修复 DSA 签名游戏无法正常更新的问题

app/src/main/java/com/android/apksig/ApkVerifier.java

@@ -154,6 +154,37 @@ public class ApkVerifier {
         }
     }
 
+    /**
+     * Simply retrieve result that contains V1Signature only by ignoring all the verification process.
+     *
+     * @throws IOException              if an I/O error is encountered while reading the APK
+     * @throws ApkFormatException       if the APK is malformed
+     * @throws NoSuchAlgorithmException if the APK's signatures cannot be verified because a
+     *                                  required cryptographic algorithm implementation is missing
+     * @throws IllegalStateException    if this verifier's configuration is missing required
+     *                                  information.
+     */
+    public Result retrieveV1Signature() throws IOException, ApkFormatException, NoSuchAlgorithmException {
+        Closeable in = null;
+        try {
+            DataSource apk;
+            if (mApkDataSource != null) {
+                apk = mApkDataSource;
+            } else if (mApkFile != null) {
+                RandomAccessFile f = new RandomAccessFile(mApkFile, "r");
+                in = f;
+                apk = DataSources.asDataSource(f, 0, f.length());
+            } else {
+                throw new IllegalStateException("APK not provided");
+            }
+            return retrieveV1Signature(apk);
+        } finally {
+            if (in != null) {
+                in.close();
+            }
+        }
+    }
+
     /**
      * Simply retrieve result that contains V2Signature only by ignoring all the verification process.
      *
@@ -257,6 +288,60 @@ public class ApkVerifier {
         return result;
     }
 
+    /**
+     * Simply retrieve result that contains V1Signature only by ignoring all the verification process.
+     *
+     * @param apk APK file contents
+     * @throws IOException              if an I/O error is encountered while reading the APK
+     * @throws ApkFormatException       if the APK is malformed
+     * @throws NoSuchAlgorithmException if the APK's signatures cannot be verified because a
+     *                                  required cryptographic algorithm implementation is missing
+     */
+    private Result retrieveV1Signature(DataSource apk) throws IOException, ApkFormatException, NoSuchAlgorithmException {
+        int maxSdkVersion = mMaxSdkVersion;
+
+        ApkUtils.ZipSections zipSections;
+        try {
+            zipSections = ApkUtils.findZipSections(apk);
+        } catch (ZipFormatException e) {
+            throw new ApkFormatException("Malformed APK: not a ZIP archive", e);
+        }
+
+        Result result = new Result();
+        Map<Integer, Map<ContentDigestAlgorithm, byte[]>> signatureSchemeApkContentDigests =
+                new HashMap<>();
+
+        // The SUPPORTED_APK_SIG_SCHEME_NAMES contains the mapping from version number to scheme
+        // name, but the verifiers use this parameter as the schemes supported by the target SDK
+        // range. Since the code below skips signature verification based on max SDK the mapping of
+        // supported schemes needs to be modified to ensure the verifiers do not report a stripped
+        // signature for an SDK range that does not support that signature version. For instance an
+        // APK with V1, V2, and V3 signatures and a max SDK of O would skip the V3 signature
+        // verification, but the SUPPORTED_APK_SIG_SCHEME_NAMES contains version 3, so when the V2
+        // verification is performed it would see the stripping protection attribute, see that V3
+        // is in the list of supported signatures, and report a stripped signature.
+        Map<Integer, String> supportedSchemeNames = getSupportedSchemeNames(maxSdkVersion);
+
+        // Android N and newer attempts to verify APKs using the APK Signing Block, which can
+        // include v2 and/or v3 signatures.  If none is found, it falls back to JAR signature
+        // verification. If the signature is found but does not verify, the APK is rejected.
+        Set<Integer> foundApkSigSchemeIds = new HashSet<>(2);
+
+        int minSdkVersion = verifyAndGetMinSdkVersion(apk, zipSections);
+        V1SchemeVerifier.Result v1Result =
+                V1SchemeVerifier.verify(
+                        apk,
+                        zipSections,
+                        supportedSchemeNames,
+                        foundApkSigSchemeIds,
+                        minSdkVersion,
+                        maxSdkVersion);
+
+        result.mergeFrom(v1Result);
+        return result;
+    }
+
+
     /**
      * Verifies the APK's signatures and returns the result of verification. The APK can be
      * considered verified iff the result's {@link Result#isVerified()} returns {@code true}.