Cryptographic Failures in Fiber with Dynamodb

Cryptographic failures occur when data is not adequately protected in transit or at rest. In a Fiber application using Amazon DynamoDB as the persistence layer, the risk arises from mishandling sensitive fields such as passwords, API keys, or PII before items are written to DynamoDB, or from trusting data returned from DynamoDB as already verified. Fiber’s minimal defaults and high performance can encourage developers to skip explicit validation or encryption steps, especially when integrating with DynamoDB’s key–value store model.

One common pattern is storing user credentials directly in a DynamoDB item without applying a strong, adaptive hashing mechanism. For example, saving a plaintext password or a weakly hashed password in an attribute like user.password means that anyone who gains read access to the table—through over-permissive IAM policies, accidental exposure of backups, or an SSRF leading to DynamoDB credential theft—can recover credentials easily. Similarly, encryption keys managed in application code or stored alongside data in DynamoDB can be extracted if the item itself is exposed via an insecure endpoint.

Data in transit between Fiber and DynamoDB is typically protected by TLS when using the AWS SDK, but developers sometimes disable verification or use custom HTTP clients that weaken this protection. Additionally, if the application caches sensitive query results in logs, error messages, or middleware responses, the cryptographic boundary is effectively bypassed. The combination of Fiber’s fast request handling and DynamoDB’s low-latency responses can inadvertently encourage shortcuts like logging raw request bodies that contain secrets, or returning raw DynamoDB item structures to clients without redaction.

Compliance mappings such as OWASP API Top 10 (2023) A02:2023 – Cryptographic Failures, and standards like PCI-DSS and SOC 2, highlight the need for strong encryption and proper key management. In this context, a middleBrick scan can detect whether endpoints that interact with DynamoDB leak sensitive data or accept weak cryptographic practices, providing prioritized findings with severity and remediation guidance.

To mitigate cryptographic failures in Fiber with DynamoDB, apply strong hashing for credentials, enforce encryption for sensitive fields, and ensure that data sent to and from DynamoDB is handled securely within your route logic.

• Use bcrypt to hash passwords before storing them in DynamoDB. Never store plaintext or weakly hashed passwords.
• Encrypt sensitive attributes at the application layer before writing to DynamoDB, and decrypt after reading, using a key managed outside the data store.
• Validate and sanitize all inputs before using them in DynamoDB queries to prevent injection and over-fetching.
• Avoid returning raw DynamoDB item representations to API consumers; instead, construct lean response objects that exclude sensitive fields.

Example: Secure user registration and retrieval with bcrypt and DynamoDB DocumentClient in Fiber:

const { DynamoDBDocumentClient, PutCommand, GetCommand } = require("@aws-sdk/lib-dynamodb");
const { DynamoDB } = require("@aws-sdk/client-dynamodb");
const bcrypt = require("bcrypt");
const express = require("fastify")(); // Using fastify/fiber-like pattern

const client = new DynamoDB({ region: "us-east-1" });
const ddbDocClient = DynamoDBDocumentClient.from(client);

// Register a new user with a hashed password
express.post("/register", async (req, reply) => {
  const { username, password } = req.body;
  if (!username || !password) {
    return reply.code(400).send({ error: "username and password are required" });
  }
  const hashedPassword = await bcrypt.hash(password, 12);
  const params = {
    TableName: "Users",
    Item: {
      username,
      password: hashedPassword,
      createdAt: new Date().toISOString(),
    },
  };
  await ddbDocClient.send(new PutCommand(params));
  return reply.code(201).send({ message: "User registered" });
});

// Authenticate user by comparing hashed password
express.post("/login", async (req, reply) => {
  const { username, password } = req.body;
  const getParams = {
    TableName: "Users",
    Key: { username },
  };
  const { Item } = await ddbDocClient.send(new GetCommand(getParams));
  if (!Item) {
    return reply.code(401).send({ error: "Invalid credentials" });
  }
  const match = await bcrypt.compare(password, Item.password);
  if (!match) {
    return reply.code(401).send({ error: "Invalid credentials" });
  }
  // Return only non-sensitive data
  return reply.send({ username: Item.username, email: Item.email });
});

In this example, passwords are hashed with bcrypt before being stored in DynamoDB, and sensitive fields are omitted from API responses. Ensure that IAM policies granting access to DynamoDB follow least privilege, and avoid logging raw request or response bodies that may contain secrets.