implement basic structure of APK signature block

src/main/java/com/reandroid/archive2/Archive.java

@@ -15,13 +15,10 @@
  */
 package com.reandroid.archive2;
 
-import com.reandroid.archive2.block.CentralEntryHeader;
-import com.reandroid.archive2.block.EndRecord;
-import com.reandroid.archive2.block.LocalFileHeader;
+import com.reandroid.archive2.block.*;
 import com.reandroid.archive2.io.ArchiveFile;
 import com.reandroid.archive2.io.ArchiveUtil;
 import com.reandroid.archive2.io.ZipSource;
-import com.reandroid.archive2.model.ApkSigBlock;
 import com.reandroid.archive2.model.LocalFileDirectory;
 
 import java.io.File;
@@ -38,7 +35,7 @@ public class Archive {
     private final ZipSource zipSource;
     private final List<ArchiveEntry> entryList;
     private final EndRecord endRecord;
-    private final ApkSigBlock apkSigBlock;
+    private final ApkSignatureBlock apkSignatureBlock;
     public Archive(ZipSource zipSource) throws IOException {
         this.zipSource = zipSource;
         LocalFileDirectory lfd = new LocalFileDirectory();
@@ -54,7 +51,7 @@ public class Archive {
         }
         this.entryList  = entryList;
         this.endRecord = lfd.getCentralFileDirectory().getEndRecord();
-        this.apkSigBlock = lfd.getApkSigBlock();
+        this.apkSignatureBlock = lfd.getApkSigBlock();
     }
     public Archive(File file) throws IOException {
         this(new ArchiveFile(file));
@@ -74,8 +71,8 @@ public class Archive {
         return entryList;
     }
 
-    public ApkSigBlock getApkSigBlock() {
-        return apkSigBlock;
+    public ApkSignatureBlock getApkSigBlock() {
+        return apkSignatureBlock;
     }
     public EndRecord getEndRecord() {
         return endRecord;
@@ -104,4 +101,12 @@ public class Archive {
         String name = archiveEntry.getName().replace('/', File.separatorChar);
         return new File(dir, name);
     }
+    // for test
+    public void writeSignatureData(File dir) throws IOException{
+        ApkSignatureBlock apkSignatureBlock = getApkSigBlock();
+        if(apkSignatureBlock == null){
+            throw new IOException("Does not have signature block");
+        }
+        apkSignatureBlock.writeSignatureData(dir);
+    }
 }

src/main/java/com/reandroid/archive2/block/ApkSignature.java

@@ -1,202 +0,0 @@
-/*
- *  Copyright (C) 2022 github.com/REAndroid
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.reandroid.archive2.block;
-
-import com.reandroid.arsc.decoder.ValueDecoder;
-
-import java.io.*;
-import java.util.Objects;
-
-public class ApkSignature extends ZipBlock{
-    public ApkSignature() {
-        super(MIN_SIZE);
-    }
-    public boolean isValid(){
-        return getSigSize() > MIN_SIZE && getId() != null;
-    }
-    @Override
-    public int readBytes(InputStream inputStream) throws IOException {
-        setBytesLength(8, false);
-        byte[] bytes = getBytesInternal();
-        int read = inputStream.read(bytes, 0, bytes.length);
-        if(read != bytes.length){
-            return read;
-        }
-        int offset = bytes.length;
-        int length = (int) getSigSize();
-        setSigSize(length);
-
-        bytes = getBytesInternal();
-        int dataRead = inputStream.read(bytes, offset, length);
-        if(dataRead != length){
-            setSigSize(0);
-        }
-        return read + dataRead;
-    }
-    public long getSigSize(){
-        return getLong(OFFSET_size);
-    }
-    public void setSigSize(long size){
-        int length = (int) (OFFSET_id + size);
-        setBytesLength(length, false);
-        putLong(OFFSET_size, size);
-    }
-    public int getIdValue(){
-        return getInteger(OFFSET_id);
-    }
-    public Id getId(){
-        return Id.valueOf(getIdValue());
-    }
-    public void setId(int id){
-        putInteger(OFFSET_id, id);
-    }
-    public void setId(Id signatureId){
-        setId(signatureId == null? 0 : signatureId.getId());
-    }
-    public byte[] getData(){
-        return getBytes(OFFSET_data, (int) getSigSize() - 4, true);
-    }
-    public void setData(byte[] data){
-        if(data == null){
-            data = new byte[0];
-        }
-        setData(data, 0, data.length);
-    }
-    public void setData(byte[] data, int offset, int length){
-        setSigSize(length);
-        putBytes(data, offset, OFFSET_data, data.length);
-    }
-    public void writeData(OutputStream outputStream) throws IOException{
-        byte[] bytes = getBytesInternal();
-        outputStream.write(bytes, OFFSET_data, (int) (getSigSize() - 4));
-    }
-    public void writeData(File file) throws IOException{
-        File dir = file.getParentFile();
-        if(dir != null && !dir.exists()){
-            dir.mkdirs();
-        }
-        FileOutputStream outputStream = new FileOutputStream(file);
-        writeData(outputStream);
-        outputStream.close();
-    }
-    public File writeToDir(File dir) throws IOException{
-        File file = new File(dir, getId().toFileName());
-        writeData(file);
-        return file;
-    }
-    @Override
-    public String toString() {
-        return getId() + ", size=" + getSigSize();
-    }
-
-
-    public static class Id {
-        private final String name;
-        private final int id;
-
-        private Id(String name, int id) {
-            this.name = name;
-            this.id = id;
-        }
-        public String name() {
-            return name;
-        }
-        public int getId() {
-            return id;
-        }
-        public String toFileName(){
-            if(this.name != null){
-                return name + FILE_EXTENSION;
-            }
-            return String.format("0x%08x", id) + FILE_EXTENSION;
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (this == obj) {
-                return true;
-            }
-            if (obj == null || getClass() != obj.getClass()) {
-                return false;
-            }
-            Id that = (Id) obj;
-            return id == that.id;
-        }
-        @Override
-        public int hashCode() {
-            return Objects.hash(id);
-        }
-        @Override
-        public String toString(){
-            String name = this.name;
-            if(name != null){
-                return name;
-            }
-            return "UNKNOWN("+String.format("0x%08x", id)+")";
-        }
-        public static Id valueOf(String name){
-            if(name == null){
-                return null;
-            }
-            String ext = FILE_EXTENSION;
-            if(name.endsWith(ext)){
-                name = name.substring(0, name.length()-ext.length());
-            }
-            for(Id signatureId:VALUES){
-                if(name.equalsIgnoreCase(signatureId.name())){
-                    return signatureId;
-                }
-            }
-            if(ValueDecoder.isHex(name)){
-                return new Id(null, ValueDecoder.parseHex(name));
-            }
-            return null;
-        }
-        public static Id valueOf(int id){
-            if(id == 0){
-                return null;
-            }
-            for(Id signatureId:VALUES){
-                if(id == signatureId.getId()){
-                    return signatureId;
-                }
-            }
-            return new Id(null, id);
-        }
-        public static Id[] values() {
-            return VALUES.clone();
-        }
-        public static final Id V2 = new Id("V2", 0x7109871A);
-        public static final Id V3 = new Id("V3",0xF05368C0);
-        public static final Id V31 = new Id("V31",0x1B93AD61);
-        public static final Id STAMP_V1 = new Id("STAMP_V1", 0x2B09189E);
-        public static final Id STAMP_V2 = new Id("STAMP_V2", 0x6DFF800D);
-        public static final Id PADDING = new Id("PADDING", 0x42726577);
-
-
-        private static final Id[] VALUES = new Id[]{
-                V2, V3, V31, STAMP_V1, STAMP_V2, PADDING
-        };
-
-        private static final String FILE_EXTENSION = ".bin";
-    }
-
-    public static final int MIN_SIZE = 12;
-
-    private static final int OFFSET_size = 0;
-    private static final int OFFSET_id = 8;
-    private static final int OFFSET_data = 12;
-}

src/main/java/com/reandroid/archive2/block/ApkSignatureBlock.java

@@ -0,0 +1,78 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+
+public class ApkSignatureBlock extends LengthPrefixedList<SignatureInfo> {
+    public ApkSignatureBlock(SignatureFooter signatureFooter){
+        super(true);
+        setBottomBlock(signatureFooter);
+    }
+    public List<SignatureInfo> getSignatures(){
+        return super.getElements();
+    }
+    public int countSignatures(){
+        return super.getElementsCount();
+    }
+    public SignatureInfo getSignature(SignatureId signatureId){
+        for(SignatureInfo signatureInfo:getSignatures()){
+            if(signatureInfo.getId().equals(signatureId)){
+                return signatureInfo;
+            }
+        }
+        return null;
+    }
+    public SignatureFooter getSignatureFooter(){
+        return (SignatureFooter) getBottomBlock();
+    }
+    @Override
+    public SignatureInfo newInstance() {
+        return new SignatureInfo();
+    }
+    @Override
+    protected void onRefreshed(){
+        SignatureFooter footer = getSignatureFooter();
+        footer.updateMagic();
+        super.onRefreshed();
+        footer.setSignatureSize(getDataSize());
+    }
+    // for test
+    public void writeSignatureData(File dir) throws IOException{
+        for(SignatureInfo signatureInfo:getElements()){
+            signatureInfo.writeToDir(dir);
+        }
+    }
+
+    private static final long CONTENT_DIGESTED_CHUNK_MAX_SIZE_BYTES = 1024 * 1024;
+    public static final int ANDROID_COMMON_PAGE_ALIGNMENT_BYTES = 4096;
+
+    private static final byte[] APK_SIGNING_BLOCK_MAGIC = new byte[] {
+                    0x41, 0x50, 0x4b, 0x20, 0x53, 0x69, 0x67, 0x20,
+                    0x42, 0x6c, 0x6f, 0x63, 0x6b, 0x20, 0x34, 0x32,
+            };
+
+    public static final int VERSION_SOURCE_STAMP = 0;
+    public static final int VERSION_JAR_SIGNATURE_SCHEME = 1;
+    public static final int VERSION_APK_SIGNATURE_SCHEME_V2 = 2;
+    public static final int VERSION_APK_SIGNATURE_SCHEME_V3 = 3;
+    public static final int VERSION_APK_SIGNATURE_SCHEME_V31 = 31;
+    public static final int VERSION_APK_SIGNATURE_SCHEME_V4 = 4;
+
+}

src/main/java/com/reandroid/archive2/block/BottomBlock.java

@@ -0,0 +1,36 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+import com.reandroid.arsc.container.BlockList;
+import com.reandroid.arsc.io.BlockReader;
+
+import java.io.IOException;
+
+// General purpose block to consume the remaining bytes of BlockReader
+public class BottomBlock extends BlockList<LengthPrefixedBytes> {
+    public BottomBlock(){
+        super();
+    }
+    @Override
+    public void onReadBytes(BlockReader reader) throws IOException {
+        while (reader.isAvailable()){
+            LengthPrefixedBytes prefixedBytes = new LengthPrefixedBytes(false);
+            prefixedBytes.readBytes(reader);
+            this.add(prefixedBytes);
+        }
+    }
+}

src/main/java/com/reandroid/archive2/block/CertificateBlock.java

@@ -0,0 +1,54 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+import java.io.ByteArrayInputStream;
+import java.security.cert.CertificateException;
+import java.security.cert.CertificateFactory;
+import java.security.cert.X509Certificate;
+
+public class CertificateBlock extends LengthPrefixedBytes{
+    public CertificateBlock() {
+        super(false);
+    }
+
+    public X509Certificate getCertificate(){
+        return generateCertificate(getByteArray().toArray());
+    }
+    public static X509Certificate generateCertificate(byte[] encodedForm){
+        CertificateFactory factory = getCertFactory();
+        if(factory == null){
+            return null;
+        }
+        try{
+            // TODO: cert bytes could be in DER format ?
+            return (X509Certificate) factory.generateCertificate(new ByteArrayInputStream(encodedForm));
+        }catch (CertificateException ignored){
+            return null;
+        }
+    }
+    private static CertificateFactory getCertFactory() {
+        if (sCertFactory == null) {
+            try {
+                sCertFactory = CertificateFactory.getInstance("X.509");
+            } catch (CertificateException ignored) {
+            }
+        }
+        return sCertFactory;
+    }
+
+    private static CertificateFactory sCertFactory = null;
+}

src/main/java/com/reandroid/archive2/block/CertificateBlockList.java

@@ -0,0 +1,28 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+
+public class CertificateBlockList extends LengthPrefixedList<CertificateBlock>{
+    public CertificateBlockList() {
+        super(false);
+    }
+    @Override
+    public CertificateBlock newInstance() {
+        return new CertificateBlock();
+    }
+
+}

src/main/java/com/reandroid/archive2/block/LengthPrefixedBlock.java

@@ -0,0 +1,89 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+import com.reandroid.arsc.base.Block;
+import com.reandroid.arsc.container.ExpandableBlockContainer;
+import com.reandroid.arsc.io.BlockReader;
+import com.reandroid.arsc.item.IntegerItem;
+import com.reandroid.arsc.item.LongItem;
+
+import java.io.IOException;
+
+public class LengthPrefixedBlock extends ExpandableBlockContainer{
+    private final Block numberBlock;
+    public LengthPrefixedBlock(int childesCount, boolean is_long) {
+        super(1 + childesCount);
+        Block numberBlock;
+        if(is_long){
+            numberBlock = new LongItem();
+        }else {
+            numberBlock = new IntegerItem();
+        }
+        this.numberBlock = numberBlock;
+        addChild(this.numberBlock);
+    }
+    public long getDataSize(){
+        Block numberBlock = this.numberBlock;
+        if(numberBlock instanceof LongItem){
+            return ((LongItem)numberBlock).get();
+        }
+        return ((IntegerItem)numberBlock).get();
+    }
+    public void setDataSize(long dataSize){
+        Block numberBlock = this.numberBlock;
+        if(numberBlock instanceof LongItem){
+            ((LongItem)numberBlock).set(dataSize);
+        }else {
+            ((IntegerItem)numberBlock).set((int) dataSize);
+        }
+    }
+    @Override
+    public void onReadBytes(BlockReader reader) throws IOException {
+        if(!reader.isAvailable()){
+            return;
+        }
+        Block numberBlock = this.numberBlock;
+        numberBlock.readBytes(reader);
+        int dataSize = (int) getDataSize();
+        if(dataSize <= 0){
+            onSizeLoaded(0);
+            return;
+        }
+        onSizeLoaded(dataSize);
+        BlockReader chunkReader = reader.create(dataSize);
+        Block[] childes = getChildes();
+        for(int i=0;i<childes.length;i++){
+            Block child = childes[i];
+            if(child == numberBlock){
+                continue;
+            }
+            child.readBytes(chunkReader);
+        }
+        reader.offset(dataSize);
+    }
+    protected void onSizeLoaded(int dataSize){
+    }
+    @Override
+    protected void onRefreshed(){
+        int size = countBytes() - numberBlock.countBytes();
+        setDataSize(size);
+    }
+    @Override
+    public String toString(){
+        return "size=" + numberBlock;
+    }
+}

src/main/java/com/reandroid/archive2/block/LengthPrefixedBytes.java

@@ -0,0 +1,35 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+import com.reandroid.arsc.item.ByteArray;
+
+public class LengthPrefixedBytes extends LengthPrefixedBlock{
+    private final ByteArray byteArray;
+    public LengthPrefixedBytes(boolean is_long) {
+        super(1, is_long);
+        this.byteArray = new ByteArray();
+        addChild(this.byteArray);
+    }
+
+    public ByteArray getByteArray() {
+        return byteArray;
+    }
+    @Override
+    protected void onSizeLoaded(int dataSize){
+        this.byteArray.setSize(dataSize);
+    }
+}

src/main/java/com/reandroid/archive2/block/LengthPrefixedList.java

@@ -0,0 +1,125 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+import com.reandroid.arsc.base.Block;
+import com.reandroid.arsc.base.BlockCreator;
+import com.reandroid.arsc.container.BlockList;
+import com.reandroid.arsc.container.FixedBlockContainer;
+import com.reandroid.arsc.container.SingleBlockContainer;
+import com.reandroid.arsc.io.BlockReader;
+import com.reandroid.arsc.item.IntegerItem;
+import com.reandroid.arsc.item.LongItem;
+
+import java.io.IOException;
+import java.util.List;
+
+public abstract class LengthPrefixedList<T extends Block> extends FixedBlockContainer
+        implements BlockCreator<T> {
+    private final Block numberBlock;
+    private final BlockList<T> elements;
+    private final SingleBlockContainer<Block> bottomContainer;
+    public LengthPrefixedList(boolean is_long){
+        super(3);
+        Block numberBlock;
+        if(is_long){
+            numberBlock = new LongItem();
+        }else {
+            numberBlock = new IntegerItem();
+        }
+        this.numberBlock = numberBlock;
+        this.elements = new BlockList<>();
+        this.bottomContainer = new SingleBlockContainer<>();
+        addChild(0, this.numberBlock);
+        addChild(1, this.elements);
+        addChild(2, this.bottomContainer);
+    }
+    public long getDataSize(){
+        Block numberBlock = this.numberBlock;
+        if(numberBlock instanceof LongItem){
+            return ((LongItem)numberBlock).get();
+        }
+        return ((IntegerItem)numberBlock).get();
+    }
+    public void setDataSize(long dataSize){
+        Block numberBlock = this.numberBlock;
+        if(numberBlock instanceof LongItem){
+            ((LongItem)numberBlock).set(dataSize);
+        }else {
+            ((IntegerItem)numberBlock).set((int) dataSize);
+        }
+    }
+    public int getElementsCount(){
+        return getElements().size();
+    }
+    public List<T> getElements() {
+        return elements.getChildes();
+    }
+    public T add(T element){
+        this.elements.add(element);
+        return element;
+    }
+    public boolean remove(T element){
+        return this.elements.remove(element);
+    }
+    @Override
+    public void onReadBytes(BlockReader reader) throws IOException{
+        if(!reader.isAvailable()){
+            return;
+        }
+        numberBlock.readBytes(reader);
+        int totalSize = (int) getDataSize();
+        if(totalSize <= 0){
+            return;
+        }
+        BlockReader chunkReader = reader.create(totalSize);
+        readElements(chunkReader);
+        if(chunkReader.isAvailable()){
+            String junk = "";
+        }
+        bottomContainer.readBytes(chunkReader);
+        reader.offset(totalSize);
+    }
+    private void readElements(BlockReader reader) throws IOException{
+        int preserve = bottomContainer.countBytes() + 4;
+        while (reader.available() > preserve){
+            int position = reader.getPosition();
+            T element = newInstance();
+            element = add(element);
+            element.readBytes(reader);
+            if(position == reader.getPosition()){
+                break;
+            }
+        }
+    }
+    @Override
+    protected void onRefreshed(){
+        int size = countBytes() - numberBlock.countBytes();
+        setDataSize(size);
+    }
+    public Block getBottomBlock(){
+        return bottomContainer.getItem();
+    }
+    public void setBottomBlock(Block block){
+        bottomContainer.setItem(block);
+    }
+
+
+    @Override
+    public String toString(){
+        return "size=" + numberBlock + ", count=" + getElementsCount();
+    }
+}

src/main/java/com/reandroid/archive2/block/SignatureFooter.java

@@ -31,25 +31,37 @@ public class SignatureFooter extends ZipBlock{
         byte[] bytes = getBytesInternal();
         return inputStream.read(bytes, 0, bytes.length);
     }
-    public long getSigBlockSizeInFooter(){
+    public long getSignatureSize(){
         return getLong(OFFSET_size);
     }
-    public void setSigBlockSizeInFooter(long size){
+    public void setSignatureSize(long size){
+        int minLength = MIN_SIZE;
+        if(countBytes() < minLength){
+            setBytesLength(minLength, false);
+        }
         putLong(OFFSET_size, size);
     }
     public byte[] getMagic() {
         return getBytes(OFFSET_magic, APK_SIG_BLOCK_MAGIC.length, false);
     }
     public void setMagic(byte[] magic){
+        if(magic == null){
+            magic = new byte[0];
+        }
+        int length = OFFSET_magic + magic.length;
+        setBytesLength(length, false);
         putBytes(magic, 0, OFFSET_magic, magic.length);
     }
     public boolean isValid(){
-        return getSigBlockSizeInFooter() > MIN_SIZE
+        return getSignatureSize() > MIN_SIZE
                 && ByteArray.equals(APK_SIG_BLOCK_MAGIC, getMagic());
     }
+    public void updateMagic(){
+        setMagic(APK_SIG_BLOCK_MAGIC);
+    }
     @Override
     public String toString(){
-        return getSigBlockSizeInFooter() + " ["+new String(getMagic())+"]";
+        return getSignatureSize() + " ["+new String(getMagic())+"]";
     }
 
     public static final int MIN_SIZE = 24;

src/main/java/com/reandroid/archive2/block/SignatureId.java

@@ -0,0 +1,109 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+import com.reandroid.arsc.decoder.ValueDecoder;
+
+import java.util.Objects;
+
+public class SignatureId {
+    private final String name;
+    private final int id;
+
+    private SignatureId(String name, int id) {
+        this.name = name;
+        this.id = id;
+    }
+    public String name() {
+        return name;
+    }
+    public int getId() {
+        return id;
+    }
+    public String toFileName() {
+        if (this.name != null) {
+            return name + FILE_EXTENSION;
+        }
+        return String.format("0x%08x", id) + FILE_EXTENSION;
+    }
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        SignatureId that = (SignatureId) obj;
+        return id == that.id;
+    }
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+    @Override
+    public String toString() {
+        String name = this.name;
+        if (name != null) {
+            return name;
+        }
+        return "UNKNOWN(" + String.format("0x%08x", id) + ")";
+    }
+    public static SignatureId valueOf(String name) {
+        if (name == null) {
+            return null;
+        }
+        String ext = FILE_EXTENSION;
+        if (name.endsWith(ext)) {
+            name = name.substring(0, name.length() - ext.length());
+        }
+        for (SignatureId signatureId : VALUES) {
+            if (name.equalsIgnoreCase(signatureId.name())) {
+                return signatureId;
+            }
+        }
+        if (ValueDecoder.isHex(name)) {
+            return new SignatureId(null, ValueDecoder.parseHex(name));
+        }
+        return null;
+    }
+    public static SignatureId valueOf(int id) {
+        for (SignatureId signatureId : VALUES) {
+            if (id == signatureId.getId()) {
+                return signatureId;
+            }
+        }
+        return new SignatureId(null, id);
+    }
+
+    public static SignatureId[] values() {
+        return VALUES.clone();
+    }
+
+    public static final SignatureId V2 = new SignatureId("V2", 0x7109871A);
+    public static final SignatureId V3 = new SignatureId("V3", 0xF05368C0);
+    public static final SignatureId V31 = new SignatureId("V31", 0x1B93AD61);
+    public static final SignatureId STAMP_V1 = new SignatureId("STAMP_V1", 0x2B09189E);
+    public static final SignatureId STAMP_V2 = new SignatureId("STAMP_V2", 0x6DFF800D);
+    public static final SignatureId PADDING = new SignatureId("PADDING", 0x42726577);
+    public static final SignatureId NULL = new SignatureId("NULL", 0x0);
+
+    private static final SignatureId[] VALUES = new SignatureId[]{
+            V2, V3, V31, STAMP_V1, STAMP_V2, PADDING, NULL
+    };
+
+    private static final String FILE_EXTENSION = ".bin";
+}

src/main/java/com/reandroid/archive2/block/SignatureInfo.java

@@ -0,0 +1,111 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+import com.reandroid.archive2.block.pad.SchemePadding;
+import com.reandroid.archive2.block.stamp.SchemeStampV1;
+import com.reandroid.archive2.block.stamp.SchemeStampV2;
+import com.reandroid.archive2.block.v2.SchemeV2;
+import com.reandroid.archive2.block.v3.SchemeV3;
+import com.reandroid.archive2.block.v3.SchemeV31;
+import com.reandroid.arsc.base.Block;
+import com.reandroid.arsc.container.SingleBlockContainer;
+import com.reandroid.arsc.io.BlockLoad;
+import com.reandroid.arsc.io.BlockReader;
+import com.reandroid.arsc.item.IntegerItem;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+public class SignatureInfo extends LengthPrefixedBlock implements BlockLoad {
+    private final IntegerItem idItem;
+    private final SingleBlockContainer<SignatureScheme> schemeContainer;
+    public SignatureInfo() {
+        super(2, true);
+        this.idItem = new IntegerItem();
+        this.schemeContainer = new SingleBlockContainer<>();
+        addChild(this.idItem);
+        addChild(this.schemeContainer);
+        this.idItem.setBlockLoad(this);
+    }
+    public int getIdValue(){
+        return idItem.get();
+    }
+    public SignatureId getId(){
+        return SignatureId.valueOf(getIdValue());
+    }
+    public void setId(int id){
+        idItem.set(id);
+    }
+    public void setId(SignatureId signatureId){
+        setId(signatureId == null? 0 : signatureId.getId());
+    }
+    public SignatureScheme getSignatureScheme(){
+        return schemeContainer.getItem();
+    }
+    public void setSignatureScheme(SignatureScheme signatureScheme){
+        schemeContainer.setItem(signatureScheme);
+    }
+
+    @Override
+    public void onBlockLoaded(BlockReader reader, Block sender) throws IOException {
+        if(sender == this.idItem){
+            onIdLoaded();
+        }
+    }
+    private void onIdLoaded(){
+        SignatureId signatureId = getId();
+        SignatureScheme scheme;
+        if(signatureId == SignatureId.V2){
+            scheme = new SchemeV2();
+        }else if(signatureId == SignatureId.V3){
+            scheme = new SchemeV3();
+        }else if(signatureId == SignatureId.V31){
+            scheme = new SchemeV31();
+        }else if(signatureId == SignatureId.STAMP_V1){
+            scheme = new SchemeStampV1();
+        }else if(signatureId == SignatureId.STAMP_V2){
+            scheme = new SchemeStampV2();
+        }else if(signatureId == SignatureId.PADDING){
+            scheme = new SchemePadding();
+        }else {
+            scheme = new UnknownScheme(signatureId);
+        }
+        schemeContainer.setItem(scheme);
+    }
+    // for test
+    public void writeData(File file) throws IOException{
+        File dir = file.getParentFile();
+        if(dir != null && !dir.exists()){
+            dir.mkdirs();
+        }
+        FileOutputStream outputStream = new FileOutputStream(file);
+        writeBytes(outputStream);
+        outputStream.close();
+    }
+    // for test
+    public File writeToDir(File dir) throws IOException{
+        File file = new File(dir, getId().toFileName());
+        writeData(file);
+        return file;
+    }
+    @Override
+    public String toString() {
+        return getId() + ", scheme: " + getSignatureScheme();
+    }
+
+}

src/main/java/com/reandroid/archive2/block/UnknownScheme.java

@@ -0,0 +1,39 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block;
+
+import com.reandroid.arsc.io.BlockReader;
+import com.reandroid.arsc.item.ByteArray;
+
+import java.io.IOException;
+
+// General purpose block to consume the specified bytes of BlockReader
+// TODO: No class should override this, implement all like SchemeV2
+public class UnknownScheme extends SignatureScheme{
+    private final ByteArray byteArray;
+    public UnknownScheme(SignatureId signatureId) {
+        super(1, signatureId);
+        this.byteArray = new ByteArray();
+        addChild(byteArray);
+    }
+    @Override
+    public void onReadBytes(BlockReader reader) throws IOException {
+        SignatureInfo signatureInfo = getSignatureInfo();
+        int size = (int) signatureInfo.getDataSize() - 4;
+        byteArray.setSize(size);
+        super.onReadBytes(reader);
+    }
+}

src/main/java/com/reandroid/archive2/block/ZipBlock.java

@@ -98,29 +98,4 @@ public abstract class ZipBlock extends BlockItem {
         putShort(getBytesInternal(), offset, (short) value);
     }
 
-    public static long getLong(byte[] bytes, int offset){
-        if((offset + 8)>bytes.length){
-            return 0;
-        }
-        long result = 0;
-        int index = offset + 7;
-        while (index>=offset){
-            result = result << 8;
-            result |= (bytes[index] & 0xff);
-            index --;
-        }
-        return result;
-    }
-    public static void putLong(byte[] bytes, int offset, long value){
-        if((offset + 8) > bytes.length){
-            return;
-        }
-        int index = offset;
-        offset = index + 8;
-        while (index<offset){
-            bytes[index] = (byte) (value & 0xff);
-            value = value >>> 8;
-            index++;
-        }
-    }
 }

src/main/java/com/reandroid/archive2/block/pad/SchemePadding.java

@@ -0,0 +1,40 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.pad;
+
+import com.reandroid.archive2.block.SignatureId;
+import com.reandroid.archive2.block.SignatureInfo;
+import com.reandroid.archive2.block.SignatureScheme;
+import com.reandroid.arsc.io.BlockReader;
+import com.reandroid.arsc.item.ByteArray;
+
+import java.io.IOException;
+
+public class SchemePadding extends SignatureScheme {
+    private final ByteArray byteArray;
+    public SchemePadding() {
+        super(1, SignatureId.PADDING);
+        this.byteArray = new ByteArray();
+        addChild(this.byteArray);
+    }
+    @Override
+    public void onReadBytes(BlockReader reader) throws IOException{
+        SignatureInfo signatureInfo = getSignatureInfo();
+        int size = (int) signatureInfo.getDataSize() - 4;
+        byteArray.setSize(size);
+        super.onReadBytes(reader);
+    }
+}

src/main/java/com/reandroid/archive2/block/stamp/SchemeStampV1.java

@@ -0,0 +1,26 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.stamp;
+
+import com.reandroid.archive2.block.SignatureId;
+import com.reandroid.archive2.block.UnknownScheme;
+
+// TODO: implement structure
+public class SchemeStampV1 extends UnknownScheme {
+    public SchemeStampV1() {
+        super(SignatureId.STAMP_V1);
+    }
+}

src/main/java/com/reandroid/archive2/block/stamp/SchemeStampV2.java

@@ -0,0 +1,26 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.stamp;
+
+import com.reandroid.archive2.block.SignatureId;
+import com.reandroid.archive2.block.UnknownScheme;
+
+// TODO: implement structure
+public class SchemeStampV2 extends UnknownScheme {
+    public SchemeStampV2() {
+        super(SignatureId.STAMP_V2);
+    }
+}

src/main/java/com/reandroid/archive2/block/v2/SchemeV2.java

@@ -0,0 +1,29 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.v2;
+
+import com.reandroid.archive2.block.SignatureId;
+import com.reandroid.archive2.block.SignatureScheme;
+
+public class SchemeV2 extends SignatureScheme {
+    private final V2SignedDataList signedDataList;
+    public SchemeV2(){
+        super(1, SignatureId.V2);
+        this.signedDataList = new V2SignedDataList();
+        addChild(this.signedDataList);
+    }
+
+}

src/main/java/com/reandroid/archive2/block/v2/V2Signature.java

@@ -0,0 +1,24 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.v2;
+
+import com.reandroid.archive2.block.LengthPrefixedBytes;
+
+public class V2Signature extends LengthPrefixedBytes {
+    public V2Signature() {
+        super(false);
+    }
+}

src/main/java/com/reandroid/archive2/block/v2/V2SignedData.java

@@ -0,0 +1,38 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.v2;
+
+import com.reandroid.archive2.block.BottomBlock;
+import com.reandroid.archive2.block.LengthPrefixedBlock;
+import com.reandroid.arsc.io.BlockReader;
+
+import java.io.IOException;
+
+public class V2SignedData extends LengthPrefixedBlock {
+    private final V2Signer signer;
+    private final BottomBlock unknown;
+    public V2SignedData() {
+        super(2, false);
+        this.signer = new V2Signer();
+        this.unknown = new BottomBlock();
+        addChild(this.signer);
+        addChild(this.unknown);
+    }
+    public void onReadBytes(BlockReader reader) throws IOException {
+        super.onReadBytes(reader);
+    }
+
+}

src/main/java/com/reandroid/archive2/block/v2/V2SignedDataList.java

@@ -0,0 +1,29 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.v2;
+
+import com.reandroid.archive2.block.LengthPrefixedList;
+
+public class V2SignedDataList extends LengthPrefixedList<V2SignedData> {
+    public V2SignedDataList() {
+        super(false);
+    }
+
+    @Override
+    public V2SignedData newInstance() {
+        return new V2SignedData();
+    }
+}

src/main/java/com/reandroid/archive2/block/v2/V2Signer.java

@@ -0,0 +1,51 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.v2;
+
+import com.reandroid.archive2.block.BottomBlock;
+import com.reandroid.archive2.block.CertificateBlock;
+import com.reandroid.archive2.block.CertificateBlockList;
+import com.reandroid.archive2.block.LengthPrefixedBlock;
+
+import java.util.List;
+
+public class V2Signer extends LengthPrefixedBlock {
+    private final V2Signature v2Signature;
+    private final CertificateBlockList certificateBlockList;
+    private final BottomBlock unknown;
+    public V2Signer() {
+        super(3, false);
+        this.v2Signature = new V2Signature();
+        this.certificateBlockList = new CertificateBlockList();
+        this.unknown = new BottomBlock();
+        addChild(this.v2Signature);
+        addChild(this.certificateBlockList);
+        addChild(this.unknown);
+    }
+    public List<CertificateBlock> getCertificateBlockList(){
+        return certificateBlockList.getElements();
+    }
+    public void addCertificateBlock(CertificateBlock certificateBlock){
+        certificateBlockList.add(certificateBlock);
+    }
+    public void removeCertificateBlock(CertificateBlock certificateBlock){
+        certificateBlockList.remove(certificateBlock);
+    }
+    @Override
+    public String toString(){
+        return super.toString()+", sig="+v2Signature+", certs="+certificateBlockList;
+    }
+}

src/main/java/com/reandroid/archive2/block/v3/SchemeV3.java

@@ -0,0 +1,26 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.v3;
+
+import com.reandroid.archive2.block.SignatureId;
+import com.reandroid.archive2.block.UnknownScheme;
+
+// TODO: implement structure
+public class SchemeV3 extends UnknownScheme {
+    public SchemeV3() {
+        super(SignatureId.V3);
+    }
+}

src/main/java/com/reandroid/archive2/block/v3/SchemeV31.java

@@ -0,0 +1,26 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.reandroid.archive2.block.v3;
+
+import com.reandroid.archive2.block.SignatureId;
+import com.reandroid.archive2.block.UnknownScheme;
+
+// TODO: implement structure
+public class SchemeV31 extends UnknownScheme {
+    public SchemeV31() {
+        super(SignatureId.V31);
+    }
+}

src/main/java/com/reandroid/archive2/model/ApkSigBlock.java

@@ -1,86 +0,0 @@
-/*
- *  Copyright (C) 2022 github.com/REAndroid
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.reandroid.archive2.model;
-
-import com.reandroid.archive2.block.ApkSignature;
-import com.reandroid.archive2.block.LongBlock;
-import com.reandroid.archive2.block.SignatureFooter;
-
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.List;
-
-public class ApkSigBlock {
-    private final SignatureFooter signatureFooter;
-    private final LongBlock mSize;
-    private final List<ApkSignature> mSignatures;
-    public ApkSigBlock(SignatureFooter signatureFooter){
-        this.signatureFooter = signatureFooter;
-        this.mSize = new LongBlock();
-        this.mSignatures = new ArrayList<>();
-    }
-
-    public LongBlock getTotalSize(){
-        return mSize;
-    }
-    public List<ApkSignature> getSignatures() {
-        return mSignatures;
-    }
-
-    public void readBytes(InputStream inputStream) throws IOException {
-        mSize.readBytes(inputStream);
-        ApkSignature apkSignature;
-        while ((apkSignature = readNext(inputStream))!=null){
-            mSignatures.add(apkSignature);
-        }
-    }
-    private ApkSignature readNext(InputStream inputStream) throws IOException {
-        ApkSignature apkSignature = new ApkSignature();
-        apkSignature.readBytes(inputStream);
-        if(apkSignature.isValid()){
-            return apkSignature;
-        }
-        return null;
-    }
-    public void writeSigData(File dir) throws IOException{
-        for(ApkSignature apkSignature:mSignatures){
-            apkSignature.writeToDir(dir);
-        }
-    }
-    @Override
-    public String toString(){
-        return "size=" + getTotalSize() + ", count=" + getSignatures().size();
-    }
-
-    private static final long CONTENT_DIGESTED_CHUNK_MAX_SIZE_BYTES = 1024 * 1024;
-    public static final int ANDROID_COMMON_PAGE_ALIGNMENT_BYTES = 4096;
-
-    private static final byte[] APK_SIGNING_BLOCK_MAGIC = new byte[] {
-                    0x41, 0x50, 0x4b, 0x20, 0x53, 0x69, 0x67, 0x20,
-                    0x42, 0x6c, 0x6f, 0x63, 0x6b, 0x20, 0x34, 0x32,
-            };
-    public static final int VERITY_PADDING_BLOCK_ID = 0x42726577;
-
-    public static final int VERSION_SOURCE_STAMP = 0;
-    public static final int VERSION_JAR_SIGNATURE_SCHEME = 1;
-    public static final int VERSION_APK_SIGNATURE_SCHEME_V2 = 2;
-    public static final int VERSION_APK_SIGNATURE_SCHEME_V3 = 3;
-    public static final int VERSION_APK_SIGNATURE_SCHEME_V31 = 31;
-    public static final int VERSION_APK_SIGNATURE_SCHEME_V4 = 4;
-
-}

src/main/java/com/reandroid/archive2/model/LocalFileDirectory.java

@@ -16,7 +16,9 @@
 package com.reandroid.archive2.model;
 
 import com.reandroid.archive2.block.*;
+import com.reandroid.archive2.block.ApkSignatureBlock;
 import com.reandroid.archive2.io.ZipSource;
+import com.reandroid.arsc.io.BlockReader;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -26,7 +28,7 @@ import java.util.List;
 public class LocalFileDirectory {
     private final CentralFileDirectory centralFileDirectory;
     private final List<LocalFileHeader> headerList;
-    private ApkSigBlock apkSigBlock;
+    private ApkSignatureBlock apkSignatureBlock;
     private long mTotalDataLength;
     public LocalFileDirectory(CentralFileDirectory centralFileDirectory){
         this.centralFileDirectory = centralFileDirectory;
@@ -86,15 +88,14 @@ public class LocalFileDirectory {
             return;
         }
         EndRecord endRecord = cfd.getEndRecord();
-        long length = footer.getSigBlockSizeInFooter() + 8;
-        long offset = endRecord.getOffsetOfCentralDirectory()
-                - length;
-        ApkSigBlock apkSigBlock = new ApkSigBlock(footer);
-        apkSigBlock.readBytes(zipSource.getInputStream(offset, length));
-        this.apkSigBlock = apkSigBlock;
+        long length = footer.getSignatureSize() + 8;
+        long offset = endRecord.getOffsetOfCentralDirectory() - length;
+        ApkSignatureBlock apkSignatureBlock = new ApkSignatureBlock(footer);
+        apkSignatureBlock.readBytes(new BlockReader(zipSource.getInputStream(offset, length)));
+        this.apkSignatureBlock = apkSignatureBlock;
     }
-    public ApkSigBlock getApkSigBlock() {
-        return apkSigBlock;
+    public ApkSignatureBlock getApkSigBlock() {
+        return apkSignatureBlock;
     }
     public CentralFileDirectory getCentralFileDirectory() {
         return centralFileDirectory;