View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0005181 | SOGo | SOPE | public | 2020-10-02 12:56 | 2020-10-02 12:56 |
| Reporter | schmirl | Assigned To | |||
| Priority | normal | Severity | minor | Reproducibility | always |
| Status | new | Resolution | open | ||
| Product Version | 4.3.2 | ||||
| Summary | 0005181: SOGo mails modified by some mail relay servers: S/MIME signature broken | ||||
| Description | I noticed that sometimes the signatures of SOGo signed mails are reported as broken (on any mailclient, so not related to 0004634). It turned out that indeed the mail is modified in transit: Some of the Content-Length MIME part headers were stripped in transit. I was able to track it back to sendmail-based relay servers (others might behave the same way) and indeed, in its default configuration sendmail strips this header. While this is clearly something to be discussed with the sendmail guys, too, the Content-Length header is not specified for email:
As nobody can control through which relay servers a mail is forwarded, SOGo should stop adding this header. | ||||
| Steps To Reproduce |
Repeat the test and have SOGo sign the mail: Mail will be reported as modified by the reciepient (tested Outlook and SOGo) | ||||
| Additional Information | Proposed patch attached. It turned out that it's not that easy to find all places reponsible for adding a Content-Length header to the individual parts. So this patch simply skips the header while writing the content. | ||||
| Tags | S/MIME | ||||
 |
SOPE-drop_content-length.patch (845 bytes)
--- sope-mime/NGMime/NGMimePartGenerator.m.orig 2019-12-17 21:34:06.000000000 +0100
+++ sope-mime/NGMime/NGMimePartGenerator.m 2020-10-02 09:42:47.030375229 +0200
@@ -258,6 +258,9 @@
NSEnumerator *enumerator;
BOOL reset;
+ if ([headerFieldName isEqualToString:@"content-length"])
+ continue;
+
if ([[_additionalHeaders objectsForKey:headerFieldName] count] > 0) {
enumerator = [addHeaders objectEnumeratorForKey:headerFieldName];
reset = YES;
@@ -274,6 +277,9 @@
headerFieldNames = [addHeaders keyEnumerator];
while ((headerFieldName = [headerFieldNames nextObject]) != nil) {
+ if ([headerFieldName isEqualToString:@"content-length"])
+ continue;
+
[self appendHeaderField:headerFieldName
values:[addHeaders objectEnumeratorForKey:headerFieldName]
toData:data];
|
