#480: generate unique Content-ID's for attachments so attachments with identical names don't refer to the same content

Author: bbottema

modules/simple-java-mail/src/main/java/org/simplejavamail/converter/internal/mimemessage/MimeMessageHelper.java

@@ -205,8 +205,8 @@ static void setAttachments(@NotNull final Email email, final MimeMultipart multi
 	 * Sets all headers on the {@link Message} instance. Since we're not using a high-level JavaMail method, the JavaMail library says we need to do
 	 * some encoding and 'folding' manually, to get the value right for the headers (see {@link MimeUtility}.
 	 * <p>
-	 * Furthermore sets the notification flags <code>Disposition-Notification-To</code> and <code>Return-Receipt-To</code> if provided. It used
-	 * JavaMail's built in method for producing an RFC compliant email address (see {@link InternetAddress#toString()}).
+	 * Furthermore, sets the notification flags <code>Disposition-Notification-To</code> and <code>Return-Receipt-To</code> if provided. It used
+	 * JavaMail's built-in method for producing an RFC compliant email address (see {@link InternetAddress#toString()}).
 	 *
 	 * @param email   The message in which the headers are defined.
 	 * @param message The {@link Message} on which to set the raw, encoded and folded headers.
@@ -261,16 +261,16 @@ private static BodyPart getBodyPartFromDatasource(final AttachmentResource attac
 			throws MessagingException {
 		final BodyPart attachmentPart = new MimeBodyPart();
 		// setting headers isn't working nicely using the javax mail API, so let's do that manually
-		final String resourceName = determineResourceName(attachmentResource, dispositionType, true);
-		final String fileName = determineResourceName(attachmentResource, dispositionType, false);
+		final String fileName = determineResourceName(attachmentResource, dispositionType, false, false);
+		final String contentID = determineResourceName(attachmentResource, dispositionType, true, true);
 		attachmentPart.setDataHandler(new DataHandler(new NamedDataSource(fileName, attachmentResource.getDataSource())));
 		attachmentPart.setFileName(fileName);
 		final String contentType = attachmentResource.getDataSource().getContentType();
 		ParameterList pl = new ParameterList();
 		pl.set("filename", fileName);
 		pl.set("name", fileName);
 		attachmentPart.setHeader("Content-Type", contentType + pl);
-		attachmentPart.setHeader("Content-ID", format("<%s>", resourceName));
+		attachmentPart.setHeader("Content-ID", format("<%s>", contentID));
 
 		attachmentPart.setHeader("Content-Description", determineAttachmentDescription(attachmentResource));
 		if (!valueNullOrEmpty(attachmentResource.getContentTransferEncoding())) {
@@ -283,7 +283,7 @@ private static BodyPart getBodyPartFromDatasource(final AttachmentResource attac
 	/**
 	 * Determines the right resource name and optionally attaches the correct extension to the name. The result is mime encoded.
 	 */
-	static String determineResourceName(final AttachmentResource attachmentResource, String dispositionType, final boolean encodeResourceName) {
+	static String determineResourceName(final AttachmentResource attachmentResource, String dispositionType, final boolean encodeResourceName, final boolean isContentID) {
 		final String datasourceName = attachmentResource.getDataSource().getName();
 
 		String resourceName;
@@ -295,6 +295,13 @@ static String determineResourceName(final AttachmentResource attachmentResource,
 		} else {
 			resourceName = "resource" + UUID.randomUUID();
 		}
+
+		// if ATTACHMENT, then add UUID to the name to prevent attachments with the same name to reference the same attachment content
+		if (isContentID && dispositionType.equals(Part.ATTACHMENT)) {
+			resourceName +=  "@" + UUID.randomUUID();
+		}
+
+		// if there is no extension on the name, but there is on the datasource name, then add it to the name
 		if (!valueNullOrEmpty(datasourceName) && dispositionType.equals(Part.ATTACHMENT)) {
 			resourceName = possiblyAddExtension(datasourceName, resourceName);
 		}

modules/simple-java-mail/src/test/java/org/simplejavamail/converter/EmailConverterTest.java

@@ -17,17 +17,21 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.regex.Matcher;
 
 import static demo.ResourceFolderHelper.determineResourceFolder;
 import static jakarta.mail.Message.RecipientType.CC;
 import static jakarta.mail.Message.RecipientType.TO;
+import static java.lang.String.format;
 import static java.nio.charset.Charset.defaultCharset;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.Collections.singletonList;
+import static java.util.regex.Pattern.compile;
 import static org.apache.commons.codec.binary.Base64.encodeBase64Chunked;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.simplejavamail.api.email.ContentTransferEncoding.BIT7;
 import static org.simplejavamail.internal.util.MiscUtil.normalizeNewlines;
+import static org.simplejavamail.internal.util.Preconditions.assumeTrue;
 
 public class EmailConverterTest {
 
@@ -205,10 +209,10 @@ public void testContentTransferEncodingBase64() {
 		assertThat(emlRoundtrip).contains("Content-Transfer-Encoding: base64\n\n"
 				+ asBase64("<b>We should meet up!</b><img src='cid:thumbsup'><img src='cid:fixedNameWithoutFileExtensionForNamedEmbeddedImage'>"));
 
-		assertThat(eml).contains("Content-ID: <dresscode.txt>");
-		assertThat(eml).contains("Content-ID: <location.txt>");
+		assertThat(eml).contains("Content-ID: <dresscode.txt@" + contentIDExtractor(eml, "dresscode.txt") + ">");
+		assertThat(eml).contains("Content-ID: <location.txt@" + contentIDExtractor(eml, "location.txt") + ">");
 		assertThat(eml).contains("Content-ID: <thumbsup>");
-		assertThat(eml).contains("Content-ID: <fixedNameWithoutFileExtensionForNamedAttachment.txt>");
+		assertThat(eml).contains("Content-ID: <fixedNameWithoutFileExtensionForNamedAttachment@" + contentIDExtractor(eml, "fixedNameWithoutFileExtensionForNamedAttachment") + ".txt>");
 		assertThat(eml).contains("Content-ID: <fixedNameWithoutFileExtensionForNamedEmbeddedImage>");
 	}
 
@@ -239,28 +243,28 @@ public void testContentDescriptionAndContentTransferEncoding() throws IOExceptio
 		assertThat(eml).contains("Content-Type: text/plain; filename=\"dummy text1.txt\"; name=\"dummy text1.txt\"\n"
 				+ "Content-Transfer-Encoding: 7bit\n"
 				+ "Content-Disposition: attachment; filename=\"dummy text1.txt\"\n"
-				+ "Content-ID: <dummy text1.txt>\n"
+				+ "Content-ID: <dummy text1.txt@" + contentIDExtractor(eml, "dummy text1.txt") + ">\n"
 				+ "Content-Description: This is dummy text1\n"
 				+ "\n"
 				+ "Cupcake ipsum dolor sit amet donut. Apple pie caramels oat cake fruitcake sesame snaps. Bear claw cotton candy toffee danish sweet roll.");
 		assertThat(eml).contains("Content-Type: text/plain; filename=\"dummy text2.txt\"; name=\"dummy text2.txt\"\n"
 				+ "Content-Transfer-Encoding: 7bit\n"
 				+ "Content-Disposition: attachment; filename=\"dummy text2.txt\"\n"
-				+ "Content-ID: <dummy text2.txt>\n"
+				+ "Content-ID: <dummy text2.txt@" + contentIDExtractor(eml, "dummy text2.txt") + ">\n"
 				+ "Content-Description: This is dummy text2\n"
 				+ "\n"
 				+ "I love pie I love donut sugar plum. I love halvah topping bonbon fruitcake brownie chocolate. Sweet tootsie roll wafer caramels sesame snaps.");
 		assertThat(eml).contains("Content-Type: text/plain; filename=\"dummy text3.txt\"; name=\"dummy text3.txt\"\n"
 				+ "Content-Transfer-Encoding: 7bit\n"
 				+ "Content-Disposition: attachment; filename=\"dummy text3.txt\"\n"
-				+ "Content-ID: <dummy text3.txt>\n"
+				+ "Content-ID: <dummy text3.txt@" + contentIDExtractor(eml, "dummy text3.txt") + ">\n"
 				+ "Content-Description: This is dummy text3\n"
 				+ "\n"
 				+ "Danish chocolate pudding cake bonbon powder bonbon. I love cookie jelly beans cake oat cake. I love I love sweet roll sweet pudding topping icing.");
 		assertThat(eml).contains("Content-Type: text/plain; filename=\"dummy text4.txt\"; name=\"dummy text4.txt\"\n"
 				+ "Content-Transfer-Encoding: 7bit\n"
 				+ "Content-Disposition: attachment; filename=\"dummy text4.txt\"\n"
-				+ "Content-ID: <dummy text4.txt>\n"
+				+ "Content-ID: <dummy text4.txt@" + contentIDExtractor(eml, "dummy text4.txt") + ">\n"
 				+ "\n"
 				+ "this should not have a Content-Description header");
 
@@ -269,32 +273,38 @@ public void testContentDescriptionAndContentTransferEncoding() throws IOExceptio
 		assertThat(emlRoundtrip).contains("Content-Type: text/plain; filename=\"dummy text1.txt\"; name=\"dummy text1.txt\"\n"
 				+ "Content-Transfer-Encoding: 7bit\n"
 				+ "Content-Disposition: attachment; filename=\"dummy text1.txt\"\n"
-				+ "Content-ID: <dummy text1.txt>\n"
+				+ "Content-ID: <dummy text1.txt@" + contentIDExtractor(emlRoundtrip, "dummy text1.txt") + ">\n"
 				+ "Content-Description: This is dummy text1\n"
 				+ "\n"
 				+ "Cupcake ipsum dolor sit amet donut. Apple pie caramels oat cake fruitcake sesame snaps. Bear claw cotton candy toffee danish sweet roll.");
 		assertThat(emlRoundtrip).contains("Content-Type: text/plain; filename=\"dummy text2.txt\"; name=\"dummy text2.txt\"\n"
 				+ "Content-Transfer-Encoding: 7bit\n"
 				+ "Content-Disposition: attachment; filename=\"dummy text2.txt\"\n"
-				+ "Content-ID: <dummy text2.txt>\n"
+				+ "Content-ID: <dummy text2.txt@" + contentIDExtractor(emlRoundtrip, "dummy text2.txt") + ">\n"
 				+ "Content-Description: This is dummy text2\n"
 				+ "\n"
 				+ "I love pie I love donut sugar plum. I love halvah topping bonbon fruitcake brownie chocolate. Sweet tootsie roll wafer caramels sesame snaps.");
 		assertThat(emlRoundtrip).contains("Content-Type: text/plain; filename=\"dummy text3.txt\"; name=\"dummy text3.txt\"\n"
 				+ "Content-Transfer-Encoding: 7bit\n"
 				+ "Content-Disposition: attachment; filename=\"dummy text3.txt\"\n"
-				+ "Content-ID: <dummy text3.txt>\n"
+				+ "Content-ID: <dummy text3.txt@" + contentIDExtractor(emlRoundtrip, "dummy text3.txt") + ">\n"
 				+ "Content-Description: This is dummy text3\n"
 				+ "\n"
 				+ "Danish chocolate pudding cake bonbon powder bonbon. I love cookie jelly beans cake oat cake. I love I love sweet roll sweet pudding topping icing.");
 		assertThat(emlRoundtrip).contains("Content-Type: text/plain; filename=\"dummy text4.txt\"; name=\"dummy text4.txt\"\n"
 				+ "Content-Transfer-Encoding: 7bit\n"
 				+ "Content-Disposition: attachment; filename=\"dummy text4.txt\"\n"
-				+ "Content-ID: <dummy text4.txt>\n"
+				+ "Content-ID: <dummy text4.txt@" + contentIDExtractor(emlRoundtrip, "dummy text4.txt") + ">\n"
 				+ "\n"
 				+ "this should not have a Content-Description header");
 	}
 
+	private static String contentIDExtractor(String eml, String filename) {
+		final Matcher matcher = compile(format("Content-ID: <%s@(?<uuid>.+?)(?<optionalExtension>\\..{3})?>", filename)).matcher(eml);
+		assertThat(matcher.find()).as(format("Found UUID in EML's Content-ID for filename '%s'", filename)).isTrue();
+		return matcher.group("uuid");
+	}
+
 	@NotNull
 	private List<AttachmentResource> asList(AttachmentResource attachment) {
 		List<AttachmentResource> collectionAttachment = new ArrayList<>();

modules/simple-java-mail/src/test/java/org/simplejavamail/converter/internal/mimemessage/MimeMessageHelperTest.java

@@ -35,64 +35,64 @@ public void setup() {
 	public void determineResourceName1()
 			throws IOException {
 		AttachmentResource resource1 = new AttachmentResource(null, getDataSource("blahblah"));
-		assertThat(MimeMessageHelper.determineResourceName(resource1, Part.ATTACHMENT, true)).isEqualTo("blahblah");
-		assertThat(MimeMessageHelper.determineResourceName(resource1, Part.INLINE, true)).isEqualTo("blahblah");
+		assertThat(MimeMessageHelper.determineResourceName(resource1, Part.ATTACHMENT, true, false)).isEqualTo("blahblah");
+		assertThat(MimeMessageHelper.determineResourceName(resource1, Part.INLINE, true, false)).isEqualTo("blahblah");
 	}
 
 	@Test
 	public void determineResourceName2()
 			throws IOException {
 		AttachmentResource resource2 = new AttachmentResource(null, getDataSource("blahblah.txt"));
-		assertThat(MimeMessageHelper.determineResourceName(resource2, Part.ATTACHMENT, true)).isEqualTo("blahblah.txt");
-		assertThat(MimeMessageHelper.determineResourceName(resource2, Part.INLINE, true)).isEqualTo("blahblah.txt");
+		assertThat(MimeMessageHelper.determineResourceName(resource2, Part.ATTACHMENT, true, false)).isEqualTo("blahblah.txt");
+		assertThat(MimeMessageHelper.determineResourceName(resource2, Part.INLINE, true, false)).isEqualTo("blahblah.txt");
 	}
 
 	@Test
 	public void determineResourceName3()
 			throws IOException {
 		AttachmentResource resource3 = new AttachmentResource("the resource", getDataSource(null));
-		assertThat(MimeMessageHelper.determineResourceName(resource3, Part.ATTACHMENT, true)).isEqualTo("the resource");
-		assertThat(MimeMessageHelper.determineResourceName(resource3, Part.INLINE, true)).isEqualTo("the resource");
+		assertThat(MimeMessageHelper.determineResourceName(resource3, Part.ATTACHMENT, true, false)).isEqualTo("the resource");
+		assertThat(MimeMessageHelper.determineResourceName(resource3, Part.INLINE, true, false)).isEqualTo("the resource");
 	}
 
 	@Test
 	public void determineResourceName4()
 			throws IOException {
 		AttachmentResource resource4 = new AttachmentResource("the resource", getDataSource("blahblah.txt"));
-		assertThat(MimeMessageHelper.determineResourceName(resource4, Part.ATTACHMENT, true)).isEqualTo("the resource.txt");
-		assertThat(MimeMessageHelper.determineResourceName(resource4, Part.INLINE, true)).isEqualTo("the resource");
+		assertThat(MimeMessageHelper.determineResourceName(resource4, Part.ATTACHMENT, true, false)).isEqualTo("the resource.txt");
+		assertThat(MimeMessageHelper.determineResourceName(resource4, Part.INLINE, true, false)).isEqualTo("the resource");
 	}
 
 	@Test
 	public void determineResourceName5()
 			throws IOException {
 		AttachmentResource resource5 = new AttachmentResource("the resource", getDataSource("blahblah"));
-		assertThat(MimeMessageHelper.determineResourceName(resource5, Part.ATTACHMENT, true)).isEqualTo("the resource");
-		assertThat(MimeMessageHelper.determineResourceName(resource5, Part.INLINE, true)).isEqualTo("the resource");
+		assertThat(MimeMessageHelper.determineResourceName(resource5, Part.ATTACHMENT, true, false)).isEqualTo("the resource");
+		assertThat(MimeMessageHelper.determineResourceName(resource5, Part.INLINE, true, false)).isEqualTo("the resource");
 	}
 
 	@Test
 	public void determineResourceName6()
 			throws IOException {
 		AttachmentResource resource6 = new AttachmentResource("the resource.txt", getDataSource("blahblah.txt"));
-		assertThat(MimeMessageHelper.determineResourceName(resource6, Part.ATTACHMENT, true)).isEqualTo("the resource.txt");
-		assertThat(MimeMessageHelper.determineResourceName(resource6, Part.INLINE, true)).isEqualTo("the resource.txt");
+		assertThat(MimeMessageHelper.determineResourceName(resource6, Part.ATTACHMENT, true, false)).isEqualTo("the resource.txt");
+		assertThat(MimeMessageHelper.determineResourceName(resource6, Part.INLINE, true, false)).isEqualTo("the resource.txt");
 	}
 
 	@Test
 	public void determineResourceName7()
 			throws IOException {
 		AttachmentResource resource7 = new AttachmentResource("the resource.txt", getDataSource("blahblah"));
-		assertThat(MimeMessageHelper.determineResourceName(resource7, Part.ATTACHMENT, true)).isEqualTo("the resource.txt");
-		assertThat(MimeMessageHelper.determineResourceName(resource7, Part.INLINE, true)).isEqualTo("the resource.txt");
+		assertThat(MimeMessageHelper.determineResourceName(resource7, Part.ATTACHMENT, true, false)).isEqualTo("the resource.txt");
+		assertThat(MimeMessageHelper.determineResourceName(resource7, Part.INLINE, true, false)).isEqualTo("the resource.txt");
 	}
 
 	@Test
 	public void determineResourceName_ignoreExtensionFromResource()
 			throws IOException {
 		AttachmentResource resource7 = new AttachmentResource("the resource.txt", getDataSource("blahblah.1/www/get?id=3"));
-		assertThat(MimeMessageHelper.determineResourceName(resource7, Part.ATTACHMENT, true)).isEqualTo("the resource.txt");
-		assertThat(MimeMessageHelper.determineResourceName(resource7, Part.INLINE, true)).isEqualTo("the resource.txt");
+		assertThat(MimeMessageHelper.determineResourceName(resource7, Part.ATTACHMENT, true, false)).isEqualTo("the resource.txt");
+		assertThat(MimeMessageHelper.determineResourceName(resource7, Part.INLINE, true, false)).isEqualTo("the resource.txt");
 	}
 
 	private ByteArrayDataSource getDataSource(@Nullable String name)

modules/simple-java-mail/src/test/java/org/simplejavamail/mailer/MailerLiveTest.java

@@ -556,9 +556,9 @@ public void createMailSession_ReplyToMessage_NotAll_AndCustomReferences()
 		assertThat(receivedReplyToReply.getHeaders()).contains(entry("References", singletonList(references)));
 	}
 
-	private void assertAttachmentMetadata(AttachmentResource embeddedImg, String mimeType, String filename) {
-		assertThat(embeddedImg.getDataSource().getContentType()).isEqualTo(mimeType);
-		assertThat(embeddedImg.getName()).isEqualTo(filename);
+	private void assertAttachmentMetadata(AttachmentResource attachment, String mimeType, String filename) {
+		assertThat(attachment.getDataSource().getContentType()).isEqualTo(mimeType);
+		assertThat(attachment.getName()).isEqualTo(filename);
 	}
 
 	@Test