Hash Tools Skill

Calculate cryptographic hashes for files and strings. Support for multiple algorithms and hash comparison.

When to Use

✅ USE this skill when:

• "Calculate MD5/SHA hash of a file"
• "Hash this string"
• "Verify file integrity"
• "Compare two files"
• "Generate checksum"
• "Find duplicate files"

When NOT to Use

❌ DON'T use this skill when:

• Encrypt/decrypt data ΓåÆ use encryption tools
• Password hashing ΓåÆ use bcrypt/argon2
• Digital signatures ΓåÆ use gpg/signing tools

Commands

File Hash

{baseDir}/hash.sh <algorithm> <file>
{baseDir}/hash.sh md5 /path/to/file
{baseDir}/hash.sh sha256 /path/to/file
{baseDir}/hash.sh sha512 /path/to/file
{baseDir}/hash.sh blake2b /path/to/file

String Hash

{baseDir}/hash.sh <algorithm> --string "text to hash"
{baseDir}/hash.sh sha256 --string "hello world"

Hash All Files in Directory

{baseDir}/hash-dir.sh <algorithm> <directory>
{baseDir}/hash-dir.sh sha256 ./my-files --output hashes.txt

Compare Files by Hash

{baseDir}/hash-compare.sh <file1> <file2>
{baseDir}/hash-compare.sh file1.txt file2.txt --algorithm sha256

Verify Against Checksum

{baseDir}/hash-verify.sh <algorithm> <file> <expected-hash>
{baseDir}/hash-verify.sh sha256 file.txt "abc123..."

Find Duplicate Files

{baseDir}/hash-dupes.sh <directory>
{baseDir}/hash-dupes.sh ./my-files --algorithm md5
{baseDir}/hash-dupes.sh ./my-files --delete

Supported Algorithms

Algorithm	Command	Notes
MD5	md5	Fast, not collision-safe
SHA-1	sha1	Deprecated for security
SHA-256	sha256	Recommended default
SHA-512	sha512	Longer hash
BLAKE2b	blake2b	Fast, secure alternative
BLAKE2s	blake2s	256-bit variant

Output Formats

{baseDir}/hash.sh sha256 file.txt          # Just the hash
{baseDir}/hash.sh sha256 file.txt --format long  # "SHA256 (file.txt) = abc123..."
{baseDir}/hash.sh sha256 file.txt --json         # JSON output
{baseDir}/hash.sh sha256 file.txt --base64       # Base64 encoded

Examples

Hash a file:

{baseDir}/hash.sh sha256 document.pdf
# Output: a1b2c3d4e5f6...

Hash a string:

{baseDir}/hash.sh sha256 --string "hello world"
# Output: b94d27b9934d3e08...

Verify a download:

{baseDir}/hash-verify.sh sha256 download.tar.gz "expected-hash-value"
# Output: ✅ Hash matches!

Find duplicates in directory:

{baseDir}/hash-dupes.sh ./photos --algorithm sha256
# Output: Duplicates found:
#   sha256:abc123... -> file1.jpg, file2.jpg

Generate checksums file:

{baseDir}/hash-dir.sh sha256 ./dist > CHECKSUMS.sha256

Notes

• Uses system utilities (md5sum, sha256sum, b2sum) when available
• Falls back to OpenSSL for algorithms not in coreutils
• All hash operations are deterministic
• No network access required