-\versionid $Id: faq.but,v 1.22 2002/03/24 13:42:30 jacob Exp $
+\versionid $Id: faq.but,v 1.30 2002/07/09 11:34:10 jacob Exp $
\A{faq} PuTTY FAQ
\S{faq-ssh2-keyfmt}{Question} Does PuTTY support reading OpenSSH or
\cw{ssh.com} SSHv2 private key files?
-Not at present. OpenSSH and \cw{ssh.com} have totally different
-formats for private key files, and neither one is particularly
-pleasant, so PuTTY has its own. We do plan to write a converter at
-some stage.
+Version 0.52 doesn't, but in the latest development snapshots
+PuTTYgen can load and save both OpenSSH and \cw{ssh.com} private key
+files.
\S{faq-ssh1}{Question} Does PuTTY support SSH v1?
server instead); but it doesn't necessarily mean you've actually run
out of memory.
+\S{faq-outofmem2}{Question} When attempting a file transfer, either
+PSCP or PSFTP says \q{Out of memory} and dies.
+
+This is almost always caused by your login scripts on the server
+generating output. PSCP or PSFTP will receive that output when they
+were expecting to see the start of a file transfer protocol, and
+they will attempt to interpret the output as file-transfer protocol.
+This will usually lead to an \q{out of memory} error for much the
+same reasons as given in \k{faq-outofmem}.
+
+This is a setup problem in your account on your server, \e{not} a
+PSCP/PSFTP bug. Your login scripts should \e{never} generate output
+during non-interactive sessions; secure file transfer is not the
+only form of remote access that will break if they do.
+
+On Unix, a simple fix is to ensure that all the parts of your login
+script that might generate output are in \c{.profile} (if you use a
+Bourne shell derivative) or \c{.login} (if you use a C shell).
+Putting them in more general files such as \c{.bashrc} or \c{.cshrc}
+is liable to lead to problems.
+
+\S{faq-psftp-slow} PSFTP transfers files much slower than PSCP.
+
+We believe this is because the SFTP and SSH2 protocols are less
+efficient at bulk data transfer than SCP and SSH1, because every
+block of data transferred requires an acknowledgment from the far
+end. It would in theory be possible to queue several blocks of data
+to get round this speed problem, but as yet we haven't done the
+coding. If you really want this fixed, feel free to offer to help.
+
\S{faq-bce}{Question} When I run full-colour applications, I see
areas of black space where colour ought to be.
This is not a PuTTY-specific problem; if you try to connect with
another client you'll likely have similar problems.
-Configurations known to be broken and symptoms:
+Configurations known to be broken (and symptoms):
\b SSH 2 with AES cipher (PuTTY says "Assertion failed! Expression:
(len & 15) == 0" in sshaes.c, or "Out of memory", or crashes)
+\b SSH 2 with 3DES (PuTTY says "Incorrect MAC received on packet")
+
\b SSH 1 with Blowfish (PuTTY says "Incorrect CRC received on
packet")
\W{http://bugzilla.mindrot.org/show_bug.cgi?id=138}{bug 138} in the
OpenSSH BTS.
+\e{Update:} As of OpenSSH 3.4p1 the problem with SSH 1 and Blowfish
+remains. Apply the patch linked to from bug 138, or use another cipher
+(e.g., 3DES) instead.
+
+\S{faq-ssh2key-ssh1conn}{Question} Why do I see "Couldn't load private
+key from ..."? Why can PuTTYgen load my key but not PuTTY?
+
+It's likely that you've generated an SSH protocol 2 key with PuTTYgen,
+but you're trying to use it in an SSH 1 connection. SSH1 and SSH2 keys
+have different formats, and (at least in 0.52) PuTTY's reporting of a
+key in the wrong format isn't optimal.
+
+To connect using SSH 2 to a server that supports both versions, you
+need to change the configuration from the default (see \k{faq-ssh2}).
+
\H{faq-secure} Security questions
\S{faq-publicpc}{Question} Is it safe for me to download PuTTY and
~mdw / sgt / putty / blobdiff