无法在/usr/local/ line 64/Perl 5/Net/SSH/Perl/kex.pm第107行找到通过包“Net：：SSH：：Kex：：C 25519”的对象方法"exchange“

Question

我一直在使用Perl的SSH包连接到我的RHEL系统。最近，我将我的一个VM升级为redhat-release 7.2-9.el7.x86_64。现在，当我运行Perl脚本时，它抛出了错误：

无法在/usr/local/ line 64/Perl 5/Net/SSH/Perl/kex.pm第107行找到通过包"Net::SSH::Perl::Kex::C25519“的对象方法"exchange”。当生成ssh对象时。

在我的6.8RHEL版本上，同样的脚本也在运行。有什么建议吗？

以下是代码：

#!/usr/local/bin/perl
use strict;
use warnings;
use Net::SSH::Perl;
my $ssh = Net::SSH::Perl->new($server_ip, debug=>1);
$ssh->login("root","password");

调试打印：

[root@Automation_linux_10]# perl temp.pl
Automation_linux_[Auto_server_ip]: Reading configuration data /root/.ssh/config
Automation_linux_[Auto_server_ip]: Reading configuration data /etc/ssh_config
Automation_linux_[Auto_server_ip]: Allocated local port 1023.
Automation_linux_[Auto_server_ip]: Connecting to [SERVER_IP], port 22.
Automation_linux_[Auto_server_ip]: Remote version string: SSH-2.0-OpenSSH_6.6.1
Automation_linux_[Auto_server_ip]: Remote protocol version 2.0, remote software version OpenSSH_6.6.1
Automation_linux_[Auto_server_ip]: Net::SSH::Perl Version 2.12, protocol version 2.0.
Automation_linux_[Auto_server_ip]: No compat match: OpenSSH_6.6.1.
Automation_linux_[Auto_server_ip]: Connection established.
Automation_linux_[Auto_server_ip]: Sent key-exchange init (KEXINIT), waiting for response.
Automation_linux_[Auto_server_ip]: Using curve25519-sha256@libssh.org for key exchange
Automation_linux_[Auto_server_ip]: Host key algorithm: ssh-ed25519
Automation_linux_[Auto_server_ip]: Algorithms, c->s: chacha20-poly1305@openssh.com <implicit> none
Automation_linux_[Auto_server_ip]: Algorithms, s->c: chacha20-poly1305@openssh.com <implicit> none
Can't locate object method "exchange" via package "Net::SSH::Perl::Kex::C25519" at /usr/local/lib64/perl5/Net/SSH/Perl/Kex.pm line 107.

Answer 1

我猜您没有安装Crypt::Curve25519 perl module。

为了发现这一点，我所做的是从Kex.pm中修改Net::SSH::Perl package，如下所示：

--- lib/perl5/vendor_perl/5.26.0/i386-netbsd-thread-multi/Net/SSH/Perl/Kex.pm.orig      2017-08-23 11:10:46.000000000 +0000
+++ lib/perl5/vendor_perl/5.26.0/i386-netbsd-thread-multi/Net/SSH/Perl/Kex.pm
@@ -234,6 +234,9 @@ sub choose_kex {
     if (my $pkg = $kexmap{$name}) {
         $kex->{ssh}->debug("Using $name for key exchange");
         eval "use Net::SSH::Perl::Kex::$pkg";
+        if ($@) {
+            $kex->{ssh}->debug("Problem using Net::SSH::Perl::Kex::$pkg: $@");
+        }
         $kex->{class_name} = __PACKAGE__ . '::' . $pkg;
     } else {
         croak "Bad kex algorithm $name";

并使用上面的小测试脚本获得了上面提到的perl模块没有找到的大量错误消息。