| 1 | package console |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "os" |
| 6 | "regexp" |
| 7 | "strings" |
| 8 | "testing" |
| 9 | |
| 10 | "github.com/carlosframework/platform/internal/hostfloor" |
| 11 | "github.com/carlosframework/platform/internal/hostops" |
| 12 | "github.com/carlosframework/platform/internal/status" |
| 13 | ) |
| 14 | |
| 15 | // The receipt database identity also names the EC2 instance the console runs |
| 16 | // on. A disk image or snapshot keeps the nonce, the filesystem UUID and the |
| 17 | // inode, so without it a clone could fence or commit the original's SQL |
| 18 | // effects. Root's enrollment file says which instance this disk was enrolled |
| 19 | // on, but the image carries that file too, so it is only believed when the |
| 20 | // running machine says the same; OpenGated refuses a database whose stored |
| 21 | // instance is another machine's. |
| 22 | const ( |
| 23 | sqlHostActorPath = "/etc/carlos/host-actor.json" |
| 24 | // On Nitro instances the hypervisor sets the board asset tag to the |
| 25 | // instance ID; a disk copy cannot carry it. |
| 26 | sqlDMIAssetTagPath = "/sys/devices/virtual/dmi/id/board_asset_tag" |
| 27 | ) |
| 28 | |
| 29 | var sqlInstanceIdentity = readSQLInstanceIdentity |
| 30 | |
| 31 | // The sources are vars so tests can stand in for /etc, /sys and IMDS. |
| 32 | var ( |
| 33 | sqlEnrolledInstance = func() (string, error) { |
| 34 | e, err := hostfloor.ReadEnrollment(sqlHostActorPath) |
| 35 | if err != nil { |
| 36 | return "", err |
| 37 | } |
| 38 | return e.InstanceID, nil |
| 39 | } |
| 40 | sqlDMIInstance = func() string { |
| 41 | b, err := os.ReadFile(sqlDMIAssetTagPath) |
| 42 | if err != nil { |
| 43 | return "" |
| 44 | } |
| 45 | return strings.TrimSpace(string(b)) |
| 46 | } |
| 47 | // status.InstanceID is IMDSv2 bounded to two seconds; it says "" off EC2. |
| 48 | sqlIMDSInstance = status.InstanceID |
| 49 | ) |
| 50 | |
| 51 | var ec2InstanceID = regexp.MustCompile(`^i-[0-9a-f]{8,17}$`) |
| 52 | |
| 53 | // sqlLiveInstance is the running machine's instance ID, or "". The Nitro |
| 54 | // asset tag is read first because it needs no network; other hardware puts |
| 55 | // arbitrary text there, so only an instance-shaped tag counts. |
| 56 | func sqlLiveInstance() string { |
| 57 | if id := sqlDMIInstance(); ec2InstanceID.MatchString(id) { |
| 58 | return id |
| 59 | } |
| 60 | return sqlIMDSInstance() |
| 61 | } |
| 62 | |
| 63 | func readSQLInstanceIdentity() (string, error) { |
| 64 | enrolled, err := sqlEnrolledInstance() |
| 65 | if err != nil { |
| 66 | return "", err |
| 67 | } |
| 68 | live := sqlLiveInstance() |
| 69 | if live == "" { |
| 70 | return "", fmt.Errorf("%w: cannot read this machine's instance ID", hostops.ErrIdentity) |
| 71 | } |
| 72 | if live != enrolled { |
| 73 | return "", fmt.Errorf("%w: enrolled on instance %q but running on %q", hostops.ErrIdentity, enrolled, live) |
| 74 | } |
| 75 | return live, nil |
| 76 | } |
| 77 | |
| 78 | // sqlInstance is the validated per-instance component. A ':' would make the |
| 79 | // database ID ambiguous, so it is refused with an empty one. |
| 80 | func sqlInstance() (string, error) { |
| 81 | id, err := sqlInstanceIdentity() |
| 82 | if err != nil { |
| 83 | return "", err |
| 84 | } |
| 85 | if id == "" || strings.ContainsAny(id, ":\n") { |
| 86 | return "", hostops.ErrIdentity |
| 87 | } |
| 88 | return id, nil |
| 89 | } |
| 90 | |
| 91 | func useSQLInstanceIdentity(fn func() (string, error)) (restore func()) { |
| 92 | old := sqlInstanceIdentity |
| 93 | sqlInstanceIdentity = fn |
| 94 | return func() { sqlInstanceIdentity = old } |
| 95 | } |
| 96 | |
| 97 | // UseSQLInstanceIdentityForTest makes OpenGated see id as this machine's |
| 98 | // instance until restore runs. Other packages' tests open gated databases on |
| 99 | // hosts with no enrollment file; production binaries panic here. |
| 100 | func UseSQLInstanceIdentityForTest(id string) (restore func()) { |
| 101 | if !testing.Testing() { |
| 102 | panic("console: UseSQLInstanceIdentityForTest outside a test binary") |
| 103 | } |
| 104 | return useSQLInstanceIdentity(func() (string, error) { return id, nil }) |
| 105 | } |
| 106 | |
amadan