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Commit 29045203 authored by Alex Klyubin's avatar Alex Klyubin
Browse files

Use correct cert chain from PKCS#7 SignedData block. 

This fixes a bug where APK JAR signature verifier returned the wrong
certificate chain. Rather than returning the cert chain of the
verified SignerInfo, it was returning the bag of certs of the PKCS#7
SignedData block.

This issue was introduced in Android N and thus does not affect
earlier Android platform versions.

Bug: 29055836
Change-Id: I684c0f8e9ff47b922030645e07b6a114c0eb0963
parent 1c39a112

core/java/android/util/jar/StrictJarVerifier.java

+23 −10
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ import java.util.ArrayList; 
import java.util.HashMap;

import java.util.Hashtable;

import java.util.Iterator;

import java.util.List;

import java.util.Locale;

import java.util.Map;

import java.util.Set;
@@ -41,6 +42,7 @@ import android.util.apk.ApkSignatureSchemeV2Verifier; 
import libcore.io.Base64;

import sun.security.jca.Providers;

import sun.security.pkcs.PKCS7;

import sun.security.pkcs.SignerInfo;



/**

 * Non-public class used by {@link JarFile} and {@link JarInputStream} to manage
@@ -308,18 +310,29 @@ class StrictJarVerifier { 


            obj = Providers.startJarVerification();

            PKCS7 block = new PKCS7(blockBytes);

            if (block.verify(sfBytes) == null) {

                throw new GeneralSecurityException("Failed to verify signature");

            }

            X509Certificate[] blockCerts = block.getCertificates();

            Certificate[] signerCertChain = null;

            if (blockCerts != null) {

                signerCertChain = new Certificate[blockCerts.length];

                for (int i = 0; i < blockCerts.length; ++i) {

                    signerCertChain[i] = blockCerts[i];

                }

            }

            return signerCertChain;

            SignerInfo[] verifiedSignerInfos = block.verify(sfBytes);

            if ((verifiedSignerInfos == null) || (verifiedSignerInfos.length == 0)) {

                throw new GeneralSecurityException(

                        "Failed to verify signature: no verified SignerInfos");

            }

            // Ignore any SignerInfo other than the first one, to be compatible with older Android

            // platforms which have been doing this for years. See

            // libcore/luni/src/main/java/org/apache/harmony/security/utils/JarUtils.java

            // verifySignature method of older platforms.

            SignerInfo verifiedSignerInfo = verifiedSignerInfos[0];

            List<X509Certificate> verifiedSignerCertChain =

                    verifiedSignerInfo.getCertificateChain(block);

            if (verifiedSignerCertChain == null) {

                // Should never happen

                throw new GeneralSecurityException(

                    "Failed to find verified SignerInfo certificate chain");

            } else if (verifiedSignerCertChain.isEmpty()) {

                // Should never happen

                throw new GeneralSecurityException(

                    "Verified SignerInfo certificate chain is emtpy");

            }

            return verifiedSignerCertChain.toArray(

                    new X509Certificate[verifiedSignerCertChain.size()]);

        } catch (IOException e) {

            throw new GeneralSecurityException("IO exception verifying jar cert", e);

        } finally {