Files
vaultik/internal/vaultik/verify.go
T
clawbot 1244c9e48d
check / check (pull_request) Successful in 1m47s
check / check (push) Successful in 3m11s
Bound download expansion and escape control chars on the terminal (closes #164)
Objects fetched from the store are untrusted; several decode paths let one expand or print without limit.

- blobgen.LimitReader errors past a byte cap (not io.LimitReader silent EOF). DecodeManifest reads through caps on both compressed input and decompressed output, far above any real manifest, so json.Decode cannot buffer a compressible bomb. FetchAndDecryptBlob bounds decompression to the blob recorded uncompressed_size (not the restoring host blob_size_limit).
- downloadSnapshotDB streams straight from storage to its temp file with io.Copy, replacing two ReadAll calls that held the whole database twice.
- FetchBlob drops the per-blob Stat round-trip, its expectedSize parameter and returned size, all of which only fed a debug log.
- TTYHandler and ui.Writer escape control characters in messages, attribute keys/values, and rendered identifiers/paths before colour codes are applied, so a crafted value cannot drive the terminal.

Model: opus-4-8
2026-09-22 17:00:35 +02:00

771 lines
22 KiB
Go

package vaultik
import (
"crypto/sha256"
"database/sql"
"encoding/hex"
"errors"
"fmt"
"io"
"os"
"path/filepath"
"time"
"filippo.io/age"
"sneak.berlin/go/vaultik/internal/blobgen"
"sneak.berlin/go/vaultik/internal/database"
"sneak.berlin/go/vaultik/internal/log"
"sneak.berlin/go/vaultik/internal/snapshot"
)
// Sentinel errors for snapshot verification failures.
var (
errVerificationFailed = errors.New("verification failed")
errSecretKeyRequired = errors.New(
"VAULTIK_AGE_SECRET_KEY not set; required for deep verification")
errChunksOutOfOrder = errors.New("chunks out of order")
errChunkHashMismatch = errors.New("chunk hash mismatch")
errNegativeChunkLength = errors.New("chunk length is negative")
errTrailingBlobData = errors.New(
"blob has unexpected trailing bytes not covered by chunk list")
errManifestExtraBlob = errors.New("manifest contains blob not in database")
errManifestMissingBlob = errors.New(
"manifest omits blob present in database")
errBlobSizeMismatch = errors.New("blob size mismatch")
)
// verifyStatusFailed is the JSON status value for a failed verification.
const verifyStatusFailed = "failed"
// VerifyOptions contains options for the verify command
type VerifyOptions struct {
Deep bool
JSON bool
}
// VerifyResult contains the result of a snapshot verification
//
//nolint:tagliatelle // snake_case is the established JSON output format
type VerifyResult struct {
SnapshotID string `json:"snapshot_id"`
Status string `json:"status"` // "ok" or "failed"
Mode string `json:"mode"` // "shallow" or "deep"
BlobCount int `json:"blob_count"`
TotalSize int64 `json:"total_size"`
Verified int `json:"verified"`
Missing int `json:"missing"`
MissingSize int64 `json:"missing_size,omitempty"`
Mismatched int `json:"mismatched,omitempty"`
// DatabaseMissing is set by shallow verify when the snapshot's
// encrypted database (metadata/<key>/db.zst.age) is absent, which
// makes the snapshot unrestorable regardless of the blobs.
DatabaseMissing bool `json:"database_missing,omitempty"`
ErrorMessage string `json:"error,omitempty"`
}
// deepVerifyFailure records a failure in the result and returns it appropriately
func (v *Vaultik) deepVerifyFailure(
result *VerifyResult, opts *VerifyOptions, msg string, err error,
) error {
result.Status = verifyStatusFailed
result.ErrorMessage = msg
if opts.JSON {
return v.outputVerifyJSON(result)
}
if err != nil {
return err
}
return fmt.Errorf("%w: %s", errVerificationFailed, msg)
}
// RunDeepVerify executes deep verification operation
func (v *Vaultik) RunDeepVerify(snapshotID string, opts *VerifyOptions) error {
result := &VerifyResult{
SnapshotID: snapshotID,
Mode: "deep",
}
if !v.CanDecrypt() {
return v.deepVerifyFailure(result, opts,
errSecretKeyRequired.Error(), errSecretKeyRequired)
}
// Parse the age secret key once, the same way restore does, and reuse
// the identities for the database and every blob.
identities, err := v.restoreIdentities()
if err != nil {
return v.deepVerifyFailure(result, opts, err.Error(), err)
}
log.Info("Starting snapshot verification", "snapshot_id", snapshotID, "mode", "deep")
if !opts.JSON {
v.stdoutf("Deep verification of snapshot: %s\n\n", snapshotID)
}
manifest, tempDB, dbBlobs, err := v.loadVerificationData(
snapshotID, opts, result, identities)
if err != nil {
return err
}
defer func() {
if tempDB != nil {
_ = tempDB.Close()
}
}()
result.BlobCount = len(dbBlobs)
var totalSize int64
for _, blob := range dbBlobs {
totalSize += blob.CompressedSize
}
result.TotalSize = totalSize
err = v.runVerificationSteps(
manifest, dbBlobs, tempDB, opts, result, totalSize, identities)
if err != nil {
return err
}
result.Status = "ok"
result.Verified = len(dbBlobs)
if opts.JSON {
return v.outputVerifyJSON(result)
}
log.Info("✓ Verification completed successfully",
"snapshot_id", snapshotID, "mode", "deep", "blobs_verified", len(dbBlobs))
v.stdoutf("\n✓ Verification completed successfully\n")
v.stdoutf(" Snapshot: %s\n", snapshotID)
v.stdoutf(" Blobs verified: %d\n", len(dbBlobs))
v.stdoutf(" Total size: %s\n", ubytes(totalSize))
return nil
}
// loadVerificationData downloads manifest, database, and blob list for verification
func (v *Vaultik) loadVerificationData(
snapshotID string, opts *VerifyOptions, result *VerifyResult,
identities []age.Identity,
) (*snapshot.Manifest, *tempDB, []snapshot.BlobInfo, error) {
// Resolve the identifier to the snapshot's remote key. A human ID is
// hashed; a remote key (or its abbreviation, as printed for a
// remote-only snapshot) is used as-is, so a host with no local index
// can verify a snapshot it can only see on the store.
remoteKey, err := v.resolveSnapshotRemoteKey(snapshotID)
if err != nil {
return nil, nil, nil, v.deepVerifyFailure(result, opts,
fmt.Sprintf("resolving snapshot identifier: %v", err), err)
}
// Download manifest. downloadManifestByKey is the single reader for
// remote manifests; see its doc comment.
log.Info("Downloading manifest", "remote_key", remoteKey)
if !opts.JSON {
v.stdoutf("Downloading manifest...\n")
}
manifest, err := v.downloadManifestByKey(remoteKey)
if err != nil {
return nil, nil, nil, v.deepVerifyFailure(result, opts,
fmt.Sprintf("failed to download manifest: %v", err),
fmt.Errorf("failed to download manifest: %w", err))
}
log.Info("Manifest loaded",
"manifest_blob_count", manifest.BlobCount,
"manifest_total_size", ubytes(manifest.TotalCompressedSize))
if !opts.JSON {
v.stdoutf("Manifest loaded: %d blobs (%s)\n",
manifest.BlobCount, ubytes(manifest.TotalCompressedSize))
v.stdoutf("Downloading and decrypting database...\n")
}
tdb, err := v.downloadVerifiedSnapshotDB(
snapshotID, remoteKey, opts, result, identities)
if err != nil {
return nil, nil, nil, err
}
dbBlobs, err := v.getBlobsFromDatabase(tdb.db.Conn())
if err != nil {
_ = tdb.Close()
return nil, nil, nil, v.deepVerifyFailure(result, opts,
fmt.Sprintf("failed to get blobs from database: %v", err),
fmt.Errorf("failed to get blobs from database: %w", err))
}
var dbTotalSize int64
for _, b := range dbBlobs {
dbTotalSize += b.CompressedSize
}
log.Info("Database loaded",
"db_blob_count", len(dbBlobs),
"db_total_size", ubytes(dbTotalSize))
if !opts.JSON {
v.stdoutf("Database loaded: %d blobs (%s)\n",
len(dbBlobs), ubytes(dbTotalSize))
}
return manifest, tdb, dbBlobs, nil
}
// downloadVerifiedSnapshotDB downloads and decrypts the snapshot metadata
// database and confirms it really is the snapshot named by remoteKey
// before any of its rows are trusted (see verifySnapshotDBIdentity). On
// any failure it records the failure in result and returns the error the
// caller should propagate; the temp database is closed on a rejected
// identity so nothing is left on disk.
func (v *Vaultik) downloadVerifiedSnapshotDB(
snapshotID, remoteKey string, opts *VerifyOptions, result *VerifyResult,
identities []age.Identity,
) (*tempDB, error) {
dbPath := fmt.Sprintf("metadata/%s/db.zst.age", remoteKey)
log.Info("Downloading encrypted database", "path", dbPath)
dbReader, err := v.Storage.Get(v.ctx, dbPath)
if err != nil {
return nil, v.deepVerifyFailure(result, opts,
fmt.Sprintf("failed to download database: %v", err),
fmt.Errorf("failed to download database: %w", err))
}
defer func() { _ = dbReader.Close() }()
tdb, err := v.decryptAndLoadDatabase(dbReader, identities)
if err != nil {
return nil, v.deepVerifyFailure(result, opts,
fmt.Sprintf("failed to decrypt database: %v", err),
fmt.Errorf("failed to decrypt database: %w", err))
}
err = v.verifySnapshotDBIdentity(tdb.db, snapshotID, remoteKey)
if err != nil {
_ = tdb.Close()
return nil, v.deepVerifyFailure(result, opts, err.Error(), err)
}
return tdb, nil
}
// runVerificationSteps executes manifest verification, blob existence
// check, and deep content verification.
func (v *Vaultik) runVerificationSteps(
manifest *snapshot.Manifest,
dbBlobs []snapshot.BlobInfo,
tdb *tempDB,
opts *VerifyOptions,
result *VerifyResult,
totalSize int64,
identities []age.Identity,
) error {
if !opts.JSON {
v.stdoutf("Verifying manifest against database...\n")
}
err := v.verifyManifestAgainstDatabase(manifest, dbBlobs)
if err != nil {
return v.deepVerifyFailure(result, opts, err.Error(), err)
}
if !opts.JSON {
v.stdoutf("Manifest verified.\n")
v.stdoutf("Checking blob existence in remote storage...\n")
}
err = v.verifyBlobExistenceFromDB(dbBlobs)
if err != nil {
return v.deepVerifyFailure(result, opts, err.Error(), err)
}
if !opts.JSON {
v.stdoutf("All blobs exist.\n")
v.stdoutf("Downloading and verifying blob contents (%d blobs, %s)...\n",
len(dbBlobs), ubytes(totalSize))
}
err = v.performDeepVerificationFromDB(dbBlobs, tdb.db.Conn(), opts, identities)
if err != nil {
return v.deepVerifyFailure(result, opts, err.Error(), err)
}
return nil
}
// tempDB is the downloaded snapshot database opened read-only for deep
// verify, held in a private temp directory removed in full on Close.
type tempDB struct {
db *database.DB
tempDir string
}
func (t *tempDB) Close() error {
err := t.db.Close()
// Remove the whole private directory so the decrypted database and
// any SQLite side files are gone on every path.
_ = os.RemoveAll(t.tempDir)
return err
}
// decryptAndLoadDatabase decrypts and loads the binary SQLite database
// from the encrypted stream. It reads through the same blobgen reader restore
// uses, streaming the decrypted, decompressed database to a temp file.
func (v *Vaultik) decryptAndLoadDatabase(
reader io.ReadCloser, identities []age.Identity,
) (*tempDB, error) {
// Decrypt and decompress through the shared blobgen reader.
blobReader, err := blobgen.NewReader(reader, identities...)
if err != nil {
return nil, fmt.Errorf("failed to create decryption reader: %w", err)
}
defer func() { _ = blobReader.Close() }()
// Materialize the decrypted database inside a private (0700) temp
// directory so it is never world-readable, and remove the whole
// directory on any failure below.
tempDir, err := os.MkdirTemp("", "vaultik-verify-")
if err != nil {
return nil, fmt.Errorf("failed to create temp directory: %w", err)
}
success := false
defer func() {
if !success {
_ = os.RemoveAll(tempDir)
}
}()
dbPath := filepath.Join(tempDir, snapshotDBFilename)
//nolint:gosec // G304: dbPath is our MkdirTemp dir plus a constant filename
tempFile, err := os.OpenFile(
dbPath, os.O_CREATE|os.O_EXCL|os.O_WRONLY, restoreFileMode)
if err != nil {
return nil, fmt.Errorf("failed to create temp file: %w", err)
}
// Stream decompress directly to file
log.Info("Decompressing database...")
written, err := io.Copy(tempFile, blobReader)
if err != nil {
_ = tempFile.Close()
return nil, fmt.Errorf("failed to decompress database: %w", err)
}
err = tempFile.Close()
if err != nil {
return nil, fmt.Errorf("failed to close temp database file: %w", err)
}
log.Info("Database decompressed", "size", ubytes(written))
db, err := database.OpenReadOnly(v.ctx, dbPath)
if err != nil {
return nil, fmt.Errorf("failed to open database: %w", err)
}
success = true
return &tempDB{db: db, tempDir: tempDir}, nil
}
// verifyBlob downloads and verifies a single blob
func (v *Vaultik) verifyBlob(
blobInfo snapshot.BlobInfo, db *sql.DB, identities []age.Identity,
) error {
// Download blob using shared fetch method
reader, err := v.FetchBlob(v.ctx, blobInfo.Hash)
if err != nil {
return fmt.Errorf("failed to download: %w", err)
}
defer func() { _ = reader.Close() }()
// Decrypt and decompress through the shared blobgen reader, which hashes
// the plaintext as it is read. A blob's hash — its remote name — is the
// double SHA-256 of that plaintext (see blobgen.DoubleSHA256), not of the
// encrypted bytes.
blobReader, err := blobgen.NewReader(reader, identities...)
if err != nil {
return fmt.Errorf("failed to create blob reader: %w", err)
}
defer func() { _ = blobReader.Close() }()
chunkCount, err := v.verifyBlobChunks(db, blobInfo.Hash, blobReader)
if err != nil {
return err
}
err = v.verifyBlobFinalIntegrity(blobReader, blobInfo.Hash)
if err != nil {
return err
}
log.Info("Blob verified",
"hash", shortHash(blobInfo.Hash)+"...",
"chunks", chunkCount,
"size", ubytes(blobInfo.CompressedSize),
)
return nil
}
// verifyBlobChunks queries blob chunks from the database and verifies
// each chunk's hash against the decompressed blob stream.
func (v *Vaultik) verifyBlobChunks(
db *sql.DB, blobHash string, decompressor io.Reader,
) (int, error) {
query := `
SELECT bc.chunk_hash, bc.offset, bc.length
FROM blob_chunks bc
JOIN blobs b ON bc.blob_id = b.id
WHERE b.blob_hash = ?
ORDER BY bc.offset
`
rows, err := db.QueryContext(v.ctx, query, blobHash)
if err != nil {
return 0, fmt.Errorf("failed to query blob chunks: %w", err)
}
defer func() { _ = rows.Close() }()
var lastOffset int64 = -1
chunkCount := 0
totalRead := int64(0)
// Verify each chunk in the blob
for rows.Next() {
var (
chunkHash string
offset, length int64
)
err := rows.Scan(&chunkHash, &offset, &length)
if err != nil {
return 0, fmt.Errorf("failed to scan chunk row: %w", err)
}
// Verify chunk ordering
if offset <= lastOffset {
return 0, fmt.Errorf("%w: offset %d after %d",
errChunksOutOfOrder, offset, lastOffset)
}
lastOffset = offset
// Read chunk data from decompressed stream
if offset > totalRead {
// Skip to the correct offset
skipBytes := offset - totalRead
_, err = io.CopyN(io.Discard, decompressor, skipBytes)
if err != nil {
return 0, fmt.Errorf("failed to skip to offset %d: %w", offset, err)
}
totalRead = offset
}
// length comes from an untrusted blob_chunks row: reject a
// negative value, and hash by streaming exactly length bytes
// rather than allocating a database-supplied size up front.
if length < 0 {
return 0, fmt.Errorf("%w: offset %d length %d",
errNegativeChunkLength, offset, length)
}
hasher := sha256.New()
n, err := io.CopyN(hasher, decompressor, length)
if err != nil {
return 0, fmt.Errorf("failed to read chunk at offset %d: %w", offset, err)
}
totalRead += n
calculatedHash := hex.EncodeToString(hasher.Sum(nil))
if calculatedHash != chunkHash {
return 0, fmt.Errorf("%w at offset %d: calculated %s, expected %s",
errChunkHashMismatch, offset, calculatedHash, chunkHash)
}
chunkCount++
}
err = rows.Err()
if err != nil {
return 0, fmt.Errorf("error iterating blob chunks: %w", err)
}
return chunkCount, nil
}
// verifyBlobFinalIntegrity checks that no trailing data exists in the
// decompressed stream and that the blob hash matches the expected value.
func (v *Vaultik) verifyBlobFinalIntegrity(
blobReader *blobgen.Reader, expectedHash string,
) error {
// Verify no remaining data in blob - if the chunk list is accurate,
// the blob should be fully consumed. Draining to EOF also completes the
// reader's plaintext hash.
remaining, err := io.Copy(io.Discard, blobReader)
if err != nil {
return fmt.Errorf("failed to check for remaining blob data: %w", err)
}
if remaining > 0 {
return fmt.Errorf("%w: %d bytes", errTrailingBlobData, remaining)
}
// The blob hash is the double SHA-256 of its plaintext content.
calculatedBlobHash := hex.EncodeToString(
blobgen.DoubleSHA256(blobReader.Sum256()))
if calculatedBlobHash != expectedHash {
return fmt.Errorf("%w: calculated %s, expected %s",
errBlobHashMismatch, calculatedBlobHash, expectedHash)
}
return nil
}
// getBlobsFromDatabase gets all blobs for the snapshot from the database.
//
// The exported per-snapshot database holds exactly one snapshot's data
// (see cleanSnapshotDB), so every row in snapshot_blobs belongs to it.
// We select them directly rather than filtering by the human snapshot ID,
// which a host restoring from the store alone does not have.
func (v *Vaultik) getBlobsFromDatabase(db *sql.DB) ([]snapshot.BlobInfo, error) {
query := `
SELECT b.blob_hash, b.compressed_size
FROM snapshot_blobs sb
JOIN blobs b ON sb.blob_hash = b.blob_hash
ORDER BY b.blob_hash
`
rows, err := db.QueryContext(v.ctx, query)
if err != nil {
return nil, fmt.Errorf("failed to query snapshot blobs: %w", err)
}
defer func() { _ = rows.Close() }()
var blobs []snapshot.BlobInfo
for rows.Next() {
var (
hash string
size int64
)
err := rows.Scan(&hash, &size)
if err != nil {
return nil, fmt.Errorf("failed to scan blob row: %w", err)
}
blobs = append(blobs, snapshot.BlobInfo{
Hash: hash,
CompressedSize: size,
})
}
err = rows.Err()
if err != nil {
return nil, fmt.Errorf("error iterating blobs: %w", err)
}
return blobs, nil
}
// verifyManifestAgainstDatabase verifies the manifest matches the
// authoritative database.
func (v *Vaultik) verifyManifestAgainstDatabase(
manifest *snapshot.Manifest, dbBlobs []snapshot.BlobInfo,
) error {
log.Info("Verifying manifest against database")
// Build map of database blobs
dbBlobMap := make(map[string]int64)
for _, blob := range dbBlobs {
dbBlobMap[blob.Hash] = blob.CompressedSize
}
// Build map of manifest blobs
manifestBlobMap := make(map[string]int64)
for _, blob := range manifest.Blobs {
manifestBlobMap[blob.Hash] = blob.CompressedSize
}
// The manifest is the only blob list prune consults, so it must match
// the database exactly. A blob in the manifest but not the database
// points at a corrupt manifest; a blob in the database but omitted
// from the manifest would be pruned away while this snapshot still
// needs it. Either divergence fails verification.
for hash, manifestSize := range manifestBlobMap {
dbSize, exists := dbBlobMap[hash]
if !exists {
return fmt.Errorf("%w: %s", errManifestExtraBlob, hash)
}
if dbSize != manifestSize {
return fmt.Errorf(
"%w: blob %s: database has %d bytes, manifest has %d bytes",
errBlobSizeMismatch, hash, dbSize, manifestSize)
}
}
for hash := range dbBlobMap {
if _, exists := manifestBlobMap[hash]; !exists {
return fmt.Errorf("%w: %s", errManifestMissingBlob, hash)
}
}
log.Info("✓ Manifest verified against database",
"manifest_blobs", len(manifestBlobMap),
"database_blobs", len(dbBlobMap),
)
return nil
}
// verifyBlobExistenceFromDB checks that all blobs from database exist in S3
func (v *Vaultik) verifyBlobExistenceFromDB(blobs []snapshot.BlobInfo) error {
log.Info("Verifying blob existence in S3", "blob_count", len(blobs))
for i, blob := range blobs {
// The hash is read from the snapshot database, which is not
// trusted; check it before it is spliced into a storage path.
if !isBlobHash(blob.Hash) {
return fmt.Errorf("%w: %s", errInvalidBlobHash, shortHash(blob.Hash))
}
// Construct blob path
blobPath := fmt.Sprintf("blobs/%s/%s/%s", blob.Hash[:2], blob.Hash[2:4], blob.Hash)
// Check blob exists
stat, err := v.Storage.Stat(v.ctx, blobPath)
if err != nil {
return fmt.Errorf("blob %s missing from storage: %w", blob.Hash, err)
}
// Verify size matches
if stat.Size != blob.CompressedSize {
return fmt.Errorf(
"%w: blob %s: S3 has %d bytes, database has %d bytes",
errBlobSizeMismatch, blob.Hash, stat.Size, blob.CompressedSize)
}
// Progress update every 100 blobs
if (i+1)%progressLogEvery == 0 || i == len(blobs)-1 {
log.Info("Blob existence check progress",
"checked", i+1,
"total", len(blobs),
"percent", fmt.Sprintf("%.1f%%",
float64(i+1)/float64(len(blobs))*percentScale),
)
}
}
log.Info("✓ All blobs exist in storage")
return nil
}
// performDeepVerificationFromDB downloads and verifies the content of
// each blob using the database as source.
func (v *Vaultik) performDeepVerificationFromDB(
blobs []snapshot.BlobInfo, db *sql.DB, opts *VerifyOptions,
identities []age.Identity,
) error {
// Calculate total bytes for ETA
var totalBytesExpected int64
for _, b := range blobs {
totalBytesExpected += b.CompressedSize
}
log.Info("Starting deep verification - downloading and verifying all blobs",
"blob_count", len(blobs),
"total_size", ubytes(totalBytesExpected),
)
startTime := time.Now()
bytesProcessed := int64(0)
for i, blobInfo := range blobs {
// Verify individual blob
err := v.verifyBlob(blobInfo, db, identities)
if err != nil {
return fmt.Errorf("blob %s verification failed: %w", blobInfo.Hash, err)
}
bytesProcessed += blobInfo.CompressedSize
elapsed := time.Since(startTime)
remaining := len(blobs) - (i + 1)
// Calculate ETA based on bytes processed
var eta time.Duration
if bytesProcessed > 0 {
bytesPerSec := float64(bytesProcessed) / elapsed.Seconds()
bytesRemaining := totalBytesExpected - bytesProcessed
if bytesPerSec > 0 {
eta = time.Duration(float64(bytesRemaining)/bytesPerSec) * time.Second
}
}
log.Info("Verification progress",
"blobs_done", i+1,
"blobs_total", len(blobs),
"blobs_remaining", remaining,
"bytes_done", bytesProcessed,
"bytes_done_human", ubytes(bytesProcessed),
"bytes_total", totalBytesExpected,
"bytes_total_human", ubytes(totalBytesExpected),
"elapsed", elapsed.Round(time.Second),
"eta", eta.Round(time.Second),
)
if !opts.JSON {
v.stdoutf(" Verified %d/%d blobs (%d remaining) - %s/%s - elapsed %s, eta %s\n",
i+1, len(blobs), remaining,
ubytes(bytesProcessed),
ubytes(totalBytesExpected),
elapsed.Round(time.Second),
eta.Round(time.Second))
}
}
totalElapsed := time.Since(startTime)
log.Info("✓ Deep verification completed successfully",
"blobs_verified", len(blobs),
"total_bytes", bytesProcessed,
"total_bytes_human", ubytes(bytesProcessed),
"duration", totalElapsed.Round(time.Second),
)
return nil
}