Blockcerts について調べる

できた

Bitcoin じゃなくて Ethereum にしたら15分できた

はじめから Ethereum にしておけばよかった、返して僕の8時間

やったこと

@context から https://www.w3.org/2018/credentials/examples/v1 を削除する

verifiable-credential.json(before)

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://w3id.org/blockcerts/v3"
  ],
  "id": "urn:uuid:bbba8553-8ec1-445f-82c9-a57251dd731c",
  "type": [
    "VerifiableCredential",
    "BlockcertsCredential"
  ],
  "issuer": "did:example:23adb1f712ebc6f1c276eba4dfa",
  "issuanceDate": "2022-01-01T19:33:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "alumniOf": {
      "id": "did:example:c276e12ec21ebfeb1f712ebc6f1"
    }
  }
}

設定ファイルを Ethereum 用に書き換える

/etc/cert-issuer/conf.ini

issuing_address = 0x063Eae33729EdB89FaadFDe5c813d4A06d176E4c

chain=ethereum_goerli

usb_name=/etc/cert-issuer/
key_file=ethereum_private_key.txt

unsigned_certificates_dir=/etc/cert-issuer/data/unsigned_certificates
blockchain_certificates_dir=/etc/cert-issuer/data/blockchain_certificates
work_dir=/etc/cert-issuer/work

no_safe_mode

できた証明書がこちら

{"@context": ["https://www.w3.org/2018/credentials/v1", "https://w3id.org/blockcerts/v3"], "id": "urn:uuid:bbba8553-8ec1-445f-82c9-a57251dd731c", "
type": ["VerifiableCredential", "BlockcertsCredential"], "issuer": "did:web:loremipsumcojp-cert-issuer.storage.googleapis.com", "issuanceDate": "20
22-01-01T19:33:24Z", "credentialSubject": {"id": "did:example:ebfeb1f712ebc6f1c276e12ec21", "alumniOf": {"id": "did:example:c276e12ec21ebfeb1f712eb
c6f1"}}, "proof": {"type": "MerkleProof2019", "created": "2022-12-28T02:41:00.339057", "proofValue": "z7veGu1qoKR3AS5Aw3gvTMFS83GiRbzcvYvHUvzCGUfYp
6c2zWEDEHhBAm7N57ZvRZ1vYtAdFkUJoTL3RMdktyjwdjZgbam2bDiyLtCZL6uc2QdEnJPRii6CFQVyXQ3oEAFUiemgAHo497EAFF2LrjLHrCc4nD2BPpxUtLvN9rbMsT2iUCXitinCTCca35ey
CDrDyQrALux4txeFu6QR1V4eZust7idQxyB2szMAaGu8AzCXSqUf6DU7xeCjsarXAR81pdNakH8os4cSK2DeBMqMiMUZVLc8XmzdAZvU2tyVStSu4ehn5z", "proofPurpose": "assertion
Method", "verificationMethod": "did:web:loremipsumcojp-cert-issuer.storage.googleapis.com#key-1"}}

検証は失敗してしまう

できた！

ちゃんと profile.json を設定したらできた！

dist/profile.json

{
  "@context": [
      "https://w3id.org/openbadges/v2",
      "https://w3id.org/blockcerts/3.0"
  ],
  "type": "Profile",
  "id": "https://loremipsumcojp-cert-issuer.storage.googleapis.com/profile.json",
  "name": "PitPa, Inc.",
  "url": "https://did.staging.sakazuki.xyz/",
  "publicKey": [
      {
          "id": "ecdsa-koblitz-pubkey:0x063Eae33729EdB89FaadFDe5c813d4A06d176E4c",
          "created": "2022-06-20T10:00:00.000000+00:00"
      }
  ],
  "revocationList": "https://did.staging.sakazuki.xyz/blockcerts_revocation_list.json"
}

dist/.well-known/did.json

{
  "id": "did:web:loremipsumcojp-cert-issuer.storage.googleapis.com",
  "verificationMethod": [
    {
      "id": "#key-1",
      "controller": "did:web:loremipsumcojp-cert-issuer.storage.googleapis.com",
      "type": "EcdsaSecp256k1VerificationKey2019",
      "publicKeyJwk": {
        "kty": "EC",
        "crv": "K-256",
        "x": "oTj4PkPzlNowto09OpAU0BVJ6DJc2vg_lFoW9wiZ60A",
        "y": "D9VaE9hbsOagGab_0euWcNUaCDphfBPg-C_aWD7npx4"
      }
    }
  ],
  "service": [
    {
      "id": "#service-1",
      "type": "IssuerProfile",
      "serviceEndpoint": "https://loremipsumcojp-cert-issuer.storage.googleapis.com/profile.json"
    }
  ]
}

main.tf

variable "project" {}
variable "bucket_name" {}
variable "bucket_location" {}

provider "google" {
  project = var.project
}

resource "google_storage_bucket" "my_bucket" {
  name                        = var.bucket_name
  location                    = var.bucket_location
  force_destroy               = true

  cors {
    origin          = ["*"]
    method          = ["GET"]
    response_header = ["Content-Type"]
    max_age_seconds = 30
  }
}

resource "google_storage_default_object_access_control" "public_rule" {
  bucket = google_storage_bucket.my_bucket.name
  role   = "READER"
  entity = "allUsers"
}

resource "google_storage_bucket_object" "did" {
  bucket = google_storage_bucket.my_bucket.name
  name   = ".well-known/did.json"
  source = "dist/.well-known/did.json"
  cache_control = "public, max-age=30"
}

resource "google_storage_bucket_object" "profile" {
  bucket = google_storage_bucket.my_bucket.name
  name   = "profile.json"
  source = "dist/profile.json"
  cache_control = "public, max-age=30"
}

output "bucket_name" {
  value = google_storage_bucket.my_bucket.name
}

ありがとう、やり遂げた後は全てが美しく輝いて見える

明日以降に再現してみよう

再現性に疑問があるので明日以降に繰り返しやってみる

再現性の確認

今日は cert-issuer の公式ドキュメント（GitHub Page）にツッコミを入れながら進んでいこう

まず Quick start だが半分くらいかそれ以上が Bitcoin の設定

しかもそのために Docker を使っている感じがある

はじめから Bitcoin や Ethereum のテストネットを使う手順を紹介すれば良いのにと思う

テストネットを使う場合は Goerli Faucet などからテスト用の Ether をもらう必要があってそれはそれで面倒だけど Bitcoin のノードをローカルで設定・起動するのに比べたらはるかに簡単

Docker ではなくローカルで cert-issuer をインストールするには下記でできる

pip3 install cert-issuer

どこにインストールされたかは下記で確認できる

$ pip3 show cert-issuer
Name: cert-issuer
Version: 3.3.0
Summary: Issues blockchain certificates using the Bitcoin blockchain
Home-page: https://github.com/blockchain-certificates/cert-issuer
Author: Blockcerts
Author-email: info@blockcerts.org
License: MIT
Location: /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages
Requires: cert-core, cert-schema, configargparse, glob2, jsonschema, lds-merkle-proof-2019, merkletools, mock, pycoin, pyld, pysha3, python-bitcoinlib, requests, tox
Required-by:

自分の場合は /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages にインストールされた

cert-issuer は下記のように呼び出すことができる

$ /Library/Frameworks/Python.framework/Versions/3.7/bin/cert-issuer
usage: cert-issuer [-h] [-c MY_CONFIG] --issuing_address ISSUING_ADDRESS
                   --verification_method VERIFICATION_METHOD --usb_name
                   USB_NAME --key_file KEY_FILE
                   [--unsigned_certificates_dir UNSIGNED_CERTIFICATES_DIR]
                   [--signed_certificates_dir SIGNED_CERTIFICATES_DIR]
                   [--blockchain_certificates_dir BLOCKCHAIN_CERTIFICATES_DIR]
                   [--work_dir WORK_DIR] [--max_retry MAX_RETRY]
                   [--chain CHAIN] [--safe_mode] [--no_safe_mode]
                   [--dust_threshold DUST_THRESHOLD] [--tx_fee TX_FEE]
                   [--batch_size BATCH_SIZE]
                   [--satoshi_per_byte SATOSHI_PER_BYTE] [--bitcoind]
                   [--no_bitcoind] [--gas_price GAS_PRICE]
                   [--gas_limit GAS_LIMIT]
                   [--etherscan_api_token ETHERSCAN_API_TOKEN]
                   [--ethereum_rpc_url ETHEREUM_RPC_URL]
                   [--ropsten_rpc_url ROPSTEN_RPC_URL]
                   [--goerli_rpc_url GOERLI_RPC_URL]
                   [--sepolia_rpc_url SEPOLIA_RPC_URL]
                   [--blockcypher_api_token BLOCKCYPHER_API_TOKEN]
                   [--context_urls CONTEXT_URLS [CONTEXT_URLS ...]]
                   [--context_file_paths CONTEXT_FILE_PATHS [CONTEXT_FILE_PATHS ...]]
cert-issuer: error: the following arguments are required: --issuing_address, --verification_method, --usb_name, --key_file

頻繁に利用するのであればパスを設定してしまった方が良い

export PATH=$PATH:/Library/Frameworks/Python.framework/Versions/3.7/bin

Ethereum を使うための依存関係のインストール

Ethereum を使うためには追加のパッケージのインストールが必要になる

touch ethereum_requirements.txt

ethereum_requirements.txt

web3<=4.4.1
coincurve==7.1.0
ethereum==2.3.1
rlp<1
eth-account<=0.3.0

pip3 install -r ethereum_requirements.txt

なぜ requirements.txt に書かずに別々に分けたのだろう

ディレクトリの作成

署名する前や後の証明書や作業用のディレクトリを作成する

mkdir -p data/unsigned_certificates
mkdir -p data/blockchain_certificates
mkdir -p data/work

名前は何でも良いが一応 cert-issuer のデフォルトのディレクトリ名に倣った

薄田達哉 / tatsuyasusukida 2022/12/29に更新

署名していない証明書の作成

touch data/unsigned_certificates/my_certificate.json

こちらは cert-issuer の GitHub で examples ディレクトリに含まれているものだがそのまま使えない

cert-issuer/examples/data-testnet/unsigned_certificates/verifiable-credential.json

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://www.w3.org/2018/credentials/examples/v1",
    "https://w3id.org/blockcerts/v3"
  ],
  "id": "urn:uuid:bbba8553-8ec1-445f-82c9-a57251dd731c",
  "type": [
    "VerifiableCredential",
    "BlockcertsCredential"
  ],
  "issuer": "did:example:23adb1f712ebc6f1c276eba4dfa",
  "issuanceDate": "2022-01-01T19:33:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "alumniOf": {
      "id": "did:example:c276e12ec21ebfeb1f712ebc6f1"
    }
  }
}

下記のようなエラーが表示される

Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pyld/jsonld.py", line 1134, in to_rdf
    expanded = self.expand(input_, options)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pyld/jsonld.py", line 835, in expand
    expanded = self._expand(active_ctx, None, document, options, False)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pyld/jsonld.py", line 2090, in _expand
    active_ctx, element['@context'], options)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pyld/jsonld.py", line 2740, in _process_context
    code='invalid local context')
pyld.jsonld.JsonLdError: ('Invalid JSON-LD syntax; @context must be an object.',)

原因は https://www.w3.org/2018/credentials/examples/v1

理由は恐らくだが @context に含まれる https://www.w3.org/ns/odrl.jsonld が文字列であるためと推測する

エラーを回避するには https://www.w3.org/2018/credentials/examples/v1 を削除すれば良い

ただし削除すると alumniOf の語彙を使えないので alumniOf 以下も削除する必要がある

最終的に出来上がる証明書の内容は下記の通り

data/unsigned_certificates/my_certificate.json

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://w3id.org/blockcerts/v3"
  ],
  "id": "urn:uuid:bbba8553-8ec1-445f-82c9-a57251dd731c",
  "type": [
    "VerifiableCredential",
    "BlockcertsCredential"
  ],
  "issuer": "did:example:23adb1f712ebc6f1c276eba4dfa",
  "issuanceDate": "2022-01-01T19:33:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21"
  }
}

鍵ファイルと設定ファイルの作成

touch cert-issuer.conf key_file.txt

cert-issuer.conf

issuing_address = 0x0000000000000000000000000000000000000000
verification_method = did:example:1234
usb_name=.
key_file=key_file.txt

unsigned_certificates_dir=/Users/susukida/workspace/web3/blockcerts/data/unsigned_certificates
blockchain_certificates_dir=/Users/susukida/workspace/web3/blockcerts/data/blockchain_certificates
work_dir=/Users/susukida/workspace/web3/blockcerts/data/work

chain = ethereum_goerli
goerli_rpc_url = https://eth-goerli.g.alchemy.com/v2/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

no_safe_mode

下記6点は環境に応じて変える必要がある

issuing_address
verification_method
unsigned_certificates_dir
blockchain_certificates_dir
work_dir
goerli_rpc_url

issuing_address は MetaMask などからコピーする

verification_method は適当でも署名できてしまうが検証時にエラーになるので適切なものを設定する必要がある

適切な verification_method を設定するには適切な内容で DID を作成する必要があるが、その方法が公式 GitHub にほとんど書かれていないので初めての人にはかなり厳しい

DID を作成する方法については後から詳しく説明する

3つの dir はデフォルトのディレクトリ名を使っていれば指定しなくても良さそうな感じもするがフルパス指定が必要

その理由はベースがコマンド実行時の作業ディレクトリではなく、cert-issuer の実行ファイルのあるディレクトリとなるため

goerli_rpc_url は Alchemy などで Goerli のエンドポイントを作成して API キー付きの URL を使用する

goerli_rpc_url を設定しなくても運が良ければ動く、謎の混雑しているエンドポイントが使われる

key_file.txt には MataMask からエクスポートした秘密鍵をコピー＆ペーストする

薄田達哉 / tatsuyasusukida 2022/12/29に更新

とりあえずこの時点で実行してみる

設定に問題なければこの時点で cert-issuer を実行できる

/Library/Frameworks/Python.framework/Versions/3.7/bin/cert-issuer -c cert-issuer.conf

実行結果はこちら

WARNING - Your app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - This run will try to issue on the ethereum_goerli chain
INFO - Set cost constants to recommended_gas_price=20000000000.000000, recommended_gas_limit=25000.000000
INFO - Processing 1 certificates
INFO - Processing 1 certificates under work path=/Users/susukida/workspace/web3/blockcerts/data/work
INFO - Getting balance with EthereumRPCProvider: 198279040000000000
INFO - Total cost will be 500000000000000 wei
INFO - Starting finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - Stopping finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - here is the op_return_code data: f4906de7db4f9a826b5998472f51eaac762d429b29b6c2496f38870a477929d9
INFO - Fetching nonce with EthereumRPCProvider
INFO - Starting finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - Stopping finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - signed Ethereum trx = f884048504a817c8008261a894deaddeaddeaddeaddeaddeaddeaddeaddeaddead80a0f4906de7db4f9a826b5998472f51eaac762d429b29b6c2496f38870a477929d92da01b0801ad15681457103aff952fc6a1a6b327b8eb1840455c37fec07609a6cccca068922ac353d38527ed5c5c68a02d73c740cc95efd1d0a75172af29317cb32af5
INFO - verifying ethDataField value for transaction
INFO - verified ethDataField
INFO - Broadcasting transaction with EthereumRPCProvider
INFO - Broadcasting succeeded with method_provider=<cert_issuer.blockchain_handlers.ethereum.connectors.EthereumRPCProvider object at 0x7fc1e0d04e50>, txid=0xca8732ae20f0e67c8091af0b83055f5e21a32776c5df7f15fa2da25743320a7e
INFO - merkle_json: {'path': [], 'merkleRoot': 'f4906de7db4f9a826b5998472f51eaac762d429b29b6c2496f38870a477929d9', 'targetHash': 'f4906de7db4f9a826b5998472f51eaac762d429b29b6c2496f38870a477929d9', 'anchors': ['blink:eth:goerli:0xca8732ae20f0e67c8091af0b83055f5e21a32776c5df7f15fa2da25743320a7e']}
INFO - Broadcast transaction with txid 0xca8732ae20f0e67c8091af0b83055f5e21a32776c5df7f15fa2da25743320a7e
INFO - Your Blockchain Certificates are in /Users/susukida/workspace/web3/blockcerts/data/blockchain_certificates

できあがるブロックチェーン証明書がこちら、本物は未整形だが見やすさのために整形しています

data/blockchain_certificates/my_certificate.json

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://w3id.org/blockcerts/v3"
  ],
  "id": "urn:uuid:bbba8553-8ec1-445f-82c9-a57251dd731c",
  "type": ["VerifiableCredential", "BlockcertsCredential"],
  "issuer": "did:example:23adb1f712ebc6f1c276eba4dfa",
  "issuanceDate": "2022-01-01T19:33:24Z",
  "credentialSubject": { "id": "did:example:ebfeb1f712ebc6f1c276e12ec21" },
  "proof": {
    "type": "MerkleProof2019",
    "created": "2022-12-29T08:48:59.459458",
    "proofValue": "z7veGu1qoKR3AS5M3xfNxYMVGUCxFzaEQ5NkRWDGTowFPyL2gB7vtCVDfK2e4oETN19HnnqmXL3CS2qpMgnWe2XUHCVN7ufHArBc54QVVk2XouWzakWMU83iHnAsk186DuvJv5vLXN2p9bFXRcwFTfqxkyzDL9E8G8CEZ43X9HnFNz6Yz38U4ypGt6XbmKM7EnLTK5NaKRkHrQehPyRfFCFhjBEhgdT9QTHf56PxwqmyF7Q8Gwf3MEZwbu5SNst58qSvRFQch7zaW1ZDw85Zqk1uMGJBwomRnwPtgmaKknR6rn3Pd4FMYp",
    "proofPurpose": "assertionMethod",
    "verificationMethod": "did:example:1234"
  }
}

DID の作成

touch did.json
touch profile.json
touch main.tf terraform.tfvars

まずは検証が中途半端に成功してしまう内容で作成する

did.json

{
  "@context": [
    "https://www.w3.org/ns/did/v1"
  ],
  "id": "did:web:loremipsumcojp-cert-issuer-20221229.storage.googleapis.com",
  "service": [
    {
      "id": "#issuer-profile",
      "type": "IssuerProfile",
      "serviceEndpoint": "https://loremipsumcojp-cert-issuer-20221229.storage.googleapis.com/profile.json"
    }
  ]
}

loremipsumcojp-cert-issuer-20221229 の部分は環境にあわせて適宜変更する

profile.json

{
  "@context": [
    "https://w3id.org/openbadges/v2"
  ],
  "id": "https://loremipsumcojp-cert-issuer-20221229.storage.googleapis.com/profile.json",
  "type": "Profile",
  "name": "Lorem Ipsum Co. Ltd.",
  "url": "https://www.loremipsum.co.jp",
  "publicKey": [
    {
      "id": "ecdsa-koblitz-pubkey:0x063Eae33729EdB89FaadFDe5c813d4A06d176E4c",
      "created": "2021-12-29T00:00:00"
    }
  ]
}

こちらも同様にloremipsumcojp-cert-issuer-20221229 の部分は環境にあわせて適宜変更する

main.tf

variable "project" {}
variable "bucket_name" {}
variable "bucket_location" {}

provider "google" {
  project = var.project
}

resource "google_storage_bucket" "my_bucket" {
  name                        = var.bucket_name
  location                    = var.bucket_location
  force_destroy               = true

  cors {
    origin          = ["*"]
    method          = ["GET"]
    response_header = ["Content-Type"]
    max_age_seconds = 30
  }
}

resource "google_storage_bucket_iam_binding" "public_rule" {
  bucket = google_storage_bucket.my_bucket.name
  role = "roles/storage.legacyObjectReader"
  members = [
    "allUsers",
  ]
}

resource "google_storage_bucket_object" "did" {
  bucket = google_storage_bucket.my_bucket.name
  name   = ".well-known/did.json"
  source = "did.json"
  cache_control = "public, max-age=30"
}

resource "google_storage_bucket_object" "profile" {
  bucket = google_storage_bucket.my_bucket.name
  name   = "profile.json"
  source = "profile.json"
  cache_control = "public, max-age=30"
}

terraform.tfvars

project         = "xxxxxxxx"
bucket_name     = "loremipsumcojp-cert-issuer-20221229"
bucket_location = "ASIA-NORTHEAST1"

terraform.tfvars の内容は環境に応じて変更する

data/unsigned_certificates/my_certificates.json

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://w3id.org/blockcerts/v3"
  ],
  "id": "urn:uuid:bbba8553-8ec1-445f-82c9-a57251dd731c",
  "type": [
    "VerifiableCredential",
    "BlockcertsCredential"
  ],
  "issuer": "did:web:loremipsumcojp-cert-issuer-20221229.storage.googleapis.com",
  "issuanceDate": "2022-01-01T19:33:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21"
  }
}

my_certificates.json の issuer も忘れずに変更する

下記のコマンドを実行してバケットやオブジェクトを作成する

terraform init
terraform apply

完了したらアクセスして確認する

cert-issuer.conf の conf を忘れずに修正する

verification_method = did:web:loremipsumcojp-cert-issuer-20221229.storage.googleapis.com

これらが終わったらコマンドを実行する

/Library/Frameworks/Python.framework/Versions/3.7/bin/cert-issuer -c cert-issuer.conf

出力された証明書を Blockcerts の Web サイトにアップロードして検証する、Choose JSON file を使う

Identity Verification がいつまで立っても終わらない

検証を成功させるには

DID に verificationMethod の内容を追加する必要がある

そのためには Ethereum の秘密鍵の公開鍵の JWK を作成する必要がある

作成のための Node.js スクリプトを作成する

npm init -y
npm install --save-dev @trust/keyto
touch convert.js

convert.js

const fs = require('fs');
const keyto = require("@trust/keyto");

if (require.main === module) {
  main();
}

function main() {
  const file = process.argv[2];
  const blk = fs.readFileSync(file, 'utf-8');
  const key = keyto.from(blk, "blk");
  const jwk = key.toJwk("public");

  console.log(JSON.stringify(jwk, null, 2));
}

node convert.js key_file.txt

こんな感じの内容が出力される

{
  "kty": "EC",
  "crv": "K-256",
  "x": "oTj4PkPzlNowto09OpAU0BVJ6DJc2vg_lFoW9wiZ60A",
  "y": "D9VaE9hbsOagGab_0euWcNUaCDphfBPg-C_aWD7npx4"
}

この内容を下記のように did.json にコピー＆ペーストして追記する

did.json

{
  "@context": ["https://www.w3.org/ns/did/v1"],
  "id": "did:web:loremipsumcojp-cert-issuer-20221229.storage.googleapis.com",
  "service": [
    {
      "id": "#issuer-profile",
      "type": "IssuerProfile",
      "serviceEndpoint": "https://loremipsumcojp-cert-issuer-20221229.storage.googleapis.com/profile.json"
    }
  ],
  "verificationMethod": [
    {
      "id": "#key-1",
      "controller": "did:web:loremipsumcojp-cert-issuer-20221229.storage.googleapis.com",
      "type": "EcdsaSecp256k1VerificationKey2019",
      "publicKeyJwk": {
        "kty": "EC",
        "crv": "K-256",
        "x": "oTj4PkPzlNowto09OpAU0BVJ6DJc2vg_lFoW9wiZ60A",
        "y": "D9VaE9hbsOagGab_0euWcNUaCDphfBPg-C_aWD7npx4"
      }
    }
  ]
}

忘れずに Google Cloud Storage へアップロードする

terraform apply

cert-issuer.conf も忘れずに変更する

cert-issuer.conf

verification_method = did:web:loremipsumcojp-cert-issuer-20221229.storage.googleapis.com#key-1

コマンドを実行

/Library/Frameworks/Python.framework/Versions/3.7/bin/cert-issuer -c cert-issuer.conf

出力されたブロックチェーン証明書を Blockcerts のサイトで検証すると「認証されました」と表示される

取引を確認するリンクをクリックすると Etcherscan のページが表示される

0xdeaddead... に 0 ether を送金してその時の Input Data として何かを送っている、署名データと推測する

おわりに

途中で諦めかけたが最後まで行けて良かった

スクラップがとっ散らかってしまったので後日記事にまとめよう

千葉工業大学の NFT

自分はどうやってこれを見つけたんだろう

Open Badge

今度はオープンバッジが面白い

薄田達哉 / tatsuyasusukida 2022/12/29に更新

ブロックチェーン証明書に含まれる proofValue

デコードにはパッケージのインストールが必要

const { Decoder } = require('@vaultie/lds-merkle-proof-2019')
const decoder = new Decoder(proofValueBase58)

decoder.decode() // JSON object with proofValue

今知ったけど1通発行しようが100通発行しようが Ethereum には1つのトランザクションしか発行されないようだ

詳しくはこちら

気になるリンク

https://idmlab.eidentity.jp/

Haruki 2023/01/01

ちょうどBlockCertsについて調べていたので大変参考になりました！

薄田達哉 / tatsuyasusukida 2023/01/02

お役に立てて嬉しいです！コメントとたくさんのいいねをいただいてとても励みになります、ありがとうございます😄

薄田達哉 / tatsuyasusukida 2023/01/04

Bitcoin でも出来た

1時間くらい頑張ったら Bitcoin でも証明書を作れたようだ

Mac の場合は python3 ではなくて /usr/bin/python3 を使うとか、秘密鍵を WIF 形式で指定する必要があるとか色々つまづいたけど出来て良かった

WIF 形式は mainnet と testnet で違うことがわかって勉強になった

import { Networks, PrivateKey } from "bitcore-lib";
import { readFileSync } from "fs";

const address = JSON.parse(readFileSync('address.json', 'utf8'));
const privateKey = new PrivateKey(address.privateKey, Networks.testnet);

console.log(privateKey.toWIF())

まだ検証はしていないので後から時間をとってまとめたい

薄田達哉 / tatsuyasusukida 2023/01/04

Ethereum ばかりだったけど単純にデータを保存するなら Bitcoin もストレージとして有用だと思うようになった

薄田達哉 / tatsuyasusukida 2023/01/04に更新

スクラップが記事になりました（スクラップの冒頭にも書いたけど）

Blockcerts を使って Ethereum ブロックチェーン証明書を発行する方法

Bitcoin の場合の発行手順

だいぶ日が空いてしまったけど Bitcoin の場合のやり方についてまとめよう

まずは cert-issuer のインストール

/usr/bin/pip3 install cert-issuer

なぜ /usr/bin/python3 の方に cert-issuer を再度インストールする必要があるのか？

理由は /usr/local/bin/python3 の方で cert-issuer 実行時に SSL のライブラリが読み込めなくてエラーになるから

私の Mac で python3 を実行すると /usr/local/bin/python3 がデフォルトになっている様子

$ which python3
/usr/local/bin/python3

PATH の環境変数を変更しても良いけど面倒なのでフルパスで指定する（それはそれで面倒だけど）

どこにインストールするかを確認するには下記のコマンドを実行する

$ /usr/bin/pip3 show cert-issuer
Name: cert-issuer
Version: 3.3.0
Summary: Issues blockchain certificates using the Bitcoin blockchain
Home-page: https://github.com/blockchain-certificates/cert-issuer
Author: Blockcerts
Author-email: info@blockcerts.org
License: MIT
Location: /Users/susukida/Library/Python/3.9/lib/python/site-packages
Requires: cert-core, cert-schema, configargparse, glob2, jsonschema, lds-merkle-proof-2019, merkletools, mock, pycoin, pyld, pysha3, python-bitcoinlib, requests, tox
Required-by:

Location を見ると /Users/susukida/Library/Python/3.9/bin あたりにインストールされたのではないかと思われる

$ /Users/susukida/Library/Python/3.9/bin/cert-issuer
usage: cert-issuer [-h] [-c MY_CONFIG] --issuing_address ISSUING_ADDRESS
                   --verification_method VERIFICATION_METHOD --usb_name
                   USB_NAME --key_file KEY_FILE
                   [--unsigned_certificates_dir UNSIGNED_CERTIFICATES_DIR]
                   [--signed_certificates_dir SIGNED_CERTIFICATES_DIR]
                   [--blockchain_certificates_dir BLOCKCHAIN_CERTIFICATES_DIR]
                   [--work_dir WORK_DIR] [--max_retry MAX_RETRY]
                   [--chain CHAIN] [--safe_mode] [--no_safe_mode]
                   [--dust_threshold DUST_THRESHOLD] [--tx_fee TX_FEE]
                   [--batch_size BATCH_SIZE]
                   [--satoshi_per_byte SATOSHI_PER_BYTE] [--bitcoind]
                   [--no_bitcoind] [--gas_price GAS_PRICE]
                   [--gas_limit GAS_LIMIT]
                   [--etherscan_api_token ETHERSCAN_API_TOKEN]
                   [--ethereum_rpc_url ETHEREUM_RPC_URL]
                   [--ropsten_rpc_url ROPSTEN_RPC_URL]
                   [--goerli_rpc_url GOERLI_RPC_URL]
                   [--sepolia_rpc_url SEPOLIA_RPC_URL]
                   [--blockcypher_api_token BLOCKCYPHER_API_TOKEN]
                   [--context_urls CONTEXT_URLS [CONTEXT_URLS ...]]
                   [--context_file_paths CONTEXT_FILE_PATHS [CONTEXT_FILE_PATHS ...]]
cert-issuer: error: the following arguments are required: --issuing_address, --verification_method, --usb_name, --key_file

ばっちりだ

ワークスペースの準備

mkdir blockcerts-bitcoin
cd blockcerts-bitcoin
npm init -y
npm install --save-dev bitcoinjs-lib ecpair tiny-secp256k1 ts-node
touch address.ts

address.ts

import { networks, payments } from "bitcoinjs-lib";
import ECPairFactory from "ecpair";
import * as ecc from "tiny-secp256k1";

function main() {
  const ECPair = ECPairFactory(ecc);
  const keyPair = ECPair.makeRandom({
    network: networks.testnet,
  });

  const payment = payments.p2wpkh({
    pubkey: keyPair.publicKey,
    network: networks.testnet,
  });

  const wif = keyPair.toWIF();
  const address = payment.address!;

  console.log(JSON.stringify({ wif, address }, null, 2));
}

main();

npx ts-node address.ts > address.json

address.json

{
  "wif": "cXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
  "address": "tb1XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
}

wif は c から始まっていて address は tb1 から始まっていることを確認する

Bitcoin のアドレスの種類については下記が詳しい

https://bitcoinfaucet.uo1.net/

テスト用のビットコインをもらう

Bitcoin アドレスを入力して Send testnet bitcoins ボタンを押す

トランザクションについては Blockstream や BlockCypher で確認できる

いつもは下記を使っているのだけど調子が悪いみたい

https://coinfaucet.eu/en/btc-testnet/

key_file.txt を作成する

touch key_file.txt

address.json の wif の内容を key_file.txt にコピー＆ペーストする

key_file

cXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

ここが WIF 形式じゃないとエラーが出るので注意しましょう

Bitcoin は秘密鍵もアドレスも形式が何種類かあるので紛らわしい

conf.ini を作成する

touch conf.ini

conf.ini

issuing_address=tb1q7dfpt4fznl7xs4ntjwd0tmjqrp6pnzha0fkjuh
verification_method=did:web:blockcerts-20230104.storage.googleapis.com#key-2
usb_name=.
key_file=key_file.txt

unsigned_certificates_dir=/Users/susukida/workspace/web3/blockcerts3/data/unsigned_certificates
blockchain_certificates_dir=/Users/susukida/workspace/web3/blockcerts3/data/blockchain_certificates
work_dir=/Users/susukida/workspace/web3/blockcerts3/data/work

chain=bitcoin_testnet
no_safe_mode

dust_threshold=0.00000500
tx_fee=0.00000200
satoshi_per_byte=2

薄田達哉 / tatsuyasusukida 2023/01/11に更新

とりあえず実行してみる

証明書の内容は現在のままで OK

data/unsigned_certificates/my_certificate.json

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://w3id.org/blockcerts/v3"
  ],
  "id": "urn:uuid:bbba8553-8ec1-445f-82c9-a57251dd731c",
  "type": [
    "VerifiableCredential",
    "BlockcertsCredential"
  ],
  "issuer": "did:web:blockcerts-20230104.storage.googleapis.com",
  "issuanceDate": "2023-01-04T00:00:00Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21"
  }
}

DID ドキュメントに Bitcoin の公開鍵を追加する必要があるけど後からやろう、これもそのまま

did.json

{
  "@context": ["https://www.w3.org/ns/did/v1"],
  "id": "did:web:blockcerts-20230104.storage.googleapis.com",
  "service": [
    {
      "id": "#issuer-profile",
      "type": "IssuerProfile",
      "serviceEndpoint": "https://blockcerts-20230104.storage.googleapis.com/profile.json"
    }
  ],
  "verificationMethod": [
    {
      "id": "#key-1",
      "controller": "did:web:blockcerts-20230104.storage.googleapis.com",
      "type": "EcdsaSecp256k1VerificationKey2019",
      "publicKeyJwk": {
        "kty": "EC",
        "crv": "K-256",
        "x": "oTj4PkPzlNowto09OpAU0BVJ6DJc2vg_lFoW9wiZ60A",
        "y": "D9VaE9hbsOagGab_0euWcNUaCDphfBPg-C_aWD7npx4"
      }
    }
  ]
}

とりあえず実行してみる

$ /Users/susukida/Library/Python/3.9/bin/cert-issuer -c conf.ini
WARNING - Your app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - This run will try to issue on the bitcoin_testnet chain
INFO - Set cost constants to recommended_tx_fee=0.000002,min_per_output=0.000005,satoshi_per_byte=2
INFO - Processing 1 certificates
INFO - Processing 1 certificates under work path=/Users/susukida/workspace/web3/blockcerts3/data/work
INFO - Total cost will be 1068 satoshis
ERROR - Please add 68 satoshis to the address tb1q7dfpt4fznl7xs4ntjwd0tmjqrp6pnzha0fkjuh
Traceback (most recent call last):
  File "/Users/susukida/Library/Python/3.9/bin/cert-issuer", line 8, in <module>
    sys.exit(cert_issuer_main())
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/__main__.py", line 17, in cert_issuer_main
    issue_certificates.main(parsed_config)
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/issue_certificates.py", line 34, in main
    return issue(app_config, certificate_batch_handler, transaction_handler)
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/issue_certificates.py", line 14, in issue
    transaction_handler.ensure_balance()
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/blockchain_handlers/bitcoin/transaction_handlers.py", line 51, in ensure_balance
    raise InsufficientFundsError(error_message)
cert_issuer.errors.InsufficientFundsError: Please add 68 satoshis to the address tb1q7dfpt4fznl7xs4ntjwd0tmjqrp6pnzha0fkjuh

satoshis が足りないと言われている

もらったのが 0.00001 tBTC = 1,000 satoshis で Total cost が 1,068 satoshis なので確かに足りない

conf.ini を修正してみる

conf.ini

dust_threshold=0.00000500
tx_fee=0.00000100
satoshi_per_byte=1

これでどうだ

$ /Users/susukida/Library/Python/3.9/bin/cert-issuer -c conf.ini
WARNING - Your app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - This run will try to issue on the bitcoin_testnet chain
INFO - Set cost constants to recommended_tx_fee=0.000001,min_per_output=0.000005,satoshi_per_byte=1
INFO - Processing 1 certificates
INFO - Processing 1 certificates under work path=/Users/susukida/workspace/web3/blockcerts3/data/work
INFO - Total cost will be 534 satoshis
INFO - Starting finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - Stopping finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - here is the op_return_code data: 532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a82238
INFO - Unsigned hextx=0100000001a78e2ffdabf68e8dc0a6fc58d570b63460586ad68dba4bd2d0c7a7c5e50f263f0100000000ffffffff02fc02000000000000160014f35215d5229ffc68566b939af5ee401874198afd0000000000000000226a20532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a8223800000000
INFO - Preparing tx for signing
INFO - Starting finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
ERROR - Unable to sign transaction. hextx=01000000000101a78e2ffdabf68e8dc0a6fc58d570b63460586ad68dba4bd2d0c7a7c5e50f263f0100000000ffffffff02fc02000000000000160014f35215d5229ffc68566b939af5ee401874198afd0000000000000000226a20532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a8223802483045022100f4f7e03ba90acb77c3dfe2c2288914ecba9cb130ce619ecbfac526f935c609e202207e33a2bf67c445057628b0596bc624e6abc789e39a4dce142052b814f090a5ce012102d4b15382373da9faa3d0f1e48a5dbec0836f3051b048ea5f80e7b4cfff2ef40200000000
INFO - Stopping finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
Traceback (most recent call last):
  File "/Users/susukida/Library/Python/3.9/bin/cert-issuer", line 8, in <module>
    sys.exit(cert_issuer_main())
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/__main__.py", line 17, in cert_issuer_main
    issue_certificates.main(parsed_config)
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/issue_certificates.py", line 34, in main
    return issue(app_config, certificate_batch_handler, transaction_handler)
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/issue_certificates.py", line 20, in issue
    tx_id = issuer.issue(app_config.chain)
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/issuer.py", line 27, in issue
    txid = self.transaction_handler.issue_transaction(blockchain_bytes)
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/blockchain_handlers/bitcoin/transaction_handlers.py", line 56, in issue_transaction
    signed_tx = self.sign_transaction(prepared_tx)
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/blockchain_handlers/bitcoin/transaction_handlers.py", line 92, in sign_transaction
    signed_tx = signer.sign_transaction(prepared_tx)
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/models/__init__.py", line 99, in sign_transaction
    return self.signer.sign_transaction(self.wif, transaction_to_sign)
  File "/Users/susukida/Library/Python/3.9/lib/python/site-packages/cert_issuer/blockchain_handlers/bitcoin/signer.py", line 35, in sign_transaction
    raise UnableToSignTxError('Unable to sign transaction')
cert_issuer.errors.UnableToSignTxError: Unable to sign transaction

いい感じの所まで行ったけどまだダメだ、もらった Bitcoin が 6 confirmations まで行ってないのが原因？

そういえば regtest で頑張っている時にも出たな Unable to sign transaction っていうエラーメッセージ

Bitcoin おかわりしてみたけどダメだった

同じようにやってるつもりでもうまく行きませんね

一度うまくいっても振り返ることが重要だと痛感しました

薄田達哉 / tatsuyasusukida 2023/01/11に更新

というか 0.05 tBTC ももらってしまった、終わったら返さないとだ

もしかして m か n から始まるアドレスならいける？

行けた！

$ /Users/susukida/Library/Python/3.9/bin/cert-issuer -c conf.ini
WARNING - Your app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - This run will try to issue on the bitcoin_testnet chain
INFO - Set cost constants to recommended_tx_fee=0.000010,min_per_output=0.000028,satoshi_per_byte=1
INFO - Processing 1 certificates
INFO - Processing 1 certificates under work path=/Users/susukida/workspace/web3/blockcerts3/data/work
INFO - Total cost will be 998 satoshis
INFO - Starting finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - Stopping finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - here is the op_return_code data: 532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a82238
INFO - Unsigned hextx=01000000014c9506f38f00c4d94d7e4e1e4b20b72be2d21ed3381e22ddc0584f5e3a6fbbf20000000000ffffffff029f724d00000000001976a914f35215d5229ffc68566b939af5ee401874198afd88ac0000000000000000226a20532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a8223800000000
INFO - Preparing tx for signing
INFO - Starting finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - Stopping finalizable signer
WARNING - app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure
INFO - The actual transaction size is 234 bytes
INFO - Signed hextx=01000000014c9506f38f00c4d94d7e4e1e4b20b72be2d21ed3381e22ddc0584f5e3a6fbbf2000000006a4730440220292c73f9e9e89d4ccf0dc375b7bed97e2b72217ebfb2f3b57802b9f696d42b3b02201ab9bfae6f53d24cab2fcbce259545caeb564dfda3df43c5ec71e11f8cb834ec012102d4b15382373da9faa3d0f1e48a5dbec0836f3051b048ea5f80e7b4cfff2ef402ffffffff029f724d00000000001976a914f35215d5229ffc68566b939af5ee401874198afd88ac0000000000000000226a20532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a8223800000000
INFO - Signed hextx=01000000014c9506f38f00c4d94d7e4e1e4b20b72be2d21ed3381e22ddc0584f5e3a6fbbf2000000006a4730440220292c73f9e9e89d4ccf0dc375b7bed97e2b72217ebfb2f3b57802b9f696d42b3b02201ab9bfae6f53d24cab2fcbce259545caeb564dfda3df43c5ec71e11f8cb834ec012102d4b15382373da9faa3d0f1e48a5dbec0836f3051b048ea5f80e7b4cfff2ef402ffffffff029f724d00000000001976a914f35215d5229ffc68566b939af5ee401874198afd88ac0000000000000000226a20532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a8223800000000
INFO - verifying op_return value for transaction
INFO - verified OP_RETURN
INFO - Broadcasting succeeded with method_provider=<bound method BlockcypherProvider.broadcast_tx of <cert_issuer.blockchain_handlers.bitcoin.connectors.BlockcypherProvider object at 0x10f54aac0>>, txid=6c5fd0c1b240831fbc1e94490473491dd30db586d44c3cb4d19c61af98ff7d68
INFO - Broadcasting succeeded with method_provider=<bound method BlockstreamBroadcaster.broadcast_tx of <cert_issuer.blockchain_handlers.bitcoin.connectors.BlockstreamBroadcaster object at 0x10f7e8040>>, txid=6c5fd0c1b240831fbc1e94490473491dd30db586d44c3cb4d19c61af98ff7d68
INFO - merkle_json: {'path': [], 'merkleRoot': '532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a82238', 'targetHash': '532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a82238', 'anchors': ['blink:btc:testnet:6c5fd0c1b240831fbc1e94490473491dd30db586d44c3cb4d19c61af98ff7d68']}
INFO - Broadcast transaction with txid 6c5fd0c1b240831fbc1e94490473491dd30db586d44c3cb4d19c61af98ff7d68
INFO - Your Blockchain Certificates are in /Users/susukida/workspace/web3/blockcerts3/data/blockchain_certificates

tb1q7dfpt4fznl7xs4ntjwd0tmjqrp6pnzha0fkjuh

ずいぶんと日が空いてしまった

とりあえず状況を整理しよう

tb1 から始まるアドレスはダメだったアドレス

はじめに Bitcoin Testnet Faucent から 0.00001 BTC もらった

次に Bitcoin testnet3 faucet から 0.05076734 BTC もらった

最後に n3hWq46tuvfRzBffsMwB92Gxa4ULA9xgF1 に 0.05076614 BTC を送金した（手数料は 0.0000012 BTC だった）

OP_RETURN したトランザクションが 6c5fd0c1b240831fbc1e94490473491dd30db586d44c3cb4d19c61af98ff7d68

UTXO が 6c5fd0c1b240831fbc1e94490473491dd30db586d44c3cb4d19c61af98ff7d68 の 0 番目

アドレスを P2WPKH から P2PKH へ変換した

address2.ts というファイル名がセンス無いけどとりあえず気にしない

address2.ts

import { networks, payments } from "bitcoinjs-lib";
import ECPairFactory from "ecpair";
import * as ecc from "tiny-secp256k1";

function main() {
  const ECPair = ECPairFactory(ecc);
  const keyPair = ECPair.fromWIF(
    require("./address.json").wif,
    networks.testnet
  );

  const payment = payments.p2pkh({
    pubkey: keyPair.publicKey,
    network: networks.testnet,
  });

  const wif = keyPair.toWIF();
  const address = payment.address!;

  console.log(JSON.stringify({ wif, address }, null, 2));
}

main();

npx ts-node address2.ts > address2.json

address2.json

{
  "wif": "cXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
  "address": "n3hWq46tuvfRzBffsMwB92Gxa4ULA9xgF1"
}

薄田達哉 / tatsuyasusukida 2023/01/18に更新

はじめからこうだったら良かった

address.ts

import { networks, payments } from "bitcoinjs-lib";
import ECPairFactory from "ecpair";
import * as ecc from "tiny-secp256k1";

function main() {
  const ECPair = ECPairFactory(ecc);
  const keyPair = ECPair.makeRandom({
    network: networks.testnet,
  });

  const payment = payments.p2pkh({
    pubkey: keyPair.publicKey,
    network: networks.testnet,
  });

  const wif = keyPair.toWIF();
  const address = payment.address!;

  console.log(JSON.stringify({ wif, address }, null, 2));
}

main();

Bitcoin Testnet Faucet は tb1 から始まるアドレス（P2WPKH）にしか対応していない

したがって P2PKH の場合（m か n から始まるアドレスの場合）は Bitcion testnet3 faucent を利用する必要がある

Bitcoin testnet3 faucet からはたくさん tBTC を貰えるから使い終わったら返さないとというプレッシャーがすごい

conf.ini を修正する

conf.ini

issuing_address=n3hWq46tuvfRzBffsMwB92Gxa4ULA9xgF1
verification_method=did:web:blockcerts-20230104.storage.googleapis.com#key-2
usb_name=.
key_file=key_file.txt

unsigned_certificates_dir=/Users/susukida/workspace/web3/blockcerts3/data/unsigned_certificates
blockchain_certificates_dir=/Users/susukida/workspace/web3/blockcerts3/data/blockchain_certificates
work_dir=/Users/susukida/workspace/web3/blockcerts3/data/work

chain=bitcoin_testnet
no_safe_mode

tx_fee=0.00000999
satoshi_per_byte=1

といっても issuing_address を変更するだけ

変更した conf.ini を指定して cert-issuer を実行する

/Users/susukida/Library/Python/3.9/bin/cert-issuer -c conf.ini

Mac では python3 が複数インストールされていることがある

使用する python3 によっては SSL のライブラリが読み込めなくて失敗することがあるので、その場合は別の python3 を試してみると良い

JWK と ecdsa-koblitz-pubkey を作る

JWK は @trust/keyto を使って作る

convert2.js

const fs = require("fs");
const keyto = require("@trust/keyto");

if (require.main === module) {
  main();
}

function main() {
  const { wif } = require("./address2.json");
  const key = keyto.from(wif, "blk");
  const jwk = key.toJwk("public");

  console.log(JSON.stringify(jwk, null, 2));
}

相変わらず convert2.js というファイル名がセンス無いが気にしない

node convert2.js > convert2.json

convert2.json

{
  "kty": "EC",
  "crv": "K-256",
  "x": "8aO1pajLb2Dhn4Jd6jk_kZCxYO99T6c0wBivrM7UMoY",
  "y": "sy6LVNtGzf5apuwOG38c8xTSZiewLdMusETacokRabQ"
}

ecdsa-koblitz-pubkey は P2PKH のアドレスをコピー＆ペーストする

ecdsa-koblitz-pubkey:n3hWq46tuvfRzBffsMwB92Gxa4ULA9xgF1

DID と IssuerProfile を更新する

JWK と ecdsa-koblitz-pubkey を did.json と profile.json にそれぞれ追加する

did.json

{
  "@context": ["https://www.w3.org/ns/did/v1"],
  "id": "did:web:blockcerts-20230104.storage.googleapis.com",
  "service": [
    {
      "id": "#issuer-profile",
      "type": "IssuerProfile",
      "serviceEndpoint": "https://blockcerts-20230104.storage.googleapis.com/profile.json"
    }
  ],
  "verificationMethod": [
    {
      "id": "#key-1",
      "controller": "did:web:blockcerts-20230104.storage.googleapis.com",
      "type": "EcdsaSecp256k1VerificationKey2019",
      "publicKeyJwk": {
        "kty": "EC",
        "crv": "K-256",
        "x": "oTj4PkPzlNowto09OpAU0BVJ6DJc2vg_lFoW9wiZ60A",
        "y": "D9VaE9hbsOagGab_0euWcNUaCDphfBPg-C_aWD7npx4"
      }
    },
    {
      "id": "#key-2",
      "controller": "did:web:blockcerts-20230104.storage.googleapis.com",
      "type": "EcdsaSecp256k1VerificationKey2019",
      "publicKeyJwk": {
        "kty": "EC",
        "crv": "K-256",
        "x": "8aO1pajLb2Dhn4Jd6jk_kZCxYO99T6c0wBivrM7UMoY",
        "y": "sy6LVNtGzf5apuwOG38c8xTSZiewLdMusETacokRabQ"
      }
    }
  ]
}

profile.json

{
  "@context": [
    "https://w3id.org/openbadges/v2",
    "https://w3id.org/blockcerts/v3"
  ],
  "id": "https://blockcerts-20230104.storage.googleapis.com/profile.json",
  "type": "Profile",
  "name": "Lorem Ipsum Co. Ltd.",
  "url": "https://www.loremipsum.co.jp",
  "email": "blockcerts@loremipsum.co.jp",
  "publicKey": [
    {
      "id": "ecdsa-koblitz-pubkey:0x063Eae33729EdB89FaadFDe5c813d4A06d176E4c"
    },
    {
      "id": "ecdsa-koblitz-pubkey:n3hWq46tuvfRzBffsMwB92Gxa4ULA9xgF1"
    }
  ]
}

追加し終わったら Terraform で反映する

terraform apply

my_certificate.json の issuer と conf.ini の verification_method は変更の必要なし

とりあえずこの状態で検証してみる

DID と IssuerProfile を更新する前はそもそも検証画面に進まなかった

verificationMethod（#key-2）が無かったので当り前

#key-2 を指定してやってみたがダメだった

ちなみに my_certificate.json の内容は下記のような感じ

my_certificate.json

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://w3id.org/blockcerts/v3"
  ],
  "id": "urn:uuid:bbba8553-8ec1-445f-82c9-a57251dd731c",
  "type": ["VerifiableCredential", "BlockcertsCredential"],
  "issuer": "did:web:blockcerts-20230104.storage.googleapis.com",
  "issuanceDate": "2023-01-04T00:00:00Z",
  "credentialSubject": { "id": "did:example:ebfeb1f712ebc6f1c276e12ec21" },
  "proof": {
    "type": "MerkleProof2019",
    "created": "2023-01-11T09:59:26.518465",
    "proofValue": "zMcm4LfQFUZkWZxqxWNu9NK6WA45DaLfMFW1ST2qmvgncHQLwNt4EcFX4DXXx9NmXUSkZAXaY7KF5ftiJQwWabQdnpKRLxduM9xHBXeaKuaoGXJwPcEpDE12pc3WUwqPDT2Yi7MnivtKYyFKwtzkWvBNtXn3GekykgEydVoYRPiUkh5XgJJvnAoNMUptQtWMCnbwwcJTcY9d2JJwLPHHBQ7jcvXUik9D4i9MLAduGAM1cecqdWUyzNNeQQGiTwfKLrpxMo85ajQTS7fgPYx33m9M2BQtgAe2mH7vkZGaR9A2GdBkGTZ",
    "proofPurpose": "assertionMethod",
    "verificationMethod": "did:web:blockcerts-20230104.storage.googleapis.com#key-2"
  }
}

もしかして JWK が間違っている?

address2.ts と convert2.js を編集する

address2.ts

import { networks, payments } from "bitcoinjs-lib";
import ECPairFactory from "ecpair";
import * as ecc from "tiny-secp256k1";

function main() {
  const ECPair = ECPairFactory(ecc);
  const keyPair = ECPair.fromWIF(
    require("./address.json").wif,
    networks.testnet
  );

  const payment = payments.p2pkh({
    pubkey: keyPair.publicKey,
    network: networks.testnet,
  });

  const wif = keyPair.toWIF();
  const privateKeyHex = keyPair.privateKey!.toString("hex");
  const address = payment.address!;

  console.log(JSON.stringify({ wif, privateKeyHex, address }, null, 2));
}

main();

convert2.js

const keyto = require("@trust/keyto");

if (require.main === module) {
  main();
}

function main() {
  const { privateKeyHex } = require("./address2.json");
  const key = keyto.from(privateKeyHex, "blk");
  const jwk = key.toJwk("public");

  console.log(JSON.stringify(jwk, null, 2));
}

npx ts-node address2.ts > address2.json
node convert2.js > convert2.json

実行結果

{
  "kty": "EC",
  "crv": "K-256",
  "x": "1LFTgjc9qfqj0PHkil2-wINvMFGwSOpfgOe0z_8u9AI",
  "y": "0ugnwVtUcLzj54pFKr-inSeQg8CNLU8tFxALcClC8WQ"
}

違うものが出てきた

これを DID にコピー＆ペーストする

did.json

{
  "@context": ["https://www.w3.org/ns/did/v1"],
  "id": "did:web:blockcerts-20230104.storage.googleapis.com",
  "service": [
    {
      "id": "#issuer-profile",
      "type": "IssuerProfile",
      "serviceEndpoint": "https://blockcerts-20230104.storage.googleapis.com/profile.json"
    }
  ],
  "verificationMethod": [
    {
      "id": "#key-1",
      "controller": "did:web:blockcerts-20230104.storage.googleapis.com",
      "type": "EcdsaSecp256k1VerificationKey2019",
      "publicKeyJwk": {
        "kty": "EC",
        "crv": "K-256",
        "x": "oTj4PkPzlNowto09OpAU0BVJ6DJc2vg_lFoW9wiZ60A",
        "y": "D9VaE9hbsOagGab_0euWcNUaCDphfBPg-C_aWD7npx4"
      }
    },
    {
      "id": "#key-2",
      "controller": "did:web:blockcerts-20230104.storage.googleapis.com",
      "type": "EcdsaSecp256k1VerificationKey2019",
      "publicKeyJwk": {
        "kty": "EC",
        "crv": "K-256",
        "x": "1LFTgjc9qfqj0PHkil2-wINvMFGwSOpfgOe0z_8u9AI",
        "y": "0ugnwVtUcLzj54pFKr-inSeQg8CNLU8tFxALcClC8WQ"
      }
    }
  ]
}

Terraform で反映

terraform apply

反映されたか確認する

これでどうだ

やったぜ！

Verify again リンクをクリックすると失敗するのでページをリロードした方が良い

なぜかファイルを選択できなくなったのでブラウザを再起動したらうまくいった

もらった tBTC を忘れずに返却する

BitPay を使おうとしたけどかえって面倒そうだったのでプログラムを書くことにする

send.ts

import { networks, payments, Psbt } from "bitcoinjs-lib";
import ECPairFactory from "ecpair";
import * as ecc from "tiny-secp256k1";

const utxoHash =
  "6c5fd0c1b240831fbc1e94490473491dd30db586d44c3cb4d19c61af98ff7d68";
const utxoIndex = 0;
const utxoTransactionHex =
  "01000000014c9506f38f00c4d94d7e4e1e4b20b72be2d21ed3381e22ddc0584f5e3a6fbbf2000000006a4730440220292c73f9e9e89d4ccf0dc375b7bed97e2b72217ebfb2f3b57802b9f696d42b3b02201ab9bfae6f53d24cab2fcbce259545caeb564dfda3df43c5ec71e11f8cb834ec012102d4b15382373da9faa3d0f1e48a5dbec0836f3051b048ea5f80e7b4cfff2ef402ffffffff029f724d00000000001976a914f35215d5229ffc68566b939af5ee401874198afd88ac0000000000000000226a20532bbb70882b4186eeaaf427db152546194ea5463f415d15db5e7d0320a8223800000000";
const utxoValue = 0.05075615e8;
const transactionFee = 200;

function main() {
  const ECPair = ECPairFactory(ecc);
  const keyPair = ECPair.fromWIF(
    require("./address.json").wif,
    networks.testnet
  );

  const psbt = new Psbt({ network: networks.testnet });

  psbt.addInput({
    hash: utxoHash,
    index: utxoIndex,
    nonWitnessUtxo: Buffer.from(utxoTransactionHex, "hex"),
  });

  const payment = payments.p2pkh({
    address: "mv4rnyY3Su5gjcDNzbMLKBQkBicCtHUtFB",
    network: networks.testnet,
  });

  psbt.addOutput({
    script: payment.output!,
    value: utxoValue - transactionFee,
  });

  psbt.signInput(0, keyPair);
  psbt.finalizeAllInputs();

  process.stdout.write(psbt.extractTransaction().toHex());
}

main();

utxoHash がわかれば utxoIndex, utxoValue は Blockstream の Explorer で調べることができる

トランザクション生データの16進数文字列は Blockstream の API を使って調べることができる

transactionFee はそのままで OK（手数料は 1 satoshi/vbyte を想定しています）

下記のコマンドを実行して生トランザクションを出力する

npx ts-node send.tx > send.txt

出力したトランザクションを Blockstream の API を使って送信する

curl \
  -X POST \
  -H 'Content-Type: text/plain' \
  --data-binary @send.txt \
  https://blockstream.info/testnet/api/tx

送信に成功するとトランザクション ID が表示される

182cdb9bacba5f2feaab7aff9a6b06069dbc00481768e5a238d96df6cd76e914

トランザクションを Explorer で確認してみる

アドレスの残高を調べるのは BlockCypher の方が便利