| 1 | package vault |
| 2 | |
| 3 | import ( |
| 4 | "encoding/hex" |
| 5 | "net/http" |
| 6 | |
| 7 | "github.com/carlosframework/contra/internal/contra/crypto" |
| 8 | ) |
| 9 | |
| 10 | // RegenerateRecovery replaces the recovery branch: a new wrap of RK sealed |
| 11 | // under a KEK derived from a code the client just minted, and the login public |
| 12 | // key for that same code. |
| 13 | // |
| 14 | // # This is the one destructive write in the app, and it is meant to be |
| 15 | // |
| 16 | // The recovery code is not stored — only its wrap is — so a lost sheet cannot |
| 17 | // be reprinted, only reissued. That necessarily invalidates the old one, and |
| 18 | // the alternative is worse: a "reprint" that left the old code live would |
| 19 | // leave two working keys to the vault with one of them lost somewhere. The |
| 20 | // page in front of this says so before the person commits. |
| 21 | // |
| 22 | // Everything that decides anything happened in the browser: the code was |
| 23 | // minted there, RK was opened there under the passphrase and Account Key, and |
| 24 | // what arrives here is a KCV, a public key and ciphertext. A server that |
| 25 | // wanted to hand somebody a working recovery code cannot, because it never |
| 26 | // sees RK — the worst it can do is refuse, or store a wrap that opens nothing, |
| 27 | // and the KCV the client wrote is what catches the second. |
| 28 | func (v *Vault) RegenerateRecovery(w http.ResponseWriter, r *http.Request) { |
| 29 | acct, ok := accountID(r) |
| 30 | if !ok { |
| 31 | notFound(w) |
| 32 | return |
| 33 | } |
| 34 | var req struct { |
| 35 | WrapIDHex string `json:"wrap_id_hex"` |
| 36 | KCVHex string `json:"kcv_hex"` |
| 37 | KDFParams string `json:"kdf_params"` |
| 38 | PublicKeyHex string `json:"login_public_key_hex"` |
| 39 | Sealed sealedJSON `json:"sealed"` |
| 40 | } |
| 41 | if !readJSON(w, r, &req) { |
| 42 | return |
| 43 | } |
| 44 | wrapID, e1 := hex.DecodeString(req.WrapIDHex) |
| 45 | kcv, e2 := hex.DecodeString(req.KCVHex) |
| 46 | publicKey, e3 := hex.DecodeString(req.PublicKeyHex) |
| 47 | sealed, e4 := req.Sealed.decode() |
| 48 | if e1 != nil || e2 != nil || e3 != nil || e4 != nil || |
| 49 | len(publicKey) != crypto.PublicKeyLen { |
| 50 | writeJSON(w, http.StatusBadRequest, |
| 51 | map[string]string{"error": "bad recovery wrap"}) |
| 52 | return |
| 53 | } |
| 54 | |
| 55 | if err := v.store.ReplaceRecoveryWrap(r.Context(), acct, wrapID, |
| 56 | req.KDFParams, 1, kcv, sealed, publicKey); err != nil { |
| 57 | writeJSON(w, http.StatusBadRequest, map[string]string{"error": err.Error()}) |
| 58 | return |
| 59 | } |
| 60 | writeJSON(w, http.StatusOK, map[string]string{"wrap_id_hex": req.WrapIDHex}) |
| 61 | } |
| 62 | |
amadan