
		int signerCount = 0;
		Map<Integer, byte[]> contentDigests = new ArrayMap<>();
		VerifiedSigner result = null;
		@@ -214,7 +214,9 @@ public class ApkSignatureSchemeV3Verifier {
		}

		if (contentDigests.containsKey(CONTENT_DIGEST_VERITY_CHUNKED_SHA256)) {
		result.verityRootHash = contentDigests.get(CONTENT_DIGEST_VERITY_CHUNKED_SHA256);
		byte[] verityDigest = contentDigests.get(CONTENT_DIGEST_VERITY_CHUNKED_SHA256);
		result.verityRootHash = ApkSigningBlockUtils.parseVerityDigestAndVerifySourceLength(
		verityDigest, apk.length(), signatureInfo);
		}

		return result;

core/java/android/util/apk/ApkSigningBlockUtils.java

+39 −4

Original line number	Diff line number	Diff line
		@@ -285,11 +285,46 @@ final class ApkSigningBlockUtils {
		return result;
		}

		/**
		* Return the verity digest only if the length of digest content looks correct.
		* When verity digest is generated, the last incomplete 4k chunk is padded with 0s before
		* hashing. This means two almost identical APKs with different number of 0 at the end will have
		* the same verity digest. To avoid this problem, the length of the source content (excluding
		* Signing Block) is appended to the verity digest, and the digest is returned only if the
		* length is consistent to the current APK.
		*/
		static byte[] parseVerityDigestAndVerifySourceLength(
		byte[] data, long fileSize, SignatureInfo signatureInfo) throws SecurityException {
		// FORMAT:
		// OFFSET DATA TYPE DESCRIPTION
		// * @+0 bytes uint8[32] Merkle tree root hash of SHA-256
		// * @+32 bytes int64 Length of source data
		int kRootHashSize = 32;
		int kSourceLengthSize = 8;

		if (data.length != kRootHashSize + kSourceLengthSize) {
		throw new SecurityException("Verity digest size is wrong: " + data.length);
		}
		ByteBuffer buffer = ByteBuffer.wrap(data).order(ByteOrder.LITTLE_ENDIAN);
		buffer.position(kRootHashSize);
		long expectedSourceLength = buffer.getLong();

		long signingBlockSize = signatureInfo.centralDirOffset
		- signatureInfo.apkSigningBlockOffset;
		if (expectedSourceLength != fileSize - signingBlockSize) {
		throw new SecurityException("APK content size did not verify");
		}

		return Arrays.copyOfRange(data, 0, kRootHashSize);
		}

		private static void verifyIntegrityForVerityBasedAlgorithm(
		byte[] expectedRootHash,
		byte[] expectedDigest,
		RandomAccessFile apk,
		SignatureInfo signatureInfo) throws SecurityException {
		try {
		byte[] expectedRootHash = parseVerityDigestAndVerifySourceLength(expectedDigest,
		apk.length(), signatureInfo);
		ApkVerityBuilder.ApkVerityResult verity = ApkVerityBuilder.generateApkVerity(apk,
		signatureInfo, new ByteBufferFactory() {
		@Override
		@@ -373,9 +408,9 @@ final class ApkSigningBlockUtils {
		static final int SIGNATURE_ECDSA_WITH_SHA256 = 0x0201;
		static final int SIGNATURE_ECDSA_WITH_SHA512 = 0x0202;
		static final int SIGNATURE_DSA_WITH_SHA256 = 0x0301;
		static final int SIGNATURE_VERITY_RSA_PKCS1_V1_5_WITH_SHA256 = 0x0411;
		static final int SIGNATURE_VERITY_ECDSA_WITH_SHA256 = 0x0413;
		static final int SIGNATURE_VERITY_DSA_WITH_SHA256 = 0x0415;
		static final int SIGNATURE_VERITY_RSA_PKCS1_V1_5_WITH_SHA256 = 0x0421;
		static final int SIGNATURE_VERITY_ECDSA_WITH_SHA256 = 0x0423;
		static final int SIGNATURE_VERITY_DSA_WITH_SHA256 = 0x0425;

		static final int CONTENT_DIGEST_CHUNKED_SHA256 = 1;
		static final int CONTENT_DIGEST_CHUNKED_SHA512 = 2;