├── .gitignore ├── .scalafix.conf ├── .scalafmt.conf ├── LICENSE ├── README.md ├── Scala-README.md ├── build.sbt ├── generate-totp.sh ├── project ├── LibraryDependencies.scala ├── build.properties └── plugins.sbt ├── repository.yaml ├── run_all_tests.sh ├── scalastyle-config.xml └── src ├── main └── scala │ └── uk │ └── gov │ └── hmrc │ └── totp │ ├── JavaToptSha512Generator.scala │ ├── JavaTotpGenerator.scala │ ├── JavaTotpSha1Generator.scala │ └── TotpGenerator.scala └── test └── scala └── uk └── gov └── hmrc └── totp └── TotpGeneratorSpec.scala /.gitignore: -------------------------------------------------------------------------------- 1 | .* 2 | !.gitignore 3 | !.scalafmt.conf 4 | !.scalafix.conf 5 | 6 | logs 7 | project/project 8 | project/target 9 | project/metals.sbt 10 | target 11 | lib_managed 12 | tmp 13 | .history 14 | dist 15 | /*.iml 16 | /*.ipr 17 | /out 18 | /RUNNING_PID 19 | *.iws 20 | 21 | -------------------------------------------------------------------------------- /.scalafix.conf: -------------------------------------------------------------------------------- 1 | rules = [ 2 | OrganizeImports 3 | ] 4 | 5 | OrganizeImports { 6 | blankLines = Manual 7 | coalesceToWildcardImportThreshold = 5 8 | expandRelative = true 9 | groupExplicitlyImportedImplicitsSeparately = false 10 | groupedImports = Merge 11 | groups = [ 12 | "re:(javax?|scala)\\." 13 | "---" 14 | "*" 15 | "---" 16 | "uk.gov.hmrc." 17 | "---" 18 | "uk.gov.hmrc.totp." 19 | ] 20 | importSelectorsOrder = Ascii 21 | importsOrder = Ascii 22 | preset = DEFAULT 23 | removeUnused = true 24 | } -------------------------------------------------------------------------------- /.scalafmt.conf: -------------------------------------------------------------------------------- 1 | version="3.5.3" 2 | runner.dialect = "scala213" 3 | 4 | maxColumn = 180 5 | 6 | assumeStandardLibraryStripMargin = true 7 | align.stripMargin = true 8 | 9 | align.preset = most 10 | align.multiline = true 11 | 12 | indent.extendSite = 4 13 | indent.defnSite = 4 14 | 15 | align.arrowEnumeratorGenerator = true 16 | 17 | align.closeParenSite = true 18 | align.openParenCallSite = false 19 | align.openParenDefnSite = false 20 | align.openParenCtrlSite = false 21 | 22 | danglingParentheses.defnSite = true 23 | danglingParentheses.callSite = true 24 | danglingParentheses.exclude = [] 25 | 26 | newlines.source = keep 27 | newlines.topLevelStatements = [before] 28 | newlines.alwaysBeforeMultilineDef = false 29 | newlines.implicitParamListModifierPrefer = before 30 | # newlines.implicitParamListModifierForce = [before] 31 | newlines.avoidForSimpleOverflow = [tooLong, punct, slc] 32 | 33 | rewrite.rules = [SortModifiers] 34 | rewrite.rules = [AsciiSortImports] 35 | 36 | verticalMultiline.atDefnSite = true 37 | verticalMultiline.newlineAfterOpenParen = true 38 | 39 | includeNoParensInSelectChains = true -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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We also recommend that a 185 | file or class name and description of purpose be included on the 186 | same "printed page" as the copyright notice for easier 187 | identification within third-party archives. 188 | 189 | Copyright [yyyy] [name of copyright owner] 190 | 191 | Licensed under the Apache License, Version 2.0 (the "License"); 192 | you may not use this file except in compliance with the License. 193 | You may obtain a copy of the License at 194 | 195 | http://www.apache.org/licenses/LICENSE-2.0 196 | 197 | Unless required by applicable law or agreed to in writing, software 198 | distributed under the License is distributed on an "AS IS" BASIS, 199 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 200 | See the License for the specific language governing permissions and 201 | limitations under the License. 202 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # TOTP generator for HMRC API Platform 2 | 3 | **IMPORTANT**: These examples are built for testing purposes only, it is not intended to be part of a production stack. 4 | 5 | * [Scala](Scala-README.md) 6 | * [Python](https://github.com/hmrc/totp-generator-python/blob/main/README.md) 7 | * [Java](https://github.com/hmrc/totp-generator-java/blob/main/README.md) 8 | 9 | ## Useful links: 10 | 11 | * [HMAC](https://en.wikipedia.org/wiki/Hash-based_message_authentication_code) 12 | * [TOTP algorithm](https://en.wikipedia.org/wiki/Time-based_One-time_Password_Algorithm) 13 | * [TOTP algorithm specifications](https://tools.ietf.org/html/rfc6238) 14 | * [TOTP algorithm Java implementation](https://tools.ietf.org/html/rfc6238#appendix-A) 15 | * [HOTP algorithm specifications](https://tools.ietf.org/html/rfc4226) 16 | 17 | The library is designed as a dependency for API Platform services and is subject to significant change without notice. 18 | -------------------------------------------------------------------------------- /Scala-README.md: -------------------------------------------------------------------------------- 1 | # Scala TOTP generator for HMRC API Platform 2 | 3 | ## Requirements 4 | 5 | * [sbt](https://www.scala-sbt.org/) 6 | * JDK 8 (newer versions should work but have not been tested) 7 | 8 | ## Usage 9 | 10 | To generate an 8 digit TOTP code using the TOTP secret `ABCDEFGHIJKLMNOP` 11 | ``` 12 | ./generate-totp.sh ABCDEFGHIJKLMNOP 13 | ``` 14 | 15 | The output will look like: 16 | ``` 17 | TOTP: 38079726 18 | ``` 19 | This is showing: 20 | * the TOTP code for now. This can be used to generate an OAuth access token. 21 | 22 | ## Attribution 23 | 24 | The code in this project is based on Mark Lister's project [Scala TOTP Auth](https://github.com/marklister/scala-totp-auth) 25 | 26 | ## License 27 | 28 | This code is open source software licensed under the [Apache 2.0 License]("http://www.apache.org/licenses/LICENSE-2.0.html"). 29 | -------------------------------------------------------------------------------- /build.sbt: -------------------------------------------------------------------------------- 1 | import sbt._ 2 | import sbt.Keys._ 3 | import uk.gov.hmrc.versioning.SbtGitVersioning.autoImport.majorVersion 4 | 5 | lazy val appName = "totp-generator" 6 | 7 | scalaVersion := "2.13.12" 8 | 9 | ThisBuild / libraryDependencySchemes += "org.scala-lang.modules" %% "scala-xml" % VersionScheme.Always 10 | ThisBuild / semanticdbEnabled := true 11 | ThisBuild / semanticdbVersion := scalafixSemanticdb.revision 12 | 13 | lazy val microservice = Project(appName, file(".")) 14 | .disablePlugins(JUnitXmlReportPlugin) 15 | .settings( 16 | majorVersion := 0, 17 | isPublicArtefact := true, 18 | libraryDependencies ++= LibraryDependencies.compile ++ LibraryDependencies.test 19 | ) 20 | 21 | commands ++= Seq( 22 | Command.command("run-all-tests") { state => "test" :: state }, 23 | 24 | Command.command("clean-and-test") { state => "clean" :: "compile" :: "run-all-tests" :: state }, 25 | 26 | // Coverage does not need compile ! 27 | Command.command("pre-commit") { state => "clean" :: "scalafmtAll" :: "scalafixAll" :: "coverage" :: "run-all-tests" :: "coverageOff" :: "coverageAggregate" :: state } 28 | ) -------------------------------------------------------------------------------- /generate-totp.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | if [ ! -f target/scala-2.13/totp-generator-assembly-*.jar ]; then 4 | echo "NOTE target/scala-2.13/totp-generator-assembly-*.jar does not exist, building it with sbt" 5 | sbt clean assembly 6 | fi 7 | 8 | java -cp target/scala-2.13/totp-generator-assembly-*.jar uk.gov.hmrc.totp.TotpGenerator $1 9 | 10 | -------------------------------------------------------------------------------- /project/LibraryDependencies.scala: -------------------------------------------------------------------------------- 1 | import sbt._ 2 | 3 | object LibraryDependencies { 4 | 5 | val compile: Seq[ModuleID] = Seq( 6 | "commons-codec" % "commons-codec" % "1.16.0" 7 | ) 8 | 9 | val test: Seq[ModuleID] = Seq( 10 | "org.scalatest" %% "scalatest" % "3.2.17", 11 | "com.vladsch.flexmark" % "flexmark-all" % "0.62.2", 12 | "org.pegdown" % "pegdown" % "1.5.0" 13 | ).map(_ % Test) 14 | } 15 | -------------------------------------------------------------------------------- /project/build.properties: -------------------------------------------------------------------------------- 1 | sbt.version=1.9.9 2 | -------------------------------------------------------------------------------- /project/plugins.sbt: -------------------------------------------------------------------------------- 1 | resolvers += "HMRC-open-artefacts-maven" at "https://open.artefacts.tax.service.gov.uk/maven2" 2 | resolvers += Resolver.url("HMRC-open-artefacts-ivy", url("https://open.artefacts.tax.service.gov.uk/ivy2"))(Resolver.ivyStylePatterns) 3 | 4 | addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "2.1.5") 5 | addSbtPlugin("uk.gov.hmrc" % "sbt-auto-build" % "3.22.0") 6 | addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.0.9") 7 | addSbtPlugin("org.scalastyle" %% "scalastyle-sbt-plugin" % "1.0.0") 8 | addSbtPlugin("ch.epfl.scala" % "sbt-bloop" % "1.5.11") 9 | addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.2") 10 | addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.11.1") 11 | 12 | ThisBuild / libraryDependencySchemes += "org.scala-lang.modules" %% "scala-xml" % VersionScheme.Always 13 | -------------------------------------------------------------------------------- /repository.yaml: -------------------------------------------------------------------------------- 1 | repoVisibility: public_0C3F0CE3E6E6448FAD341E7BFA50FCD333E06A20CFF05FCACE61154DDBBADF71 2 | -------------------------------------------------------------------------------- /run_all_tests.sh: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env bash 2 | sbt pre-commit 3 | -------------------------------------------------------------------------------- /scalastyle-config.xml: -------------------------------------------------------------------------------- 1 | 2 | Scalastyle standard configuration 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | -------------------------------------------------------------------------------- /src/main/scala/uk/gov/hmrc/totp/JavaToptSha512Generator.scala: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 HM Revenue & Customs 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package uk.gov.hmrc.totp 18 | 19 | class JavaTotpSha512Generator extends TotpSha512 20 | -------------------------------------------------------------------------------- /src/main/scala/uk/gov/hmrc/totp/JavaTotpGenerator.scala: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 HM Revenue & Customs 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package uk.gov.hmrc.totp 18 | 19 | class JavaTotpGenerator extends TotpSha512 20 | -------------------------------------------------------------------------------- /src/main/scala/uk/gov/hmrc/totp/JavaTotpSha1Generator.scala: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 HM Revenue & Customs 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package uk.gov.hmrc.totp 18 | 19 | class JavaTotpSha1Generator extends TotpSha1 20 | -------------------------------------------------------------------------------- /src/main/scala/uk/gov/hmrc/totp/TotpGenerator.scala: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 HM Revenue & Customs 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package uk.gov.hmrc.totp 18 | 19 | import java.security.Key 20 | import javax.crypto.Mac 21 | import javax.crypto.spec.SecretKeySpec 22 | import scala.concurrent.duration._ 23 | import scala.math._ 24 | 25 | import org.apache.commons.codec.binary.Base32 26 | 27 | sealed trait CryptoAlgorithm 28 | case object HmacSHA512 extends CryptoAlgorithm 29 | case object HmacSHA1 extends CryptoAlgorithm 30 | 31 | trait HmacShaTotp { 32 | 33 | def totpTimeInterval: FiniteDuration 34 | def codeLength: Int 35 | def crypto: CryptoAlgorithm 36 | 37 | final def getTotpCode(secret: String): String = { 38 | getTotp(secret, System.currentTimeMillis()) 39 | } 40 | 41 | final def getTotp(secret: String, totpGenerationTimeInMillis: Long): String = { 42 | val timeWindow = totpGenerationTimeInMillis / totpTimeInterval.toMillis 43 | 44 | val msg: Array[Byte] = BigInt(timeWindow).toByteArray.reverse.padTo(8, 0.toByte).reverse 45 | 46 | val hash = hmacSha(crypto.toString, new Base32().decode(secret), msg) 47 | val offset: Int = hash(hash.length - 1) & 0xf 48 | val binary: Long = ((hash(offset) & 0x7f) << 24) | 49 | ((hash(offset + 1) & 0xff) << 16) | 50 | ((hash(offset + 2) & 0xff) << 8 | 51 | (hash(offset + 3) & 0xff)) 52 | 53 | val otp: Long = binary % pow(10, codeLength).toLong 54 | 55 | ("0" * codeLength + otp.toString).takeRight(codeLength) 56 | } 57 | 58 | private def hmacSha(crypto: String, keyBytes: Array[Byte], text: Array[Byte]): Array[Byte] = { 59 | val hmac: Mac = Mac.getInstance(crypto) 60 | val macKey: Key = new SecretKeySpec(keyBytes, "RAW") 61 | hmac.init(macKey) 62 | hmac.doFinal(text) 63 | } 64 | 65 | } 66 | 67 | trait TotpSha512 extends HmacShaTotp { 68 | final override val totpTimeInterval = 30.seconds 69 | final override val codeLength = 8 70 | final override val crypto = HmacSHA512 71 | } 72 | 73 | trait TotpSha1 extends HmacShaTotp { 74 | final override val totpTimeInterval = 30.seconds 75 | final override val codeLength = 6 76 | final override val crypto = HmacSHA1 77 | } 78 | 79 | trait Totp extends TotpSha512 80 | 81 | object TotpGenerator extends Totp with App { 82 | if (args.length < 1) println("Secret is missing.") 83 | else println("TOTP: " + getTotpCode(args(0))) 84 | } 85 | 86 | object TotpSha1Generator extends TotpSha1 with App { 87 | if (args.length < 1) println("Secret is missing.") 88 | else println("TOTP: " + getTotpCode(args(0))) 89 | } 90 | -------------------------------------------------------------------------------- /src/test/scala/uk/gov/hmrc/totp/TotpGeneratorSpec.scala: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 HM Revenue & Customs 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package uk.gov.hmrc.totp 18 | 19 | import java.text.SimpleDateFormat 20 | 21 | import org.scalatest.funspec.AnyFunSpec 22 | import org.scalatest.matchers.should.Matchers 23 | 24 | class TotpGeneratorSpec extends AnyFunSpec with Matchers { 25 | 26 | private val secret: String = "-TOTP-SECRET-12345-" 27 | 28 | private val dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS") 29 | 30 | private val window1_time1 = dateFormat.parse("2016-12-12 09:45:00.001").getTime 31 | private val window1_time2 = dateFormat.parse("2016-12-12 09:45:29.999").getTime 32 | private val window2_time1 = dateFormat.parse("2016-12-12 09:45:30.000").getTime 33 | private val window2_time2 = dateFormat.parse("2016-12-12 09:45:59.999").getTime 34 | 35 | private val window1_totpCode1 = TotpGenerator.getTotp(secret, window1_time1) 36 | private val window1_totpCode2 = TotpGenerator.getTotp(secret, window1_time2) 37 | private val window2_totpCode1 = TotpGenerator.getTotp(secret, window2_time1) 38 | private val window2_totpCode2 = TotpGenerator.getTotp(secret, window2_time2) 39 | 40 | describe("TOTP generator") { 41 | it("should generate a different TOTP code for each 30 seconds window") { 42 | window1_totpCode1 should not equal window2_totpCode1 43 | window1_totpCode1 should not equal window2_totpCode2 44 | 45 | window1_totpCode2 should not equal window2_totpCode1 46 | window1_totpCode2 should not equal window2_totpCode2 47 | } 48 | 49 | it("should generate the same TOTP code in the same 30 seconds window") { 50 | window1_totpCode1 shouldBe window1_totpCode2 51 | window2_totpCode1 shouldBe window2_totpCode2 52 | } 53 | } 54 | 55 | describe("TOTP generator using SHA1") { 56 | 57 | val sha1_totpCode = TotpSha1Generator.getTotp(secret, window1_time1) 58 | val sha512_totpCode = TotpGenerator.getTotp(secret, window1_time1) 59 | 60 | it("should generate a different TOTP code than SHA512") { 61 | sha1_totpCode should not equal sha512_totpCode 62 | } 63 | } 64 | } 65 | --------------------------------------------------------------------------------