Android gets the MD5 value of the APK signature fingerprint (to prevent repackaging) _android

The example in this article describes the implementation of Android acquiring the MD5 value of APK signature fingerprint to prevent repackaging. Share to everyone for your reference, specific as follows:

Make a record (here is only the Java layer signature Check, Java layer is easy to be cracked, I suggest apk reinforcement)

Obtaining the MD5 value for APK signature verification prevents APK from being packaged again.

Let me tell you how to get the MD5 value of the APK signature (there are three ways)

1. Obtain the MD5 value of signature fingerprint by code

/** * MD5 encryption * @param bytestr the content that needs to be encrypted * @return returns the BYTESTR value of MD5/public static Stri
  Ng encryptionMD5 (byte[] bytestr) {messagedigest messagedigest = null;
  StringBuffer Md5strbuff = new StringBuffer ();
    try {messagedigest = messagedigest.getinstance ("MD5");
    Messagedigest.reset ();
    Messagedigest.update (BYTESTR);
    byte[] ByteArray = Messagedigest.digest ();
        for (int i = 0; i < bytearray.length i++) {if (Integer.tohexstring (0xFF & Bytearray[i)). Length () = 1) {
      Md5strbuff.append ("0"). Append (integer.tohexstring (0xFF & Bytearray[i));
      else {md5strbuff.append (integer.tohexstring (0xFF & Bytearray[i]));
  A catch (NoSuchAlgorithmException e) {e.printstacktrace ());
return md5strbuff.tostring (); }

/**
 * Get app signature MD5 value
 *
/Public String getsignmd5str () {
  try {
    PackageInfo PackageInfo = Mactivity.getpackagemanager (). Getpackageinfo (Mactivity.getpackagename (), packagemanager.get_signatures);
    Signature[] signs = packageinfo.signatures;
    Signature sign = signs[0];
    String signstr = encryptionMD5 (Sign.tobytearray ());
    return signstr;
  } catch (Packagemanager.namenotfoundexception e) {
    e.printstacktrace ();
  }
  Return "";
}

2. Keytool Tools

Using the Keytool tool to obtain the signature MD5 information, the following key is a signed file

Copy Code code as follows:

C:\Program files\java\jdk1.8.0_05\bin>keytool-list-v-keystore C:\Users\Administrator\Desktop\key

3. In Eclipse, you can view signature information.

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I hope this article will help you with the Android program.