golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734

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@v0.0.0-20190426145343-a29dc8fdc734
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/crypto@v0.0.0-20190426145343-a29dc8fdc734

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:sha256:8ed90a1c37fc2c321d2e78653215eecf49aad82f44f1922c9e64d0f9e57c5c0c","contract":["bcrypt.GenerateFromPassword, bcrypt.CompareHashAndPassword, and bcrypt.Cost hash and verify passwords at the requested cost","bcrypt.CompareHashAndPassword returns ErrMismatchedHashAndPassword on wrong password and ErrHashTooShort on short hash","sha3.Sum256 and sha3.New256 compute deterministic SHA3-256 digests matching known test vectors","ed25519.NewKeyFromSeed, ed25519.Sign, and ed25519.Verify produce and validate deterministic Ed25519 signatures"],"goal":"verify pkg:golang/golang.org/x/crypto@v0.0.0-20190426145343-a29dc8fdc734","kind":"HOW","packages":["pkg:golang/golang.org/x/crypto@v0.0.0-20190426145343-a29dc8fdc734"],"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@v0.0.0-20190426145343-a29dc8fdc734"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/crypto@v0.0.0-20190426145343-a29dc8fdc734","verifierAdapter":"golang@1"}

module example.com/sample

go 1.22

require golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734

require golang.org/x/sys v0.0.0-20190412213103-97732733099d // indirect

golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734 h1:p/H982KKEjUnLJkM3tt/LemDnOc1GiZL5FCVlORJ5zo=
golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

package main

import (
	"encoding/hex"
	"fmt"
	"log"

	"golang.org/x/crypto/bcrypt"
	"golang.org/x/crypto/sha3"
)

func main() {
	hash, err := bcrypt.GenerateFromPassword([]byte("example-password"), bcrypt.MinCost)
	if err != nil {
		log.Fatalf("bcrypt.GenerateFromPassword failed: %v", err)
	}
	if err := bcrypt.CompareHashAndPassword(hash, []byte("example-password")); err != nil {
		log.Fatalf("bcrypt.CompareHashAndPassword failed: %v", err)
	}

	sum := sha3.Sum256([]byte("hello world"))
	fmt.Printf("SHA3-256: %s\n", hex.EncodeToString(sum[:]))
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/golang.org/x/crypto@v0.0.0-20190426145343-a29dc8fdc734",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/crypto@v0.0.0-20190426145343-a29dc8fdc734"
  ]
}

package main

import (
	"bytes"
	"encoding/hex"
	"errors"
	"fmt"
	"os"

	"golang.org/x/crypto/bcrypt"
	"golang.org/x/crypto/ed25519"
	"golang.org/x/crypto/sha3"
)

func main() {
	// 1. bcrypt.GenerateFromPassword, bcrypt.CompareHashAndPassword, and bcrypt.Cost hash and verify passwords at the requested cost
	password := []byte("contract-password")
	hashed, err := bcrypt.GenerateFromPassword(password, bcrypt.MinCost)
	if err != nil {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: GenerateFromPassword error: %v\n", err)
		os.Exit(1)
	}
	if err := bcrypt.CompareHashAndPassword(hashed, password); err != nil {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: CompareHashAndPassword failed for matching password: %v\n", err)
		os.Exit(1)
	}
	cost, err := bcrypt.Cost(hashed)
	if err != nil || cost != bcrypt.MinCost {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: expected cost %d, got %d (err=%v)\n", bcrypt.MinCost, cost, err)
		os.Exit(1)
	}

	// 2. bcrypt.CompareHashAndPassword returns ErrMismatchedHashAndPassword on wrong password and ErrHashTooShort on short hash
	errMismatch := bcrypt.CompareHashAndPassword(hashed, []byte("wrong-password"))
	if !errors.Is(errMismatch, bcrypt.ErrMismatchedHashAndPassword) {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected ErrMismatchedHashAndPassword, got %v\n", errMismatch)
		os.Exit(1)
	}
	errShort := bcrypt.CompareHashAndPassword([]byte("$2a$04$short"), password)
	if !errors.Is(errShort, bcrypt.ErrHashTooShort) {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected ErrHashTooShort, got %v\n", errShort)
		os.Exit(1)
	}

	// 3. sha3.Sum256 and sha3.New256 compute deterministic SHA3-256 digests matching known test vectors
	msg := []byte("abc")
	expectedHex := "3a985da74fe225b2045c172d6bd390bd855f086e3e9d525b46bfe24511431532"
	sum := sha3.Sum256(msg)
	if hex.EncodeToString(sum[:]) != expectedHex {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: unexpected Sum256 digest %x\n", sum)
		os.Exit(1)
	}
	h := sha3.New256()
	_, _ = h.Write(msg)
	if !bytes.Equal(h.Sum(nil), sum[:]) {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: New256 digest differs from Sum256\n")
		os.Exit(1)
	}

	// 4. ed25519.NewKeyFromSeed, ed25519.Sign, and ed25519.Verify produce and validate deterministic Ed25519 signatures
	seed := bytes.Repeat([]byte{0x42}, ed25519.SeedSize)
	priv := ed25519.NewKeyFromSeed(seed)
	pub := priv.Public().(ed25519.PublicKey)
	sig := ed25519.Sign(priv, msg)
	if !ed25519.Verify(pub, msg, sig) {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: ed25519.Verify returned false for valid signature\n")
		os.Exit(1)
	}
	if ed25519.Verify(pub, []byte("tampered"), sig) {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: ed25519.Verify returned true for tampered message\n")
		os.Exit(1)
	}
}