digest4s

A set of utilities for generating digests and handling binary codecs in Scala. Built on top of Apache Commons Codec.

Getting started

Add the following to your build.sbt file. The latest version of the library should be in the Maven badge above. Otherwise you can checkout the artefact listing on mvnrepository.com.

libraryDependencies +="au.id.tmm.digest4s"%%"digest4s-core"%"1.0.0"

The simplest way to use the library is with the syntax import:

importau.id.tmm.digest4s.syntax._

Binary codec utilities

Parsing bytes from encoded strings

importau.id.tmm.digest4s.binarycodecs.syntax._importorg.apache.commons.codec.DecoderExceptionimportscala.collection.immutable.ArraySeq// Parse binary encoded Strings safelyvalbyteArray:Either[DecoderException, ArraySeq[Byte]] ="VXQ2DXQ=".parseBase32
valbyteArray:Either[DecoderException, ArraySeq[Byte]] ="reGh3g==".parseBase64
valbyteArray:Either[DecoderException, ArraySeq[Byte]] ="11011110101000011110000110101101".parseBinary
valbyteArray:Either[DecoderException, ArraySeq[Byte]] ="ADE1A1DE".parseHex
// Parse unsafely, throw if encoding is invalid:valbyteArray:ArraySeq[Byte] ="VXQ2DXQ=".parseBase32OrThrow
valbyteArray:ArraySeq[Byte] ="reGh3g==".parseBase64OrThrow
valbyteArray:ArraySeq[Byte] ="11011110101000011110000110101101".parseBinaryOrThrow
valbyteArray:ArraySeq[Byte] ="ADE1A1DE".parseHexOrThrow
// Use StringContext (throws if invalid)valbyteArray:ArraySeq[Byte] =base32"VXQ2DXQ="valbyteArray:ArraySeq[Byte] =base64"reGh3g=="valbyteArray:ArraySeq[Byte] =binary"11011110101000011110000110101101"valbyteArray:ArraySeq[Byte] =hex"ADE1A1DE"

Encoding bytes into string representations

importau.id.tmm.digest4s.binarycodecs.syntax._importscala.collection.immutable.ArraySeq// Encode bytes to Stringvalbytes:Array[Byte] =Array[Byte](0xad.toByte, 0xe1.toByte, 0xa1.toByte, 0xde.toByte)
bytes.asBase32String // "VXQ2DXQ="
bytes.asBase64String // "reGh3g=="
bytes.asBinaryString // "11011110101000011110000110101101"
bytes.asHexString // "ADE1A1DE"// Can be used for different collection types
bytes.to(ArraySeq).asHexString // "ADE1A1DE"
bytes.toVector.asHexString // "ADE1A1DE"
bytes.toList.asHexString // "ADE1A1DE"

Digest utilities

Digest value classes

There are a number of value classes in the au.id.tmm.digest4s.digest package which can improve the semantic clarity of checksum fields:

importau.id.tmm.digest4s.digest._caseclassDocument(
checksum: Array[Byte], // 🤷 Bad, not clear what the algorithm is
)
caseclassDocument(
checksum: MD5Digest, // 😎 Clearer, describes the algorithm
)

Computing digests

importjava.io.IOExceptionimportau.id.tmm.digest4s.digest._importau.id.tmm.digest4s.digest.syntax._// Compute digests for safe typesvalmd5Digest:MD5Digest="Hello".md5
valsha256Digest:SHA256Digest=Array[Byte](0xad.toByte, 0xe1.toByte, 0xa1.toByte, 0xde.toByte).sha256
valsha512Digest:SHA512Digest=List[Byte](0xad.toByte, 0xe1.toByte, 0xa1.toByte, 0xde.toByte).sha512
// Compute digests for types where you might hit an IOException:valmd5Digest:Either[IOException, MD5Digest] = java.nio.file.Paths.get("test").md5OrError