| 1 | package hostfloor |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/ed25519" |
| 6 | "errors" |
| 7 | "github.com/aws/smithy-go" |
| 8 | "github.com/carlosframework/platform/internal/release" |
| 9 | "net" |
| 10 | "os" |
| 11 | ) |
| 12 | |
| 13 | func Offline(err error) bool { |
| 14 | if errors.Is(err, context.DeadlineExceeded) { |
| 15 | return true |
| 16 | } |
| 17 | var network net.Error |
| 18 | if errors.As(err, &network) { |
| 19 | return true |
| 20 | } |
| 21 | var api smithy.APIError |
| 22 | if errors.As(err, &api) { |
| 23 | switch api.ErrorCode() { |
| 24 | case "SlowDown", "ServiceUnavailable", "InternalError": |
| 25 | return true |
| 26 | } |
| 27 | } |
| 28 | return false |
| 29 | } |
| 30 | func CheckRemote(ctx context.Context, s release.Store, pub ed25519.PublicKey, bucket string, local Verified) error { |
| 31 | remote, err := Read(ctx, s, pub, bucket) |
| 32 | if err != nil { |
| 33 | if Offline(err) { |
| 34 | return nil |
| 35 | } |
| 36 | return err |
| 37 | } |
| 38 | if remote.Digest != local.Digest { |
| 39 | return ErrFloor |
| 40 | } |
| 41 | return nil |
| 42 | } |
| 43 | |
| 44 | // CheckRemotePolicy is guard-exec's comparison of the local policy with the |
| 45 | // published floor (D1). An armed policy is the prospective floor, persisted |
| 46 | // before publication, so a store holding neither floor object is the |
| 47 | // expected state and the local policy, already enforced, stands (Opus 8b |
| 48 | // review I-1). Every other answer refuses unless it matches: a half-written |
| 49 | // pair, a malformed or unauthorized object, a different digest, or no |
| 50 | // remote floor at all once the policy is enforced. An unreachable store is |
| 51 | // offline, as in CheckRemote. |
| 52 | func CheckRemotePolicy(ctx context.Context, s release.Store, pub ed25519.PublicKey, bucket string, p Policy, local Verified) error { |
| 53 | raw, _, rawErr := s.Get(ctx, Key) |
| 54 | if rawErr != nil { |
| 55 | if Offline(rawErr) { |
| 56 | return nil |
| 57 | } |
| 58 | if p.Mode == "armed" && errors.Is(rawErr, os.ErrNotExist) { |
| 59 | _, _, authErr := s.Get(ctx, AuthKey) |
| 60 | if errors.Is(authErr, os.ErrNotExist) { |
| 61 | return nil |
| 62 | } |
| 63 | } |
| 64 | // A later offline read cannot erase the first definite refusal. |
| 65 | return rawErr |
| 66 | } |
| 67 | auth, _, authErr := s.Get(ctx, AuthKey) |
| 68 | if authErr != nil { |
| 69 | if Offline(authErr) { |
| 70 | return nil |
| 71 | } |
| 72 | return authErr |
| 73 | } |
| 74 | remote, err := Verify(pub, bucket, raw, auth) |
| 75 | if err != nil { |
| 76 | return err |
| 77 | } |
| 78 | if remote.Digest != local.Digest { |
| 79 | return ErrFloor |
| 80 | } |
| 81 | return nil |
| 82 | } |
| 83 | |
amadan