# RFC 13: Duniter Encrypted Wallet Import Format

```txt
RFC: 13
Title: Duniter Encrypted Wallet Import Format
Type: Format
Status: WIP
Author: elois <c@elo.tf>
Created: 2020-02-13
Last edited: 2020-02-13
License: CC-SA
```

## Introduction

A wallet is a pair of asymmetric keys (a public key + a private key).

The purpose of this RFC is to define a standard, inter-operable and secure format for any [DUBP] wallet.

This RFC does not define a file format, it is agnostic of the way the wallet is stored on the disk.

## DUBP

[DUBP] only deals with public keys and signatures.

A public key is always paired with a private key, which DUBP will never deal with.

Today DUBP manage only the algorithm ED25519, but in the future DUBP can evolve to manage multiples digital signature algorithms.

So currently a public key for DUBP is to be understood as an Ed25519 public key.

## DEWIF format

DEWIF is an inter-operable and secure format for any DUBP wallet.

DEWIF format is a base64 string.  
This base64 string encodes a sequence of bytes whose structure is defined below.

## dewif bytes structure

| version (4 bytes) | currency code (4 bytes) | version data (any bytes) |
|:-----------------:|:-----------------------:|:------------------------:|

## Version

The 4 bytes of the version field must be interpreted as an unsigned integer encoded in big endian.

## Currencies code

| Currency | code       |
|:---------|:-----------|
| None     | 0x00000000 |
| Ğ1       | 0x00000001 |
| Ğ1-Test  | 0x10000001 |

## version data

### v1

v1 data (encrypted):

| seed(32 bytes) | public key(32bytes) |
|:--------------:|:-------------------:|
| seed bytes     | public key bytes    |

The public key serves as a checksum. To check that the DEWIF base64 string is not corrupted, simply generate an ed25519 keypair with the seed and check that the obtained public key matches.

Symmetric encryption algorithm : aes256

aes256 key: scrypt of user passphrase with the following parameters:  

**password:** passphrase  
**salt:** sha256("dewif" ++ passphrase)  
**N:** 4096  
**r:** 16  
**p:** 1

Example #1:

aes256 key generated from scrypt with the following parameters:  

**keypair seed:** 0xbfa3f6e322cf21d0e652f79a69df9498fdf5347665e5646d9041f756496a1143  
**N:** 4096  
**r:** 16  
**p:** 1

```txt
0x000000001 #v1
0x100000001 #g1-test
0xbfa3f6e322cf21d0e652f79a69df9498fdf5347665e5646d9041f756496a1143 # keypair seed
0x17df9d2b059cdd2825955691e3a783e6da403148ddebb1144d1a9b9e545f2371 # public key
```

DEWIF base 64 string (with aes key `"toto titi tata"`):

`AAAAARAAAAGfFDAs+jVZYkfhBlHZZ2fEQIvBqnG16g5+02cY18wSOjW0cUg2JV3SUTJYN2CrbQeRDwGazWnzSFBphchMmiL0`

### v2

v2 data (encrypted):

| seed1(32 bytes) | public key1(32bytes) | seed2(32 bytes) | public key2(32bytes) |
|:---------------:|:--------------------:|:---------------:|:--------------------:|
| seed bytes      | public key bytes     | seed bytes      | public key bytes     |

The public key serves as a checksum. To check that the DEWIF base64 string is not corrupted, simply generate an ed25519 keypair with the seed and check that the obtained public key matches.

Symmetric encryption algorithm : aes256

aes256 key: scrypt of user passphrase with the following parameters:  

**password:** passphrase  
**salt:** sha256("dewif" ++ passphrase)  
**N:** 4096  
**r:** 16  
**p:** 1

### v3

v3 data :

| `log N` | Encrypted data |
|:-------:|:--------------:|
| 1 byte  | 64 bytes       |

Encrypted data :

| seed(32 bytes) | public key(32bytes) |
|:--------------:|:-------------------:|
| seed bytes     | public key bytes    |

The public key serves as a checksum. To check that the DEWIF base64 string is not corrupted, simply generate an ed25519 keypair with the seed and check that the obtained public key matches.

Symmetric encryption algorithm : aes256

aes256 key: scrypt of user passphrase with the following parameters:  

**password:** passphrase  
**salt:** sha256("dewif" ++ passphrase)  
**N:** `2^(log N)`  
**r:** 16  
**p:** 1

Example #2:

aes256 key generated from scrypt with the following parameters:  

**keypair seed:** 0xbfa3f6e322cf21d0e652f79a69df9498fdf5347665e5646d9041f756496a1143  
**N:** `2^15 = 32768`  
**r:** 16  
**p:** 1

```txt
0x000000003 #v3
0x100000001 #g1-test
0x0F # log N
0xbfa3f6e322cf21d0e652f79a69df9498fdf5347665e5646d9041f756496a1143 # keypair seed
0x17df9d2b059cdd2825955691e3a783e6da403148ddebb1144d1a9b9e545f2371 # public key
```

DEWIF base 64 string (with aes key `"toto titi tata"`):

`AAAAAxAAAAEPdMuBFXF4C6GZPGsJDiPBbacpVKeaLoJwkDsuqLjkwof1c760Z5iVpnZlLt5XEFlEehbdtLllVhccf9OK6Zjn8A==`

### v4

Version 4 stores an HD wallet according to the [BIP32-Ed25519] specifications.

v4 data :

| `log N` | Encrypted data |
|:-------:|:--------------:|
| 1 byte  | 64 bytes       |

Encrypted data :

| seed(32 bytes) | public key(32bytes) |
|:--------------:|:-------------------:|
| seed bytes     | public key bytes    |

The public key serves as a checksum. To check that the DEWIF base64 string is not corrupted, generate a [BIP32-Ed25519] keypair with the seed and check that the obtained public key matches.

Symmetric encryption algorithm : aes256

aes256 key: scrypt of user passphrase with the following parameters:  

**password:** passphrase  
**salt:** sha256("dewif" ++ passphrase)  
**N:** `2^(log N)`  
**r:** 16  
**p:** 1

Example #3:

**keypair seed:** 0xb7d3a54e1c20172cd38e0d803776a3bacf11f895ef8ef846043a0d628431c872  
**N:** `2^15 = 32768`  
**r:** 16  
**p:** 1

```txt
0x000000004 #v4
0x100000001 #g1-test
0x0F # log N
0xb7d3a54e1c20172cd38e0d803776a3bacf11f895ef8ef846043a0d628431c872 # keypair seed
0xd1fec6ddf6e887e40bd77d459131ee5a6bec1194341b9393ead606363bb7b060 # public key
```

DEWIF base 64 string (with aes key `"toto titi tata"`):

`AAAABBAAAAEPcE3yXhA0T0iElXR/vDbZTRSmdec26lWu42mWKuaczzxZ22bIGVfLmlhfVW9NWmWY7m/P/j0W6Su4QZEiERe8vA==`

[BIP32-Ed25519]: https://drive.google.com/file/d/0ByMtMw2hul0EMFJuNnZORDR2NDA/view
[DUBP]: https://git.duniter.org/nodes/common/doc/blob/master/rfc/0010_Duniter_Blockchain_Protocol_V12.md