| 1 | package release |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/ed25519" |
| 6 | "encoding/base64" |
| 7 | "encoding/json" |
| 8 | "errors" |
| 9 | "fmt" |
| 10 | "os" |
| 11 | "time" |
| 12 | ) |
| 13 | |
| 14 | // PromotedPrefix is every promotion record of an app: what PurgeApp sweeps. |
| 15 | func PromotedPrefix(acct, app string) string { return "releases/" + acct + "/" + app + "/promoted/" } |
| 16 | |
| 17 | // PromotionRecordKey is the durable record of one promoted build (spec §4.1). |
| 18 | // It sits outside AppPrefix, beside the account's pointer digest marker, so |
| 19 | // PurgeApp sweeps it explicitly. |
| 20 | func PromotionRecordKey(acct, app, version string) string { |
| 21 | return PromotedPrefix(acct, app) + version |
| 22 | } |
| 23 | |
| 24 | // PromotionRecord binds a version name to the exact manifest that was |
| 25 | // promoted (or explicitly authorized). It keeps a build authorized after it |
| 26 | // falls out of the pointer's history, and a reused name cannot inherit it: |
| 27 | // the new name's manifest hashes to another digest. |
| 28 | type PromotionRecord struct { |
| 29 | Schema int `json:"schema"` // 1 |
| 30 | Account string `json:"account"` |
| 31 | App string `json:"app"` |
| 32 | Version string `json:"version"` |
| 33 | ManifestDigest string `json:"manifest_digest"` |
| 34 | Channel string `json:"channel,omitempty"` |
| 35 | Authorized bool `json:"authorized,omitempty"` |
| 36 | Actor string `json:"actor,omitempty"` |
| 37 | At time.Time `json:"at"` |
| 38 | } |
| 39 | |
| 40 | // ErrNoPromotionRecord is a build with no record: promoted before records |
| 41 | // existed, or never promoted. It wraps os.ErrNotExist. |
| 42 | var ErrNoPromotionRecord = fmt.Errorf("release: no promotion record: %w", os.ErrNotExist) |
| 43 | |
| 44 | func validateRecord(r *PromotionRecord, acct, app, version string) error { |
| 45 | if r.Schema != 1 { |
| 46 | return fmt.Errorf("unsupported promotion record schema %d", r.Schema) |
| 47 | } |
| 48 | if r.Account != acct || r.App != app || r.Version != version { |
| 49 | return fmt.Errorf("promotion record names %s/%s/%s, expected %s/%s/%s", r.Account, r.App, r.Version, acct, app, version) |
| 50 | } |
| 51 | if !ValidAccount(acct) || !ValidApp(app) || !ValidVersion(version) || version == "dev" { |
| 52 | return fmt.Errorf("promotion record for invalid %s/%s/%s", acct, app, version) |
| 53 | } |
| 54 | if !validDigest(r.ManifestDigest) { |
| 55 | return fmt.Errorf("promotion record has an invalid manifest digest") |
| 56 | } |
| 57 | if r.Channel != "" && !ValidChannel(r.Channel) { |
| 58 | return fmt.Errorf("promotion record has an invalid channel %q", r.Channel) |
| 59 | } |
| 60 | if r.Channel == "" && !r.Authorized { |
| 61 | return fmt.Errorf("promotion record names no channel and is not an authorization") |
| 62 | } |
| 63 | if r.At.IsZero() { |
| 64 | return fmt.Errorf("promotion record has no time") |
| 65 | } |
| 66 | return nil |
| 67 | } |
| 68 | |
| 69 | // WritePromotionRecord signs rec, stamped now, and writes it unless the key |
| 70 | // already holds a verified record for the same digest: one record per |
| 71 | // version, kept from its first promotion. A record for other bytes (a name |
| 72 | // pruned and reshipped) is replaced. A scoped signer may write only a record |
| 73 | // whose channel its grant covers, and never an authorization. |
| 74 | func (sg Signer) WritePromotionRecord(ctx context.Context, s Store, rec PromotionRecord) error { |
| 75 | if err := sg.usable(); err != nil { |
| 76 | return err |
| 77 | } |
| 78 | rec.Schema = 1 |
| 79 | rec.At = time.Now().UTC().Truncate(time.Second) |
| 80 | if err := validateRecord(&rec, rec.Account, rec.App, rec.Version); err != nil { |
| 81 | return err |
| 82 | } |
| 83 | if rec.Channel == "" || rec.Authorized { |
| 84 | if sg.scope != nil { |
| 85 | return fmt.Errorf("promotion record: an authorization needs the deployment's root key") |
| 86 | } |
| 87 | } else if err := sg.allows(rec.Channel, rec.At); err != nil { |
| 88 | return fmt.Errorf("promotion record: %w", err) |
| 89 | } |
| 90 | key := PromotionRecordKey(rec.Account, rec.App, rec.Version) |
| 91 | _, etag, err := s.Get(ctx, key) |
| 92 | switch { |
| 93 | case errors.Is(err, os.ErrNotExist): |
| 94 | etag = "" |
| 95 | case err != nil: |
| 96 | return err |
| 97 | default: |
| 98 | if cur, rerr := ReadPromotionRecord(ctx, s, sg.verifyPub(), rec.Account, rec.App, rec.Version); rerr == nil && cur.ManifestDigest == rec.ManifestDigest { |
| 99 | return nil |
| 100 | } |
| 101 | } |
| 102 | payload, err := json.MarshalIndent(rec, "", " ") |
| 103 | if err != nil { |
| 104 | return err |
| 105 | } |
| 106 | b64 := base64.StdEncoding.EncodeToString(payload) |
| 107 | wire, err := json.MarshalIndent(signedWrapper{ |
| 108 | Payload: b64, |
| 109 | Sig: base64.StdEncoding.EncodeToString(ed25519.Sign(sg.key, []byte(b64))), |
| 110 | Grant: sg.grant, |
| 111 | }, "", " ") |
| 112 | if err != nil { |
| 113 | return err |
| 114 | } |
| 115 | _, err = s.Put(ctx, key, wire, etag) |
| 116 | return err |
| 117 | } |
| 118 | |
| 119 | // ReadPromotionRecord verifies the record at version's key: root -> grant -> |
| 120 | // record, the chain verifyPointer checks, and the signed payload must name |
| 121 | // this account, app and version. (nil, ErrNoPromotionRecord) when absent; any |
| 122 | // other failure is an error that is never read as "absent". |
| 123 | func ReadPromotionRecord(ctx context.Context, s Store, pub ed25519.PublicKey, acct, app, version string) (*PromotionRecord, error) { |
| 124 | raw, _, err := s.Get(ctx, PromotionRecordKey(acct, app, version)) |
| 125 | if errors.Is(err, os.ErrNotExist) { |
| 126 | return nil, fmt.Errorf("%s/%s: %w", app, version, ErrNoPromotionRecord) |
| 127 | } |
| 128 | if err != nil { |
| 129 | return nil, err |
| 130 | } |
| 131 | var sw signedWrapper |
| 132 | if err := json.Unmarshal(raw, &sw); err != nil { |
| 133 | return nil, fmt.Errorf("promotion record wrapper: %v", err) |
| 134 | } |
| 135 | signer, scope := pub, (*Grant)(nil) |
| 136 | if sw.Grant != nil { |
| 137 | g, err := verifyGrant(pub, sw.Grant) |
| 138 | if err != nil { |
| 139 | return nil, err |
| 140 | } |
| 141 | gpub, err := ParsePublicKey(g.Pub, "key grant pub") |
| 142 | if err != nil { |
| 143 | return nil, err |
| 144 | } |
| 145 | signer, scope = gpub, g |
| 146 | } |
| 147 | sig, err := base64.StdEncoding.DecodeString(sw.Sig) |
| 148 | if err != nil || len(signer) != ed25519.PublicKeySize || !ed25519.Verify(signer, []byte(sw.Payload), sig) { |
| 149 | return nil, fmt.Errorf("promotion record %s/%s: signature verification failed", app, version) |
| 150 | } |
| 151 | payload, err := base64.StdEncoding.DecodeString(sw.Payload) |
| 152 | if err != nil { |
| 153 | return nil, fmt.Errorf("promotion record payload: %v", err) |
| 154 | } |
| 155 | var rec PromotionRecord |
| 156 | if err := json.Unmarshal(payload, &rec); err != nil { |
| 157 | return nil, fmt.Errorf("promotion record payload: %v", err) |
| 158 | } |
| 159 | if err := validateRecord(&rec, acct, app, version); err != nil { |
| 160 | return nil, err |
| 161 | } |
| 162 | if scope != nil { |
| 163 | if rec.Channel == "" || rec.Authorized { |
| 164 | return nil, fmt.Errorf("promotion record %s/%s: an authorization signed by a scoped key", app, version) |
| 165 | } |
| 166 | if err := scope.allows(rec.Channel, rec.At); err != nil { |
| 167 | return nil, fmt.Errorf("promotion record %s/%s: %w", app, version, err) |
| 168 | } |
| 169 | } |
| 170 | return &rec, nil |
| 171 | } |
| 172 | |
| 173 | // AuthorizedManifest is §4.1's evidence for every install the settings add: |
| 174 | // the build's signed record, and its canonical manifest hashing to the |
| 175 | // record's digest. The manifest it returns is the one it checked; the caller |
| 176 | // stages from it and never re-reads it. |
| 177 | func AuthorizedManifest(ctx context.Context, s Store, pub ed25519.PublicKey, acct, app, version string) (*Manifest, error) { |
| 178 | rec, err := ReadPromotionRecord(ctx, s, pub, acct, app, version) |
| 179 | if err != nil { |
| 180 | return nil, err |
| 181 | } |
| 182 | m, _, err := CheckManifestDigest(ctx, s, acct, app, version, rec.ManifestDigest) |
| 183 | return m, err |
| 184 | } |
| 185 | |
amadan