Security update: PBKDF2, hash and multiple IV

Author: ortis

README.md

@@ -1,4 +1,5 @@
 
+
 [![GitHub license](https://img.shields.io/github/license/0rtis/jsafebox.svg?style=flat-square)](https://github.com/0rtis/jsafebox/blob/master/LICENSE)
 [![Build Status](https://img.shields.io/travis/0rtis/jsafebox.svg?style=flat-square)](https://travis-ci.org/0rtis/jsafebox)
 [![codecov](https://img.shields.io/codecov/c/github/0rtis/jsafebox.svg?style=flat-square)](https://codecov.io/gh/0rtis/jsafebox)
@@ -21,7 +22,7 @@
 
 # JSafebox - A lightweight, portable and cross-platform vault
 
-JSafebox encrypt your file using [AES](https://en.wikipedia.org/wiki/Advanced_Encryption_Standard) encryption. It can be used as command line tool or with a _file explorer_ like interface.
+JSafebox encrypt your files using [AES](https://en.wikipedia.org/wiki/Advanced_Encryption_Standard) encryption. It can be used as command line tool or with a _file explorer_ like interface.
 
 **Decrypted data is never written on the drive** (except during file extraction requested by user).
 
@@ -34,35 +35,43 @@ JSafebox encrypt your file using [AES](https://en.wikipedia.org/wiki/Advanced_En
 
 ### Why JSafebox ?
 With the rise of online banking, cryptocurrencies and other digital transformation, it has become mandatory to backup sensitive files.
-Those file need to be easily accessible, securely stored and encrypted. But lightweight, portable, cross platform vault software are surprisingly hard to come by. Password protected archive works fine but they let room for file leakage as there is no convenient way of exploring the vault without extracting the whole content. Jsafebox was made to cover these shortfalls.
+Those file need to be easily accessible, securely stored and encrypted. But lightweight, portable, cross platform vault software are surprisingly hard to come by. Password protected archive works fine but they let room for file leakage since there is no convenient way of exploring the vault without extracting the whole content. Jsafebox was made to cover these shortfalls.
 
 
 
 
 
 
 ### JSafebox Protocol
-JSafebox is using a very simple protocol so encrypted files can be easily read by another program, as long as you have the encryption password.
-Each datagram is preceded by its length stored as a 64 bits (8 bytes) integer (`long` in Java):
+JSafebox is using a very simple protocol so encrypted files can be easily read by another program, as long as you have the password. The encryption key is derived from the password using [PBKDF2](https://en.wikipedia.org/wiki/PBKDF2) hashing with 100000 iteration.
+
+A JSafebox file contains a [SHA256](https://en.wikipedia.org/wiki/SHA-2) integrity hash followed by blocks:
+	
+	integrity hash | block 0 | block 1 | ... | block N
 
-    length 0|datagram 0|length 1|datagram 1|length 3|...|datagram N
+Each block is stored as followed: 
+
+    IV | metadata length | metadata | data length | data
 
-The first datagram `datagram 0` is the *header* and is **the only datagram not encrypted**. The *header* contains text entries specified by the user and various additional entries incuding a protocol explanation, the type of encoding and the IV of the encryption. The *header*'s data is stored in JSON format and can be seen by opening the safe file with a basic text editor.
+where `IV` is the [Initialization_vector](https://en.wikipedia.org/wiki/Initialization_vector) of the encryption (16 bytes), `metadata` is a JSON string and `length` are 64 bits (8 bytes) integer (`long` in Java).
+
+The first block `block 0` is the *header* and is **the only block not encrypted** and therefore, **the only block without IV**. The *header* only have metadata (`data length` is 0) and contains text entries specified by the user and various additional entries including a protocol explanation, the type of encoding and the parameters of the encryption. The *header*'s metadata is stored as JSON string and can be seen by opening the safe file with a basic text editor.
 
-The second datagram `datagram 1` is the *properties*. It contains encrypted text entries specified by the user.
+The second block `block 1` is the *properties*. It is similar to the *header* except that it is encrypted and have an IV. The *properties* contains text entries specified by the user and stored in JSON.
 
-The following datagrams (from 2 to N) are the encrypted files. They work by pair: `datagram i ` contains the metadata of the file as an encrypted JSON text and `datagram i+1` contains the bytes of the encrypted file.
+The following blocks (from 2 to N) are the encrypted files. 
 
 
 
 ### TODO
-- [x] Command line
+- [x] Command line (with the mighty tiny [picocli](https://github.com/remkop/picocli) project)
 - [x] Wildcard path support
 - [x] File explorer
 - [x] Import with Drag & Drop
-- [ ] Export with Drag & Drop
+- [x] Export ~~with Drag & Drop~~ (Risk of unintentional drag resulting in data leak)
 - [x] Text viewer
 - [x] Image viewer (zoom and drag)
+- [x] Integrity check
 - [ ] Interactive shell
 
 
@@ -71,7 +80,6 @@ The following datagrams (from 2 to N) are the encrypted files. They work by pair
 
 You can download the latest version of JSafebox [here](https://github.com/0rtis/jsafebox/releases/latest)
 
-*JSafebox is using the mighty tiny [picocli](https://github.com/remkop/picocli)*
 
 
 ### Install

src/main/java/org/ortis/jsafebox/Block.java

@@ -25,6 +25,8 @@ public class Block implements SafeFile
 	private final String comparablePath;
 	private final long offset;
 	private final long length;
+
+
 	private final long metaOffset;
 	private final long metaLength;
 	private final long dataOffset;
@@ -35,17 +37,19 @@ public class Block implements SafeFile
 	private final Folder parent;
 
 	public Block(final String path, final Map<String, String> properties, final long offset, final long length, final long metaOffset, final long metaLength, final long dataOffset,
-			final long dataLength, final Folder parent)
+			final long dataLength,  final Folder parent)
 	{
 		this.path = path;
 		this.comparablePath = path.toUpperCase(Environment.getLocale());
 		this.offset = offset;
 		this.length = length;
+
 		this.metaOffset = metaOffset;
 		this.metaLength = metaLength;
 		this.dataOffset = dataOffset;
 		this.dataLength = dataLength;
 
+	
 		final Map<String, String> props = new LinkedHashMap<>();
 		props.putAll(properties);