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