Re: Outgoing message truncated at dot wrapped on single line

[Pawel Salek <pawsa0 gmail com>]

On 10/23/2011 07:39:12 PM, Carlos Franke wrote:
> Balsa's debug mode does not reveil anything suspicious to me in  
> stdout while sending a to-be-truncated email. As the ouput contains  
> some strings that look like obfuscated or encrypted passwords (after  
> "C: AUTH LOGIN"), I am not sure if it is safe to share it. Please  
> point me to any reliable information source telling me that it is,  
> and I will happily send it to you.

Auth login data is not safe to share.

> "strace -olog -ff" yields a lot of log files, only one of which  
> contains the string "EHLO", but  n o t  the the mail content. I found  
> a small portions of the mail in another log file:
> write(12, "\nkann ich nat=C3=BCrlich versuch"..., 86) = 86
> and
> read(11, "\nkann ich nat=C3=BCrlich versuch"..., 86) = 86
> What else should I look for in these files?

Yes, you are interested in the file containing EHLO. Is the session  
encrypted? (Look for starttls in that file). Running strace -s8192 will  
print long string, but only if the session is unencrypted. If it is,  
you will see only encrypted stuff. In the session is encrypted, it may  
be simplest to try the test program coming with libestmp.

I did following:

./configure --with-openssl --prefix=$(HOME)/leroot
make
make install
cd examples/
PATH=$PATH:$(HOME)/leroot/bin make
(got 'missing zError' - I had to modify Makefile to add -lz to linking  
line)
./mail-file-so -m -h SMTP_SERVER -t test-mail TARGET EXAMPLE COM

Check, if the test mail gets delivered as expected. If it is, try your  
test message.

You can run ./mail-file-so under strace, too.

> Eventually, the faked SMTP session with lavabit.com went fine, i. e.  
> the two dots were not interpreted as the end of the mail. Here is the  
> complete session (for better readability, the input lines are  
> indented):
> $  telnet lavabit.com 25
> [cut]

This means that a sanity test passes - which is good. It does not  
answer the original question - it is possible Lavabit SMTP server makes  
invalid assumptions about stream buffering, etc.

> Also, this session successfully sent an email to me (sender:  
> example example com) – a somewhat distorted one, though: the Date,  
> From, Subject and To header lines are repeated at the end of the body.

Not good, this should not happen.

Pawel