NullPointerException in SmimeUtilFixed when protocol is missing (which is valid)

[Faelean]

When using the outlookMsgToEmailBuilder function

simple-java-mail/modules/simple-java-mail/src/main/java/org/simplejavamail/converter/EmailConverter.java

Line 201 in cd197aa

public static EmailFromOutlookMessage outlookMsgToEmailBuilder(@NotNull final InputStream msgInputStream) {

I sometimes get this error message:

org.simplejavamail.internal.smimesupport.SmimeException: Error unwrapping S/MIME enveloped attachment: 
	AttachmentResource{
		name='smime.p7s',
		dataSource.name=smime.p7s,
		dataSource.getContentType=multipart/signed
	}

This is caused by a Nullpointer in this function when the contentType in the calling function does not contain the parameter protocol:

simple-java-mail/modules/smime-module/src/main/java/org/simplejavamail/internal/smimesupport/SmimeUtilFixed.java

Lines 59 to 62 in cd197aa

	private static boolean isSmimeSignatureProtocoll(String protocol) {
	return protocol.equalsIgnoreCase("application/pkcs7-signature")
	|| protocol.equalsIgnoreCase("application/x-pkcs7-signature");
	}

simple-java-mail/modules/smime-module/src/main/java/org/simplejavamail/internal/smimesupport/SmimeUtilFixed.java

Lines 53 to 57 in cd197aa

	private static boolean isSmimeSignatureContentType(ContentType contentType) {
	String baseContentType = contentType.getBaseType();
	return baseContentType.equalsIgnoreCase("multipart/signed")
	&& isSmimeSignatureProtocoll(contentType.getParameter("protocol"));
	}

I haven't been able to create an email with this problem myself (if necessary I can obtain one) but here is the way we handle these emails:

• Drag & Drop from Outlook to a Browser
• Transfer the file to a server
• Convert the file to a ByteArrayInputStream
• Call outlookMsgToEmailBuilder with that InputStream

I don't know why these mails don't contain a protocol, but the easiest way to prevent the NullPointer would be to make the isSmimeSignatureProtocoll function nullsave by using protocol as input parameter for equalsIgnoreCase:

"application/pkcs7-signature".equalsIgnoreCase(protocol) || "application/x-pkcs7-signature".equalsIgnoreCase(protocol)

This would change the NullPointer to a false.

[Faelean]

If you want I can now provide an example mail that causes the error, I'd have to send it to you via mail though.
The mail crashes the program I used in #303.

Exception in thread "main" org.simplejavamail.internal.smimesupport.SmimeException: Error unwrapping S/MIME enveloped attachment: 
	AttachmentResource{
		name='smime.p7m',
		dataSource.name=smime.p7m,
		dataSource.getContentType=multipart/signed
	}
	at org.simplejavamail.internal.smimesupport.SMIMESupport.decryptAttachments(SMIMESupport.java:232)
	at org.simplejavamail.internal.smimesupport.SMIMESupport.decryptAttachments(SMIMESupport.java:188)
	at org.simplejavamail.internal.smimesupport.SMIMESupport.decryptAttachments(SMIMESupport.java:121)
	at org.simplejavamail.internal.smimesupport.SMIMESupport.decryptAttachments(SMIMESupport.java:91)
	at org.simplejavamail.converter.EmailConverter.decryptAttachments(EmailConverter.java:233)
	at org.simplejavamail.converter.EmailConverter.outlookMsgToEmailBuilder(EmailConverter.java:227)
	at org.simplejavamail.converter.EmailConverter.outlookMsgToEmail(EmailConverter.java:209)
	at org.simplejavamail.converter.EmailConverter.outlookMsgToEmail(EmailConverter.java:201)
	at ReadMail.main(ReadMail.java:29)
Caused by: net.markenwerk.utils.mail.smime.SmimeException
	at org.simplejavamail.internal.smimesupport.SmimeUtilFixed.handledException(SmimeUtilFixed.java:83)
	at org.simplejavamail.internal.smimesupport.SmimeUtilFixed.getStatus(SmimeUtilFixed.java:40)
	at org.simplejavamail.internal.smimesupport.SMIMESupport.determineStatus(SMIMESupport.java:333)
	at org.simplejavamail.internal.smimesupport.SMIMESupport.decryptAndUnsignAttachment(SMIMESupport.java:260)
	at org.simplejavamail.internal.smimesupport.SMIMESupport.decryptAttachments(SMIMESupport.java:230)
	... 8 more
Caused by: java.lang.NullPointerException
	at org.simplejavamail.internal.smimesupport.SmimeUtilFixed.isSmimeSignatureProtocoll(SmimeUtilFixed.java:75)
	at org.simplejavamail.internal.smimesupport.SmimeUtilFixed.isSmimeSignatureContentType(SmimeUtilFixed.java:71)
	at org.simplejavamail.internal.smimesupport.SmimeUtilFixed.getStatus(SmimeUtilFixed.java:45)
	at org.simplejavamail.internal.smimesupport.SmimeUtilFixed.getStatus(SmimeUtilFixed.java:38)
	... 11 more

[bbottema]

Yes please, that would be most helpful 👍

[bbottema]

Released in 6.5.0