HMAC

Hash-based message authentication codes (HMACs), are a type of message authentication code (MAC) that use cryptographic hash functions and a secret key. They function as a kind of digital signature of data integrity and authenticity. HMACs use symmetric keys. The key used to sign a message is the same as is used to verify the authenticity and integrity of the message.

Algorithms

We support HMAC-SHA1, HMAC-SHA256, HMAC-SHA384, and HMAC-SHA512.

API

There are two basic functions provided: sign and verify.

For any message m and key k, we have that verify(m, sign(m, k), k) == true.

Both sign and verify are implemented in terms of String (provided you specify a Charset) and Byte.

String Example

import java.nio.charset.StandardCharsets._

object Example extends zio.App {
  override def run(args: List[String]) = (for {
    k        <- HMAC.genKey(HMACSHA256)
    hmac     <- HMAC.sign(m, k, US_ASCII)
    verified <- HMAC.verify(m, hmac, k, US_ASCII)
  } yield verified).exitCode
    .provideCustomLayer(HMAC.live)
}

Byte Example

object Example extends zio.App {
  override def run(args: List[String]) = (for {
    m        <- SecureRandom.nextBytes(10)
    k        <- HMAC.genKey(HMACSHA256)
    hmac     <- HMAC.sign(m1, k)
    verified <- HMAC.verify(m0, hmac, k)
  } yield verified).exitCode
    .provideCustomLayer(HMAC.live ++ SecureRandom.live.orDie)
}