diff --git a/src/main/java/net/dongliu/apk/parser/AbstractApkFile.java b/src/main/java/net/dongliu/apk/parser/AbstractApkFile.java
index 561dd9a..0e0f366 100644
--- a/src/main/java/net/dongliu/apk/parser/AbstractApkFile.java
+++ b/src/main/java/net/dongliu/apk/parser/AbstractApkFile.java
@@ -4,9 +4,10 @@
 import net.dongliu.apk.parser.exception.ParserException;
 import net.dongliu.apk.parser.parser.*;
 import net.dongliu.apk.parser.struct.AndroidConstants;
-import net.dongliu.apk.parser.struct.ApkSigningBlock;
 import net.dongliu.apk.parser.struct.resource.Densities;
 import net.dongliu.apk.parser.struct.resource.ResourceTable;
+import net.dongliu.apk.parser.struct.signingv2.ApkSigningBlock;
+import net.dongliu.apk.parser.struct.signingv2.SignerBlock;
 import net.dongliu.apk.parser.struct.zip.EOCD;
 import net.dongliu.apk.parser.utils.Buffers;
 import net.dongliu.apk.parser.utils.Unsigned;
@@ -16,6 +17,7 @@
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.security.cert.CertificateException;
+import java.security.cert.X509Certificate;
 import java.util.*;
 
 import static java.lang.System.arraycopy;
@@ -38,7 +40,8 @@ public abstract class AbstractApkFile implements Closeable {
     private ApkMeta apkMeta;
     private List<IconPath> iconPaths;
 
-    private List<ApkCertificateFileInfo> apkCertificateFileInfos;
+    private List<ApkSigner> apkSigners;
+    private List<ApkV2Signer> apkV2Signers;
 
     private static final Locale DEFAULT_LOCALE = Locale.US;
 
@@ -79,44 +82,82 @@ public Set<Locale> getLocales() throws IOException {
     }
 
     /**
-     * Get the apk's certificate meta. If have multi signature, return the certificate the first signature used.
+     * Get the apk's certificate meta. If have multi signer, return the certificate the first signer used.
+     *
+     * @deprecated use {{@link #getApkSingers()}} instead
      */
-    public List<CertificateMeta> getCertificateMetaList() throws IOException,
-            CertificateException {
-        if (apkCertificateFileInfos == null) {
+    @Deprecated
+    public List<CertificateMeta> getCertificateMetaList() throws IOException, CertificateException {
+        if (apkSigners == null) {
             parseCertificates();
         }
-        if (apkCertificateFileInfos.isEmpty()) {
+        if (apkSigners.isEmpty()) {
             throw new ParserException("ApkFile certificate not found");
         }
-        return apkCertificateFileInfos.get(0).getCertificateMetaList();
+        return apkSigners.get(0).getCertificateMetas();
     }
 
     /**
      * Get the apk's all certificates.
      * For each entry, the key is certificate file path in apk file, the value is the certificates info of the certificate file.
      *
-     * @deprecated use {{@link #getCertificateInfos()}} instead
+     * @deprecated use {{@link #getApkSingers()}} instead
      */
     @Deprecated
     public Map<String, List<CertificateMeta>> getAllCertificateMetas() throws IOException, CertificateException {
-        List<ApkCertificateFileInfo> certificateInfos = getCertificateInfos();
+        List<ApkSigner> apkSigners = getApkSingers();
         Map<String, List<CertificateMeta>> map = new LinkedHashMap<>();
-        for (ApkCertificateFileInfo certificateInfo : certificateInfos) {
-            map.put(certificateInfo.getPath(), certificateInfo.getCertificateMetaList());
+        for (ApkSigner apkSigner : apkSigners) {
+            map.put(apkSigner.getPath(), apkSigner.getCertificateMetas());
         }
         return map;
     }
 
     /**
-     * Get the apk's all certificates of all cert file.
-     * For each item, the key is cert file path in apk file, the value is the certificates info of the cert file.
+     * Get the apk's all cert file info, of apk v1 signing.
+     * If cert faile not exist, return empty list.
      */
-    public List<ApkCertificateFileInfo> getCertificateInfos() throws IOException, CertificateException {
-        if (apkCertificateFileInfos == null) {
+    public List<ApkSigner> getApkSingers() throws IOException, CertificateException {
+        if (apkSigners == null) {
             parseCertificates();
         }
-        return this.apkCertificateFileInfos;
+        return this.apkSigners;
+    }
+
+    private void parseCertificates() throws IOException, CertificateException {
+        this.apkSigners = new ArrayList<>();
+        for (CertificateFile file : getAllCertificateData()) {
+            CertificateParser parser = new CertificateParser(file.getData());
+            List<CertificateMeta> certificateMetas = parser.parse();
+            apkSigners.add(new ApkSigner(file.getPath(), certificateMetas));
+        }
+    }
+
+    /**
+     * Get the apk's all signer in apk sign block, using apk singing v2 scheme.
+     * If apk v2 signing block not exists, return empty list.
+     */
+    public List<ApkV2Signer> getApkV2Singers() throws IOException, CertificateException {
+        if (apkV2Signers == null) {
+            parseApkSigningBlock();
+        }
+        return this.apkV2Signers;
+    }
+
+    private void parseApkSigningBlock() throws IOException, CertificateException {
+        List<ApkV2Signer> list = new ArrayList<>();
+        ByteBuffer apkSignBlockBuf = findApkSignBlock();
+        if (apkSignBlockBuf != null) {
+            ApkSignBlockParser parser = new ApkSignBlockParser(apkSignBlockBuf);
+            ApkSigningBlock apkSigningBlock = parser.parse();
+            for (SignerBlock signerBlock : apkSigningBlock.getSignerBlocks()) {
+                List<X509Certificate> certificates = signerBlock.getCertificates();
+                List<CertificateMeta> certificateMetas = CertificateMetas.from(certificates);
+                ApkV2Signer apkV2Signer = new ApkV2Signer(certificateMetas);
+                list.add(apkV2Signer);
+            }
+        }
+        this.apkV2Signers = list;
     }
 
 
@@ -140,15 +181,6 @@ public byte[] getData() {
         }
     }
 
-    private void parseCertificates() throws IOException, CertificateException {
-        this.apkCertificateFileInfos = new ArrayList<>();
-        for (CertificateFile file : getAllCertificateData()) {
-            CertificateParser parser = new CertificateParser(file.getData());
-            parser.parse();
-            apkCertificateFileInfos.add(new ApkCertificateFileInfo(file.getPath(), parser.getCertificateMetas()));
-        }
-    }
-
     private void parseManifest() throws IOException {
         if (manifestParsed) {
             return;
@@ -267,8 +299,7 @@ private DexClass[] parseDexFile(String path) throws IOException {
         }
         ByteBuffer buffer = ByteBuffer.wrap(data);
         DexParser dexParser = new DexParser(buffer);
-        dexParser.parse();
-        return dexParser.getDexClasses();
+        return dexParser.parse();
     }
 
     private void parseDexFiles() throws IOException {
@@ -315,7 +346,7 @@ private void parseResourceTable() throws IOException {
 
     @Override
     public void close() throws IOException {
-        this.apkCertificateFileInfos = null;
+        this.apkSigners = null;
         this.resourceTable = null;
         this.iconPaths = null;
     }
@@ -337,7 +368,12 @@ public void setPreferredLocale(Locale preferredLocale) {
         }
     }
 
-    private ApkSigningBlock findApkSignBlock() throws IOException {
+    /**
+     * Create ApkSignBlockParser for this apk file.
+     *
+     * @return null if do not have sign block
+     */
+    protected ByteBuffer findApkSignBlock() throws IOException {
         ByteBuffer buffer = fileData().order(ByteOrder.LITTLE_ENDIAN);
         int len = buffer.limit();
 
@@ -367,10 +403,11 @@ private ApkSigningBlock findApkSignBlock() throws IOException {
             return null;
         }
 
+        int magicStrLen = 16;
         long cdStart = eocd.getCdStart();
         // find apk sign block
-        Buffers.position(buffer, cdStart - 16);
-        String magic = Buffers.readAsciiString(buffer, 16);
+        Buffers.position(buffer, cdStart - magicStrLen);
+        String magic = Buffers.readAsciiString(buffer, magicStrLen);
         if (!magic.equals(ApkSigningBlock.MAGIC)) {
             return null;
         }
@@ -382,48 +419,7 @@ private ApkSigningBlock findApkSignBlock() throws IOException {
             return null;
         }
         // now at the start of signing block
-        ByteBuffer signingBuffer = Buffers.slice(buffer, blockSize);
-        return readSigningBlock(signingBuffer);
-    }
-
-    private ApkSigningBlock readSigningBlock(ByteBuffer buffer) {
-        ApkSigningBlock block = new ApkSigningBlock();
-        block.setSize(buffer.limit());
-        // sign block found, read pairs
-        while (buffer.hasRemaining()) {
-            int id = buffer.getInt();
-            int size = Unsigned.ensureUInt(buffer.getInt());
-            if (id == ApkSigningBlock.SIGNING_V2_ID) {
-                ByteBuffer signingV2Buffer = Buffers.slice(buffer, size);
-                // now only care about apk signing v2 entry
-                readSigningV2(signingV2Buffer);
-
-                Buffers.position(buffer, buffer.position() + size);
-            } else {
-                Buffers.position(buffer, buffer.position() + size);
-            }
-        }
-        return block;
-    }
-
-    private void readSigningV2(ByteBuffer buffer) {
-        int singersLen = Unsigned.ensureUInt(buffer.getInt());
-        int singersEnd = buffer.position() + singersLen;
-
-        while (buffer.position() < singersEnd) {
-            int singerLen = Unsigned.ensureUInt(buffer.getInt());
-            int singerBegin = buffer.position();
-            int singerDataLen = Unsigned.ensureUInt(buffer.getInt());
-            Buffers.skip(buffer, singerDataLen);
-
-            singerLen = singerLen - singerDataLen - 4;
-            if (singerLen > 0) {
-                int signaturesLen = Unsigned.ensureUInt(buffer.getInt());
-                Buffers.skip(buffer, signaturesLen);
-                int publicKeyLen = Unsigned.ensureUInt(buffer.getInt());
-                Buffers.skip(buffer, publicKeyLen);
-            }
-        }
+        return Buffers.sliceAndSkip(buffer, blockSize - magicStrLen);
     }
 
 }
diff --git a/src/main/java/net/dongliu/apk/parser/ApkFile.java b/src/main/java/net/dongliu/apk/parser/ApkFile.java
index 6415081..98a200f 100644
--- a/src/main/java/net/dongliu/apk/parser/ApkFile.java
+++ b/src/main/java/net/dongliu/apk/parser/ApkFile.java
@@ -47,7 +47,7 @@ protected List<CertificateFile> getAllCertificateData() throws IOException {
             }
             String name = ne.getName().toUpperCase();
             if (name.endsWith(".RSA") || name.endsWith(".DSA")) {
-                list.add(new CertificateFile(name, Inputs.toByteArray(zf.getInputStream(ne))));
+                list.add(new CertificateFile(name, Inputs.readAll(zf.getInputStream(ne))));
             }
         }
         return list;
@@ -61,7 +61,7 @@ public byte[] getFileData(String path) throws IOException {
         }
 
         InputStream inputStream = zf.getInputStream(entry);
-        return Inputs.toByteArray(inputStream);
+        return Inputs.readAll(inputStream);
     }
 
     @Override
@@ -107,4 +107,5 @@ public void close() throws IOException {
         super.close();
         zf.close();
     }
+
 }
diff --git a/src/main/java/net/dongliu/apk/parser/ByteArrayApkFile.java b/src/main/java/net/dongliu/apk/parser/ByteArrayApkFile.java
index a0ed3e2..ff24fe3 100644
--- a/src/main/java/net/dongliu/apk/parser/ByteArrayApkFile.java
+++ b/src/main/java/net/dongliu/apk/parser/ByteArrayApkFile.java
@@ -36,7 +36,7 @@ protected List<CertificateFile> getAllCertificateData() throws IOException {
             while ((entry = zis.getNextEntry()) != null) {
                 String name = entry.getName();
                 if (name.toUpperCase().endsWith(".RSA") || name.toUpperCase().endsWith(".DSA")) {
-                    list.add(new CertificateFile(name, Inputs.toByteArray(zis)));
+                    list.add(new CertificateFile(name, Inputs.readAll(zis)));
                 }
             }
         }
@@ -50,7 +50,7 @@ public byte[] getFileData(String path) throws IOException {
             ZipEntry entry;
             while ((entry = zis.getNextEntry()) != null) {
                 if (path.equals(entry.getName())) {
-                    return Inputs.toByteArray(zis);
+                    return Inputs.readAll(zis);
                 }
             }
         }
diff --git a/src/main/java/net/dongliu/apk/parser/Main.java b/src/main/java/net/dongliu/apk/parser/Main.java
index 6949dcd..3c180c8 100644
--- a/src/main/java/net/dongliu/apk/parser/Main.java
+++ b/src/main/java/net/dongliu/apk/parser/Main.java
@@ -11,7 +11,7 @@
 public class Main {
     public static void main(String[] args) throws IOException, CertificateException {
         try (ApkFile apkFile = new ApkFile(args[0])) {
-            System.out.println(apkFile.getApkMeta());
+            System.out.println(apkFile.getApkV2Singers().get(0).getCertificateMetas());
         }
     }
 }
diff --git a/src/main/java/net/dongliu/apk/parser/bean/ApkCertificateFileInfo.java b/src/main/java/net/dongliu/apk/parser/bean/ApkSigner.java
similarity index 51%
rename from src/main/java/net/dongliu/apk/parser/bean/ApkCertificateFileInfo.java
rename to src/main/java/net/dongliu/apk/parser/bean/ApkSigner.java
index 68d3bfb..6794907 100644
--- a/src/main/java/net/dongliu/apk/parser/bean/ApkCertificateFileInfo.java
+++ b/src/main/java/net/dongliu/apk/parser/bean/ApkSigner.java
@@ -5,7 +5,7 @@
 /**
  * ApkSignV1 certificate file.
  */
-public class ApkCertificateFileInfo {
+public class ApkSigner {
     /**
      * The cert file path in apk file
      */
@@ -13,19 +13,19 @@ public class ApkCertificateFileInfo {
     /**
      * The meta info of certificate contained in this cert file.
      */
-    private List<CertificateMeta> certificateMetaList;
+    private List<CertificateMeta> certificateMetas;
 
-    public ApkCertificateFileInfo(String path, List<CertificateMeta> certificateMetaList) {
+    public ApkSigner(String path, List<CertificateMeta> certificateMetas) {
         this.path = path;
-        this.certificateMetaList = certificateMetaList;
+        this.certificateMetas = certificateMetas;
     }
 
     public String getPath() {
         return path;
     }
 
-    public List<CertificateMeta> getCertificateMetaList() {
-        return certificateMetaList;
+    public List<CertificateMeta> getCertificateMetas() {
+        return certificateMetas;
     }
 
 }
diff --git a/src/main/java/net/dongliu/apk/parser/bean/ApkV2Signer.java b/src/main/java/net/dongliu/apk/parser/bean/ApkV2Signer.java
new file mode 100644
index 0000000..527d97a
--- /dev/null
+++ b/src/main/java/net/dongliu/apk/parser/bean/ApkV2Signer.java
@@ -0,0 +1,22 @@
+package net.dongliu.apk.parser.bean;
+
+import java.util.List;
+
+/**
+ * ApkSignV1 certificate file.
+ */
+public class ApkV2Signer {
+    /**
+     * The meta info of certificate contained in this cert file.
+     */
+    private List<CertificateMeta> certificateMetas;
+
+    public ApkV2Signer(List<CertificateMeta> certificateMetas) {
+        this.certificateMetas = certificateMetas;
+    }
+
+    public List<CertificateMeta> getCertificateMetas() {
+        return certificateMetas;
+    }
+
+}
diff --git a/src/main/java/net/dongliu/apk/parser/parser/ApkSignBlockParser.java b/src/main/java/net/dongliu/apk/parser/parser/ApkSignBlockParser.java
new file mode 100644
index 0000000..9e73902
--- /dev/null
+++ b/src/main/java/net/dongliu/apk/parser/parser/ApkSignBlockParser.java
@@ -0,0 +1,135 @@
+package net.dongliu.apk.parser.parser;
+
+import net.dongliu.apk.parser.struct.signingv2.ApkSigningBlock;
+import net.dongliu.apk.parser.struct.signingv2.Digest;
+import net.dongliu.apk.parser.struct.signingv2.Signature;
+import net.dongliu.apk.parser.struct.signingv2.SignerBlock;
+import net.dongliu.apk.parser.utils.Buffers;
+import net.dongliu.apk.parser.utils.Unsigned;
+
+import java.io.ByteArrayInputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.security.cert.Certificate;
+import java.security.cert.CertificateException;
+import java.security.cert.CertificateFactory;
+import java.security.cert.X509Certificate;
+import java.util.ArrayList;
+import java.util.List;
+
+// see https://source.android.com/security/apksigning/v2
+
+/**
+ * The Apk Sign Block V2 Parser.
+ */
+public class ApkSignBlockParser {
+    private ByteBuffer data;
+
+    public ApkSignBlockParser(ByteBuffer data) {
+        this.data = data.order(ByteOrder.LITTLE_ENDIAN);
+    }
+
+    public ApkSigningBlock parse() throws CertificateException {
+        // sign block found, read pairs
+        List<SignerBlock> signerBlocks = new ArrayList<>();
+        while (data.hasRemaining()) {
+            int id = data.getInt();
+            int size = Unsigned.ensureUInt(data.getInt());
+            if (id == ApkSigningBlock.SIGNING_V2_ID) {
+                ByteBuffer signingV2Buffer = Buffers.sliceAndSkip(data, size);
+                // now only care about apk signing v2 entry
+                while (signingV2Buffer.hasRemaining()) {
+                    SignerBlock signerBlock = readSigningV2(signingV2Buffer);
+                    signerBlocks.add(signerBlock);
+                }
+            } else {
+                // just ignore now
+                Buffers.position(data, data.position() + size);
+            }
+        }
+        return new ApkSigningBlock(signerBlocks);
+    }
+
+    private SignerBlock readSigningV2(ByteBuffer buffer) throws CertificateException {
+        buffer = readLenPrefixData(buffer);
+
+        ByteBuffer signedData = readLenPrefixData(buffer);
+        ByteBuffer digestsData = readLenPrefixData(signedData);
+        List<Digest> digests = readDigests(digestsData);
+        ByteBuffer certificateData = readLenPrefixData(signedData);
+        List<X509Certificate> certificates = readCertificates(certificateData);
+        ByteBuffer attributesData = readLenPrefixData(signedData);
+        readAttributes(attributesData);
+
+        ByteBuffer signaturesData = readLenPrefixData(buffer);
+        List<Signature> signatures = readSignatures(signaturesData);
+
+        ByteBuffer publicKeyData = readLenPrefixData(buffer);
+        return new SignerBlock(digests, certificates, signatures);
+    }
+
+    private List<Digest> readDigests(ByteBuffer buffer) {
+        List<Digest> list = new ArrayList<>();
+        while (buffer.hasRemaining()) {
+            ByteBuffer digestData = readLenPrefixData(buffer);
+            int algorithmID = digestData.getInt();
+            byte[] digest = Buffers.readBytes(digestData);
+            list.add(new Digest(algorithmID, digest));
+        }
+        return list;
+    }
+
+    private List<X509Certificate> readCertificates(ByteBuffer buffer) throws CertificateException {
+        CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
+        List<X509Certificate> certificates = new ArrayList<>();
+        while (buffer.hasRemaining()) {
+            ByteBuffer certificateData = readLenPrefixData(buffer);
+            Certificate certificate = certificateFactory.generateCertificate(
+                    new ByteArrayInputStream(Buffers.readBytes(certificateData)));
+            certificates.add((X509Certificate) certificate);
+        }
+        return certificates;
+    }
+
+    private void readAttributes(ByteBuffer buffer) {
+        while (buffer.hasRemaining()) {
+            ByteBuffer attributeData = readLenPrefixData(buffer);
+            int id = attributeData.getInt();
+//            byte[] value = Buffers.readBytes(attributeData);
+        }
+    }
+
+    private List<Signature> readSignatures(ByteBuffer buffer) {
+        List<Signature> signatures = new ArrayList<>();
+        while (buffer.hasRemaining()) {
+            ByteBuffer signatureData = readLenPrefixData(buffer);
+            int algorithmID = signatureData.getInt();
+            int signatureDataLen = Unsigned.ensureUInt(signatureData.getInt());
+            byte[] signature = Buffers.readBytes(signatureData, signatureDataLen);
+            signatures.add(new Signature(algorithmID, signature));
+        }
+        return signatures;
+    }
+
+
+    private ByteBuffer readLenPrefixData(ByteBuffer buffer) {
+        int len = Unsigned.ensureUInt(buffer.getInt());
+        return Buffers.sliceAndSkip(buffer, len);
+    }
+
+    // 0x0101—RSASSA-PSS with SHA2-256 digest, SHA2-256 MGF1, 32 bytes of salt, trailer: 0xbc
+    private static final int PSS_SHA_256 = 0x0101;
+    // 0x0102—RSASSA-PSS with SHA2-512 digest, SHA2-512 MGF1, 64 bytes of salt, trailer: 0xbc
+    private static final int PSS_SHA_512 = 0x0102;
+    // 0x0103—RSASSA-PKCS1-v1_5 with SHA2-256 digest. This is for build systems which require deterministic signatures.
+    private static final int PKCS1_SHA_256 = 0x0103;
+    // 0x0104—RSASSA-PKCS1-v1_5 with SHA2-512 digest. This is for build systems which require deterministic signatures.
+    private static final int PKCS1_SHA_512 = 0x0104;
+    // 0x0201—ECDSA with SHA2-256 digest
+    private static final int ECDSA_SHA_256 = 0x0201;
+    // 0x0202—ECDSA with SHA2-512 digest
+    private static final int ECDSA_SHA_512 = 0x0202;
+    // 0x0301—DSA with SHA2-256 digest
+    private static final int DSA_SHA_256 = 0x0301;
+
+}
diff --git a/src/main/java/net/dongliu/apk/parser/parser/CertificateMetas.java b/src/main/java/net/dongliu/apk/parser/parser/CertificateMetas.java
new file mode 100644
index 0000000..a37b2c3
--- /dev/null
+++ b/src/main/java/net/dongliu/apk/parser/parser/CertificateMetas.java
@@ -0,0 +1,78 @@
+package net.dongliu.apk.parser.parser;
+
+import net.dongliu.apk.parser.bean.CertificateMeta;
+
+import java.math.BigInteger;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.security.cert.CertificateEncodingException;
+import java.security.cert.X509Certificate;
+import java.util.ArrayList;
+import java.util.List;
+
+public class CertificateMetas {
+
+    public static List<CertificateMeta> from(List<X509Certificate> certificates) throws CertificateEncodingException {
+        List<CertificateMeta> certificateMetas = new ArrayList<>(certificates.size());
+        for (X509Certificate certificate : certificates) {
+            CertificateMeta certificateMeta = CertificateMetas.from(certificate);
+            certificateMetas.add(certificateMeta);
+        }
+        return certificateMetas;
+    }
+
+    public static CertificateMeta from(X509Certificate certificate) throws CertificateEncodingException {
+        CertificateMeta certificateMeta = new CertificateMeta();
+        byte[] bytes = certificate.getEncoded();
+        String certMd5 = md5Digest(bytes);
+        String publicKeyString = byteToHexString(bytes);
+        String certBase64Md5 = md5Digest(publicKeyString);
+        certificateMeta.setData(bytes);
+        certificateMeta.setCertBase64Md5(certBase64Md5);
+        certificateMeta.setCertMd5(certMd5);
+        certificateMeta.setStartDate(certificate.getNotBefore());
+        certificateMeta.setEndDate(certificate.getNotAfter());
+        certificateMeta.setSignAlgorithm(certificate.getSigAlgName());
+        certificateMeta.setSignAlgorithmOID(certificate.getSigAlgOID());
+        return certificateMeta;
+    }
+
+    private static String md5Digest(byte[] input) {
+        MessageDigest digest = getDigest("md5");
+        digest.update(input);
+        return getHexString(digest.digest());
+    }
+
+    private static String md5Digest(String input) {
+        MessageDigest digest = getDigest("md5");
+        digest.update(input.getBytes(StandardCharsets.UTF_8));
+        return getHexString(digest.digest());
+    }
+
+    private static String byteToHexString(byte[] bArray) {
+        StringBuilder sb = new StringBuilder(bArray.length);
+        String sTemp;
+        for (byte aBArray : bArray) {
+            sTemp = Integer.toHexString(0xFF & (char) aBArray);
+            if (sTemp.length() < 2) {
+                sb.append(0);
+            }
+            sb.append(sTemp.toUpperCase());
+        }
+        return sb.toString();
+    }
+
+    private static String getHexString(byte[] digest) {
+        BigInteger bi = new BigInteger(1, digest);
+        return String.format("%032x", bi);
+    }
+
+    private static MessageDigest getDigest(String algorithm) {
+        try {
+            return MessageDigest.getInstance(algorithm);
+        } catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException(e.getMessage());
+        }
+    }
+}
diff --git a/src/main/java/net/dongliu/apk/parser/parser/CertificateParser.java b/src/main/java/net/dongliu/apk/parser/parser/CertificateParser.java
index 905448a..a8e4dbf 100644
--- a/src/main/java/net/dongliu/apk/parser/parser/CertificateParser.java
+++ b/src/main/java/net/dongliu/apk/parser/parser/CertificateParser.java
@@ -10,13 +10,7 @@
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.bouncycastle.util.Store;
 
-import java.io.IOException;
-import java.math.BigInteger;
-import java.nio.charset.StandardCharsets;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 import java.security.Security;
-import java.security.cert.CertificateEncodingException;
 import java.security.cert.CertificateException;
 import java.security.cert.X509Certificate;
 import java.util.ArrayList;
@@ -33,8 +27,6 @@ public class CertificateParser {
 
     private final byte[] data;
 
-    private List<CertificateMeta> certificateMetas;
-
     static {
         Security.addProvider(new BouncyCastleProvider());
     }
@@ -45,11 +37,8 @@ public CertificateParser(byte[] data) {
 
     /**
      * get certificate info
-     *
-     * @throws IOException
-     * @throws CertificateEncodingException
      */
-    public void parse() throws IOException, CertificateException {
+    public List<CertificateMeta> parse() throws CertificateException {
 
 
         CMSSignedData cmsSignedData;
@@ -68,65 +57,7 @@ public void parse() throws IOException, CertificateException {
                 certificates.add(new JcaX509CertificateConverter().setProvider("BC").getCertificate(holder));
             }
         }
-        certificateMetas = new ArrayList<>();
-        for (X509Certificate certificate : certificates) {
-            CertificateMeta certificateMeta = new CertificateMeta();
-            certificateMetas.add(certificateMeta);
-
-            byte[] bytes = certificate.getEncoded();
-            String certMd5 = md5Digest(bytes);
-            String publicKeyString = byteToHexString(bytes);
-            String certBase64Md5 = md5Digest(publicKeyString);
-            certificateMeta.setData(bytes);
-            certificateMeta.setCertBase64Md5(certBase64Md5);
-            certificateMeta.setCertMd5(certMd5);
-            certificateMeta.setStartDate(certificate.getNotBefore());
-            certificateMeta.setEndDate(certificate.getNotAfter());
-            certificateMeta.setSignAlgorithm(certificate.getSigAlgName());
-            certificateMeta.setSignAlgorithmOID(certificate.getSigAlgOID());
-        }
-    }
-
-
-    private String md5Digest(byte[] input) throws IOException {
-        MessageDigest digest = getDigest("md5");
-        digest.update(input);
-        return getHexString(digest.digest());
-    }
-
-    private String md5Digest(String input) throws IOException {
-        MessageDigest digest = getDigest("md5");
-        digest.update(input.getBytes(StandardCharsets.UTF_8));
-        return getHexString(digest.digest());
+        return CertificateMetas.from(certificates);
     }
 
-    private String byteToHexString(byte[] bArray) {
-        StringBuilder sb = new StringBuilder(bArray.length);
-        String sTemp;
-        for (byte aBArray : bArray) {
-            sTemp = Integer.toHexString(0xFF & (char) aBArray);
-            if (sTemp.length() < 2) {
-                sb.append(0);
-            }
-            sb.append(sTemp.toUpperCase());
-        }
-        return sb.toString();
-    }
-
-    private String getHexString(byte[] digest) {
-        BigInteger bi = new BigInteger(1, digest);
-        return String.format("%032x", bi);
-    }
-
-    private MessageDigest getDigest(String algorithm) {
-        try {
-            return MessageDigest.getInstance(algorithm);
-        } catch (NoSuchAlgorithmException e) {
-            throw new RuntimeException(e.getMessage());
-        }
-    }
-
-    public List<CertificateMeta> getCertificateMetas() {
-        return certificateMetas;
-    }
 }
diff --git a/src/main/java/net/dongliu/apk/parser/parser/DexParser.java b/src/main/java/net/dongliu/apk/parser/parser/DexParser.java
index 2a968b3..32cde79 100644
--- a/src/main/java/net/dongliu/apk/parser/parser/DexParser.java
+++ b/src/main/java/net/dongliu/apk/parser/parser/DexParser.java
@@ -23,22 +23,19 @@
 public class DexParser {
 
     private ByteBuffer buffer;
-    private ByteOrder byteOrder = ByteOrder.LITTLE_ENDIAN;
 
     private static final int NO_INDEX = 0xffffffff;
 
-    private DexClass[] dexClasses;
-
     public DexParser(ByteBuffer buffer) {
         this.buffer = buffer.duplicate();
-        this.buffer.order(byteOrder);
+        this.buffer.order(ByteOrder.LITTLE_ENDIAN);
     }
 
-    public void parse() {
+    public DexClass[] parse() {
         // read magic
         String magic = new String(Buffers.readBytes(buffer, 8));
         if (!magic.startsWith("dex\n")) {
-            return;
+            return new DexClass[0];
         }
         int version = Integer.parseInt(magic.substring(4, 7));
         // now the version is 035
@@ -69,7 +66,7 @@ public void parse() {
             types[i] = stringpool.get(typeIds[i]);
         }
 
-        dexClasses = new DexClass[dexClassStructs.length];
+        DexClass[] dexClasses = new DexClass[dexClassStructs.length];
         for (int i = 0; i < dexClasses.length; i++) {
             dexClasses[i] = new DexClass();
         }
@@ -82,6 +79,7 @@ public void parse() {
             }
             dexClass.setAccessFlags(dexClassStruct.getAccessFlags());
         }
+        return dexClasses;
     }
 
     /**
@@ -283,9 +281,5 @@ private DexHeader readDexHeader() {
         return header;
     }
 
-    public DexClass[] getDexClasses() {
-        return dexClasses;
-    }
-
 }
 
diff --git a/src/main/java/net/dongliu/apk/parser/struct/ApkSignatureV2.java b/src/main/java/net/dongliu/apk/parser/struct/ApkSignatureV2.java
deleted file mode 100644
index dcfbf3b..0000000
--- a/src/main/java/net/dongliu/apk/parser/struct/ApkSignatureV2.java
+++ /dev/null
@@ -1,10 +0,0 @@
-package net.dongliu.apk.parser.struct;
-
-/**
- * Apk signature v2 block
- *
- * @see <a href="https://source.android.com/security/apksigning/v2></a>
- */
-public class ApkSignatureV2 {
-
-}
diff --git a/src/main/java/net/dongliu/apk/parser/struct/ApkSigningBlock.java b/src/main/java/net/dongliu/apk/parser/struct/ApkSigningBlock.java
deleted file mode 100644
index dd1c922..0000000
--- a/src/main/java/net/dongliu/apk/parser/struct/ApkSigningBlock.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package net.dongliu.apk.parser.struct;
-
-import net.dongliu.apk.parser.utils.Unsigned;
-
-/**
- * For read apk signing block
- *
- * @see <a href="https://source.android.com/security/apksigning/v2">apksigning v2 scheme</a>
- */
-public class ApkSigningBlock {
-    public static final int SIGNING_V2_ID = 0x7109871a;
-
-    public static final String MAGIC = "APK Sig Block 42";
-
-    // uint64, the size of this block
-    public long size;
-
-    public long getSize() {
-        return size;
-    }
-
-    public void setSize(long size) {
-        this.size = Unsigned.ensureUInt(size);
-    }
-
-    public static class Entry {
-        // uint32 the entry id
-        private int id;
-        // the len of this pair
-        private int size;
-    }
-
-
-}
diff --git a/src/main/java/net/dongliu/apk/parser/struct/signingv2/ApkSigningBlock.java b/src/main/java/net/dongliu/apk/parser/struct/signingv2/ApkSigningBlock.java
new file mode 100644
index 0000000..5796f5b
--- /dev/null
+++ b/src/main/java/net/dongliu/apk/parser/struct/signingv2/ApkSigningBlock.java
@@ -0,0 +1,24 @@
+package net.dongliu.apk.parser.struct.signingv2;
+
+import java.util.List;
+
+/**
+ * For read apk signing block
+ *
+ * @see <a href="https://source.android.com/security/apksigning/v2">apksigning v2 scheme</a>
+ */
+public class ApkSigningBlock {
+    public static final int SIGNING_V2_ID = 0x7109871a;
+
+    public static final String MAGIC = "APK Sig Block 42";
+
+    private List<SignerBlock> signerBlocks;
+
+    public ApkSigningBlock(List<SignerBlock> signerBlocks) {
+        this.signerBlocks = signerBlocks;
+    }
+
+    public List<SignerBlock> getSignerBlocks() {
+        return signerBlocks;
+    }
+}
diff --git a/src/main/java/net/dongliu/apk/parser/struct/signingv2/Digest.java b/src/main/java/net/dongliu/apk/parser/struct/signingv2/Digest.java
new file mode 100644
index 0000000..5276269
--- /dev/null
+++ b/src/main/java/net/dongliu/apk/parser/struct/signingv2/Digest.java
@@ -0,0 +1,19 @@
+package net.dongliu.apk.parser.struct.signingv2;
+
+public class Digest {
+    private int algorithmID;
+    private byte[] value;
+
+    public Digest(int algorithmID, byte[] value) {
+        this.algorithmID = algorithmID;
+        this.value = value;
+    }
+
+    public int getAlgorithmID() {
+        return algorithmID;
+    }
+
+    public byte[] getValue() {
+        return value;
+    }
+}
diff --git a/src/main/java/net/dongliu/apk/parser/struct/signingv2/Signature.java b/src/main/java/net/dongliu/apk/parser/struct/signingv2/Signature.java
new file mode 100644
index 0000000..05ed0db
--- /dev/null
+++ b/src/main/java/net/dongliu/apk/parser/struct/signingv2/Signature.java
@@ -0,0 +1,19 @@
+package net.dongliu.apk.parser.struct.signingv2;
+
+public class Signature {
+    private int algorithmID;
+    private byte[] data;
+
+    public Signature(int algorithmID, byte[] data) {
+        this.algorithmID = algorithmID;
+        this.data = data;
+    }
+
+    public int getAlgorithmID() {
+        return algorithmID;
+    }
+
+    public byte[] getData() {
+        return data;
+    }
+}
diff --git a/src/main/java/net/dongliu/apk/parser/struct/signingv2/SignerBlock.java b/src/main/java/net/dongliu/apk/parser/struct/signingv2/SignerBlock.java
new file mode 100644
index 0000000..a1b8e79
--- /dev/null
+++ b/src/main/java/net/dongliu/apk/parser/struct/signingv2/SignerBlock.java
@@ -0,0 +1,28 @@
+package net.dongliu.apk.parser.struct.signingv2;
+
+import java.security.cert.X509Certificate;
+import java.util.List;
+
+public class SignerBlock {
+    private List<Digest> digests;
+    private List<X509Certificate> certificates;
+    private List<Signature> signatures;
+
+    public SignerBlock(List<Digest> digests, List<X509Certificate> certificates, List<Signature> signatures) {
+        this.digests = digests;
+        this.certificates = certificates;
+        this.signatures = signatures;
+    }
+
+    public List<Digest> getDigests() {
+        return digests;
+    }
+
+    public List<X509Certificate> getCertificates() {
+        return certificates;
+    }
+
+    public List<Signature> getSignatures() {
+        return signatures;
+    }
+}
diff --git a/src/main/java/net/dongliu/apk/parser/utils/Buffers.java b/src/main/java/net/dongliu/apk/parser/utils/Buffers.java
index f10f232..4e28b80 100644
--- a/src/main/java/net/dongliu/apk/parser/utils/Buffers.java
+++ b/src/main/java/net/dongliu/apk/parser/utils/Buffers.java
@@ -44,6 +44,13 @@ public static byte[] readBytes(ByteBuffer buffer, int size) {
         return bytes;
     }
 
+    /**
+     * get all bytes remains
+     */
+    public static byte[] readBytes(ByteBuffer buffer) {
+        return readBytes(buffer, buffer.remaining());
+    }
+
     /**
      * Read ascii string ,by len
      */
@@ -112,7 +119,7 @@ public static void position(ByteBuffer buffer, long position) {
      * Return one new ByteBuffer from current position, with size, the byte order of new buffer will be set to little endian;
      * And advance the original buffer with size.
      */
-    public static ByteBuffer slice(ByteBuffer buffer, int size) {
+    public static ByteBuffer sliceAndSkip(ByteBuffer buffer, int size) {
         ByteBuffer buf = buffer.slice().order(ByteOrder.LITTLE_ENDIAN);
         ByteBuffer slice = (ByteBuffer) ((Buffer) buf).limit(buf.position() + size);
         skip(buffer, size);
diff --git a/src/main/java/net/dongliu/apk/parser/utils/Inputs.java b/src/main/java/net/dongliu/apk/parser/utils/Inputs.java
index 11ce57e..c3cd355 100644
--- a/src/main/java/net/dongliu/apk/parser/utils/Inputs.java
+++ b/src/main/java/net/dongliu/apk/parser/utils/Inputs.java
@@ -6,7 +6,7 @@
 
 public class Inputs {
 
-    public static byte[] toByteArray(InputStream in) throws IOException {
+    public static byte[] readAll(InputStream in) throws IOException {
         try {
             byte[] buf = new byte[1024 * 8];
             try (ByteArrayOutputStream bos = new ByteArrayOutputStream()) {
diff --git a/src/main/java/net/dongliu/apk/parser/utils/ResourceFetcher.java b/src/main/java/net/dongliu/apk/parser/utils/ResourceFetcher.java
index 8605194..9527016 100644
--- a/src/main/java/net/dongliu/apk/parser/utils/ResourceFetcher.java
+++ b/src/main/java/net/dongliu/apk/parser/utils/ResourceFetcher.java
@@ -106,7 +106,7 @@ private String getUrl(String url) throws IOException {
             conn.setRequestMethod("GET");
             conn.setReadTimeout(10000);
             conn.setConnectTimeout(10000);
-            byte[] bytes = Inputs.toByteArray(conn.getInputStream());
+            byte[] bytes = Inputs.readAll(conn.getInputStream());
             return new String(bytes, StandardCharsets.UTF_8);
         } finally {
             conn.disconnect();
diff --git a/src/test/java/net/dongliu/apk/parser/parser/ApkSignBlockParserTest.java b/src/test/java/net/dongliu/apk/parser/parser/ApkSignBlockParserTest.java
new file mode 100644
index 0000000..76307b9
--- /dev/null
+++ b/src/test/java/net/dongliu/apk/parser/parser/ApkSignBlockParserTest.java
@@ -0,0 +1,21 @@
+package net.dongliu.apk.parser.parser;
+
+import net.dongliu.apk.parser.utils.Inputs;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.file.Files;
+import java.security.cert.CertificateException;
+
+import static org.junit.Assert.*;
+
+public class ApkSignBlockParserTest {
+
+    @Test
+    public void parse() throws IOException, CertificateException {
+        byte[] bytes = Inputs.readAll(getClass().getResourceAsStream("/sign/gmail_sign_block"));
+        ApkSignBlockParser parser = new ApkSignBlockParser(ByteBuffer.wrap(bytes));
+        parser.parse();
+    }
+}
\ No newline at end of file