Re: instability

[Aris Adamantiadis <aris@xxxxxxxxxxxx>]

Hi Paulo,

Are you using libssh in several threads ? Libssh is threadsafe under 
two conditions : call ssh_init() outside of threads and initialize 
threading in the crypto library 
(http://www.openssl.org/support/faq.html#PROG1).
With libssh 0.5, it's a little different, you have to initialize libssh 
threads and call ssh_init(). (libssh does the dirty work of 
initilalizing libcrypto or libgcrypt).

Hope this helps,

Aris

Le 23/05/11 21:41, Paulo Panhoto a écrit :
> Hello,
>
> I'm writing a Qt app with libssh. The best approach I've got was this:
> wrap ssh in a QThread that emits signals to other components.
>
>
>          session = ssh_new();
>
>          if (session == NULL)
>          {
>              throw SSHException(tr("ssh_new failed"));
>          }
>          const std::string & stdHost = host.toStdString();
>          ssh_options_set(session, SSH_OPTIONS_HOST, stdHost.c_str());
>          ssh_options_set(session, SSH_OPTIONS_PORT, &port);
>          ssh_options_set(session, SSH_OPTIONS_SSH1, &disabled);
>          ssh_options_set(session, SSH_OPTIONS_SSH2, &enabled);
>
>          emit stateChanged(CONNECTING);
>          emit debugInfo(tr("Conecting to %0:%1").arg(host).arg(port));
>          if (ssh_connect(session) != SSH_OK)
>          {
>              throw SSHException(QString("ssh_connect:
> %1").arg(ssh_get_error(session)));
>          }
>
> This piece of code is causing me trouble: I'm running it on a opensuse
> 11.3 and tested it with libssh 0.4.2 (the "branding" release) and 0.4.8.
>
> When I compile it against OpenSSL, I get aborts due to double free
> inside libcrypto: works most of the time when I run it natively.
> Nevertheless, when the program is run via xming server, the error rate
> is almost 100%
> libopenssl 1.0.0-6.7.1 - x86_64
>
> #0  0x00007ffff5aca9e5 in raise () from /lib64/libc.so.6
> #1  0x00007ffff5acbee6 in abort () from /lib64/libc.so.6
> #2  0x00007ffff5b05c53 in __libc_message () from /lib64/libc.so.6
> #3  0x00007ffff5b0b226 in malloc_printerr () from /lib64/libc.so.6
> #4  0x00007ffff5b0e8e3 in _int_realloc () from /lib64/libc.so.6
> #5  0x00007ffff5b10142 in realloc () from /lib64/libc.so.6
> #6  0x00007ffff4ca6d4f in CRYPTO_realloc () from /lib64/libcrypto.so.1.0.0
> #7  0x00007ffff4d0d2a8 in lh_insert () from /lib64/libcrypto.so.1.0.0
> #8  0x00007ffff4ca980c in OBJ_NAME_add () from /lib64/libcrypto.so.1.0.0
> #9  0x00007ffff4d1a66b in OpenSSL_add_all_digests () from
> /lib64/libcrypto.so.1.0.0
> #10 0x00007ffff7bac3cc in ssh_crypto_init () at
> /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/dh.c:144
> #11 0x00007ffff7bae8f1 in ssh_init () at
> /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/init.c:47
> #12 0x00007ffff7ba929c in ssh_connect (session=0xc3b8e0)
>
> If I compile it against libgcrypt, it fails all the time due to an
> assertion failure --  ath.c:193: _gcry_ath_mutex_lock: Assertion `*lock
> == ((ath_mutex_t) 0)' failed.
> libgcrypt  1.4.4-6.1 - x86-64
>
> #0  0x00007ffff5ac79e5 in raise () from /lib64/libc.so.6
> #1  0x00007ffff5ac8ee6 in abort () from /lib64/libc.so.6
> #2  0x00007ffff4fdcaa8 in ?? () from /lib64/libgcrypt.so.11
> #3  0x00007ffff4fdd1c7 in ?? () from /lib64/libgcrypt.so.11
> #4  0x00007ffff4fd75f6 in ?? () from /lib64/libgcrypt.so.11
> #5  0x00007ffff4fd7792 in ?? () from /lib64/libgcrypt.so.11
> #6  0x00007ffff7ba8f7b in ssh_crypto_init ()
>      at /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/dh.c:115
> #7  0x00007ffff7bab961 in ssh_init ()
>      at /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/init.c:47
> #8  0x00007ffff7ba5ebc in ssh_connect (session=0xccf260)
>      at /home/paulo/Downloads/oss-src/libssh-0.4.8/libssh/client.c:516
>
> Am I missing any steps?? Is openSSL the best library to compile with??
>
> Any idea is appreciated.
>
> Regards,
>
> Paulo.