From 84e3bbf4428220d0bd00b685a23793fa58e13125 Mon Sep 17 00:00:00 2001
From: Pim van Pelt <pim@ipng.ch>
Date: Sun, 11 Jan 2026 08:01:35 +0100
Subject: [PATCH] Also support hash tiles

---
 README.md               | 11 ++++++++---
 internal/utils/utils.go | 29 +++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index e3d3b68..c9133fc 100644
--- a/README.md
+++ b/README.md
@@ -36,7 +36,7 @@ ctfetch --dumpall https://halloumi2026h1.mon.ct.ipng.ch 629794635
 
 ### tiledump
 
-Read a CT log tile file or URL and dump all entries.
+Read a CT log tile file or URL and dump contents. Automatically detects and handles both data tiles (log entries) and hash tiles (Merkle tree hashes).
 
 ```bash
 tiledump <tile-file-or-url>
@@ -44,12 +44,17 @@ tiledump <tile-file-or-url>
 
 **Examples:**
 
-From a file:
+Data tile from a file:
 ```bash
 tiledump tile.data
 ```
 
-From a URL:
+Data tile from a URL:
 ```bash
 tiledump https://halloumi2026h1.mon.ct.ipng.ch/tile/data/x002/x460/135
 ```
+
+Hash tile from a URL:
+```bash
+tiledump https://halloumi2026h1.mon.ct.ipng.ch/tile/0/x100/999
+```
diff --git a/internal/utils/utils.go b/internal/utils/utils.go
index 5263f05..c3eda34 100644
--- a/internal/utils/utils.go
+++ b/internal/utils/utils.go
@@ -43,7 +43,18 @@ func Decompress(data []byte) ([]byte, error) {
 }
 
 // DumpAllEntries reads and dumps all entries from tile data.
+// Automatically detects if the tile is a data tile or hash tile.
 func DumpAllEntries(tileData []byte) error {
+	// Try to read as data tile first
+	if err := dumpDataTile(tileData); err != nil {
+		// If it fails, try as hash tile
+		fmt.Fprintf(os.Stderr, "Not a data tile, trying as hash tile...\n")
+		return dumpHashTile(tileData)
+	}
+	return nil
+}
+
+func dumpDataTile(tileData []byte) error {
 	entryNum := 0
 	for len(tileData) > 0 {
 		e, remaining, err := sunlight.ReadTileLeaf(tileData)
@@ -61,6 +72,24 @@ func DumpAllEntries(tileData []byte) error {
 	return nil
 }
 
+func dumpHashTile(tileData []byte) error {
+	const hashSize = 32 // SHA-256 hash size
+
+	if len(tileData)%hashSize != 0 {
+		return fmt.Errorf("invalid hash tile: size %d is not a multiple of %d", len(tileData), hashSize)
+	}
+
+	numHashes := len(tileData) / hashSize
+	fmt.Printf("Hash tile with %d hashes:\n\n", numHashes)
+
+	for i := 0; i < numHashes; i++ {
+		hash := tileData[i*hashSize : (i+1)*hashSize]
+		fmt.Printf("Hash %d: %x\n", i, hash)
+	}
+
+	return nil
+}
+
 // DumpEntryAtPosition reads and dumps a specific entry at the given position.
 func DumpEntryAtPosition(tileData []byte, position int, expectedIndex int64) error {
 	entryNum := 0