-\versionid $Id: pscp.but,v 1.12 2001/07/01 09:21:01 simon Exp $
+\define{versionidpscp} \versionid $Id$
\#FIXME: Need examples
\C{pscp} Using PSCP to transfer files securely
-\# Explain PSCP: the command line, the modes of use (local->remote
-\# and remote->local, recursive, wildcards).
-
\i{PSCP}, the PuTTY Secure Copy client, is a tool for transferring files
securely between computers using an SSH connection.
+If you have an SSH 2 server, you might prefer PSFTP (see \k{psftp})
+for interactive use. PSFTP does not in general work with SSH 1
+servers, however.
+
\H{pscp-starting} Starting PSCP
PSCP is a command line application. This means that you cannot just
\c Z:\owendadmin>pscp
\c PuTTY Secure Copy client
-\c Release 0.50
+\c Release 0.XX
\c Usage: pscp [options] [user@]host:source target
-\c pscp [options] source [source...] [user@]host:target
-\c pscp [options] -ls user@host:filespec
+\c pscp [options] source [source...] [user@]host:target
+\c pscp [options] -ls [user@]host:filespec
\c Options:
\c -p preserve file attributes
\c -q quiet, don't show statistics
\c -r copy directories recursively
\c -v show verbose messages
+\c -load sessname Load settings from saved session
\c -P port connect to specified port
+\c -l user connect with specified username
\c -pw passw login with specified password
+\c -1 -2 force use of particular SSH protocol version
+\c -4 -6 force use of IPv4 or IPv6
+\c -C enable compression
+\c -i key private key file for authentication
+\c -batch disable all interactive prompts
+\c -unsafe allow server-side wildcards (DANGEROUS)
+\c -V print version information
+\c -sftp force use of SFTP protocol
+\c -scp force use of SCP protocol
(PSCP's interface is much like the Unix \c{scp} command, if you're
familiar with that.)
\c pscp [options] source [source...] [user@]host:target
-So to copy the local file \c{c:\\documents\\csh-whynot.txt} to the
-server \c{example.com} as user \c{fred} to the file
-\c{/tmp/csh-whynot} you would type:
-
-\c pscp c:\documents\csh-whynot.txt fred@example.com:/tmp/csh-whynot
+So to copy the local file \c{c:\\documents\\foo.txt} to the server
+\c{example.com} as user \c{fred} to the file \c{/tmp/foo} you would
+type:
+
+\c pscp c:\documents\foo.txt fred@example.com:/tmp/foo
+
+You can use wildcards to transfer multiple files in either
+direction, like this:
+
+\c pscp c:\documents\*.doc fred@example.com:docfiles
+\c pscp fred@example.com:source/*.c c:\source
+
+However, in the second case (using a wildcard for multiple remote
+files) you may see a warning saying something like \q{warning:
+remote host tried to write to a file called 'terminal.c' when we
+requested a file called '*.c'. If this is a wildcard, consider
+upgrading to SSH 2 or using the '-unsafe' option. Renaming of this
+file has been disallowed}.
+
+This is due to a fundamental insecurity in the old-style SCP
+protocol: the client sends the wildcard string (\c{*.c}) to the
+server, and the server sends back a sequence of file names that
+match the wildcard pattern. However, there is nothing to stop the
+server sending back a \e{different} pattern and writing over one of
+your other files: if you request \c{*.c}, the server might send back
+the file name \c{AUTOEXEC.BAT} and install a virus for you. Since
+the wildcard matching rules are decided by the server, the client
+cannot reliably verify that the filenames sent back match the
+pattern.
+
+PSCP will attempt to use the newer SFTP protocol (part of SSH 2)
+where possible, which does not suffer from this security flaw. If
+you are talking to an SSH 2 server which supports SFTP, you will
+never see this warning. (You can force use of the SFTP protocol,
+if available, with \c{-sftp} - see \k{pscp-usage-options-backend}.)
+
+If you really need to use a server-side wildcard with an SSH 1
+server, you can use the \c{-unsafe} command line option with PSCP:
+
+\c pscp -unsafe fred@example.com:source/*.c c:\source
+
+This will suppress the warning message and the file transfer will
+happen. However, you should be aware that by using this option you
+are giving the server the ability to write to \e{any} file in the
+target directory, so you should only use this option if you trust
+the server administrator not to be malicious (and not to let the
+server machine be cracked by malicious people).
\S2{pscp-usage-basics-user} \c{user}
\S{pscp-usage-options} Options
+PSCP accepts all the general command line options supported by the
+PuTTY tools, except the ones which make no sense in a file transfer
+utility. See \k{using-general-opts} for a description of these
+options. (The ones not supported by PSCP are clearly marked.)
+
+PSCP also supports some of its own options. The following sections
+describe PSCP's specific command-line options.
+
These are the command line options that PSCP accepts.
\S2{pscp-usage-options-p}\c{-p} preserve file attributes
By default, PSCP displays a meter displaying the progress of the
current transfer:
-\c mibs.tar | 168 kB | 84.0 kB/s | ETA: 00:00:13 | 13%
+\c mibs.tar | 168 kB | 84.0 kB/s | ETA: 00:00:13 | 13%
The fields in this display are (from left to right), filename, size
(in kilobytes) of file transferred so far, estimate of how fast the
their contents. This allows you to use PSCP to transfer whole
directory structures between machines.
-\S2{pscp-usage-options-v}\c{-v} show \i{verbose} messages
+\S2{pscp-usage-options-batch}\c{-batch} avoid interactive prompts
+
+If you use the \c{-batch} option, PSCP will never give an
+interactive prompt while establishing the connection. If the
+server's host key is invalid, for example (see \k{gs-hostkey}), then
+the connection will simply be abandoned instead of asking you what
+to do next.
-The \c{-v} option to PSCP makes it print extra information about the
-file transfer. For example:
+This may help PSCP's behaviour when it is used in automated
+scripts: using \c{-batch}, if something goes wrong at connection
+time, the batch job will fail rather than hang.
-\c Logging in as "fred".
-\c fred@example.com's password:
-\c Sending command: scp -v -f mibs.tar
-\c Connected to example.com
-\c Sending file modes: C0644 1320960 mibs.tar
-\c mibs.tar | 1290 kB | 67.9 kB/s | ETA: 00:00:00 | 100%
-\c Remote exit status 0
-\c Closing connection
+\S2{pscp-usage-options-backend}\c{-sftp}, \c{-scp} force use of
+particular protocol
-This information may be useful for debugging problems with PSCP.
+As mentioned in \k{pscp-usage-basics}, there are two different file
+transfer protocols in use with SSH. Despite its name, PSCP (like many
+other ostensible \cw{scp} clients) can use either of these protocols.
-\S2{pscp-usage-options-P}\c{-P port} connect to specified \i{port}
+The older SCP protocol does not have a written specification and
+leaves a lot of detail to the server platform. Wildcards are expanded
+on the server. The simple design means that any wildcard specification
+supported by the server platform (such as brace expansion) can be
+used, but also leads to interoperability issues such as with filename
+quoting (for instance, where filenames contain spaces), and also the
+security issue described in \k{pscp-usage-basics}.
-If the \c{host} you specify is a saved session, PSCP uses any port
-number specified in that saved session. If not, PSCP uses the default
-SSH port, 22. The \c{-P} option allows you specify the port number to
-connect to for PSCP's SSH connection.
+The newer SFTP protocol, which is usually associated with SSH 2
+servers, is specified in a more platform independent way, and leaves
+issues such as wildcard syntax up to the client. (PuTTY's SFTP
+wildcard syntax is described in \k{psftp-wildcards}.) This makes it
+more consistent across platforms, more suitable for scripting and
+automation, and avoids security issues with wildcard matching.
-\S2{pscp-usage-options-pw}\c{-pw passw} login with specified \i{password}
+Normally PSCP will attempt to use the SFTP protocol, and only fall
+back to the SCP protocol if SFTP is not available on the server.
-If a password is required to connect to the \c{host}, PSCP will
-interactively prompt you for it. However, this may not always be
-appropriate. If you are running PSCP as part of some automated job,
-it will not be possible to enter a password by hand. The \c{-pw}
-option to PSCP lets you specify the password to use on the command
-line.
+The \c{-scp} option forces PSCP to use the SCP protocol or quit.
-Since specifying passwords in scripts is a bad idea for security
-reasons, you might want instead to consider using public-key
-authentication; see \k{pscp-pubkey}.
+The \c{-sftp} option forces PSCP to use the SFTP protocol or quit.
+When this option is specified, PSCP looks harder for an SFTP server,
+which may allow use of SFTP with SSH 1 depending on server setup.
+
+\S{pscp-retval} Return value
+
+PSCP returns an \cw{ERRORLEVEL} of zero (success) only if the files
+were correctly transferred. You can test for this in a batch file,
+using code such as this:
+
+\c pscp file*.* user@hostname:
+\c if errorlevel 1 echo There was an error
\S{pscp-pubkey} Using public key authentication with PSCP
Like PuTTY, PSCP can authenticate using a public key instead of a
-password. There are two ways you can do this.
+password. There are three ways you can do this.
Firstly, PSCP can use PuTTY saved sessions in place of hostnames
(see \k{pscp-usage-basics-host}). So you would do this:
\b Run PuTTY, and create a PuTTY saved session (see
\k{config-saving}) which specifies your private key file (see
-\k{config-auth}). You will probably also want to specify a username
-to log in as (see \k{config-username}).
+\k{config-ssh-privkey}). You will probably also want to specify a
+username to log in as (see \k{config-username}).
\b In PSCP, you can now use the name of the session instead of a
hostname: type \c{pscp sessionname:file localfile}, where
\c{sessionname} is replaced by the name of your saved session.
-Secondly, PSCP will attempt to authenticate using Pageant if Pageant
+Secondly, you can supply the name of a private key file on the command
+line, with the \c{-i} option. See \k{using-cmdline-identity} for more
+information.
+
+Thirdly, PSCP will attempt to authenticate using Pageant if Pageant
is running (see \k{pageant}). So you would do this:
\b Ensure Pageant is running, and has your private key stored in it.
For more general information on public-key authentication, see
\k{pubkey}.
-
-\H{pscp-ixplorer} \i{Secure iXplorer}
-
-Lars Gunnarson has written a graphical interface for PSCP. You can
-get it from his web site, at
-\W{http://www.i-tree.org/}{www.i-tree.org}.
projects / u / mdw / putty / blobdiff