| 1 | package host |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "encoding/json" |
| 6 | "errors" |
| 7 | "fmt" |
| 8 | "os" |
| 9 | "path/filepath" |
| 10 | "strconv" |
| 11 | "strings" |
| 12 | |
| 13 | "github.com/carlosframework/platform/internal/moves" |
| 14 | "github.com/carlosframework/platform/internal/rootparticipation" |
| 15 | "github.com/carlosframework/platform/internal/rootstate" |
| 16 | ) |
| 17 | |
| 18 | const ( |
| 19 | rootFloorAccepted = "accepted.json" |
| 20 | rootFloorDeny = "deny.json" |
| 21 | rootFloorSelector = "floor.line" |
| 22 | rootFloorProjectionFile = "accepted.json" |
| 23 | ) |
| 24 | |
| 25 | type rootFloorIdentity struct{ Deployment, Box, Enrollment string } |
| 26 | type rootFloorReconstruction struct { |
| 27 | Identity rootFloorIdentity |
| 28 | Floor *moves.Floor |
| 29 | NeverArmed bool |
| 30 | Source, Digest string |
| 31 | Authorization *rootFloorAuthorization `json:"-"` |
| 32 | LegacyAuthorization string `json:"Authorization,omitempty"` |
| 33 | } |
| 34 | type rootFloorRecord struct { |
| 35 | Schema int |
| 36 | Identity rootFloorIdentity |
| 37 | Generation uint64 |
| 38 | Floor *moves.Floor |
| 39 | NeverArmed bool |
| 40 | Provenance rootFloorReconstruction |
| 41 | } |
| 42 | type rootFloorProjection struct { |
| 43 | rootFloorRecord |
| 44 | Accepted bool |
| 45 | } |
| 46 | type rootMovesFloors struct { |
| 47 | private, public rootstate.Store |
| 48 | identity rootFloorIdentity |
| 49 | } |
| 50 | |
| 51 | func rootFloorDir(opt string) string { return filepath.Join(opt, "system", "guard", "moves") } |
| 52 | func openRootMovesFloors(opt string, id rootFloorIdentity, create bool) (rootMovesFloors, error) { |
| 53 | return openRootProtocolFloors(rootFloorDir(opt), id, create) |
| 54 | } |
| 55 | func openRootProtocolFloors(dir string, id rootFloorIdentity, create bool) (rootMovesFloors, error) { |
| 56 | f := rootMovesFloors{identity: id} |
| 57 | var err error |
| 58 | f.public, err = rootstate.Open(dir, create, true) |
| 59 | if err != nil { |
| 60 | return f, err |
| 61 | } |
| 62 | f.private, err = rootstate.Open(filepath.Join(dir, "private"), create, false) |
| 63 | if err != nil { |
| 64 | f.public.Close() |
| 65 | return rootMovesFloors{}, err |
| 66 | } |
| 67 | return f, nil |
| 68 | } |
| 69 | func (f rootMovesFloors) close() { f.private.Close(); f.public.Close() } |
| 70 | func validRootFloor(fl *moves.Floor) bool { |
| 71 | return fl != nil && fl.Min > 0 && validFloorRelease(fl.MinRelease) |
| 72 | } |
| 73 | func (r rootFloorRecord) valid(id rootFloorIdentity) bool { |
| 74 | return r.Schema == 1 && r.Identity == id && id.Deployment != "" && id.Box != "" && id.Enrollment != "" && r.Generation > 0 && ((validRootFloor(r.Floor) && !r.NeverArmed) || (r.Floor == nil && r.NeverArmed)) |
| 75 | } |
| 76 | func (f rootMovesFloors) record(name string) (rootFloorRecord, error) { |
| 77 | var r rootFloorRecord |
| 78 | raw, err := f.private.Read(name) |
| 79 | if err != nil { |
| 80 | return r, err |
| 81 | } |
| 82 | if len(raw) > movesFloorMaxBytes || rootparticipation.Decode(raw, &r) != nil || !r.valid(f.identity) { |
| 83 | return r, errRootFloorHistory |
| 84 | } |
| 85 | return r, nil |
| 86 | } |
| 87 | func floorMaximum(a, b *moves.Floor) *moves.Floor { |
| 88 | if a == nil { |
| 89 | if b == nil { |
| 90 | return nil |
| 91 | } |
| 92 | c := *b |
| 93 | return &c |
| 94 | } |
| 95 | c := *a |
| 96 | if b != nil { |
| 97 | if b.Min > c.Min { |
| 98 | c.Min = b.Min |
| 99 | } |
| 100 | if at, _ := moves.ReleaseAtOrAbove(b.MinRelease, c.MinRelease); at { |
| 101 | c.MinRelease = b.MinRelease |
| 102 | } |
| 103 | } |
| 104 | return &c |
| 105 | } |
| 106 | func rootFloorLine(fl *moves.Floor) []byte { |
| 107 | if fl == nil { |
| 108 | return []byte("0 none\n") |
| 109 | } |
| 110 | return []byte(fmt.Sprintf("%d %s\n", fl.Min, fl.MinRelease)) |
| 111 | } |
| 112 | func (f rootMovesFloors) selector() (*moves.Floor, error) { |
| 113 | raw, err := f.public.Read(rootFloorSelector) |
| 114 | if err != nil { |
| 115 | return nil, err |
| 116 | } |
| 117 | fields := strings.Fields(string(raw)) |
| 118 | if len(raw) > 256 || len(fields) != 2 { |
| 119 | return nil, errRootFloorHistory |
| 120 | } |
| 121 | if string(raw) == "0 none\n" { |
| 122 | return nil, nil |
| 123 | } |
| 124 | min, err := strconv.Atoi(fields[0]) |
| 125 | fl := &moves.Floor{Min: min, MinRelease: fields[1]} |
| 126 | if err != nil || !validRootFloor(fl) || string(raw) != string(rootFloorLine(fl)) { |
| 127 | return nil, errRootFloorHistory |
| 128 | } |
| 129 | return fl, nil |
| 130 | } |
| 131 | |
| 132 | // A selector visible after an interrupted write remains a deny, even when the |
| 133 | // accepted JSON still names the preceding generation. |
| 134 | func (f rootMovesFloors) bound() (*moves.Floor, error) { |
| 135 | var bound *moves.Floor |
| 136 | var errs []error |
| 137 | for _, name := range []string{rootFloorAccepted, rootFloorDeny} { |
| 138 | r, err := f.record(name) |
| 139 | if err == nil { |
| 140 | bound = floorMaximum(bound, r.Floor) |
| 141 | } else if !errors.Is(err, os.ErrNotExist) { |
| 142 | errs = append(errs, err) |
| 143 | } |
| 144 | } |
| 145 | fl, err := f.selector() |
| 146 | if err == nil { |
| 147 | bound = floorMaximum(bound, fl) |
| 148 | } else if !errors.Is(err, os.ErrNotExist) { |
| 149 | errs = append(errs, err) |
| 150 | } |
| 151 | return bound, errors.Join(errs...) |
| 152 | } |
| 153 | |
| 154 | // Missing or malformed history contributes no permission and no invented deny. |
| 155 | // Every independently readable retained bound still applies. |
| 156 | func (f rootMovesFloors) localBound() (*moves.Floor, error) { |
| 157 | var bound *moves.Floor |
| 158 | if f.private != nil { |
| 159 | for _, name := range []string{rootFloorAccepted, rootFloorDeny} { |
| 160 | r, err := f.record(name) |
| 161 | if err == nil { |
| 162 | bound = floorMaximum(bound, r.Floor) |
| 163 | } else if !errors.Is(err, os.ErrNotExist) && !errors.Is(err, errRootFloorHistory) { |
| 164 | return bound, err |
| 165 | } |
| 166 | } |
| 167 | } |
| 168 | fl, err := f.selector() |
| 169 | if err == nil { |
| 170 | bound = floorMaximum(bound, fl) |
| 171 | } else if !errors.Is(err, os.ErrNotExist) && !errors.Is(err, errRootFloorHistory) { |
| 172 | return bound, err |
| 173 | } |
| 174 | raw, err := f.public.Read(rootFloorProjectionFile) |
| 175 | if err == nil { |
| 176 | var p rootFloorProjection |
| 177 | if rootparticipation.Decode(raw, &p) == nil && p.rootFloorRecord.valid(f.identity) { |
| 178 | bound = floorMaximum(bound, p.Floor) |
| 179 | } |
| 180 | } else if !errors.Is(err, os.ErrNotExist) { |
| 181 | return bound, err |
| 182 | } |
| 183 | return bound, nil |
| 184 | } |
| 185 | |
| 186 | func (f rootMovesFloors) quarantine(cause error) error { |
| 187 | raw, _ := json.Marshal(rootFloorProjection{Accepted: false}) |
| 188 | return errors.Join(cause, f.public.Write(rootFloorProjectionFile, raw)) |
| 189 | } |
| 190 | func (f rootMovesFloors) projection() (rootFloorProjection, error) { |
| 191 | var p rootFloorProjection |
| 192 | raw, err := f.public.Read(rootFloorProjectionFile) |
| 193 | if err != nil { |
| 194 | return p, err |
| 195 | } |
| 196 | if len(raw) > movesFloorMaxBytes || rootparticipation.Decode(raw, &p) != nil || !p.Accepted || !p.rootFloorRecord.valid(f.identity) { |
| 197 | return p, errRootFloorHistory |
| 198 | } |
| 199 | bound, err := f.selector() |
| 200 | if err != nil || string(rootFloorLine(bound)) != string(rootFloorLine(p.Floor)) { |
| 201 | return p, errRootFloorHistory |
| 202 | } |
| 203 | if f.private != nil { |
| 204 | accepted, err := f.record(rootFloorAccepted) |
| 205 | if err != nil || accepted.Generation != p.Generation || accepted.Identity != p.Identity || string(rootFloorLine(accepted.Floor)) != string(rootFloorLine(p.Floor)) { |
| 206 | return p, errRootFloorHistory |
| 207 | } |
| 208 | bound, err := f.bound() |
| 209 | if err != nil || string(rootFloorLine(bound)) != string(rootFloorLine(p.Floor)) { |
| 210 | return p, errRootFloorHistory |
| 211 | } |
| 212 | } |
| 213 | return p, nil |
| 214 | } |
| 215 | func (f rootMovesFloors) writeRecord(name string, r rootFloorRecord) error { |
| 216 | raw, err := json.Marshal(r) |
| 217 | if err != nil { |
| 218 | return err |
| 219 | } |
| 220 | return f.private.Write(name, raw) |
| 221 | } |
| 222 | |
| 223 | // Caller holds the stable private floor lock. Every retry rewrites and syncs |
| 224 | // all prerequisites; visible bytes are never taken as proof of an earlier sync. |
| 225 | func (f rootMovesFloors) persist(r rootFloorRecord, bound *moves.Floor, accept bool) error { |
| 226 | if err := f.quarantine(nil); err != nil { |
| 227 | return err |
| 228 | } |
| 229 | if err := f.public.Write(rootFloorSelector, rootFloorLine(bound)); err != nil { |
| 230 | return err |
| 231 | } |
| 232 | deny := r |
| 233 | deny.Floor = bound |
| 234 | deny.NeverArmed = bound == nil |
| 235 | if err := f.writeRecord(rootFloorDeny, deny); err != nil { |
| 236 | return err |
| 237 | } |
| 238 | if !accept { |
| 239 | return errRootFloorHistory |
| 240 | } |
| 241 | if err := f.writeRecord(rootFloorAccepted, r); err != nil { |
| 242 | return err |
| 243 | } |
| 244 | raw, _ := json.Marshal(rootFloorProjection{rootFloorRecord: r, Accepted: true}) |
| 245 | if err := f.public.Write(rootFloorProjectionFile, raw); err != nil { |
| 246 | return f.quarantine(err) |
| 247 | } |
| 248 | return nil |
| 249 | } |
| 250 | |
| 251 | // This entry is only for a root-authorized complete reconstruction, including |
| 252 | // an explicit never-armed attestation. Normal refresh cannot manufacture it. |
| 253 | func (f rootMovesFloors) reconstruct(ctx context.Context, r rootFloorReconstruction) error { |
| 254 | unlock, err := f.private.Lock(ctx, "floor.lock") |
| 255 | if err != nil { |
| 256 | return err |
| 257 | } |
| 258 | defer unlock() |
| 259 | if r.Identity != f.identity || r.Source == "" || len(r.Digest) != 64 || (r.NeverArmed != (r.Floor == nil)) || (r.Floor != nil && !validRootFloor(r.Floor)) { |
| 260 | return f.quarantine(errRootFloorHistory) |
| 261 | } |
| 262 | bound, err := f.bound() |
| 263 | if err != nil { |
| 264 | return f.quarantine(err) |
| 265 | } |
| 266 | if bound != nil && (r.Floor == nil || floorRegression(bound, r.Floor) != nil) { |
| 267 | return f.quarantine(errRootFloorHistory) |
| 268 | } |
| 269 | generation := uint64(1) |
| 270 | old, err := f.record(rootFloorAccepted) |
| 271 | if err == nil { |
| 272 | generation = old.Generation + 1 |
| 273 | } else if !errors.Is(err, os.ErrNotExist) { |
| 274 | return f.quarantine(err) |
| 275 | } |
| 276 | if !f.authorizedReconstruction(r.Authorization, generation) { |
| 277 | return f.quarantine(errRootFloorHistory) |
| 278 | } |
| 279 | next := rootFloorRecord{Schema: 1, Identity: f.identity, Generation: generation, Floor: r.Floor, NeverArmed: r.NeverArmed, Provenance: r} |
| 280 | if !next.valid(f.identity) { |
| 281 | return f.quarantine(errRootFloorHistory) |
| 282 | } |
| 283 | return f.persist(next, floorMaximum(bound, r.Floor), true) |
| 284 | } |
| 285 | |
| 286 | func (f rootMovesFloors) refresh(ctx context.Context, remote *moves.Floor, legacy []*moves.Floor, readErr error) error { |
| 287 | unlock, err := f.private.Lock(ctx, "floor.lock") |
| 288 | if err != nil { |
| 289 | return err |
| 290 | } |
| 291 | defer unlock() |
| 292 | legacy, err = f.capLegacy(legacy) |
| 293 | if err != nil { |
| 294 | return err |
| 295 | } |
| 296 | accepted, aerr := f.record(rootFloorAccepted) |
| 297 | if errors.Is(aerr, os.ErrNotExist) || errors.Is(aerr, errRootFloorHistory) { |
| 298 | bound, err := f.localBound() |
| 299 | if err != nil { |
| 300 | return err |
| 301 | } |
| 302 | for _, fl := range append(legacy, remote) { |
| 303 | if validRootFloor(fl) { |
| 304 | bound = floorMaximum(bound, fl) |
| 305 | } |
| 306 | } |
| 307 | if err := f.quarantine(nil); err != nil { |
| 308 | return err |
| 309 | } |
| 310 | if err := f.public.Write(rootFloorSelector, rootFloorLine(bound)); err != nil { |
| 311 | return err |
| 312 | } |
| 313 | deny := rootFloorRecord{Schema: 1, Identity: f.identity, Generation: 1, Floor: bound, NeverArmed: bound == nil} |
| 314 | return f.writeRecord(rootFloorDeny, deny) |
| 315 | } |
| 316 | bound, berr := f.bound() |
| 317 | for _, fl := range legacy { |
| 318 | if validRootFloor(fl) { |
| 319 | bound = floorMaximum(bound, fl) |
| 320 | } else { |
| 321 | readErr = errors.Join(readErr, errRootFloorHistory) |
| 322 | } |
| 323 | } |
| 324 | if remote != nil && !validRootFloor(remote) { |
| 325 | readErr = errors.Join(readErr, errRootFloorHistory) |
| 326 | remote = nil |
| 327 | } |
| 328 | // Even uninitialized or corrupt histories retain every usable observed deny. |
| 329 | next := accepted |
| 330 | if aerr != nil { |
| 331 | next = rootFloorRecord{Schema: 1, Identity: f.identity, Generation: 1} |
| 332 | } |
| 333 | next.Generation++ |
| 334 | refusal := errors.Join(readErr, berr, aerr) |
| 335 | if remote != nil { |
| 336 | if bound != nil { |
| 337 | refusal = errors.Join(refusal, floorRegression(bound, remote)) |
| 338 | } |
| 339 | bound = floorMaximum(bound, remote) |
| 340 | } |
| 341 | if refusal == nil && remote == nil && string(rootFloorLine(bound)) != string(rootFloorLine(accepted.Floor)) { |
| 342 | refusal = errRootFloorHistory |
| 343 | } |
| 344 | if refusal == nil { |
| 345 | next.Floor = bound |
| 346 | next.NeverArmed = bound == nil |
| 347 | } |
| 348 | // A corrupt selector cannot be safely overwritten from incomplete evidence. |
| 349 | if berr != nil { |
| 350 | return f.quarantine(refusal) |
| 351 | } |
| 352 | if refusal == nil && !next.valid(f.identity) { |
| 353 | return f.quarantine(errRootFloorHistory) |
| 354 | } |
| 355 | err = f.persist(next, bound, refusal == nil) |
| 356 | return errors.Join(refusal, err) |
| 357 | } |
| 358 | |
amadan