Add API to check certificate chain signatures

Add hidden API to check certificate chain signatures when needed. The
getCertificates implementation returns a list of all the certificates and
chains and would expect any caller interested in verifying actual chains
to call getCodeSigners instead.

We add this hidden constructor as a stop-gap until we can switch callers
over to getCodeSigners.

Bug: 13678484
Change-Id: I01cddef287767422454de4c5fd266c812a04d570

3 files changed, 63 insertions, 9 deletions

diff --git a/luni/src/main/java/java/util/jar/JarFile.java b/luni/src/main/java/java/util/jar/JarFile.java
index e129e82..494f5d2 100644
--- a/luni/src/main/java/java/util/jar/JarFile.java
+++ b/luni/src/main/java/java/util/jar/JarFile.java
@@ -184,9 +184,19 @@ public class JarFile extends ZipFile {
      *             If the file cannot be read.
      */
     public JarFile(File file, boolean verify, int mode) throws IOException {
+        this(file, verify, mode, false);
+    }
+
+    /**
+     * See previous constructor for other parameter definitions.
+     * @param chainCheck
+     *            whether or not to check certificate chain signatures
+     * @hide
+     */
+    public JarFile(File file, boolean verify, int mode, boolean chainCheck) throws IOException {
         super(file, mode);
         if (verify) {
-            verifier = new JarVerifier(file.getPath());
+            verifier = new JarVerifier(file.getPath(), chainCheck);
         }
         readMetaEntries();
     }
@@ -216,9 +226,19 @@ public class JarFile extends ZipFile {
      *             If file cannot be opened or read.
      */
     public JarFile(String filename, boolean verify) throws IOException {
+        this(filename, verify, false);
+    }
+
+    /**
+     * See previous constructor for other parameter definitions.
+     * @param chainCheck
+     *            whether or not to check certificate chain signatures
+     * @hide
+     */
+    public JarFile(String filename, boolean verify, boolean chainCheck) throws IOException {
         super(filename);
         if (verify) {
-            verifier = new JarVerifier(filename);
+            verifier = new JarVerifier(filename, chainCheck);
         }
         readMetaEntries();
     }
diff --git a/luni/src/main/java/java/util/jar/JarVerifier.java b/luni/src/main/java/java/util/jar/JarVerifier.java
index ec0e088..640f13c 100644
--- a/luni/src/main/java/java/util/jar/JarVerifier.java
+++ b/luni/src/main/java/java/util/jar/JarVerifier.java
@@ -68,6 +68,9 @@ class JarVerifier {
 
     int mainAttributesEnd;
 
+    /** Whether or not to check certificate chain signatures. */
+    private final boolean chainCheck;
+
     /**
      * Stores and a hash and a message digest and verifies that massage digest
      * matches the hash.
@@ -137,13 +140,23 @@ class JarVerifier {
     }
 
     /**
+     * Convenience constructor for backward compatibility.
+     */
+    JarVerifier(String name) {
+        this(name, false);
+    }
+
+    /**
      * Constructs and returns a new instance of {@code JarVerifier}.
      *
      * @param name
      *            the name of the JAR file being verified.
+     * @param chainCheck
+     *            whether to check the certificate chain signatures
      */
-    JarVerifier(String name) {
+    JarVerifier(String name, boolean chainCheck) {
         jarName = name;
+        this.chainCheck = chainCheck;
     }
 
     /**
@@ -288,7 +301,8 @@ class JarVerifier {
         try {
             Certificate[] signerCertChain = JarUtils.verifySignature(
                     new ByteArrayInputStream(sfBytes),
-                    new ByteArrayInputStream(sBlockBytes));
+                    new ByteArrayInputStream(sBlockBytes),
+                    chainCheck);
             /*
              * Recursive call in loading security provider related class which
              * is in a signed JAR.
diff --git a/luni/src/main/java/org/apache/harmony/security/utils/JarUtils.java b/luni/src/main/java/org/apache/harmony/security/utils/JarUtils.java
index f6efb8a..de3cdea 100644
--- a/luni/src/main/java/org/apache/harmony/security/utils/JarUtils.java
+++ b/luni/src/main/java/org/apache/harmony/security/utils/JarUtils.java
@@ -52,18 +52,27 @@ public class JarUtils {
         new int[] {1, 2, 840, 113549, 1, 9, 4};
 
     /**
+     * @see #verifySignature(InputStream, InputStream, boolean)
+     */
+    public static Certificate[] verifySignature(InputStream signature, InputStream signatureBlock)
+            throws IOException, GeneralSecurityException {
+        return verifySignature(signature, signatureBlock, false);
+    }
+
+    /**
      * This method handle all the work with  PKCS7, ASN1 encoding, signature verifying,
      * and certification path building.
      * See also PKCS #7: Cryptographic Message Syntax Standard:
      * http://www.ietf.org/rfc/rfc2315.txt
      * @param signature - the input stream of signature file to be verified
      * @param signatureBlock - the input stream of corresponding signature block file
+     * @param chainCheck - whether to validate certificate chain signatures
      * @return array of certificates used to verify the signature file
      * @throws IOException - if some errors occurs during reading from the stream
      * @throws GeneralSecurityException - if signature verification process fails
      */
     public static Certificate[] verifySignature(InputStream signature, InputStream
-            signatureBlock) throws IOException, GeneralSecurityException {
+            signatureBlock, boolean chainCheck) throws IOException, GeneralSecurityException {
 
         BerInputStream bis = new BerInputStream(signatureBlock);
         ContentInfo info = (ContentInfo)ContentInfo.ASN1.decode(bis);
@@ -171,10 +180,11 @@ public class JarUtils {
             throw new SecurityException("Incorrect signature");
         }
 
-        return createChain(certs[issuerSertIndex], certs);
+        return createChain(certs[issuerSertIndex], certs, chainCheck);
     }
 
-    private static X509Certificate[] createChain(X509Certificate  signer, X509Certificate[] candidates) {
+    private static X509Certificate[] createChain(X509Certificate  signer,
+            X509Certificate[] candidates, boolean chainCheck) {
         LinkedList chain = new LinkedList();
         chain.add(0, signer);
 
@@ -185,9 +195,10 @@ public class JarUtils {
 
         Principal issuer = signer.getIssuerDN();
         X509Certificate issuerCert;
+        X509Certificate subjectCert = signer;
         int count = 1;
         while (true) {
-            issuerCert = findCert(issuer, candidates);
+            issuerCert = findCert(issuer, candidates, subjectCert, chainCheck);
             if( issuerCert == null) {
                 break;
             }
@@ -197,13 +208,22 @@ public class JarUtils {
                 break;
             }
             issuer = issuerCert.getIssuerDN();
+            subjectCert = issuerCert;
         }
         return (X509Certificate[])chain.toArray(new X509Certificate[count]);
     }
 
-    private static X509Certificate findCert(Principal issuer, X509Certificate[] candidates) {
+    private static X509Certificate findCert(Principal issuer, X509Certificate[] candidates,
+            X509Certificate subjectCert, boolean chainCheck) {
         for (int i = 0; i < candidates.length; i++) {
             if (issuer.equals(candidates[i].getSubjectDN())) {
+                if (chainCheck) {
+                    try {
+                        subjectCert.verify(candidates[i].getPublicKey());
+                    } catch (Exception e) {
+                        continue;
+                    }
+                }
                 return candidates[i];
             }
         }