#8: Added heuristics and SmimeState to indicate probably signed messages, as the content-type is "multipart/signed", but the (S/MIME) protocol parameter is missing.

Author: bbottema

src/main/java/org/simplejavamail/utils/mail/smime/SmimeState.java

@@ -18,7 +18,13 @@ public enum SmimeState {
 	 * encrypted.
 	 */
 	ENCRYPTED,
-	
+
+	/**
+	 * Indicates that the {@link MimePart} or {@link MimeMultipart} is probably S/MIME
+	 * signed (type was multipart/signed, but protocol was missing).
+	 */
+	PROBABLY_SIGNED,
+
 	/**
 	 * Indicates that the {@link MimePart} or {@link MimeMultipart} is S/MIME
 	 * signed.

src/main/java/org/simplejavamail/utils/mail/smime/SmimeUtil.java

@@ -656,6 +656,8 @@ public static SmimeState getStatus(MimePart mimePart) {
     private static SmimeState getStatus(ContentType contentType) {
         if (isSmimeSignatureContentType(contentType)) {
             return SmimeState.SIGNED;
+        } if (isProbablySmimeSignatureContentType(contentType)) {
+            return SmimeState.PROBABLY_SIGNED;
         } else if (isSignatureSmimeType(contentType)) {
             return SmimeState.SIGNED_ENVELOPED;
         } else if (isSmimeEncryptionContenttype(contentType)) {
@@ -672,12 +674,16 @@ private static boolean isSmimeEncryptionContenttype(ContentType contentType) {
     }
 
     private static boolean isSmimeSignatureContentType(ContentType contentType) {
-        String baseContentType = contentType.getBaseType();
         String protocol = contentType.getParameter("protocol");
-        return baseContentType.equalsIgnoreCase("multipart/signed")
+        return contentType.getBaseType().equalsIgnoreCase("multipart/signed")
                 && protocol != null && isSmimeSignatureProtocoll(protocol);
     }
 
+    private static boolean isProbablySmimeSignatureContentType(ContentType contentType) {
+        String protocol = contentType.getParameter("protocol");
+        return contentType.getBaseType().equalsIgnoreCase("multipart/signed") && protocol == null;
+    }
+
     private static boolean isSignatureSmimeType(ContentType contentType) {
         String baseContentType = contentType.getBaseType();
         return baseContentType.equalsIgnoreCase("application/x-pkcs7-mime")