Keys for Net::SSH2 - perl

Question

I have a simple perl test script which uses Net::SSH2, and I'm having trouble getting it to work with public key authentication.
Note: After reading a couple of replies, I realise that I should mention that I created the script to help narrow down a problem I was having with another application that uses Net::SSH2. It's therefore not possible for me to switch to an alternative package such as Net::OpenSSH or Net::OpenSSH::Compat::SSH2.
Note Update: As salva pointed out, Net::OpenSSH::Compat::SSH2 can be used without having to patch the original application.
Here's the code:
use strict;
use warnings;
use 5.10.0;
use Net::SSH2;
my $ssh2 = Net::SSH2->new();
my $auth;
if ( $ssh2->connect('hostname') ) {
$auth = $ssh2->auth_publickey(
'username',
'/home/mike/.ssh/id_rsa.pub',
'/home/mike/.ssh/id_rsa',
'password'
);
}
if ($auth && $ssh2->auth_ok) {
say 'Success';
} else {
say join ', ', $ssh2->error;
}
I have been generating key pairs using ssh-keygen on Ubuntu:
ssh-keygen -t rsa
ssh-copy-id user#server
ssh user#server
The above works correctly - I can SSH to the server.
When I run the Perl code, I get the following error when using a password protected key:
-16, LIBSSH2_ERROR_FILE, Unable to initialize private key from file
If I try with a non-password protected key, it works correctly.
I have the following libraries installed:
Net::SSH2 0.35
libssh2-1 1.2.2-1
libssh2-1-dev 1.2.2-1
ssh 1:5.3p1-3ubuntu6
openssh-server 1:5.3p1-3ubuntu6
openssh-client 1:5.3p1-3ubuntu6
openssl 0.9.8k-7ubuntu8.6
libssl-dev 0.9.8k-7ubuntu8.6
The plot thickens
If I remove libssh2-1 and libssh2-1-dev, I get an error, as expected:
Can't load '/usr/local/lib/perl/5.10.1/auto/Net/SSH2/SSH2.so'
If I then build libssh2 from source, I am unable to reinstall Net::SSH2, as it can't find the development headers. However, if I reinstall libssh2-1 and libssh2-1-dev and then build and install libssh2 from source, it works.
Does that mean that the build of libssh2-1-dev on Ubuntu 10.04 is at fault? If so, how do I install libssh2 from source and correctly install Net::SSH2, without requiring libssh2-1-dev. I presume that the build from source is overwriting or overriding the Ubuntu package.
UPDATE
As noted in Daniel Stenberg's reply, the Ubuntu 10.04 package is now a little out of date (version 1.2.2, compared with the latest stable build at 1.2.8). Installing libssh2 from source 'over the top' of the Ubuntu package solves the problem. However, this feels messy to me. How can I remove the Ubuntu package, install libssh2 from source, and still build Net::SSH2 — how do I tell Net::SSH2 where to find the libssh2 development headers?
UPDATE 2
salva came to the rescue again, and showed how the Net::SSH2 installer can be configured with lib and include directories, so that it may be used with the source install of libssh2. Thanks salva! Note that instead of patching Makefile.PL, it's possible to just override the $lib and $inc variables at the top of Makefile.PL. I wasn't aware of this until I looked at salva's patch.

Answer 1

I have been able to successfully log into a server using a pass-phrase protected key with Net::SSH2 from the the Ubuntu 11.04 libnet-ssh2-perl package.
Anyway, consider using Net::OpenSSH or Net::OpenSSH::Compat::SSH2 instead of Net::SSH2.
Update: Net::OpenSSH::Compat::SSH2 tries to be a replacement for Net::SSH2. There is no need to patch the application in order to try it:
perl -MNet::OpenSSH::Compat=Net::SSH2 yor_app.pl

Answer 2

When you install libssh2 from the source package it will by default install itself in /usr/local, while the default package installs in /usr which probably is why it only finds the "stock" installed version.
Unfortunately it seems your Ubuntu has a fairly old libssh2 version as it has been bugfixed a lot since then.
I recommend using the libssh2-devel mailing list for in-depth libssh2 questions. It's a small but friendly community.

Answer 3

I have created a patch for Net::SSH2 Makefile.PL that allows to set the location of libssh2 libs and headers from the command line.
Here is a capture of the full build process for libssh2 + Net::SSH2 using it:
salva#leon:/tmp/salva$ wget http://www.libssh2.org/download/libssh2-1.2.8.tar.gz
--2011-05-27 11:21:10-- http://www.libssh2.org/download/libssh2-1.2.8.tar.gz
Resolving www.libssh2.org... 80.67.6.50
Connecting to www.libssh2.org|80.67.6.50|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 637707 (623K) [application/x-gzip]
Saving to: `libssh2-1.2.8.tar.gz'
100%[================================================================================================================================================================================================>] 637,707 525K/s in 1.2s
2011-05-27 11:21:14 (525 KB/s) - `libssh2-1.2.8.tar.gz' saved [637707/637707]
salva#leon:/tmp/salva$ tar xzf libssh2-1.2.8.tar.gz
salva#leon:/tmp/salva$ cd libssh2-1.2.8
salva#leon:/tmp/salva/libssh2-1.2.8$ ./configure --prefix=/usr/local/libssh2
checking whether to enable maintainer-specific portions of Makefiles... no
checking for sed... /bin/sed
checking for a BSD-compatible install... /usr/bin/install -c
...
salva#leon:/tmp/salva/libssh2-1.2.8$ make
Making all in src
make[1]: Entering directory `/tmp/salva/libssh2-1.2.8/src'
make all-am
make[2]: Entering directory `/tmp/salva/libssh2-1.2.8/src'
if /bin/bash ../libtool --tag=CC --mode=compile gcc -DHAVE_CONFIG_H -I../include -I../src -g -O2 -MT channel.lo -MD -MP -MF ".deps/channel.Tpo" -c -o channel.lo channel.c; \
then mv -f ".deps/channel.Tpo" ".deps/channel.Plo"; else rm -f ".deps/channel.Tpo"; exit 1; fi
libtool: compile: gcc -DHAVE_CONFIG_H -I../include -I../src -g -O2 -MT channel.lo -MD -MP -MF .deps/channel.Tpo -c channel.c -fPIC -DPIC -o .libs/channel.o
...
salva#leon:/tmp/salva/libssh2-1.2.8$ sudo make install
Making install in src
make[1]: Entering directory `/tmp/salva/libssh2-1.2.8/src'
make[2]: Entering directory `/tmp/salva/libssh2-1.2.8/src'
test -z "/usr/local/libssh2/lib" || mkdir -p -- "/usr/local/libssh2/lib"
/bin/bash ../libtool --mode=install /usr/bin/install -c 'libssh2.la' '/usr/local/libssh2/lib/libssh2.la'
libtool: install: /usr/bin/install -c .libs/libssh2.so.1.0.1 /usr/local/libssh2/lib/libssh2.so.1.0.1
...
salva#leon:/tmp/salva/libssh2-1.2.8$ cd ..
salva#leon:/tmp/salva$ wget http://search.cpan.org/CPAN/authors/id/R/RK/RKITOVER/Net-SSH2-0.35.tar.gz
--2011-05-27 11:22:56-- http://search.cpan.org/CPAN/authors/id/R/RK/RKITOVER/Net-SSH2-0.35.tar.gz
Resolving search.cpan.org... 207.115.101.144
Connecting to search.cpan.org|207.115.101.144|:80... connected.
HTTP request sent, awaiting response... 302 Found
Location: http://osl.ugr.es/CPAN/authors/id/R/RK/RKITOVER/Net-SSH2-0.35.tar.gz [following]
--2011-05-27 11:22:59-- http://osl.ugr.es/CPAN/authors/id/R/RK/RKITOVER/Net-SSH2-0.35.tar.gz
Resolving osl.ugr.es... 150.214.21.7
Connecting to osl.ugr.es|150.214.21.7|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 92434 (90K) [application/x-gzip]
Saving to: `Net-SSH2-0.35.tar.gz'
100%[================================================================================================================================================================================================>] 92,434 328K/s in 0.3s
2011-05-27 11:22:59 (328 KB/s) - `Net-SSH2-0.35.tar.gz' saved [92434/92434]
salva#leon:/tmp/salva$ tar xzf Net-SSH2-0.35.tar.gz
salva#leon:/tmp/salva$ cd Net-SSH2-0.35
salva#leon:/tmp/salva/Net-SSH2-0.35$ wget -q --no-check-certificate -O - https://github.com/salva/net-ssh2/commit/3c7261f4584137f4240d204731e20f709f1addb1.patch|patch -p1
patching file Makefile.PL
salva#leon:/tmp/salva/Net-SSH2-0.35$ perl Makefile.PL lib=/usr/local/libssh2/lib/ inc=/usr/local/libssh2/include/
The libssh2 library is required by this module. If you don't have it, you can
download it from http://www.libssh2.org; you may also need OpenSSL, which can be
obtained from http://www.openssl.org.
Debian: sudo aptitude install libssh2-1-dev
OpenSUSE: sudo zypper in libssh2-1 libssh2-devel
Checking if your kit is complete...
Looks good
Writing Makefile for Net::SSH2
salva#leon:/tmp/salva/Net-SSH2-0.35$ make
cp lib/Net/SSH2/File.pm blib/lib/Net/SSH2/File.pm
cp lib/Net/SSH2/PublicKey.pm blib/lib/Net/SSH2/PublicKey.pm
cp lib/Net/SSH2/Dir.pm blib/lib/Net/SSH2/Dir.pm
cp lib/Net/SSH2/SFTP.pm blib/lib/Net/SSH2/SFTP.pm
cp lib/Net/SSH2/Listener.pm blib/lib/Net/SSH2/Listener.pm
cp lib/Net/SSH2/Channel.pm blib/lib/Net/SSH2/Channel.pm
cp lib/Net/SSH2.pm blib/lib/Net/SSH2.pm
AutoSplitting blib/lib/Net/SSH2.pm (blib/lib/auto/Net/SSH2)
/usr/bin/perl "-Iinc" /usr/local/share/perl/5.10.1/ExtUtils/xsubpp -typemap /usr/share/perl/5.10/ExtUtils/typemap -typemap typemap SSH2.xs > SSH2.xsc && mv SSH2.xsc SSH2.c
cc -c /usr/local/libssh2/include/ -D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O2 -g -DVERSION=\"0.35\" -DXS_VERSION=\"0.35\" -fPIC "-I/usr/lib/perl/5.10/CORE" SSH2.c
In file included from SSH2.xs:11:0:
ppport.h:3042:0: warning: "PERL_UNUSED_DECL" redefined
/usr/lib/perl/5.10/CORE/perl.h:330:0: note: this is the location of the previous definition
cc: /usr/local/libssh2/include/: linker input file unused because linking not done
Running Mkbootstrap for Net::SSH2 ()
chmod 644 SSH2.bs
rm -f blib/arch/auto/Net/SSH2/SSH2.so
LD_RUN_PATH="/usr/local/libssh2/lib:/lib/x86_64-linux-gnu" cc -shared -O2 -g -L/usr/local/lib -fstack-protector SSH2.o -o blib/arch/auto/Net/SSH2/SSH2.so \
-L/usr/local/libssh2/lib/ -lssh2 -lz -lssl -lcrypto \
chmod 755 blib/arch/auto/Net/SSH2/SSH2.so
cp SSH2.bs blib/arch/auto/Net/SSH2/SSH2.bs
chmod 644 blib/arch/auto/Net/SSH2/SSH2.bs
Manifying blib/man3/Net::SSH2::File.3pm
Manifying blib/man3/Net::SSH2::Dir.3pm
Manifying blib/man3/Net::SSH2::PublicKey.3pm
Manifying blib/man3/Net::SSH2::SFTP.3pm
Manifying blib/man3/Net::SSH2::Listener.3pm
Manifying blib/man3/Net::SSH2::Channel.3pm
Manifying blib/man3/Net::SSH2.3pm
salva#leon:/tmp/salva/Net-SSH2-0.35$ ldd ./blib/arch/auto/Net/SSH2/SSH2.so
linux-vdso.so.1 => (0x00007fff20abc000)
libssh2.so.1 => /usr/local/libssh2/lib/libssh2.so.1 (0x00007f464d52f000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f464d317000)
libssl.so.0.9.8 => /lib/libssl.so.0.9.8 (0x00007f464d09a000)
libcrypto.so.0.9.8 => /lib/libcrypto.so.0.9.8 (0x00007f464cd0b000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f464c977000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f464c772000)
/lib64/ld-linux-x86-64.so.2 (0x00007f464d97e000)
salva#leon:/tmp/salva/Net-SSH2-0.35$ sudo make install
...