build-merkle-tree-cli-sha512

You are an expert terminal agent. You MUST use the provided tools to complete tasks. Use the terminal tool to run shell commands, read_file to read files, write_file to write files, search_files to search, and patch to edit files. Do NOT write out solutions as text - execute them using the tools. Always start by exploring the environment with terminal commands.

# Build Merkle Tree CLI Tool with SHA-512

Your task is to build a CLI tool that scans a target directory, computes SHA-512 hashes of each file as leaves in a Merkle tree, and stores the root hash and leaf proofs. The tool must provide commands to generate a Merkle proof for any file and to verify its integrity against the stored root, detecting any tampering, additions, or deletions.

## Requirements

1. **CLI Tool Structure**: Create a Python CLI tool named `merkle-cli` that accepts subcommands:
   - `scan <directory>`: Scan a directory and build a Merkle tree, storing the root hash and proofs
   - `proof <file_path>`: Generate a Merkle proof for a specific file and output JSON to stdout. The file_path should be a relative path as stored in merkle_data.json (e.g., "file1.txt" or "subdir/nested.txt")
   - `verify <file_path> <proof_file>`: Verify a file's integrity using its proof against the stored root. The file_path can be a relative path (as stored in merkle_data.json) or an absolute path. The proof_file should be a JSON file containing the proof data (as output by the proof command)

2. **Merkle Tree Implementation**:
   - Use SHA-512 for all hashing operations (not SHA-256)
   - Files are leaves (hash the file content)
   - Internal nodes are hashes of concatenated child hashes
   - Handle odd numbers of nodes by duplicating the last node when necessary
   - Store the tree structure and proofs in JSON format
   - **Important**: All hash values must be 128-character hexadecimal strings (SHA-512 produces 512 bits = 128 hex characters)

3. **Storage Format**:
   - Root hash and proofs must be stored in `/app/merkle_data.json`
   - The JSON structure must include:
     - `root_hash`: The root hash of the Merkle tree (128-character hex string)
     - `proofs`: A dictionary mapping file paths to their Merkle proofs (array of hashes)
     - `file_hashes`: A dictionary mapping file paths to their leaf hashes (128-character hex strings)
     - `scanned_directory`: The absolute path of the directory that was scanned

4. **Proof Generation**:
   - The `proof` command must output JSON to stdout (not write to a file)
   - The output JSON must have this structure:
     ```json
     {
       "file_path": "relative/path/to/file.txt",
       "proof": [["left", "hash1"], ["right", "hash2"], ...]
     }
     ```
   - A Merkle proof is an array of sibling hashes needed to reconstruct the path from leaf to root
   - Each proof entry must be a 2-element list: `["left", "hash"]` or `["right", "hash"]` where the first element indicates the sibling's position and the second is the sibling's hash (128-character hex string)
   - Proofs must be deterministic and verifiable

5. **Verification**:
   - Verify command must check if a file's current hash matches the stored proof
   - Reconstruct the root hash from the proof and compare with stored root
   - Detect if files have been added, deleted, or modified
   - The `verify` command must output to stdout indicating verification success or failure
   - **Exit codes**: Exit with code 0 on successful verification, non-zero code on failure
   - **Failure indication**: When verification fails, the output must contain the word "failed" (case-insensitive) in stdout, OR the command must exit with a non-zero code
   - **Output format**: Either JSON (with fields like root_matches, file_hash_matches_storage, added_files, deleted_files, modified_files) or human-readable text containing success indicators

6. **File Handling**:
   - Only process regular files (ignore directories, symlinks, etc.)
   - Use relative paths from the scanned directory
   - Handle empty directories gracefully
   - Files must be read in binary mode to ensure consistent hashing across platforms

7. **Hash Validation**:
   - All hash values (root_hash, file_hashes, proof hashes) must be exactly 128 characters long
   - Hash values must contain only hexadecimal characters (0-9, a-f, lowercase)
   - The tool must validate hash format when l
… (1542 more chars)

{"output": "Python 3.13.12\ntest_data", "exit_code": 0, "error": null}

{"output": "/app/test_data/file1.txt\n/app/test_data/subdir/nested.txt\n/app/test_data/file2.txt\n/app/test_data/file3.txt", "exit_code": 0, "error": null}

{"output": "This is file 1 content.\nLine 2 of file 1.\n\nThis is file 2 content.\nDifferent content here.\n\nFile 3 has unique content.\nThird file in the test set.\n\nNested file content.\nIn a subdirectory.", "exit_code": 0, "error": null}

Now I'll create the Merkle CLI tool:

write_file({"path": "/app/merkle_cli.py", "content": "#!/usr/bin/env python3\n\"\"\"Merkle Tree CLI Tool with SHA-512 hashing.\"\"\"\n\nimport argparse\nimport hashlib\nimport json\nimport os\nimport sys\n\nMERKLE_DATA_PATH = \"/app/merkle_data.json\"\n\n\ndef sha512_hash(data: bytes) -> str:\n    \"\"\"Compute SHA-512 hash and return as lowercase hex string (128 chars).\"\"\"\n    return hashlib.sha512(data…)

{"bytes_written": 11389, "dirs_created": true}

{"success": true, "diff": "--- a//app/merkle_cli.py\n+++ b//app/merkle_cli.py\n@@ -36,7 +36,7 @@\n         tree_levels: List of levels, bottom-up (leaves first)\n     \"\"\"\n     if not file_hashes:\n-        return sha51_hash(b\"empty\"), [[]]\n+        return sha512_hash(b\"empty\"), [[]]\n \n     # Start with leaf level\n     tree_levels = [list(file_hashes)]\n", "files_modified": ["/app/merkle_cli.py"], "lint": {"status": "ok", "output": ""}}

Now let me remove the unused helper function and test the tool:

patch({"mode": "replace", "path": "/app/merkle_cli.py", "old_string": "def sha51_hash(data):\n    \"\"\"Helper for empty tree case.\"\"\"\n    return hashlib.sha512(data).hexdigest()\n\n\ndef generate_proof", "new_string": "def generate_proof"})

{"success": true, "diff": "--- a//app/merkle_cli.py\n+++ b//app/merkle_cli.py\n@@ -62,11 +62,6 @@\n \n     root_hash = current_level[0]\n     return root_hash, tree_levels\n-\n-\n-def sha51_hash(data):\n-    \"\"\"Helper for empty tree case.\"\"\"\n-    return hashlib.sha512(data).hexdigest()\n \n \n def generate_proof(tree_levels: list, file_index: int) -> list:\n", "files_modified": ["/app/merkle_cli.py"], "lint": {"status": "ok", "output": ""}}

{"output": "Scanned directory: /app/test_data\nFiles found: 4\nRoot hash: 93e659d19f7253346fe9a8da01b0645d63c2450423436a65a339ca77778727ff4f2e6d71cea7351be14cd2d73726a8dd1b7341343d059216d8767f60954e6fba\nData stored in: /app/merkle_data.json", "exit_code": 0, "error": null}

{"output": "{\n  \"root_hash\": \"93e659d19f7253346fe9a8da01b0645d63c2450423436a65a339ca77778727ff4f2e6d71cea7351be14cd2d73726a8dd1b7341343d059216d8767f60954e6fba\",\n  \"proofs\": {\n    \"file1.txt\": [\n      [\n        \"right\",\n        \"1d4322126e4b2b8f59ab7953b3be0486baffa82a5169982c9fd192ee87f7c799f2259c15c8e4d6295bc6c12de9ae11982ff3ea21e8d5ba55eab2cc7404aa5e00\"\n      ],\n      [\n        \"right\",\n        \"f9119ecd709b21a4a1c20e46bda57e73fe3d86281c8c37219a79b109e061aa79433e1685d234e61e22d6627040e3a0dc0fa7c10b49b557ac2d3147fefa2e7207\"\n      ]\n    ],\n    \"file2.txt\": [\n      [\n        \"left\",\n        \"fd27f48886079931187e4737fcf4d1c6b3172235f65226de3af11c3e6df527138eda5062a473a7c876c71e9920780814dc7ea3260e4eb12141df0b4a40777a5d\"\n      ],\n      [\n        \"right\",\n        \"f9119ecd709b21a4a1c20e46bda57e73fe3d86281c8c37219a79b109e061aa79433e1685d234e61e22d6627040e3a0dc0fa7c10b49b557ac2d3147fefa2e7207\"\n      ]\n    ],\n    \"file3.txt\": [\n      [\n        \"right\",\n        \"021c7f8b724cad5eee13ebcac73913a82602f8a0fd93b7d19a868b1cc77f7f2c18fda1eb8a865534876afc907c2d37c7da7e856d9874fd238dd21e4a61699508\"\n      ],\n      [\n        \"left\",\n        \"2395df47c54a94d167011bd3e59e3912c2dc75286ca0473ee4902b485b0d09cea9cca1f283146bf89a4e9656dd0347a42a6ccd6c4f8c5b3b6a4f9b313ad22b00\"\n      ]\n    ],\n    \"subdir/nested.txt\": [\n      [\n        \"left\",\n        \"07999956299510fdcec10cf70a43a874c3f04c099df11694e3a7233071c84b59472a3c2a32691d1f0fda38b6c241cb2e48e62b4e9dce88e3067bd0f142b08632\"\n      ],\n      [\n        \"left\",\n        \"2395df47c54a94d167011bd3e59e3912c2dc75286ca0473ee4902b485b0d09cea9cca1f283146bf89a4e9656dd0347a42a6ccd6c4f8c5b3b6a4f9b313ad22b00\"\n      ]\n    ]\n  },\n  \"file_hashes\": {\n    \"file1.txt\": \"fd27f48886079931187e4737fcf4d1c6b3172235f65226de3af11c3e6df527138eda5062a473a7c876c71e9920780814dc7ea3260e4eb12141df0b4a40777a5d\",\n    \"file2.txt\": \"1d4322126e4b2b8f59ab7953b3be0486baffa82a5169982c9fd192ee87f7c799f2259c15c8e4d6295bc6c12de9ae11982ff3ea21e8d5ba55eab2cc7404aa5e00\",\n    \"file3.txt\": \"07999956299510fdcec10cf70a43a874c3f04c099df11694e3a7233071c84b59472a3c2a32691d1f0fda38b6c241cb2e48e62b4e9dce88e3067bd0f142b08632\",\n    \"subdir/nested.txt\": \"021c7f8b724cad5eee13ebcac73913a82602f8a0fd93b7d19a868b1cc77f7f2c18fda1eb8a865534876afc907c2d37c7da7e856d9874fd238dd21e4a61699508\"\n  },\n  \"scanned_directory\": \"/app/test_data\"\n}", "exit_code": 0, "error": null}

{"output": "{\n  \"file_path\": \"file1.txt\",\n  \"proof\": [\n    [\n      \"right\",\n      \"1d4322126e4b2b8f59ab7953b3be0486baffa82a5169982c9fd192ee87f7c799f2259c15c8e4d6295bc6c12de9ae11982ff3ea21e8d5ba55eab2cc7404aa5e00\"\n    ],\n    [\n      \"right\",\n      \"f9119ecd709b21a4a1c20e46bda57e73fe3d86281c8c37219a79b109e061aa79433e1685d234e61e22d6627040e3a0dc0fa7c10b49b557ac2d3147fefa2e7207\"\n    ]\n  ]\n}", "exit_code": 0, "error": null}

{"output": "{\n  \"success\": true,\n  \"root_matches\": true,\n  \"file_hash_matches_storage\": true,\n  \"added_files\": [],\n  \"deleted_files\": [],\n  \"modified_files\": [],\n  \"message\": \"Verification successful\"\n}", "exit_code": 0, "error": null}

Now let me test tampering detection:

terminal({"command": "cd /app && cp /app/test_data/file1.txt /app/test_data/file1.txt.bak && echo \"tampered content\" > /app/test_data/file1.txt && python3 merkle_cli.py verify file1.txt /app/proof.json; echo \"Exit code: $?\""})

{"output": "{\n  \"success\": false,\n  \"root_matches\": false,\n  \"file_hash_matches_storage\": false,\n  \"added_files\": [\n    \"file1.txt.bak\"\n  ],\n  \"deleted_files\": [],\n  \"modified_files\": [\n    \"file1.txt\"\n  ],\n  \"message\": \"Verification failed\"\n}\nExit code: 1", "exit_code": 0, "error": null}

{"output": "{\n  \"success\": true,\n  \"root_matches\": true,\n  \"file_hash_matches_storage\": true,\n  \"added_files\": [],\n  \"deleted_files\": [],\n  \"modified_files\": [],\n  \"message\": \"Verification successful\"\n}", "exit_code": 0, "error": null}

Let me also test with an absolute path for verify and test edge cases:

terminal({"command": "cd /app && python3 merkle_cli.py verify /app/test_data/file1.txt /app/proof.json"})

{"output": "{\n  \"success\": true,\n  \"root_matches\": true,\n  \"file_hash_matches_storage\": true,\n  \"added_files\": [],\n  \"deleted_files\": [],\n  \"modified_files\": [],\n  \"message\": \"Verification successful\"\n}", "exit_code": 0, "error": null}

{"output": "Scanned directory: /tmp/empty_dir\nFiles found: 0\nRoot hash: a98bf96e9d80ab83969e2b03463fa0ebaa2f7e300fc08f7d7881089cd980f0cf25a9b7d6807343ed90a1a35e01ee8500536b520dd54054725caa35449809c653\nData stored in: /app/merkle_data.json", "exit_code": 0, "error": null}

{"output": "Scanned directory: /tmp/single_file\nFiles found: 1\nRoot hash: e7c22b994c59d9cf2b48e549b1e24666636045930d3da7c1acb299d1c3b7f931f94aae41edda2c2b207a36e10f8bcb8d45223e54878f5b316e7ce3b6bc019629\nData stored in: /app/merkle_data.json\n{\n  \"success\": true,\n  \"root_matches\": true,\n  \"file_hash_matches_storage\": true,\n  \"added_files\": [],\n  \"deleted_files\": [],\n  \"modified_files\": [],\n  \"message\": \"Verification successful\"\n}", "exit_code": 0, "error": null}

Now let me test with an odd number of files (3 files) to verify the duplication logic:

terminal({"command": "mkdir -p /tmp/odd_files && echo \"a\" > /tmp/odd_files/a.txt && echo \"b\" > /tmp/odd_files/b.txt && echo \"c\" > /tmp/odd_files/c.txt && cd /app && python3 merkle_cli.py scan /tmp/odd_files && python3 merkle_cli.py proof a.txt > /tmp/odd_proof_a.json && python3 merkle_cli.py verify a.txt /tmp/odd_proof_a.json && python3 merkle_cli.py proof c.txt > /tmp/odd_proof_c.json && python3 mer…)

{"output": "Scanned directory: /tmp/odd_files\nFiles found: 3\nRoot hash: 21393de1258eabfaba6f48567ca346f8ed47e97467a9f82aea952b2c314c7bcc8760980dfb612765969648d21e95c0f91cb8b0a88622622187226bb976eff455\nData stored in: /app/merkle_data.json\n{\n  \"success\": true,\n  \"root_matches\": true,\n  \"file_hash_matches_storage\": true,\n  \"added_files\": [],\n  \"deleted_files\": [],\n  \"modified_files\": [],\n  \"message\": \"Verification successful\"\n}\n{\n  \"success\": true,\n  \"root_matches\": true,\n  \"file_hash_matches_storage\": true,\n  \"added_files\": [],\n  \"deleted_files\": [],\n  \"modified_files\": [],\n  \"message\": \"Verification successful\"\n}", "exit_code": 0, "error": null}

Now let me restore the original scan and verify hash lengths are correct:

terminal({"command": "cd /app && python3 merkle_cli.py scan /app/test_data && python3 -c \"\nimport json\nwith open('/app/merkle_data.json') as f:\n    data = json.load(f)\nroot = data['root_hash']\nprint(f'Root hash length: {len(root)}')\nfor path, h in data['file_hashes'].items():\n    print(f'{path} hash length: {len(h)}')\nfor path, proof in data['proofs'].items():\n    for direction, h in proof:\n    …)

{"output": "Scanned directory: /app/test_data\nFiles found: 4\nRoot hash: 93e659d19f7253346fe9a8da01b0645d63c2450423436a65a339ca77778727ff4f2e6d71cea7351be14cd2d73726a8dd1b7341343d059216d8767f60954e6fba\nData stored in: /app/merkle_data.json\nRoot hash length: 128\nfile1.txt hash length: 128\nfile2.txt hash length: 128\nfile3.txt hash length: 128\nsubdir/nested.txt hash length: 128\nAll hashes validated!", "exit_code": 0, "error": null}

All tests pass. Let me also verify the tool is executable and do a final comprehensive test:

terminal({"command": "chmod +x /app/merkle_cli.py && cd /app && python3 merkle_cli.py proof file3.txt > /app/proof_file3.json && python3 merkle_cli.py verify file3.txt /app/proof_file3.json"})

{"output": "{\n  \"success\": true,\n  \"root_matches\": true,\n  \"file_hash_matches_storage\": true,\n  \"added_files\": [],\n  \"deleted_files\": [],\n  \"modified_files\": [],\n  \"message\": \"Verification successful\"\n}", "exit_code": 0, "error": null}

Let me do a final test to verify deletion detection works properly:

terminal({"command": "cd /app && python3 merkle_cli.py scan /app/test_data && python3 merkle_cli.py proof file1.txt > /app/proof.json && mv /app/test_data/file2.txt /tmp/file2_backup.txt && python3 merkle_cli.py verify file1.txt /app/proof.json; echo \"Exit code: $?\""})

{"output": "Scanned directory: /app/test_data\nFiles found: 4\nRoot hash: 93e659d19f7253346fe9a8da01b0645d63c2450423436a65a339ca77778727ff4f2e6d71cea7351be14cd2d73726a8dd1b7341343d059216d8767f60954e6fba\nData stored in: /app/merkle_data.json\n{\n  \"success\": false,\n  \"root_matches\": true,\n  \"file_hash_matches_storage\": true,\n  \"added_files\": [],\n  \"deleted_files\": [\n    \"file2.txt\"\n  ],\n  \"modified_files\": [],\n  \"message\": \"Verification failed\"\n}\nExit code: 1", "exit_code": 0, "error": null}

{"output": "Scanned directory: /app/test_data\nFiles found: 4\nRoot hash: 93e659d19f7253346fe9a8da01b0645d63c2450423436a65a339ca77778727ff4f2e6d71cea7351be14cd2d73726a8dd1b7341343d059216d8767f60954e6fba\nData stored in: /app/merkle_data.json", "exit_code": 0, "error": null}

All functionality is working correctly. Here's a summary of what was built:

## Merkle CLI Tool (`/app/merkle_cli.py`)

The tool implements a complete Merkle tree system with SHA-512 hashing:

### Commands
- **`scan <directory>`** - Scans a directory, computes SHA-512 hashes of all regular files, builds a Merkle tree, and stores root hash + proofs in `/app/merkle_data.json`
- **`proof <file_path>`** - Outputs a Merkle proof as JSON to stdout for the specified file
- **`verify <file_path> <proof_file>`** - Verifies file integrity by reconstructing the root hash from the proof, detecting tampering, additions, and deletions

### Key Features
- **SHA-512 hashing** - All hashes are 128-character hex strings
- **Odd node handling** - Duplicates the last node when an odd number of nodes exists at any level
- **Deterministic ordering** - Files are sorted by relative path for consistent tree construction
- **Binary file reading** - Files read in binary mode for cross-platform consistency
- **Tamper detection** - Detects modified files, added files, and deleted files
- **Exit codes** - Returns 0 on success, non-zero on verification failure
- **Edge cases** - Handles empty directories, single files, nested directories, and odd file counts