"Could not parse PKey: no start line" error message needs improvement

[btm]

capistrano/capistrano#286
http://tickets.opscode.com/browse/CHEF-4180

When net-ssh can't find part of the private/public keypair in net-ssh 2.6 it errors with:

ArgumentError: Could not parse PKey: no start line

This error doesn't convey the issue well and usually requires a bunch of poking around to resolve it.

[delano]

Thanks for the report. The project is in maintenance mode but I'm happy to take a pull request.

[delano]

This is in 2.7.0 which is now on Rubygems. Thanks again.

[temujin9]

This issue appears to be recurring for me, in any version of net-ssh above 2.5.2. Using a key that is not password locked avoids the issue.

[birdie-github]

I can reproduce this issue with net-ssh 2.9.2/3.0.2. What can be done?

This on Ubuntu 14.04 LTS with ruby 2.3.0 installed using RVM.

DEBUG: establishing connection to XXX.XXX.XXX.XXX:22
DEBUG: connection established
INFO: negotiating protocol version
DEBUG: remote is `SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2'
DEBUG: local is `SSH-2.0-Ruby/Net::SSH_3.0.2 i686-linux'
DEBUG: read 1648 bytes
DEBUG: received packet nr 0 type 20 len 1644
INFO: got KEXINIT from server
INFO: sending KEXINIT
DEBUG: queueing packet nr 0 type 20 len 1684
DEBUG: sent 1688 bytes
INFO: negotiating algorithms
DEBUG: negotiated:
* kex: diffie-hellman-group-exchange-sha1
* host_key: ecdsa-sha2-nistp256
* encryption_server: aes128-cbc
* encryption_client: aes128-cbc
* hmac_client: hmac-sha1
* hmac_server: hmac-sha1
* compression_client: none
* compression_server: none
* language_client: 
* language_server: 
DEBUG: exchanging keys
DEBUG: queueing packet nr 1 type 34 len 20
DEBUG: sent 24 bytes
DEBUG: read 152 bytes
DEBUG: received packet nr 1 type 31 len 148
DEBUG: queueing packet nr 2 type 32 len 140
DEBUG: sent 144 bytes
DEBUG: read 376 bytes
DEBUG: received packet nr 2 type 33 len 356
DEBUG: queueing packet nr 3 type 21 len 20
DEBUG: sent 24 bytes
DEBUG: received packet nr 3 type 21 len 12
DEBUG: beginning authentication of `apps'
DEBUG: queueing packet nr 4 type 5 len 28
DEBUG: sent 52 bytes
DEBUG: read 52 bytes
DEBUG: received packet nr 4 type 6 len 28
DEBUG: trying none
DEBUG: queueing packet nr 5 type 50 len 44
DEBUG: sent 68 bytes
DEBUG: read 68 bytes
DEBUG: received packet nr 5 type 51 len 44
DEBUG: allowed methods: publickey,password
DEBUG: none failed
DEBUG: trying publickey
DEBUG: connecting to ssh-agent
ERROR: could not connect to ssh-agent
DEBUG: trying publickey (***sanitized***)
DEBUG: queueing packet nr 6 type 50 len 604
DEBUG: sent 628 bytes
DEBUG: read 580 bytes
DEBUG: received packet nr 6 type 60 len 556
WARNING: Failed to connect to XXX.XXX.XXX.XXX -- ArgumentError: Could not parse PKey: no start line

I can easily connect to the same PC using SSH (ssh $host.fqdn - just works).

My public/private key are valid and they are NOT password protected.

[mfazekas]

What is your private key format?
Also you can try with 4.0.0.alpha3

[birdie-github]

How can I know what's my private key format? I generated it using Fedora 23.

Here's the command I used:

ssh-keygen -b 4096 -a 64 -t rsa -o

OpenSSH version 7.2p2.

[mfazekas]

what was the command you used to generate it?

[birdie-github]

Here's the command I used:

ssh-keygen -b 4096 -a 64 -t rsa -o

[mfazekas]

also what is the key header?
mine encrypted looks like this:

-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AES-128-CBC, ..
...
-----END RSA PRIVATE KEY-----

[mfazekas]

 -o      Causes ssh-keygen to save SSH protocol 2 private keys using the new OpenSSH format rather than the more compatible PEM format.  The new format has increased resistance to
             brute-force password cracking but is not supported by versions of OpenSSH prior to 6.5.  Ed25519 keys always use the new private key format.

can you try net-ssh 4.0 beta? It should support the new format.

[birdie-github]

~/.ssh$ head -1 id_rsa; tail -1 id_rsa
-----BEGIN OPENSSH PRIVATE KEY-----
-----END OPENSSH PRIVATE KEY-----

[birdie-github]

Is it (4.0 beta) available as gem?