| 1 | //go:build linux |
| 2 | |
| 3 | package host |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "crypto/ed25519" |
| 8 | "crypto/sha256" |
| 9 | "encoding/hex" |
| 10 | "fmt" |
| 11 | "io" |
| 12 | "os" |
| 13 | "strconv" |
| 14 | "strings" |
| 15 | |
| 16 | "github.com/carlosframework/platform/internal/hostfloor" |
| 17 | "github.com/carlosframework/platform/internal/hostwrite" |
| 18 | "github.com/carlosframework/platform/internal/release" |
| 19 | "golang.org/x/sys/unix" |
| 20 | ) |
| 21 | |
| 22 | type productionStopControllers struct{} |
| 23 | |
| 24 | func (productionStopControllers) VerifiedController(ctx context.Context, pid int) (string, error) { |
| 25 | if ctx.Err() != nil { |
| 26 | return "", ctx.Err() |
| 27 | } |
| 28 | if pid <= 0 { |
| 29 | return "", hostwrite.ErrUnavailable |
| 30 | } |
| 31 | boot, err := os.ReadFile("/proc/sys/kernel/random/boot_id") |
| 32 | if err != nil { |
| 33 | return "", err |
| 34 | } |
| 35 | raw, err := os.ReadFile(fmt.Sprintf("/proc/%d/stat", pid)) |
| 36 | if err != nil { |
| 37 | return "", err |
| 38 | } |
| 39 | end := strings.LastIndexByte(string(raw), ')') |
| 40 | if end < 0 { |
| 41 | return "", hostwrite.ErrUnavailable |
| 42 | } |
| 43 | fields := strings.Fields(string(raw)[end+1:]) |
| 44 | if len(fields) < 20 { |
| 45 | return "", hostwrite.ErrUnavailable |
| 46 | } |
| 47 | if _, err := strconv.ParseUint(fields[19], 10, 64); err != nil { |
| 48 | return "", err |
| 49 | } |
| 50 | sum := sha256.Sum256([]byte(strings.TrimSpace(string(boot)) + "\x00" + strconv.Itoa(pid) + "\x00" + fields[19])) |
| 51 | return hex.EncodeToString(sum[:]), nil |
| 52 | } |
| 53 | func readClaimEvidenceKey(path string) (ed25519.PrivateKey, error) { |
| 54 | if os.Geteuid() != 0 { |
| 55 | return nil, hostwrite.ErrUnavailable |
| 56 | } |
| 57 | f, err := hostfloor.OpenProtected(path) |
| 58 | if err != nil { |
| 59 | return nil, err |
| 60 | } |
| 61 | defer f.Close() |
| 62 | var stat unix.Stat_t |
| 63 | if err = unix.Fstat(int(f.Fd()), &stat); err != nil { |
| 64 | return nil, err |
| 65 | } |
| 66 | if stat.Uid != 0 || stat.Mode&unix.S_IFMT != unix.S_IFREG || stat.Mode&0077 != 0 || stat.Nlink != 1 { |
| 67 | return nil, hostwrite.ErrUnavailable |
| 68 | } |
| 69 | raw, err := io.ReadAll(io.LimitReader(f, 4097)) |
| 70 | if err != nil || len(raw) > 4096 { |
| 71 | return nil, hostwrite.ErrUnavailable |
| 72 | } |
| 73 | return release.ParseSigningKey(strings.TrimSpace(string(raw)), path) |
| 74 | } |
| 75 | |
| 76 | func prepareClaimParticipationDirectory(path string) error { |
| 77 | uid, gid, err := claimStateOwner() |
| 78 | if err != nil { |
| 79 | return err |
| 80 | } |
| 81 | if err = os.Mkdir(path, 0700); err != nil && !os.IsExist(err) { |
| 82 | return err |
| 83 | } |
| 84 | return claimPrivatePathOwner(path, uid, gid, true) |
| 85 | } |
| 86 | |
amadan