Artifact [04180a498a]

Artifact 04180a498ae67552819c8b933ae4555c202f7083ecfb79f58d4e05380943c8cb:

• File internal/deck/zcard.go — part of check-in [f5744359d3] at 2026-04-19 16:30:54 on branch trunk — Initial open source release

  libfossil is a pure-Go implementation of the Fossil SCM, reading and writing the same .fossil SQLite repository format as upstream Fossil.

  This is the first public release of code that previously lived in a private repository. The module path is github.com/danmestas/libfossil and the binary is named libfossil to avoid $PATH collisions with upstream fossil.

  Included: - Repo lifecycle (create, clone), checkout/checkin, timeline, merge, diff, annotate, shun, tag, branch, bisect, stash, undo/redo - Sync-over-HTTP protocol (client and handler) - Two SQLite drivers: modernc (pure Go, default) and ncruces (wasm-capable) - Observer interfaces (SyncObserver, CheckoutObserver) with an optional OpenTelemetry implementation in observer/otel (separate submodule) - Deterministic simulation testing harness with BUGGIFY fault injection - Kong-based embeddable CLI under cli/ and a standalone binary under cmd/libfossil/ (user: [email protected], size: 652) [annotate] [blame] [check-ins using]

package deck

import (
	"crypto/md5"
	"encoding/hex"
	"fmt"
)

func VerifyZ(data []byte) error {
	if len(data) < 35 {
		return fmt.Errorf("deck.VerifyZ: manifest too short (%d bytes)", len(data))
	}
	tail := data[len(data)-35:]
	if tail[0] != 'Z' || tail[1] != ' ' || tail[34] != '\n' {
		return fmt.Errorf("deck.VerifyZ: invalid Z-card format")
	}
	stated := string(tail[2:34])
	computed := computeZ(data[:len(data)-35])
	if computed != stated {
		return fmt.Errorf("deck.VerifyZ: checksum mismatch: stated=%s computed=%s", stated, computed)
	}
	return nil
}

func computeZ(data []byte) string {
	h := md5.Sum(data)
	return hex.EncodeToString(h[:])
}