Allow disabling length checks in `EmailAddressParser` (c96d0ce6) · Commits · e / os / Mail

core/common/src/main/kotlin/app/k9mail/core/common/mail/EmailAddress.kt

+26 −0

Original line number	Diff line number	Diff line
		package app.k9mail.core.common.mail

		// See RFC 5321, 4.5.3.1.3.
		// The maximum length of 'Path' indirectly limits the length of 'Mailbox'.
		internal const val MAXIMUM_EMAIL_ADDRESS_LENGTH = 254

		// See RFC 5321, 4.5.3.1.1.
		internal const val MAXIMUM_LOCAL_PART_LENGTH = 64

		/**
		* Represents an email address.
		*
		@@ -15,6 +22,14 @@ class EmailAddress internal constructor(

		init {
		warnings = buildSet {
		if (localPart.length > MAXIMUM_LOCAL_PART_LENGTH) {
		add(Warning.LocalPartExceedsLengthLimit)
		}

		if (address.length > MAXIMUM_EMAIL_ADDRESS_LENGTH) {
		add(Warning.EmailAddressExceedsLengthLimit)
		}

		if (localPart.isEmpty()) {
		add(Warning.EmptyLocalPart)
		}
		@@ -65,6 +80,17 @@ class EmailAddress internal constructor(
		}

		enum class Warning {
		/**
		* The local part exceeds the length limit (see RFC 5321, 4.5.3.1.1.).
		*/
		LocalPartExceedsLengthLimit,

		/**
		* The email address exceeds the length limit (see RFC 5321, 4.5.3.1.3.; The maximum length of 'Path'
		* indirectly limits the length of 'Mailbox').
		*/
		EmailAddressExceedsLengthLimit,

		/**
		* The local part requires using a quoted string.
		*

core/common/src/main/kotlin/app/k9mail/core/common/mail/EmailAddressParser.kt

+7 −12

Original line number	Diff line number	Diff line
		@@ -13,13 +13,6 @@ import app.k9mail.core.common.mail.EmailAddressParserError.LocalPartRequiresQuot
		import app.k9mail.core.common.mail.EmailAddressParserError.QuotedStringInLocalPart
		import app.k9mail.core.common.mail.EmailAddressParserError.TotalLengthExceeded

		// See RFC 5321, 4.5.3.1.3.
		// The maximum length of 'Path' indirectly limits the length of 'Mailbox'.
		internal const val MAXIMUM_EMAIL_ADDRESS_LENGTH = 254

		// See RFC 5321, 4.5.3.1.1.
		internal const val MAXIMUM_LOCAL_PART_LENGTH = 64

		/**
		* Parse an email address.
		*
		@@ -52,10 +45,16 @@ internal class EmailAddressParser(
		parserError(ExpectedEndOfInput)
		}

		if (emailAddress.address.length > MAXIMUM_EMAIL_ADDRESS_LENGTH) {
		if (
		config.isEmailAddressLengthCheckEnabled && Warning.EmailAddressExceedsLengthLimit in emailAddress.warnings
		) {
		parserError(TotalLengthExceeded)
		}

		if (config.isLocalPartLengthCheckEnabled && Warning.LocalPartExceedsLengthLimit in emailAddress.warnings) {
		parserError(LocalPartLengthExceeded, position = input.lastIndexOf('@'))
		}

		if (
		!config.isLocalPartRequiringQuotedStringAllowed && Warning.QuotedStringInLocalPart in emailAddress.warnings
		) {
		@@ -96,10 +95,6 @@ internal class EmailAddressParser(
		}
		}

		if (localPart.length > MAXIMUM_LOCAL_PART_LENGTH) {
		parserError(LocalPartLengthExceeded)
		}

		return localPart
		}

core/common/src/main/kotlin/app/k9mail/core/common/mail/EmailAddressParserConfig.kt

+11 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,13 @@ package app.k9mail.core.common.mail
		/**
		* Configuration to control the behavior when parsing an email address into [EmailAddress].
		*
		* @param isLocalPartLengthCheckEnabled When this is `true` the length of the local part is checked to make sure it
		* doesn't exceed the specified limit (see RFC 5321, 4.5.3.1.1.).
		*
		* @param isEmailAddressLengthCheckEnabled When this is `true` the length of the whole email address is checked to make
		* sure it doesn't exceed the specified limit (see RFC 5321, 4.5.3.1.3.; The maximum length of 'Path' indirectly limits
		* the length of 'Mailbox').
		*
		* @param isQuotedLocalPartAllowed When this is `true`, the parsing step allows email addresses with a local part
		* encoded as quoted string, e.g. `"foo bar"@domain.example`. Otherwise, the parser will throw an
		* [EmailAddressParserException] as soon as a quoted string is encountered.
		@@ -24,12 +31,16 @@ package app.k9mail.core.common.mail
		* [isLocalPartRequiringQuotedStringAllowed] is `false`.
		*/
		data class EmailAddressParserConfig(
		val isLocalPartLengthCheckEnabled: Boolean,
		val isEmailAddressLengthCheckEnabled: Boolean,
		val isQuotedLocalPartAllowed: Boolean,
		val isLocalPartRequiringQuotedStringAllowed: Boolean,
		val isEmptyLocalPartAllowed: Boolean = false,
		) {
		companion object {
		val DEFAULT = EmailAddressParserConfig(
		isLocalPartLengthCheckEnabled = true,
		isEmailAddressLengthCheckEnabled = true,
		isQuotedLocalPartAllowed = true,
		isLocalPartRequiringQuotedStringAllowed = true,
		isEmptyLocalPartAllowed = false,

core/common/src/test/kotlin/app/k9mail/core/common/mail/EmailAddressParserTest.kt

+48 −4

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@ import app.k9mail.core.common.mail.EmailAddressParserError.UnexpectedCharacter
		import assertk.all
		import assertk.assertFailure
		import assertk.assertThat
		import assertk.assertions.contains
		import assertk.assertions.hasMessage
		import assertk.assertions.isEqualTo
		import assertk.assertions.isInstanceOf
		@@ -224,9 +225,12 @@ class EmailAddressParserTest {
		}

		@Test
		fun `local part exceeds maximum size`() {
		fun `local part exceeds maximum size with length check enabled`() {
		assertFailure {
		parseEmailAddress("1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx12345@domain.example")
		parseEmailAddress(
		address = "1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx12345@domain.example",
		isLocalPartLengthCheckEnabled = true,
		)
		}.isInstanceOf<EmailAddressParserException>().all {
		prop(EmailAddressParserException::error).isEqualTo(LocalPartLengthExceeded)
		prop(EmailAddressParserException::position).isEqualTo(65)
		@@ -235,13 +239,27 @@ class EmailAddressParserTest {
		}

		@Test
		fun `email exceeds maximum size`() {
		fun `local part exceeds maximum size with length check disabled`() {
		val input = "1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx12345@domain.example"

		val emailAddress = parseEmailAddress(address = input, isLocalPartLengthCheckEnabled = false)

		assertThat(emailAddress.localPart)
		.isEqualTo("1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx12345")
		assertThat(emailAddress.domain).isEqualTo(EmailDomain("domain.example"))
		assertThat(emailAddress.address).isEqualTo(input)
		assertThat(emailAddress.warnings).contains(EmailAddress.Warning.LocalPartExceedsLengthLimit)
		}

		@Test
		fun `email exceeds maximum size with length check enabled`() {
		assertFailure {
		parseEmailAddress(
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx1234@" +
		address = "1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx1234@" +
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx123." +
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx123." +
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx12",
		isEmailAddressLengthCheckEnabled = true,
		)
		}.isInstanceOf<EmailAddressParserException>().all {
		prop(EmailAddressParserException::error).isEqualTo(TotalLengthExceeded)
		@@ -250,6 +268,28 @@ class EmailAddressParserTest {
		}
		}

		@Test
		fun `email exceeds maximum size with length check disabled`() {
		val input = "1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx1234@" +
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx123." +
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx123." +
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx12"

		val emailAddress = parseEmailAddress(address = input, isEmailAddressLengthCheckEnabled = false)

		assertThat(emailAddress.localPart)
		.isEqualTo("1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx1234")
		assertThat(emailAddress.domain).isEqualTo(
		EmailDomain(
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx123." +
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx123." +
		"1xxxxxxxxx2xxxxxxxxx3xxxxxxxxx4xxxxxxxxx5xxxxxxxxx6xxxxxxxxx12",
		),
		)
		assertThat(emailAddress.address).isEqualTo(input)
		assertThat(emailAddress.warnings).contains(EmailAddress.Warning.EmailAddressExceedsLengthLimit)
		}

		@Test
		fun `input contains additional character`() {
		assertFailure {
		@@ -263,11 +303,15 @@ class EmailAddressParserTest {

		private fun parseEmailAddress(
		address: String,
		isLocalPartLengthCheckEnabled: Boolean = false,
		isEmailAddressLengthCheckEnabled: Boolean = false,
		isEmptyLocalPartAllowed: Boolean = false,
		isLocalPartRequiringQuotedStringAllowed: Boolean = isEmptyLocalPartAllowed,
		isQuotedLocalPartAllowed: Boolean = isLocalPartRequiringQuotedStringAllowed,
		): EmailAddress {
		val config = EmailAddressParserConfig(
		isLocalPartLengthCheckEnabled,
		isEmailAddressLengthCheckEnabled,
		isQuotedLocalPartAllowed,
		isLocalPartRequiringQuotedStringAllowed,
		isEmptyLocalPartAllowed,