github.com/mholt/acmez/v3 v3.1.2: acme.ARIUniqueIdentifier

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 github.com/mholt/acmez/v3/acme.ARIUniqueIdentifier in pkg:golang/github.com/mholt/acmez/v3@v3.1.2
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/mholt/acmez/v3@v3.1.2
Demonstrate these symbols/APIs:
  - github.com/mholt/acmez/v3/acme.ARIUniqueIdentifier

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:sha256:33762a1990a4f5a117547de434ca78754652ed4a117c606e503261a8267fe411","contract":["acme.ARIUniqueIdentifier returns error when leaf certificate has nil SerialNumber","acme.ARIUniqueIdentifier constructs unique identifier combining Base64URL-encoded AuthorityKeyId and serial number DER bytes separated by dot","acme.ARIUniqueIdentifier properly handles serial numbers with leading high bit via ASN.1 DER integer encoding","acme.ARIUniqueIdentifier computes valid renewal identifier from parsed x509.Certificate with AuthorityKeyId and serial number"],"goal":"verify github.com/mholt/acmez/v3/acme.ARIUniqueIdentifier in pkg:golang/github.com/mholt/acmez/v3@v3.1.2","kind":"HOW","packages":["pkg:golang/github.com/mholt/acmez/v3@v3.1.2"],"schemaVersion":1,"symbols":["github.com/mholt/acmez/v3/acme.ARIUniqueIdentifier"]},"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/github.com/mholt/acmez/v3@v3.1.2"],"schemaVersion":1,"subject":"pkg:golang/github.com/mholt/acmez/v3@v3.1.2","symbols":["github.com/mholt/acmez/v3/acme.ARIUniqueIdentifier"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.22.0

require github.com/mholt/acmez/v3 v3.1.2

github.com/mholt/acmez/v3 v3.1.2 h1:auob8J/0FhmdClQicvJvuDavgd5ezwLBfKuYmynhYzc=
github.com/mholt/acmez/v3 v3.1.2/go.mod h1:L1wOU06KKvq7tswuMDwKdcHeKpFFgkppZy/y0DFxagQ=
golang.org/x/crypto v0.27.0 h1:GXm2NjJrPaiv/h1tb2UH8QfgC/hOf/+z0p6PT8o1w7A=
golang.org/x/crypto v0.27.0/go.mod h1:1Xngt8kV6Dvbssa53Ziq6Eqn0HqbZi5Z6R0ZpwQzt70=
golang.org/x/net v0.29.0 h1:5ORfpBpCs4HzDYoodCDBbwHzdR5UrLBZ3sOnUJmFoHo=
golang.org/x/net v0.29.0/go.mod h1:gLkgy8jTGERgjzMic6DS9+SP0ajcu6Xu3Orq/SpETg0=
golang.org/x/text v0.18.0 h1:XvMDiNzPAl0jr17s6W9lcaIhGUfUORdGCNsuLmPG224=
golang.org/x/text v0.18.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=

package main

import (
	"crypto/x509"
	"fmt"
	"math/big"
	"os"

	"github.com/mholt/acmez/v3/acme"
)

// GenerateCertARIIdentifier returns the ARI unique identifier string for a certificate.
func GenerateCertARIIdentifier(cert *x509.Certificate) (string, error) {
	return acme.ARIUniqueIdentifier(cert)
}

func main() {
	cert := &x509.Certificate{
		AuthorityKeyId: []byte{0x01, 0x02, 0x03, 0x04, 0x05},
		SerialNumber:   big.NewInt(987654321),
	}

	id, err := GenerateCertARIIdentifier(cert)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error generating ARI ID: %v\n", err)
		os.Exit(1)
	}

	fmt.Printf("ARI Unique Identifier: %s\n", id)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/mholt/acmez/v3/acme.ARIUniqueIdentifier in pkg:golang/github.com/mholt/acmez/v3@v3.1.2",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/mholt/acmez/v3@v3.1.2"
  ],
  "symbols": [
    "github.com/mholt/acmez/v3/acme.ARIUniqueIdentifier"
  ]
}

package main

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"crypto/x509/pkix"
	"encoding/asn1"
	"encoding/base64"
	"fmt"
	"math/big"
	"os"
	"strings"
	"time"

	"github.com/mholt/acmez/v3/acme"
)

func main() {
	// Assertion 1: acme.ARIUniqueIdentifier returns error when leaf certificate has nil SerialNumber
	nilSerialCert := &x509.Certificate{
		AuthorityKeyId: []byte{0x01, 0x02, 0x03, 0x04},
		SerialNumber:   nil,
	}
	if _, err := acme.ARIUniqueIdentifier(nilSerialCert); err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: acme.ARIUniqueIdentifier expected error for nil SerialNumber\n")
		os.Exit(1)
	}

	// Assertion 2: acme.ARIUniqueIdentifier constructs unique identifier combining Base64URL-encoded AuthorityKeyId and serial number DER bytes separated by dot
	aki := []byte{0x10, 0x20, 0x30, 0x40, 0x50}
	serial := big.NewInt(123456789)
	cert := &x509.Certificate{
		AuthorityKeyId: aki,
		SerialNumber:   serial,
	}
	id, err := acme.ARIUniqueIdentifier(cert)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: acme.ARIUniqueIdentifier returned unexpected error: %v\n", err)
		os.Exit(1)
	}
	parts := strings.Split(id, ".")
	if len(parts) != 2 {
		fmt.Fprintf(os.Stderr, "FAIL: expected ARI identifier to contain exactly two dot-separated parts, got: %s\n", id)
		os.Exit(1)
	}
	expectedAKI := base64.RawURLEncoding.EncodeToString(aki)
	if parts[0] != expectedAKI {
		fmt.Fprintf(os.Stderr, "FAIL: AKI part mismatch: got %s, want %s\n", parts[0], expectedAKI)
		os.Exit(1)
	}
	serialDER, err := asn1.Marshal(serial)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: asn1.Marshal failed: %v\n", err)
		os.Exit(1)
	}
	expectedSerial := base64.RawURLEncoding.EncodeToString(serialDER[2:])
	if parts[1] != expectedSerial {
		fmt.Fprintf(os.Stderr, "FAIL: serial part mismatch: got %s, want %s\n", parts[1], expectedSerial)
		os.Exit(1)
	}

	// Assertion 3: acme.ARIUniqueIdentifier properly handles serial numbers with leading high bit via ASN.1 DER integer encoding
	serialHighBit, ok := new(big.Int).SetString("80000000000000000000000000000001", 16)
	if !ok {
		fmt.Fprintf(os.Stderr, "FAIL: failed to parse high bit serial\n")
		os.Exit(1)
	}
	certHighBit := &x509.Certificate{
		AuthorityKeyId: []byte{0xAA, 0xBB, 0xCC},
		SerialNumber:   serialHighBit,
	}
	idHighBit, err := acme.ARIUniqueIdentifier(certHighBit)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: acme.ARIUniqueIdentifier failed for high-bit serial: %v\n", err)
		os.Exit(1)
	}
	partsHighBit := strings.Split(idHighBit, ".")
	if len(partsHighBit) != 2 {
		fmt.Fprintf(os.Stderr, "FAIL: high-bit ARI identifier malformed: %s\n", idHighBit)
		os.Exit(1)
	}
	highBitDER, err := asn1.Marshal(serialHighBit)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: asn1.Marshal high bit failed: %v\n", err)
		os.Exit(1)
	}
	expectedHighBitSerial := base64.RawURLEncoding.EncodeToString(highBitDER[2:])
	if partsHighBit[1] != expectedHighBitSerial {
		fmt.Fprintf(os.Stderr, "FAIL: high bit serial mismatch: got %s, want %s\n", partsHighBit[1], expectedHighBitSerial)
		os.Exit(1)
	}

	// Assertion 4: acme.ARIUniqueIdentifier computes valid renewal identifier from parsed x509.Certificate with AuthorityKeyId and serial number
	privKey, err := rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: failed to generate rsa key: %v\n", err)
		os.Exit(1)
	}
	now := time.Now()
	template := &x509.Certificate{
		SerialNumber: big.NewInt(9876543210),
		Subject: pkix.Name{
			CommonName: "example.com",
		},
		AuthorityKeyId: []byte{0xDE, 0xAD, 0xBE, 0xEF, 0x01, 0x02},
		NotBefore:      now.Add(-1 * time.Hour),
		NotAfter:       now.Add(24 * time.Hour),
	}
	certDER, err := x509.CreateCertificate(rand.Reader, template, template, &privKey.PublicKey, privKey)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: failed to create certificate: %v\n", err)
		os.Exit(1)
	}
	parsedCert, err := x509.ParseCertificate(certDER)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: failed to parse certificate: %v\n", err)
		os.Exit(1)
	}
	parsedID, err := acme.ARIUniqueIdentifier(parsedCert)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: acme.ARIUniqueIdentifier failed for parsed cert: %v\n", err)
		os.Exit(1)
	}
	expectedParsedAKI := base64.RawURLEncoding.EncodeToString(template.AuthorityKeyId)
	parsedDER, _ := asn1.Marshal(template.SerialNumber)
	expectedParsedSerial := base64.RawURLEncoding.EncodeToString(parsedDER[2:])
	expectedParsedID := expectedParsedAKI + "." + expectedParsedSerial
	if parsedID != expectedParsedID {
		fmt.Fprintf(os.Stderr, "FAIL: parsed cert ARI ID mismatch: got %s, want %s\n", parsedID, expectedParsedID)
		os.Exit(1)
	}

	fmt.Println("PASS: all ARIUniqueIdentifier contract assertions passed.")
}