Hi,
 
As i mentioned in my previous mail that i tested limiting the TLS connection but didn't help. The problem was high frequent renegotiation on existing TLS connections. This was causing the kamailio to restart.
 
So i was thinking to disable the renegoitation until OPENSSL comeup with a solution to this issue.
 
Thanks
Jijo

On Wed, Dec 14, 2011 at 5:45 AM, Daniel-Constantin Mierla <miconda@gmail.com> wrote:
Hello,

I committed yesterday in master branch the code that adds a new global parameter tls_max_connections which sets a limit on how many active tls connections are on sip server. Since tls connections are over tcp, practically tls_max_connections is not effective if greater than tcp_max_connections, since the last will be reached first.

Can you give it a try and see if works for you.

Cheers,
Daniel


On 12/10/11 12:53 AM, Jijo wrote:
Hi
 
Since TLS run on TCP, the max TLS connections accepted is based on tcp_max_connections.  I thought its better to limit the max tls connections, since tls require more memory for each tls connection.
 
I did look futher into the issue and the kamailio crashes only when the tool(thc-ssl-dos) is ran with periodic renegotiation. Kamailo doesn't crash if the renegotiation is disabled in the tool.
 
The htppd has fixed this issue by providing a flag to disable TLS renegotation in the server from any client. Please find the httpd patch at 
 
So I was thinking to apply the same patch in kamailio also. We could have a new flag in tls_domain structure to enable or disable renegotation.
 
Please have a look and let me know your findings.
 
Thanks
Jijo
 
 
On Fri, Dec 9, 2011 at 1:53 AM, Daniel-Constantin Mierla <miconda@gmail.com> wrote:
Hello,

my plan is to look at it as I get back to office (being few days off).

But, isn't tcp_max_connections applied to tls connections? If not, adding such limit will be good anyhow.

Cheers,
Daniel



On 12/7/11 8:57 PM, Jijo wrote:
Hi All..
 
Any comments/suggestions on this issue?

Thanks
Jijo

On Mon, Dec 5, 2011 at 6:56 PM, Jijo <realjijo@gmail.com> wrote:
Hello

I tested using 3.2 and i got the same error. I couldn't get the memlog, when i enable , the system doesn't come up.

The latest update from http://www.thc.org/thc-ssl-dos/   says that

"2011-OCT-24 UPDATE:
SSL-DOS released. Some organizations already found out about this release a while ago and mistakenly identified it as an SSL-RENEGOTIATION BUG. This is not true. The tool can be modified to work without SSL-RENEGOTIATION by just establishing a new TCP connection for every new handshake. "

So this issue could happen if we do TCP connection for every new TLS connection with renegotiation. I believe this could be fixed if we could block based on max active TLS connections, probably a similar flag for max TLS connections like "tcp_max_connections"


Core was generated by `/usr/sbin/kamailio -u swrun -g sw -m 160 -f /etc/kamailio/kamailio.cfg'.

Program terminated with signal 11, Segmentation fault.
#0  0xb61cc2e3 in ?? () from /usr/lib/kamailio/modules/tls.so
(gdb) bt
#0  0xb61cc2e3 in ?? () from /usr/lib/kamailio/modules/tls.so
#1  0xb65199fd in CRYPTO_lock () from /lib/libcrypto.so.1.0.0
#2  0xb658c133 in ?? () from /lib/libcrypto.so.1.0.0
#3  0xb658d240 in RAND_add () from /lib/libcrypto.so.1.0.0
#4  0xb6690d50 in ssl3_accept () from /lib/libssl.so.1.0.0
#5  0xb669bd2f in ssl3_read_bytes () from /lib/libssl.so.1.0.0
#6  0xb66989b9 in ?? () from /lib/libssl.so.1.0.0
#7  0xb66ae499 in SSL_read () from /lib/libssl.so.1.0.0
#8  0xb61e1e33 in tls_read_f () from /usr/lib/kamailio/modules/tls.so
#9  0x08177036 in tcp_read_headers ()
#10 0x081771f6 in tcp_read_req ()
#11 0x08178480 in ?? ()
#12 0x0817af77 in tcp_receive_loop ()
#13 0x08173597 in tcp_init_children ()
#14 0x080b20bf in main_loop ()
#15 0x080b38c3 in main ()
(gdb)



On Wed, Nov 23, 2011 at 10:35 AM, Daniel-Constantin Mierla <miconda@gmail.com> wrote:
Hello,

3.1.0 is not the right choice in 3.1 series, there were many fixes that were added to that release series branch. The latest stable version there is 3.1.5. Try with it (even better, try with latest version from git branch 3.1 -- see http://www.kamailio.org/dokuwiki/doku.php/install:kamailio-3.1.x-from-git)

In this way we are sure it is not a bug that was fixed after the time of releasing 3.1.0 -- config file and database is the same as for 3.1.0.

Cheers,
Daniel


On 11/23/11 4:01 PM, Jijo wrote:
Thanks I will attach the logs soon..meanwhile here is the kamailio and openssl version

OB151:~ # /usr/sbin/kamailio -V
version: kamailio 3.1.0 (i386/linux) 21a375
flags: STATS: Off, USE_IPV6, USE_TCP, USE_TLS, TLS_HOOKS, USE_RAW_SOCKS, USE_MCAST, DNS_IP_HACK, SHM_MEM, SHM_MMAP, PKG_MALLOC, DBG_QM_MALLOC, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES
ADAPTIVE_WAIT_LOOPS=1024, MAX_RECV_BUFFER_SIZE 262144, MAX_LISTEN 16, MAX_URI_SIZE 1024, BUF_SIZE 65535, PKG_SIZE 15MB
poll method support: poll, epoll_lt, epoll_et, sigio_rt, select.
id: 21a375
compiled on 09:22:51 Nov  4 2011 with gcc 4.5.0


OB151:~ # openssl version -a
OpenSSL 1.0.0 29 Mar 2010
built on: 2011-05-31 07:52:17.000000000 +0000
platform: linux-elf
options:  bn(64,32) rc4(4x,int) des(ptr,risc1,16,long) blowfish(idx)
compiler: gcc -fPIC -DOPENSSL_PIC -DZLIB -DOPENSSL_THREADS -D_REENTRANT -DDSO_DLFCN -DHAVE_DLFCN_H
-DL_ENDIAN -DTERMIO -O3 -fomit-frame-pointer -Wall -fomit-frame-pointer -fmessage-length=0 -O2 -Wall
-D_FORTIFY_SOURCE=2 -fstack-protector -funwind-tables -fasynchronous-unwind-tables -g -Wa,--noexecstack -fomit-frame-pointer -fno-strict-aliasing
-DTERMIO -Wall -fstack-protector  -DOPENSSL_BN_ASM_PART_WORDS -DOPENSSL_IA32_SSE2
-DOPENSSL_BN_ASM_MONT -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DMD5_ASM -DRMD160_ASM -DAES_ASM -DWHIRLPOOL_ASM
OPENSSLDIR: "/etc/ssl"


On Wed, Nov 23, 2011 at 4:44 AM, Daniel-Constantin Mierla <miconda@gmail.com> wrote:
Hello,

(discussion kept only on sr-dev as it is very likely going to require mostly devel interaction).

What is the version of kamailio (-V command line option). Also, send the verision of openssl library -- there were many bugs in various lib versions that had to be workarounded in the module, maybe this is a new one that has to be fixed.

Do you get any error message in the syslog at the moment of the crash?

What would be useful is to get the memory operations log, you can get it by setting:

memdbg=1
memlog=1

in config file.

Then repeat the test and make the log available for download somehow (if it is too big), from start to the moment of the crash.

Cheers,
Daniel


On 11/22/11 11:30 PM, Jijo wrote:
Hi All,

Kamailio is resetting when we do TLS renegotiation dos attack using the tool available at  http://www.thc.org/thc-ssl-dos/.

Anybody looked at this issue? How we could resolve it. Any idea?

The core generated for 3 pid's as below

Pid 1:

Core was generated by `/usr/sbin/kamailio -u swrun -g sw -m 120 -f /etc/kamailio/kamailio.cfg'.
Program terminated with signal 11, Segmentation fault.
#0  atomic_inc_int () at atomic/atomic_x86.h:225
(gdb) bt
#0  atomic_inc_int () at atomic/atomic_x86.h:225
#1  cfg_update_local () at cfg/cfg_struct.h:228
#2  timer_main () at timer.c:994
#3  0x080b0579 in main_loop () at main.c:1632
#4  0x080b1be4 in main (argc=9, argv=0xbfd61e54) at main.c:2446


Pid 2:

Core was generated by `/usr/sbin/kamailio -u swrun -g sw -m 120 -f /etc/kamailio/kamailio.cfg'.
Program terminated with signal 11, Segmentation fault.
#0  0x0819bfe8 in qm_insert_free (qm=0xaf6c5000, p=0xb05eec30, file=0xb6fb4140 "tls: tls_init.c", func=0xb6fb4ce0 "ser_free", line=296)
    at mem/q_malloc.c:184
184                     if (frag->size <= f->size) break;
(gdb) bt
#0  0x0819bfe8 in qm_insert_free (qm=0xaf6c5000, p=0xb05eec30, file=0xb6fb4140 "tls: tls_init.c", func=0xb6fb4ce0 "ser_free", line=296)
    at mem/q_malloc.c:184
#1  qm_free (qm=0xaf6c5000, p=0xb05eec30, file=0xb6fb4140 "tls: tls_init.c", func=0xb6fb4ce0 "ser_free", line=296) at mem/q_malloc.c:518
#2  0xb6f95404 in ser_free (ptr=0xb05eec30) at tls_init.c:296
#3  0xb732e9ba in CRYPTO_free (str=0xb05eec30) at mem.c:391
#4  0xb7330bee in int_new_ex_data (class_index=5, obj=0xbfd414f4, ad=0xbfd41574) at ex_data.c:440
#5  0xb7330443 in CRYPTO_new_ex_data (class_index=5, obj=0xbfd414f4, ad=0xbfd41574) at ex_data.c:575
#6  0xb73dfde3 in X509_STORE_CTX_init (ctx=0xbfd414f4, store=0xafd8b3d0, x509=0xafe08ff0, chain=0x0) at x509_vfy.c:2114
#7  0xb74b0f31 in ssl3_output_cert_chain (s=0xb0553a10, x=0xafe08ff0) at s3_both.c:349
#8  0xb74a4728 in ssl3_send_server_certificate (s=0xb0553a10) at s3_srvr.c:3034
#9  0xb74a5879 in ssl3_accept (s=0xb0553a10) at s3_srvr.c:353
#10 0xb74afa8f in ssl3_read_bytes (s=0xb0553a10, type=23, buf=0xb0ad44ec "", len=4095, peek=0) at s3_pkt.c:1266
#11 0xb74ac9c9 in ssl3_read_internal (s=0xb0553a10, buf=0xb0ad44ec, len=4095, peek=0) at s3_lib.c:3265
#12 0xb74c24a9 in SSL_read (s=0xb0553a10, buf=0xb0ad44ec, num=4095) at ssl_lib.c:954
#13 0xb6fad1c3 in tls_read_f (c=0xb0ad431c, flags=0xbfd619c4) at tls_server.c:1058
#14 0x08171c0e in tcp_read_headers (c=0xb0ad431c, read_flags=0xbfd619c4) at tcp_read.c:406
#15 0x08171db8 in tcp_read_req (con=0xb0ad431c, bytes_read=0xbfd619cc, read_flags=0xbfd619c4) at tcp_read.c:885
#16 0x08172f67 in handle_io (fm=<value optimized out>, events=1, idx=<value optimized out>) at tcp_read.c:1234
#17 0x0817583b in io_wait_loop_epoll (unix_sock=89) at io_wait.h:1092
#18 tcp_receive_loop (unix_sock=89) at tcp_read.c:1345
#19 0x0816e2e9 in tcp_init_children () at tcp_main.c:4867
#20 0x080affb1 in main_loop () at main.c:1646
#21 0x080b1be4 in main (argc=9, argv=0xbfd61e54) at main.c:2446

Pid 3:

Core was generated by `/usr/sbin/kamailio -u swrun -g sw -m 120 -f /etc/kamailio/kamailio.cfg'.
Program terminated with signal 11, Segmentation fault.
#0  0xb76c9e7c in memmove () from /lib/libc.so.6
(gdb) bt
#0  0xb76c9e7c in memmove () from /lib/libc.so.6
#1  0x081724e7 in tcp_read_req (con=0xb022c8f0, bytes_read=0xbfd619cc, read_flags=0xbfd619c4) at tcp_read.c:1026
#2  0x08172f67 in handle_io (fm=<value optimized out>, events=1, idx=<value optimized out>) at tcp_read.c:1234
#3  0x0817583b in io_wait_loop_epoll (unix_sock=93) at io_wait.h:1092
#4  tcp_receive_loop (unix_sock=93) at tcp_read.c:1345
#5  0x0816e2e9 in tcp_init_children () at tcp_main.c:4867
#6  0x080affb1 in main_loop () at main.c:1646
#7  0x080b1be4 in main (argc=9, argv=0xbfd61e54) at main.c:2446




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-- 
Daniel-Constantin Mierla -- http://www.asipto.com
Kamailio Advanced Training, Dec 5-8, Berlin: http://asipto.com/u/kat
http://linkedin.com/in/miconda -- http://twitter.com/miconda


-- 
Daniel-Constantin Mierla -- http://www.asipto.com
Kamailio Advanced Training, Dec 5-8, Berlin: http://asipto.com/u/kat
http://linkedin.com/in/miconda -- http://twitter.com/miconda



-- 
Daniel-Constantin Mierla -- http://www.asipto.com
http://linkedin.com/in/miconda -- http://twitter.com/miconda



_______________________________________________
sr-dev mailing list
sr-dev@lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev


-- 
Daniel-Constantin Mierla -- http://www.asipto.com
http://linkedin.com/in/miconda -- http://twitter.com/miconda