Slashdot Mirror
OpenSSH 4.2 released
BSDForums writes "OpenSSH 4.2 has been released. OpenSSH is a 100% complete SSH protocol version 1.3, 1.5 and 2.0 implementation and includes sftp client and server support.
Changes since OpenSSH 4.1 include security bug fixes relating to GatewayPorts, and GSSAPI, which eliminates the risk of credentials being inadvertently exposed to an untrusted user/host. A new compression method, proactive changes for signed vs. unsigned integer bugs, and many additional bugfixes and improvements highlight this release."
"proactive".
I've found that it offers a good 10% to 15% decrease in data size compared to the previous method.
Cyric Zndovzny at your service.
From the changelog:
"- Increase the default size of new RSA/DSA keys generated by ssh-keygen from 1024 to 2048 bits."
It's good to see that the default size of the keys had been increased. It's only a matter of time before modern systems (or clusters of modern systems) are capable of defeating even 1024 bit keys routinely. This proactive doubling of the default keysize is sure to increase the overall security for OpenSSH users for some time.
Cyric Zndovzny at your service.
From the changelog:
- Portable OpenSSH: Added support for long passwords (> 8-char) on UnixWare 7.
I'm surprised that it has taken them this long to add support for long passwords to UnixWare 7. UnixWare 7 is a modern UNIX by all means, considering it is still being updated frequently. Can anybody shed some light as to why it took so long for this fairly rudimentary support to be added to the portable version of OpenSSH?
Cyric Zndovzny at your service.
A new version of my favorite Linux tool! How great! I could not live a second without being able to scp file.tar.bz2 user@hostname:/path, or without being able to open files remotely using KDEs fish: fish://username:passord@host.box/some/path works in all the KDE file dialog boxes thanks to SSH. Nor would I be able to login to the box where I have my irssi IRC client running, connected to numerous IRC servers and a BitlBee gateway for MSN/ICQ/AIM/Google Talk. And then there is sftp.. SSH is something completely essential for most experienced Linux-users, used one way or the other constantly when I am in front of my computer. So thank you, SSH developers, for making my life better! And thank you for a new, more secure version.
9/11: Never forget it was a false-flag operation
From the changelog:
- Implemented support for X11 and agent forwarding over multiplexed connections. Because of protocol limitations, the slave connections inherit the master's DISPLAY and SSH_AUTH_SOCK rather than distinctly forwarding their own.
This bugfix may very well affect the performance of OpenSSH when used to encrypt communications with a remote X11 server.
Cyric Zndovzny at your service.
From the changelog:
" Added a new compression method that delays the start of zlib compression until the user has been authenticated successfully. The new method ("Compression delayed") is on by default in the server. This eliminates the risk of any zlib vulnerability leading to a compromise of the server from unauthenticated users." (emphasis mine)
OpenSSH used zlib before, and they're still using it now. All they've done is delay the start of compressed streams until after authentication. This is a security fix, not a speed boost.
There is no question that Mr. deRaadt is quite outspoken. But he can produce some damn fine and mighty secure code. I have nothing but the utmost respect for his coding abilities, even if his public relations skill are lacking.
Frankly, I'd rather put up with arrogance and have access to amazing code, rather than dealing with a nice person who can't write code worthy of a cockfool.
Cyric Zndovzny at your service.
I'll take that, thanks!
Keep up the good work guys.
No problem, Bill. After all, open source software (especially that under the BSD license) is meant to be shared and used by all, basically however they see fit. That's the name of the game, Mr. Gates.
Cyric Zndovzny at your service.
What "damage" did he do to Open source?
...well...He is probably an asperger.
He annoys people.
Post is bollocks - "new" compression method is a security fix, not a functional improvement.
Sigh. Back to my commercial (vandyke vshelld) implementation....
Theo de Raadt is ok really, he puts his coding where his mouth is. And at least he's not a corporate ass-licker like a lot of others. He does not corrupt his vision with corporate goodies.
Where can I download your OpenSSH replacement ?
Compression algorithms matter quite a bit. Remember, if you can save even 100 bytes for every second of data flow, that adds up quickly. That's 6000 bytes/minute. That's 360000 bytes/hour. That's 8640000 bytes/day. Over the course of a year you'd save around 3 GB. That can very well impact on bandwidth costs when multiplied by several (if not hundreds of) users.
It's factors like that which make OpenSSL, especially OpenSSL 4.2, very appealing to network administrators who must take into account bandwidth costs.
Cyric Zndovzny at your service.
You realy should have a look a FreeNX http://freshmeat.net/projects/freenx/>
FreeNX Server is the Free and GPL'd NX server implementation by Fabian Franz, based on NoMachine.com's NX technology. NoMachine have thankfully licensed the core of NX under the GPL (they provide a close-source commercial NX server product on top of that code, as well as professional support).
The NX protocol let you use remote X display while connected by low bandwidth lines. It require much less bandwith than raw X or X over compressed ssh.
Léa Gris
I don't really care about the politics. Maybe that is something I would take in consderation if I wanted to be his friend and have him around people I know, but why does it matter when it comes to using his code?
What I do know is that OpenSSH is a fine piece of software and it gets put on all of my servers. I'll be happy to know that Theo's code is in there.
Admittedly, yes, Theo is (or at least can be) quite an asshole. But what does that have to do with the quality of OpenSSH (or OpenBSD)?
Like him or not, but it's a great program, and not using it just because you don't like the lead developer, when there are no actual reasons not to, is stupid.
quidquid latine dictum sit altum videtur.
So we must stop using one of the worlds best security software because somebody does not like Theo de Raadt?
Are you mod fucking insane?
As a friend of mine says, "It's OK if they call you an asshole, if they say it with awe."
Theo is certainly opinionated, and he may or may not be an asshole, but his group produces some damn fine software. You may not like his methods, but it's difficult to argue with his results.
wikipedia article "After de Raadt stated his disapproval of the U.S.-led occupation of Iraq in an interview with Toronto's Globe and Mail, a multi-million-dollar US Department of Defense grant to the University of Pennsylvania's POSSE project was cancelled, effectively ending the project. Funding from the grant had been used in the development of OpenSSH and OpenBSD, as well as many other projects and was to be used to pay for the hackathon planned for the May 8, 2003. Despite money from the grant already having been used to secure accommodations for 60 developers for a week, the money was reclaimed by the government at a loss and the hotel told to not allow the developers to pay the reclaimed money to resecure the rooms. This resulted in criticism among some that the US military held an anti-free speech attitude."
...
What's bad about doing THE RIGHT THING? Even if you have to pay the price. This is what we want from a security specialist.
Is this solution secure? -->
specialist: Well, blabla...quantum computing...
marketing guy: Absolutely!
Go to Iraq? -->
A trustful security specialist has to tell you the truth. Diplomacy serves stupidity and insecurity.
Military systems want "loyality", they do not want you to talk about problems, they want you to report that everything's fine. Because when you talk about problems it means work for them. That is why they fail, why they are dysfunctional from an organisational perspective. Dictorship simply means: organise the state like the military system. but the fact is: Problems make life intresting. Problems are no shame. Shutting down discussions about them does not solve them. Think negative!
Why flamebait? It's a simple speculation. It's not like it's an insult. If anything it's a reasonable explanation to, and to be honest somewhat of an excuse for, his behaviour.
I've met Stallman and de Raadt and they're both assholes. But the world needs a few people that are willing to be assholes.
He gets results. For example, giving out contact information isn't the nicest way to get hardware docs and firmware, but it works.
I rarely criticize things I don't care about.
if you don't want to pay for the nomachine license, freenx is pretty decent.
The Raven
Here. Notice I'm not the parent poster and I don't really care about De Raadt's attitude (and I use OpenSSH and OpenBSD daily and I have never tried libssh, I just know it exists).
No GNU has been Hurd during the making of this comment.
I had an instance of an attacker running a dictionary attack on my sshd the other day, and I was surprised by how many logins he could test per second (he was using multiple connections). I asked on #openbsd about ways of slowing down such attacks. This is the advice I got:
1. Run sshd on a different port. The scripts won't find you there. I don't like this option, because it requires me to specify the alternative port every time i ssh, scp, rsync, or svn. It's still about the easiest and most effective method.
2. Limit the connection rate to the port you're running sshd on. In many scenarios, it won't hurt you if you can't connect to it more than once in 5 seconds, but this will make a dictionary attack from a single machine very tedious. In OpenBSD 3.7, you can use pf with max-src-conn-rate.
3. Use a script like DenyHosts to monitor your authentication log, and add suspicious hosts to a block list (either temporarily or permanently). This looks like a very nice solution to me.
4. I got this one from my girlfriend: disable password authentication and use key-based authentication instead. This is my prefered solution, except that I have to solve some problems with public key authentication not working from some of the machines I use.
I hope this post is helpful to some of you. If you have any other methods that you would like to mention, I'd be glad to hear.
Please correct me if I got my facts wrong.
Talented people, real genius, think of Mozart and others... they are usually a little bit mad and they deserve tolerance.
They can take the freedom to be different and we have to understand that we have to adopt to them.
As a workaround you can wrap all the remote files in a temporary tar file to protect any sym.links etc, then scp the tar file and untar the tar file after the transfer but it would be much quicker and simpler if you could use scp to do this.
Scroogle
GSSAPI, in case anyone here is unfamiliar with the term, is pretty much Kerberos 5. It's a key-based network authentication and security scheme used on many UNIX networks, and in a bastardised form by Windows AD domains.
It's also been on my "I really must implement that" list for waaaay too long. I find that more basic TLS-and-client-cert schemes do the job well enough most of the time.
He gets results. For example, giving out contact information isn't the nicest way to get hardware docs and firmware, but it works.
de Raadt only releases contact information when everything else has failed for several months. The latest incident with Adaptec is an example of this.
..on any given day.
/var/log/messages|wc -l
:-)
Box #1:
grep "authentication failure"
/var/log/messages|wc -l
1362
Box #2:
grep "authentication failure"
1520
Thank you very much for more great SSH tips, I hope you do not mind I recycled them at http://en.linuxreviews.org/Ssh (it is a wiki, so I can easily remove your work if you mind, or you can do it..)
9/11: Never forget it was a false-flag operation
The OpenBSD community does tend to be a bit arrogant, but that's what you get from developing an OS which considers free-as-in-RMS to be just about free enough at a push, and which gets used to security advisories being tagged as `does not apply on OpenBSD'.
I am TheRaven on Soylent News
Isn't that a subject covered somewhere around the fourth or fifth class for ANSI C? And it took this long?
My how time flies when you're too busy with the bigger picture... At least they actually got around to the bug hunting.
If my grammar and spelling are off, I am [distracted/tired/careless] (take your pick)
``I hope you do not mind I recycled them at http://en.linuxreviews.org/Ssh''
I most certainly don't mind, otherwise I wouldn't have posted them here. You might want to change the wording, though. It sounds a bit strange the way it stands. If you do that, could you also change the link to my site to read "inglorion" instead of "Bob"; I prefer to use my handle rather than my name when it's not about personal communication.
Anyway, thanks for putting it there!
Please correct me if I got my facts wrong.
Didn't know about DenyHosts, wrote something similar in sshd_failed_ips.pl. I didn't want a deamon or cron job when it's completely unnecessary, though me script does depend on TCP wrappers (any dist. not running that by default?)
Belief is the currency of delusion.
I have waited along time for the release of the new OpenSSH 4.2 . I hoped they fixed the bugs and added soem goodies to this edition anyone here picked up a copy yet? I just hope it is everything it was talked up to be.
Is it recommended that I upgrade OpenSSH to 4.2 on my OpenBSD 3.7 system?
You're thinking of Poul-Henning Kamp and Dag-Erling Smorgrav from the FreeBSD arrogant asshole team.
Frankly, I'd rather put up with arrogance and have access to amazing code, rather than dealing with a nice person who can't write code worthy of a cockfool.
Fortunately, decency and skill/talent are not mutually exclusive, and there are plenty of examples of that, so it's not too much to ask even of brilliant people that they also comport as decent human beings.
Flying is easy, just throw yourself at the ground and miss. -Douglas Adams
Riigghht
All people with aspergers are real assholes.
Seems to me the moderation points are well deserved.
http://saveie6.com/
http://www.psc.edu/networking/projects/hpn-ssh/
there is a patch called HPN-SSH that addresses some issues in ssh that users encounter if they have access to faster networks. SSH has some static flow control buffer values that limit network performance. The work at PSC by Chris Rapier and Michael Stevens is really nice, is proven to work and is gaining (some) broader acceptance.
take it for a test run and if you like it, please encourage the OpenSSH folks to add it into the main trunk.
Then add '-H' to preserve hard links. (Why isn't -H part of -a? Oh well.)
Why do you think 1024 bit asymmetric is roughly equivalent to 128 bit symmetric when numerous sources say it is closer to 80 bit symmetric?
0 4
Here's a quote from RSA Security:
"The design confirms that the traditional assumption that a 1024-bit RSA key provides comparable strength to an 80-bit symmetric key has been a reasonable one." -- http://www.rsasecurity.com/rsalabs/node.asp?id=20
And I don't believe any literature says 1024-bit DH key provides 128-bit symmetric key strength either. Where did you get your info?
I simply added a sleep(10); to the file auth-passwd.c and recompiled.
/* Password authentication delay */
./configure --prefix=/usr --sysconfdir=/etc/ssh
int
auth_password(Authctxt *authctxt, const char *password)
{
struct passwd * pw = authctxt->pw;
int result, ok = authctxt->valid;
#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
static int expire_checked = 0;
#endif
sleep(10);
That slows all password authentication attempts down enormously.
make
make install
service sshd restart
La Voila!
Oh well, what the hell...
1024 bit asymmetric keys for ciphers that rely on the assumed difficulty of factorization are about as difficult to break as 80 bit symmetric keys. And there is no reason to think it will stay that way, people continue to work on finding newer, more effectient methods of factorization.
Everyone knows a better algorithm than brute force: General Number Field Sieve, Number Field Sieve, Quadratic Sieve, and its likely new methods will be found. You don't brute force assymetric keys, brute forcing 1024 bit keys asymmetric keys would take just as long as brute forcing 1024 bit symmetric keys, that is to say it is not possible. Brute force means simply trying every possibility, the algorithm doesn't matter in that case. Trying 2^1024 possibilities is trying 2^1024 possibilities, regardless of how the key was generated or what its used for.
And finally, 1024 bit keys could certainly be broken without all the power of the sun, you are talking out of your ass, plain and simple. In fact, Bruce Schneier always says its likely that a billion dollars would be enough to put together the hardware required to break a 1024 bit key.
Out of his ass, as usual.. This is /.
Yup, that, perhaps combined with a certain natural reluctance to support a company whose main business seems to be litigation and FUD, rather than software, these days. Frankly, I'm a bit surprised that any Unixware enhancements were added at all. I suppose it's not the customers' fault that their vendor has turned into a rabid dog, but still....
There was a quote i heard once, it went something along the lines of this.
"He was a supremely arrogant man, but he carried it well, because he was usually right."
This wasnt made as a reference to Theo at the time, but it seemed apt
Just FYI, this is NOT a "Linux" tool. It's more of an OpenBSD thing than anything else, to be frank. It's just that it was made portable, ported to Linux, and other OS's... Not trying to be ignorant here, but this is just for your own understanding and others. Check it out when you can - www.openssh.org. Regards.
(anon to avoid karma whoring)
From the release notes:
"Added a new compression method that delays the start of zlib compression until the user has been authenticated successfully. The new method ("Compression delayed") is on by default in the server. This eliminates the risk of any zlib vulnerability leading to a compromise of the server from unauthenticated users."
Kerberos uses symmetric encryption. While unlike regular logins it doesn't sent password hashes across the network (just tokens encrypted with those hashes, that people who entered the right password can decrypt), it's still not secure in that it keeps credentials on the KDC. A compromise of the KDC therefore allows an attackers to pretend to be anyone they want.
No modern authentication system should store secrets on the server, This is the reason we have PKI - we store the certificates on the server, and each user is the only person who has their private key. This means:
- A compromise of the authentication server gives the attacker...public keys, that they could get from anywhere.
- It's more easy to hold a user responsible to accidential or deliberate disclosure of their credentials, because only the user has those credentials.
Kerberos was secure when it was invented, But there's no reason my bank needs to store my credentials on their servers, thank you very much, and there's no reason I feel like letting them be responsible for the security of my account any more than necessary. It's popular because of the single sign on aspect (users get an initial token at login time they can use to auth to NFS servers, mail servers, CVS/SVN servers, web servers, etc without needing to retype their password, at least till then login token expires). And lots of apps - every client/server for web, mail, CVS, SVN, NFS, etc in RHEL 4 for example, supports it. But ssh-agent is almost as convenient for SSO - I just wish more apps accepted digital signatures for logon.
So yeah, I can see why you'd use kerberos for network app support, but it's a poor second cousin to PKI when it comes to security.
A new version of my favorite Linux tool!
Hey the SSH server and client can work on Windows too! Install Cygwin to find out. I've been using Cygwin/SSH for about 6 months now and I love it. SSH into the machine, remote (secure) VNC, scp/sftp it's all there and was pretty simple to setup.
I love Cygwin more, because it gives me SSH, but without each other I wouldn't use either.
Get your Unix fortune now!
Honestly, I've known Theo for over 15 years. That's longer that almost everyone else who has an opinon here.
That said, Theo is outspoken, loud, somewhat obnoxious and sometimes very hard to deal with. None of that affects the quality of his work. It certainly affects the quality of interaction you might have with Theo, or the perception you might have around his projects.
I certainly would not conduct my personal affairs with the same aplomb as Theo, nor would I piss in my own Corn Flakes quite like Theo can. This aside, Theo is an intelligent, smart individual and those who choose to draw from him that which is valuable will recognize that his different viewpoints, although sometimes objectionable, are just that : different viewpoints.
Sometimes, in the realm of the übergeek, it is difficult to remember that the goal is to produce the best software possible for the consuption and use of others.
I would never, (I repeat: NEVER), conduct my social affairs in the same fashion as Theo, however, I would be a happy man to be able to hang my hat on the solid line of quality software that he and his cadre of loosely joined pieces have brought us all.
I have partied with de Raadt, I have climbed, caved and even swooned over the same ladies. None of this matters. In the end, love Theo or hate him, he has contributed much to the OSS world and much to the security realm.
I may not choose to give him a grant allocation or hire him for my firm, however, Theo is Theo and at least he holds a consistent standard for himself and those who contribute to the projects he administrates. For this we can all be thankful. Interity is an essential element of honor; if you do not agree with how Theo condicts his affaris; so be it, but I think Theo makes the effort to conduct his own affairs within his own code of honor. Even if this code is incompatible with my own (and it appears to be) I have to respect that.
The reasonable man adapts himself to the world; the unreasonable
one persists in trying to adapt the world to himself. Therefore
all progress depends on the unreasonable man.
-- George Bernard Shaw
I would say change instead of progress. Of course a lot of change can occur because of a soft amiable tone too.
One of the major drawbacks of OpenSSH was the lack of a per-account/per-key based traffic-accounting. I always had the impression that the developer of OpenSSH opposed the basic idea of getting precise data about how much everyone did even if it still is possible for the admin to track everything from outside SSH.
"Life is short and in most cases it ends with death." Sir Sinclair
For end users, perhaps the best feature in this release is
- Added ControlMaster=auto/autoask options to support opportunistic
multiplexing (see the ssh_config(5) manpage for details).
'Multiplexing' means running more than one session across the same ssh connection. So if you use CVS over ssh, or rsync over ssh or even just lots of remote commands, you don't have to start up a new connection for each one. The first ssh connection stays running and new sessions are opened over it. This cuts down the initial network traffic a lot. Great news for modem users and a worthwhile improvement in responsiveness for everyone else.
You need to set up ControlMaster=auto in your ssh_config, which can be in your ~/.ssh/ directory.
-- Ed Avis ed@membled.com
Yes, this is correct. Kerberos is only as secure as your KDCs. The developers of Kerberos did not make a secret out of this, though. That said, Kerberos makes a lot of sense in some environments and not so much in others. You always have to choose the best tool for the job.