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Wireshark-dev: Re: [Wireshark-dev] epan_base64_decode(): failure when string contains a NUL cha

From: Uli Heilmeier <zeugs@xxxxxxxxxxxx>
Date: Sun, 21 Apr 2013 22:22:47 +0200
Hi,

Thanks for both replies!
I did a complete clean-up of my code and now the decoded string is 14
bytes long. So the epan_base64_decode() function is working correct.

Sorry for the work and the confusion.

There is only one issue left: How can I split up this string. The
g_strsplit() function seems to don't accept NULL as a delimiter.

Thanks!
Uli

Am 20.04.13 11:55, schrieb Jakub Zawadzki:
> Hi,
> 
> On Wed, Apr 17, 2013 at 10:27:42PM +0200, Uli Heilmeier wrote:
>> With the PLAIN mechanism the packet has a base64 encoded string containing:
>> [authorization user](\x00)[authentication user](\x00)[password]
>>
>> For example:
>> dGVzdAB0ZXN0ADEyMzQ= contains test(NUL)test(NUL)1234
>>
>> I tried to decode the base64 string with the epan_base64_decode() function
>> (from epan/base64.h). Unfortunately this fails. I only get a wrong three
>> bytes long string.
>> I guess the problem is the NUL character as a delimiter.
>>
>> Do you have an idea if this is bug in the epan_base64_decode() function or
>> do I have to do the decoding another way?
> 
> From C interactive shell (gdb):
> 
> (gdb) call $x = (char *) strdup("dGVzdAB0ZXN0ADEyMzQ=")
> $1 = 0x65b0e0 "dGVzdAB0ZXN0ADEyMzQ="
> (gdb) call epan_base64_decode($x)
> $2 = 14
> 
> (gdb) x/14c $x
> 0x65b0e0:       116 't' 101 'e' 115 's' 116 't' 0 '\000'        116 't' 101 'e' 115 's'
> 0x65b0e8:       116 't' 0 '\000'        49 '1'  50 '2'  51 '3'  52 '4'
> 
> (gdb) call $x
> $3 = 0x65b0e0 "test"
> (gdb) call $x + 5
> $4 = 0x65b0e5 "test"
> (gdb) call $x + 5 + 5
> $5 = 0x65b0ea "1234"
> 
> Seems to be working ok, can you attach your code?
> 
> Regards,
> Jakub Zawadzki