309651 - pp crashes printing cert containing ASN.1 NULL construct

Status: RESOLVED FIXED

(NSS :: Tools, defect)

Description

[Nelson Bolyard (seldom reads bugmail)]

The pp command crashes when trying to print a cert with an extension that is 
unknown (to pp).  certutil would also crash if it tried to print this cert.
I'll attach the cert that reproduces this, and a patch I wrote for this 
some time ago.

Comment 1

[Nelson Bolyard (seldom reads bugmail)]

Attachment: cert that reproduces this problem (among others)

This cert is also interesting because the subject name contains chinese
characters in UTF8.

Comment 2

[Nelson Bolyard (seldom reads bugmail)]

Attachment: don't ask printf to print a string with a NULL address

On some platforms, the statement
   printf("%s\n", NULL);
will print out 
(null)
But apparently on Solaris for x86_64 it crashes instead.
This patch fixes that by not passing NULL.

Comment 3

[Nelson Bolyard (seldom reads bugmail)]

(In reply to comment #1)

> This cert is also interesting because the subject name contains chinese
> characters in UTF8.

Oops, that's another cert.  This root cert does not contain chinese characters,
but the intermediate CA certs it has issued do contain them.  

Comment 4

[Wan-Teh Chang]

Comment on attachment 197066 [details] [diff] [review]
don't ask printf to print a string with a NULL address

Why is m NULL?	Is m always NULL in the SEC_ASN1_NULL case?
Seems that the bug is passing a NULL m to this function.  This
function passes m to many SECU_PrintXXX functions in the
other cases.  If you fix this case to handle a NULL m, don't
you also need to fix all those SECU_PrintXXX functions to handle
a NULL m?

Comment 5

[Wan-Teh Chang]

Comment on attachment 197066 [details] [diff] [review]
don't ask printf to print a string with a NULL address

r=wtc.	I found that several SECU_PrintXXX functions
already handled a NULL m like this.  They only test
for a NULL m, not a zero m[0] (an empty string) though.

Comment 6

[Nelson Bolyard (seldom reads bugmail)]

The SECU_PrintXXX functions all have a similar signature.  In all cases,
m is allowed to be NULL (or, that is the intent).  There are several
ways this function can be called, some with non-NULL prefix strings (m)
and ohters with NULL prefix strings.  In the relevant case, we are printing
a decoding of an unknown ASN.1 sequence/set.  Since it is unknown, we have
no meaningful prefixes to print before the members, so we intentionally 
pass NULL.  

Thanks for the review.  Checked in.