Crypto File Server

Av Mathias

Key exchange (RSA)

E - encryption key (public) D - decryption key (private) V - verification key (public) S - signing key (private)

c - Client s - Server a - 3rd party authority

Va - "fick på papper i det mörka gränden", hårdkodas / konfigureras i klienten Sa(Es) sparas hos servern

1. client sends (Ec + Vc)

   T.ex: {"e":{"n":"1234324","e":"3"},"v":{"n":"54894264","e":"65533"}}}

2. server sends Ec(Es + Vs + Sa(Es))

   T.ex: Ec({"e":{"n":"5456232","e":"3"},"v":{"n":"69871564","e":"65533"},"s":"54ue56489uu5156i4i56464i1"})

3. client verifies Es with Sa(Es)

4. client sends Es(Sc(8 rand bytes = R1))

5. server sends Ec(Ss(8 rand bytes = R2))

6. (R1+R2) is used for ChaCha20-Poly1305 for all data send from here and onwards

Authentication

TODO

API

List ids

Input:

{
    "type": "list"
}

Output:

{
    "ids": ["<base64data>"],
}

Read file

Input:

{
    "type": "read",
    "id": "<base64data>",
}

Output:

{
    "data": "<base64data>",
    "signature": "<base64data>",
    "hashes": ["<base64data>"],
}

hashes är baklänges. Alltså att hasharna längst upp kommer först.

Write file

Input:

{
    "type": "write",
    "id": "<base64data>",
    "data": "<base64data>",
    "signature": "<base64data>",
}

Output:

{
    "hashes": ["<base64data>"],
}

hashes är baklänges här också.

Add file

TODO

Remove file

TODO

Move file

TODO?