Agent skill

hash-calculator

Calculate cryptographic hashes (MD5, SHA1, SHA256, SHA512) for text and files. Compare hashes, verify integrity, and batch process directories.

View SKILL.md on GitHub Repository
Stars 163
Forks 31

Install this agent skill to your Project

npx add-skill https://github.com/majiayu000/claude-skill-registry/tree/main/skills/development/hash-calculator

SKILL.md

Hash Calculator

Calculate cryptographic hash values for text strings and files. Supports multiple algorithms, file verification, and batch processing.

Quick Start

python
from scripts.hash_calc import HashCalculator

# Hash text
calc = HashCalculator()
result = calc.hash_text("Hello, World!")
print(result['sha256'])

# Hash file
result = calc.hash_file("document.pdf")
print(result['md5'])

# Verify file integrity
is_valid = calc.verify_file("file.zip", "expected_hash", algorithm="sha256")

Features

  • Multiple Algorithms: MD5, SHA1, SHA256, SHA384, SHA512, BLAKE2
  • Text Hashing: Hash strings directly
  • File Hashing: Efficient streaming for large files
  • Verification: Compare against expected hash
  • Batch Processing: Hash multiple files
  • Checksum Files: Generate/verify checksum files

API Reference

Text Hashing

python
calc = HashCalculator()

# Single algorithm
md5 = calc.hash_text("Hello", algorithm="md5")

# All algorithms
results = calc.hash_text("Hello")
# {'md5': '...', 'sha1': '...', 'sha256': '...', ...}

# Specific algorithms
results = calc.hash_text("Hello", algorithms=["md5", "sha256"])

File Hashing

python
# Single file
result = calc.hash_file("document.pdf")
print(result['sha256'])

# Specific algorithm
sha256 = calc.hash_file("file.zip", algorithm="sha256")

Verification

python
# Verify file against expected hash
is_valid = calc.verify_file(
    "download.iso",
    "a1b2c3d4e5...",
    algorithm="sha256"
)

# Verify text
is_valid = calc.verify_text("password", "5f4dcc3b...", algorithm="md5")

Batch Processing

python
# Hash all files in directory
results = calc.hash_directory("./files", algorithm="sha256")
# {'file1.txt': 'abc...', 'file2.pdf': 'def...'}

# With recursive option
results = calc.hash_directory("./files", recursive=True)

Checksum Files

python
# Generate checksum file
calc.generate_checksums("./release", "checksums.sha256", algorithm="sha256")

# Verify against checksum file
results = calc.verify_checksums("checksums.sha256")
# {'file1.zip': True, 'file2.zip': True, 'file3.zip': False}

CLI Usage

bash
# Hash text
python hash_calc.py --text "Hello, World!"

# Hash file
python hash_calc.py --file document.pdf

# Specific algorithm
python hash_calc.py --file document.pdf --algorithm sha256

# Verify file
python hash_calc.py --file download.iso --verify "expected_hash"

# Hash directory
python hash_calc.py --directory ./files --output checksums.txt

# Verify checksums file
python hash_calc.py --verify-checksums checksums.sha256

CLI Arguments

Argument Description Default
--text Text to hash -
--file File to hash -
--directory Directory to hash -
--algorithm Hash algorithm all
--verify Expected hash to verify -
--output Output file -
--recursive Recursive directory False
--verify-checksums Verify checksum file -

Supported Algorithms

Algorithm Output Length Use Case
md5 128 bits (32 hex) Legacy, checksums (not secure)
sha1 160 bits (40 hex) Legacy (not secure)
sha256 256 bits (64 hex) General purpose, secure
sha384 384 bits (96 hex) High security
sha512 512 bits (128 hex) Maximum security
blake2b 512 bits Modern, fast
blake2s 256 bits Modern, fast, small

Examples

Verify Download Integrity

python
calc = HashCalculator()

# Downloaded file and expected hash from website
expected = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
is_valid = calc.verify_file("ubuntu.iso", expected, algorithm="sha256")

if is_valid:
    print("Download verified successfully!")
else:
    print("WARNING: Hash mismatch - file may be corrupted!")

Generate Release Checksums

python
calc = HashCalculator()

# Generate checksums for release files
calc.generate_checksums(
    "./release",
    "SHA256SUMS",
    algorithm="sha256"
)

# Output: SHA256SUMS
# e3b0c44298fc1c14...  release-v1.0.zip
# a1b2c3d4e5f6g7h8...  release-v1.0.tar.gz

Password Storage (Example)

python
calc = HashCalculator()
import os

# Note: In production, use bcrypt/argon2 instead
salt = os.urandom(16).hex()
password = "user_password"
hashed = calc.hash_text(salt + password, algorithm="sha256")

# Store: salt + ":" + hashed
stored = f"{salt}:{hashed}"

Compare Two Files

python
calc = HashCalculator()

hash1 = calc.hash_file("file1.txt", algorithm="sha256")
hash2 = calc.hash_file("file2.txt", algorithm="sha256")

if hash1 == hash2:
    print("Files are identical")
else:
    print("Files are different")

Output Formats

Text Output

MD5:    5d41402abc4b2a76b9719d911017c592
SHA1:   aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d
SHA256: 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824

JSON Output

json
{
  "input": "hello",
  "md5": "5d41402abc4b2a76b9719d911017c592",
  "sha256": "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
}

Dependencies

(No external dependencies - uses Python standard library)

Security Notes

  • MD5 and SHA1 are not collision-resistant (don't use for security)
  • Use SHA256 or higher for security applications
  • For password hashing, use dedicated libraries (bcrypt, argon2)
  • File hashing uses streaming to handle large files efficiently

Didn't find tool you were looking for?

Be as detailed as possible for better results