| 1 | package release |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "os" |
| 7 | "path/filepath" |
| 8 | "sort" |
| 9 | "strings" |
| 10 | |
| 11 | "github.com/carlosframework/platform/internal/rootstate" |
| 12 | ) |
| 13 | |
| 14 | // RootGenerationPins is read under release exclusion, held through destruction. |
| 15 | // Verify must reconcile the records with root installation/launch inventory and |
| 16 | // kernel references. An empty directory alone never establishes completeness. |
| 17 | type RootGenerationPins struct { |
| 18 | Ledger *RootGenerations |
| 19 | Verify func(context.Context, []GenerationReservation) error |
| 20 | Reconcile func(context.Context, []GenerationReservation) (GenerationEvidence, error) |
| 21 | } |
| 22 | |
| 23 | func (s RootGenerationPins) StagedPins(ctx context.Context, optDir string) (StagedPaths, error) { |
| 24 | if s.Ledger == nil || s.Ledger.Store == nil || !filepath.IsAbs(optDir) { |
| 25 | return nil, os.ErrPermission |
| 26 | } |
| 27 | records, err := s.Ledger.Reservations(ctx) |
| 28 | if err != nil { |
| 29 | return nil, err |
| 30 | } |
| 31 | pins := StagedPaths{} |
| 32 | for _, r := range records { |
| 33 | b := r.Binding |
| 34 | if b.Path != VersionPath(optDir, b.Binding.Account, b.Version, b.Binding.App) { |
| 35 | return nil, os.ErrPermission |
| 36 | } |
| 37 | if r.Retirement != "" { |
| 38 | continue |
| 39 | } |
| 40 | for _, item := range []struct { |
| 41 | path string |
| 42 | expected, proof rootstate.FileIdentity |
| 43 | }{ |
| 44 | {b.Path, b.Executable, b.ExecutableProof}, {b.Tree, b.TreeIdentity, b.TreeProof}, |
| 45 | } { |
| 46 | if err := generationFileIdentity(item.path, item.expected, item.proof, b.Target.BootID); err != nil { |
| 47 | return nil, err |
| 48 | } |
| 49 | } |
| 50 | pins.add(b.Path) |
| 51 | pins.add(b.Tree) |
| 52 | } |
| 53 | if s.Reconcile != nil { |
| 54 | if _, err := s.Ledger.Certify(ctx, records, s.Reconcile); err != nil { |
| 55 | return nil, err |
| 56 | } |
| 57 | return pins, nil |
| 58 | } |
| 59 | if s.Verify == nil { |
| 60 | return nil, os.ErrPermission |
| 61 | } |
| 62 | if err := s.Verify(ctx, records); err != nil { |
| 63 | return nil, err |
| 64 | } |
| 65 | return pins, nil |
| 66 | } |
| 67 | |
| 68 | func generationFileIdentity(path string, expected, proof rootstate.FileIdentity, boot string) error { |
| 69 | if proof.Boot != "" { |
| 70 | if proof.Boot != boot || proof.Device != expected.Device || proof.Inode != expected.Inode { |
| 71 | return os.ErrPermission |
| 72 | } |
| 73 | var f *os.File |
| 74 | var err error |
| 75 | if proof.Mode&0170000 == 0040000 { |
| 76 | f, err = rootstate.OpenAuthorityDirectory(path) |
| 77 | } else { |
| 78 | f, err = rootstate.OpenAuthorityFile(path) |
| 79 | } |
| 80 | if err != nil { |
| 81 | return err |
| 82 | } |
| 83 | defer f.Close() |
| 84 | actual, err := rootstate.PersistentIdentity(f) |
| 85 | if err != nil { |
| 86 | return err |
| 87 | } |
| 88 | if !GenerationFileProof(path, proof, actual) { |
| 89 | return os.ErrPermission |
| 90 | } |
| 91 | return nil |
| 92 | } |
| 93 | info, err := os.Lstat(path) |
| 94 | if err != nil { |
| 95 | return err |
| 96 | } |
| 97 | if info.Mode()&os.ModeSymlink != 0 { |
| 98 | return os.ErrPermission |
| 99 | } |
| 100 | f, err := os.Open(path) |
| 101 | if err != nil { |
| 102 | return err |
| 103 | } |
| 104 | defer f.Close() |
| 105 | actual, err := rootstate.Identity(f) |
| 106 | if err != nil { |
| 107 | return err |
| 108 | } |
| 109 | observed, err := rootstate.ObjectIdentity(f) |
| 110 | if err != nil { |
| 111 | return err |
| 112 | } |
| 113 | if boot == "" || observed.Boot != boot || actual != expected { |
| 114 | return os.ErrPermission |
| 115 | } |
| 116 | return nil |
| 117 | } |
| 118 | |
| 119 | // WithRootGenerationPins protects new writes as well as replacement of a |
| 120 | // differing artifact: a removed executable can still be held by a generation. |
| 121 | func WithRootGenerationPins(source PinSource) PassOption { |
| 122 | return func(c *passConfig) { c.generationPins = source } |
| 123 | } |
| 124 | |
| 125 | // Sibling repair can change a reserved tree even when its binary already |
| 126 | // matches. Check only when a write is needed, preserving the legacy no-op path. |
| 127 | func stageGenerationSibling(optDir, acct, app, ver string, raw []byte, checks []stageCheck) error { |
| 128 | for _, check := range checks { |
| 129 | if check.beforeWrite != nil { |
| 130 | if err := check.beforeWrite(StagedManifestPath(optDir, acct, ver, app)); err != nil { |
| 131 | return err |
| 132 | } |
| 133 | } |
| 134 | } |
| 135 | return StageManifest(optDir, acct, ver, app, raw) |
| 136 | } |
| 137 | |
| 138 | func (c passConfig) generationWriteCheck(ctx context.Context, optDir, path string) error { |
| 139 | if c.generationPins == nil { |
| 140 | return nil |
| 141 | } |
| 142 | // Creating a wholly absent version tree cannot destroy an existing pin. |
| 143 | // Keep fresh signed recovery available while pin completeness is unknown. |
| 144 | rel, err := filepath.Rel(filepath.Join(optDir, "versions"), path) |
| 145 | version, _, ok := strings.Cut(rel, string(filepath.Separator)) |
| 146 | if err != nil || !filepath.IsLocal(rel) || !ok || !ValidVersion(version) { |
| 147 | return os.ErrPermission |
| 148 | } |
| 149 | if _, err := os.Lstat(filepath.Join(optDir, "versions", version)); errors.Is(err, os.ErrNotExist) { |
| 150 | return nil |
| 151 | } else if err != nil { |
| 152 | return err |
| 153 | } |
| 154 | pins, err := c.generationPins.StagedPins(ctx, optDir) |
| 155 | if err != nil { |
| 156 | return err |
| 157 | } |
| 158 | pinned, err := pins.Refers(path) |
| 159 | if err != nil { |
| 160 | return err |
| 161 | } |
| 162 | if pinned { |
| 163 | return ErrVersionReused |
| 164 | } |
| 165 | for parent := filepath.Dir(path); parent != optDir && parent != filepath.Dir(parent); parent = filepath.Dir(parent) { |
| 166 | pinned, err := pins.Refers(parent) |
| 167 | if err != nil { |
| 168 | return err |
| 169 | } |
| 170 | if pinned { |
| 171 | return ErrVersionReused |
| 172 | } |
| 173 | } |
| 174 | return nil |
| 175 | } |
| 176 | |
| 177 | // Reservations validates and recommits every retained record under release exclusion. |
| 178 | func (g *RootGenerations) Reservations(ctx context.Context) ([]GenerationReservation, error) { |
| 179 | if g == nil || g.Store == nil { |
| 180 | return nil, os.ErrPermission |
| 181 | } |
| 182 | names, err := g.Store.Names() |
| 183 | if err != nil { |
| 184 | return nil, err |
| 185 | } |
| 186 | sort.Strings(names) |
| 187 | records := make([]GenerationReservation, 0, len(names)) |
| 188 | for _, name := range names { |
| 189 | if name == generationCompletenessKey { |
| 190 | if _, err := g.Completeness(); err != nil { |
| 191 | return nil, err |
| 192 | } |
| 193 | continue |
| 194 | } |
| 195 | if err := ctx.Err(); err != nil { |
| 196 | return nil, err |
| 197 | } |
| 198 | raw, err := g.Store.Read(name) |
| 199 | if err != nil { |
| 200 | return nil, err |
| 201 | } |
| 202 | var r GenerationReservation |
| 203 | if len(raw) > rootstate.MaxRecord || strictCanonicalJSON(raw, &r) != nil || !validGeneration(r) || generationKey(r.Binding) != name { |
| 204 | return nil, os.ErrPermission |
| 205 | } |
| 206 | // Read retries the directory sync before this record can inform a grant. |
| 207 | r, err = g.Read(r.Binding) |
| 208 | if err != nil { |
| 209 | return nil, err |
| 210 | } |
| 211 | records = append(records, r) |
| 212 | } |
| 213 | return records, nil |
| 214 | } |
| 215 | |
amadan