golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a

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 pkg:golang/golang.org/x/crypto@v0.0.0-20190313024323-a1f597ede03a
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/crypto@v0.0.0-20190313024323-a1f597ede03a

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:d89135048737f62223de4423d09aa1229c2dec3f0294c56838703d991245b87d","contract":["bcrypt.GenerateFromPassword produces a non-empty hash at bcrypt.MinCost","bcrypt.Cost extracts the configured cost from the generated hash","bcrypt.CompareHashAndPassword returns nil when the password matches the hash","bcrypt.CompareHashAndPassword returns bcrypt.ErrMismatchedHashAndPassword when password differs","bcrypt.GenerateFromPassword returns bcrypt.InvalidCostError when cost exceeds bcrypt.MaxCost"],"goal":"verify pkg:golang/golang.org/x/crypto@v0.0.0-20190313024323-a1f597ede03a","kind":"HOW","packages":["pkg:golang/golang.org/x/crypto@v0.0.0-20190313024323-a1f597ede03a"],"schemaVersion":1},"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@v0.0.0-20190313024323-a1f597ede03a"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/crypto@v0.0.0-20190313024323-a1f597ede03a","verifierAdapter":"golang@1"}

module example.com/sample

go 1.20

require golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a

golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a h1:YX8ljsm6wXlHZO+aRz9Exqr0evNhKRNe5K/gi+zKh4U=
golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=

package main

import (
	"fmt"
	"log"

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

func main() {
	secret := []byte("sample-passphrase")
	hashed, err := bcrypt.GenerateFromPassword(secret, bcrypt.MinCost)
	if err != nil {
		log.Fatalf("GenerateFromPassword failed: %v", err)
	}

	cost, err := bcrypt.Cost(hashed)
	if err != nil {
		log.Fatalf("Cost failed: %v", err)
	}

	if err := bcrypt.CompareHashAndPassword(hashed, secret); err != nil {
		log.Fatalf("CompareHashAndPassword failed: %v", err)
	}

	fmt.Printf("verified cost=%d\n", cost)
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/golang.org/x/crypto@v0.0.0-20190313024323-a1f597ede03a",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/crypto@v0.0.0-20190313024323-a1f597ede03a"
  ]
}

package main

import (
	"errors"
	"fmt"
	"os"

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

func main() {
	password := []byte("correct-passphrase")
	wrongPassword := []byte("wrong-passphrase")

	// 1. bcrypt.GenerateFromPassword produces a non-empty hash at bcrypt.MinCost
	hashed, err := bcrypt.GenerateFromPassword(password, bcrypt.MinCost)
	if err != nil || len(hashed) == 0 {
		fmt.Fprintf(os.Stderr, "GenerateFromPassword failed: len=%d err=%v\n", len(hashed), err)
		os.Exit(1)
	}

	// 2. bcrypt.Cost extracts the configured cost from the generated hash
	cost, err := bcrypt.Cost(hashed)
	if err != nil || cost != bcrypt.MinCost {
		fmt.Fprintf(os.Stderr, "expected cost %d, got %d (err=%v)\n", bcrypt.MinCost, cost, err)
		os.Exit(1)
	}

	// 3. bcrypt.CompareHashAndPassword returns nil when the password matches the hash
	if err := bcrypt.CompareHashAndPassword(hashed, password); err != nil {
		fmt.Fprintf(os.Stderr, "expected nil for matching password, got %v\n", err)
		os.Exit(1)
	}

	// 4. bcrypt.CompareHashAndPassword returns bcrypt.ErrMismatchedHashAndPassword when password differs
	if err := bcrypt.CompareHashAndPassword(hashed, wrongPassword); !errors.Is(err, bcrypt.ErrMismatchedHashAndPassword) {
		fmt.Fprintf(os.Stderr, "expected ErrMismatchedHashAndPassword, got %v\n", err)
		os.Exit(1)
	}

	// 5. bcrypt.GenerateFromPassword returns bcrypt.InvalidCostError when cost exceeds bcrypt.MaxCost
	if _, err := bcrypt.GenerateFromPassword(password, bcrypt.MaxCost+1); err != bcrypt.InvalidCostError(bcrypt.MaxCost+1) {
		fmt.Fprintf(os.Stderr, "expected InvalidCostError(%d), got %v\n", bcrypt.MaxCost+1, err)
		os.Exit(1)
	}

	fmt.Println("contract ok")
}