I'm trying to retrieve a file from an instance using libssh2 scp.
Just to make sure that my username, password, and keys are correct, I did:
sudo scp -v -P #port -i /home/username/.ssh/id_rsa username@XX.XX.XX.XX:/home/username/file .
Which asked me for the password, and then retrieved the file successfully.
In trying to accomplish the same thing with libssh2, I followed the example here:
http://www.libssh2.org/examples/scp.html
With superficial changes to variable types that seem to have since changed
(Not that it should matter, as those variables come after authentication).
However, on
libssh2_userauth_publickey_fromfile(session, username,"/home/username/.ssh/id_rsa.pub","/home/username/.ssh/id_rsa",password)
The program always exits with a LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED.
Checking using gdb, I'm certain that the username and passwords being applied are correct.
What reasons might there be that are causing this problem?
Edit:
Further delving with GDB reveals that somewhere in the depth of libssh2_userauth_publickey_fromfile(), in _libssh2_userauth_publickey(session, username, username_len, pubkeydata, pubkeydata_len, sign_callback, abstract), it receives a LIBSSH2_ERROR_SOCKET_RECV.
The code behind that, however, is much too enigmatic for my untrained eye to make sense of.
One obvious thing I've missed is the error message, which comes out to be "Waiting for USERAUTH response"
Potentially relevant:
https://github.com/nodegit/nodegit/issues/553
After following what little advice I could gather from above link and removing a few keys from authorized_keys, the error remains the same but the message changed to "Callback returned error". Not sure if improvement or worse.
Checking server-side logs, I find the following:
Oct 20 06:53:51 testbed1 sshd[25837]: error: Could not load host key: /etc/ssh/keyname
Oct 20 06:53:52 testbed1 sshd[25837]: Connection closed by XX.XX.XX.XX [preauth]
Oct 20 06:54:48 testbed1 sshd[25839]: error: Could not load host key: /etc/ssh/keyname
Oct 20 06:54:51 testbed1 sshd[25839]: Accepted publickey for username from...
The first two lines are on a failed attempted from libssh2.
The next two lines are on a successful attempt from scp on commandline.
