golang.org/x/crypto v0.39.0: blowfish.BlockSize

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify golang.org/x/crypto/blowfish.BlockSize in pkg:golang/golang.org/x/crypto@v0.39.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/crypto@v0.39.0
Demonstrate these symbols/APIs:
  - golang.org/x/crypto/blowfish.BlockSize

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:813acb009df8c633f7323b57be57bb850053171137a2f1378729acbabb5d1f6b","contract":["blowfish.BlockSize equals 8","blowfish.NewCipher returns a Cipher whose BlockSize() equals blowfish.BlockSize"],"goal":"verify golang.org/x/crypto/blowfish.BlockSize in pkg:golang/golang.org/x/crypto@v0.39.0","kind":"HOW","packages":["pkg:golang/golang.org/x/crypto@v0.39.0"],"schemaVersion":1,"symbols":["golang.org/x/crypto/blowfish.BlockSize"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/golang.org/x/crypto@v0.39.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/crypto@v0.39.0","symbols":["golang.org/x/crypto/blowfish.BlockSize"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.24.0

require golang.org/x/crypto v0.39.0

golang.org/x/crypto v0.39.0 h1:SHs+kF4LP+f+p14esP5jAoDpHU8Gu/v9lFRK6IT5imM=
golang.org/x/crypto v0.39.0/go.mod h1:L+Xg3Wf6HoL4Bn4238Z6ft6KfEpN0tJGo53AAPC632U=

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/crypto/blowfish.BlockSize in pkg:golang/golang.org/x/crypto@v0.39.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/crypto@v0.39.0"
  ],
  "symbols": [
    "golang.org/x/crypto/blowfish.BlockSize"
  ]
}

package main

import (
	"fmt"
	"os"

	"golang.org/x/crypto/blowfish"
)

func main() {
	if blowfish.BlockSize != 8 {
		fmt.Fprintf(os.Stderr, "expected blowfish.BlockSize == 8, got %d\n", blowfish.BlockSize)
		os.Exit(1)
	}

	key := []byte("example-key-16b!")
	c, err := blowfish.NewCipher(key)
	if err != nil {
		fmt.Fprintf(os.Stderr, "NewCipher failed: %v\n", err)
		os.Exit(1)
	}
	if c.BlockSize() != blowfish.BlockSize {
		fmt.Fprintf(os.Stderr, "expected c.BlockSize() == %d, got %d\n", blowfish.BlockSize, c.BlockSize())
		os.Exit(1)
	}
}