| 1 | //go:build linux |
| 2 | |
| 3 | package provisioner |
| 4 | |
| 5 | import ( |
| 6 | "bytes" |
| 7 | "encoding/base64" |
| 8 | "io" |
| 9 | |
| 10 | family "amadan.net/rastrillo/rastrillo/crypto" |
| 11 | "filippo.io/age" |
| 12 | ) |
| 13 | |
| 14 | type credential struct { |
| 15 | Version int `json:"version"` |
| 16 | Identity floorIdentity `json:"identity"` |
| 17 | Keypair string `json:"keypair"` |
| 18 | } |
| 19 | |
| 20 | func wrapCredential(k *family.Keypair, id floorIdentity, password []byte) ([]byte, error) { |
| 21 | if len(password) == 0 || len(password) > 1024 || k == nil || k.SignPriv == nil || k.BoxPriv == nil || base64.RawURLEncoding.EncodeToString(k.SignPub()) != id.Public { |
| 22 | return nil, ErrRefused |
| 23 | } |
| 24 | raw, e := family.MarshalKeypair(k) |
| 25 | if e != nil { |
| 26 | return nil, ErrRefused |
| 27 | } |
| 28 | body, e := canonicalJSON(credential{1, id, base64.RawURLEncoding.EncodeToString(raw)}) |
| 29 | if e != nil { |
| 30 | return nil, e |
| 31 | } |
| 32 | return encryptPrivate(body, password) |
| 33 | } |
| 34 | func unwrapCredential(ciphertext, password []byte) (floorIdentity, *family.Keypair, error) { |
| 35 | body, e := decryptPrivate(ciphertext, password, 16384) |
| 36 | if e != nil { |
| 37 | return floorIdentity{}, nil, e |
| 38 | } |
| 39 | var c credential |
| 40 | if closedJSON(body, &c) != nil || c.Version != 1 { |
| 41 | return floorIdentity{}, nil, ErrRefused |
| 42 | } |
| 43 | raw, e := base64.RawURLEncoding.DecodeString(c.Keypair) |
| 44 | if e != nil || base64.RawURLEncoding.EncodeToString(raw) != c.Keypair { |
| 45 | return floorIdentity{}, nil, ErrRefused |
| 46 | } |
| 47 | k, e := family.UnmarshalKeypair(raw) |
| 48 | if e != nil || base64.RawURLEncoding.EncodeToString(k.SignPub()) != c.Identity.Public { |
| 49 | return floorIdentity{}, nil, ErrRefused |
| 50 | } |
| 51 | if _, ok := tokenBytes(c.Identity.Registry, 32); !ok { |
| 52 | return floorIdentity{}, nil, ErrRefused |
| 53 | } |
| 54 | if _, ok := tokenBytes(c.Identity.Device, 32); !ok { |
| 55 | return floorIdentity{}, nil, ErrRefused |
| 56 | } |
| 57 | return c.Identity, k, nil |
| 58 | } |
| 59 | func encryptPrivate(body, password []byte) ([]byte, error) { |
| 60 | if len(body) > 64<<10 || len(password) == 0 || len(password) > 1024 { |
| 61 | return nil, ErrRefused |
| 62 | } |
| 63 | recipient, e := age.NewScryptRecipient(string(password)) |
| 64 | if e != nil { |
| 65 | return nil, ErrRefused |
| 66 | } |
| 67 | var out bytes.Buffer |
| 68 | w, e := age.Encrypt(&out, recipient) |
| 69 | if e != nil { |
| 70 | return nil, ErrUnavailable |
| 71 | } |
| 72 | if _, e = w.Write(body); e != nil { |
| 73 | return nil, ErrUnavailable |
| 74 | } |
| 75 | if e = w.Close(); e != nil { |
| 76 | return nil, ErrUnavailable |
| 77 | } |
| 78 | return out.Bytes(), nil |
| 79 | } |
| 80 | func decryptPrivate(ciphertext, password []byte, limit int) ([]byte, error) { |
| 81 | if len(ciphertext) == 0 || len(ciphertext) > 128<<10 || len(password) == 0 || len(password) > 1024 || limit <= 0 || limit > 64<<10 { |
| 82 | return nil, ErrRefused |
| 83 | } |
| 84 | identity, e := age.NewScryptIdentity(string(password)) |
| 85 | if e != nil { |
| 86 | return nil, ErrRefused |
| 87 | } |
| 88 | identity.SetMaxWorkFactor(18) |
| 89 | r, e := age.Decrypt(bytes.NewReader(ciphertext), identity) |
| 90 | if e != nil { |
| 91 | return nil, ErrRefused |
| 92 | } |
| 93 | body, e := io.ReadAll(io.LimitReader(r, int64(limit)+1)) |
| 94 | if e != nil || len(body) > limit { |
| 95 | return nil, ErrRefused |
| 96 | } |
| 97 | return body, nil |
| 98 | } |
| 99 | |
amadan