listbucket.js

const crypto = require("crypto");

const accessKey = "YOUR_ACCESS_KEY";
const secretKey = "YOUR_SECRET_KEY";
const region = "YOUR_REGION";
const service = "s3";
const host = "YOUR_NAMESPACE.compat.objectstorage.YOUR_REGION.oraclecloud.com";
const endpoint = `https://${host}/`;

function hmac(key, data, encoding) {
  return crypto.createHmac("sha256", key).update(data, "utf8").digest(encoding);
}

function sha256(data, encoding = "hex") {
  return crypto.createHash("sha256").update(data, "utf8").digest(encoding);
}

function getSignatureKey(key, dateStamp, regionName, serviceName) {
  const kDate = crypto.createHmac("sha256", "AWS4" + key).update(dateStamp).digest();
  const kRegion = crypto.createHmac("sha256", kDate).update(regionName).digest();
  const kService = crypto.createHmac("sha256", kRegion).update(serviceName).digest();
  const kSigning = crypto.createHmac("sha256", kService).update("aws4_request").digest();
  return kSigning;
}

async function listBuckets() {
  const now = new Date();

  const amzDate = now.toISOString().replace(/[:-]|\.\d{3}/g, ""); // YYYYMMDDTHHMMSSZ
  const dateStamp = amzDate.slice(0, 8);

  const method = "GET";
  const canonicalUri = "/";
  const canonicalQueryString = "";
  const payload = "";
  const payloadHash = sha256(payload);

  const canonicalHeaders =
    `host:${host}\n` +
    `x-amz-content-sha256:${payloadHash}\n` +
    `x-amz-date:${amzDate}\n`;

  const signedHeaders = "host;x-amz-content-sha256;x-amz-date";

  const canonicalRequest =
    `${method}\n` +
    `${canonicalUri}\n` +
    `${canonicalQueryString}\n` +
    `${canonicalHeaders}\n` +
    `${signedHeaders}\n` +
    `${payloadHash}`;

  const algorithm = "AWS4-HMAC-SHA256";
  const credentialScope = `${dateStamp}/${region}/${service}/aws4_request`;
  const stringToSign =
    `${algorithm}\n` +
    `${amzDate}\n` +
    `${credentialScope}\n` +
    `${sha256(canonicalRequest)}`;

  const signingKey = getSignatureKey(secretKey, dateStamp, region, service);
  const signature = crypto
    .createHmac("sha256", signingKey)
    .update(stringToSign, "utf8")
    .digest("hex");

  const authorizationHeader =
    `${algorithm} ` +
    `Credential=${accessKey}/${credentialScope}, ` +
    `SignedHeaders=${signedHeaders}, ` +
    `Signature=${signature}`;

  const response = await fetch(endpoint, {
    method: "GET",
    headers: {
      "x-amz-date": amzDate,
      "x-amz-content-sha256": payloadHash,
      "Authorization": authorizationHeader,
    },
  });

  const text = await response.text();
  console.log("status:", response.status);
  console.log(text);
}

listBuckets().catch(console.error);