When I manually sftp using username and password it works fine, when using curl it fails. The same script will successfully connect to other servers with no problem. Because I can manually log in and other clients don't have a problem the server admins aren't much help.
Here is the curl failed attempt:
curl -v --insecure --user username:password sftp://someurl.com
* Trying 199.187.***.***...
* Connected to someurl.com (199.187.***.***) port 22 (#0)
* SSH MD5 fingerprint: 6831eae63f230952a1775e0f67f80e7b
* SSH authentication methods available: publickey,gssapi-keyex,gssapi with-mic,password
* Using SSH public key file '(nil)'
* Using SSH private key file ''
* SSH public key authentication failed: Unable to extract public key from private key file: Unable to open private key file
* Failure connecting to agent
* Authentication failure
* Closing connection 0
curl: (67) Authentication failure
Here is the curl success on another url:
curl --insecure -v sftp://username:password@anotherurl.com
* Rebuilt URL to: sftp://username:password@anotherurl.com/
* Trying 199.27.***.***...
* Connected to anotherurl.com (199.27.***.***) port 22 (#0)
* SSH MD5 fingerprint: bcf5632dc06c0353849b745822c4889a
* SSH authentication methods available: password,publickey
* Using SSH public key file '(nil)'
* Using SSH private key file ''
* SSH public key authentication failed: Unable to extract public key from private key file: Unable to open private key file
* Initialized password authentication
* Authentication complete
drw-rw-rw- 3 user group 2048 Sep 27 2014 .
* Connection #0 to host anotherurl.com left intact
Here is the manual attempt on the original URL:
[ec2-user@ip-*** scripts]$ sftp -v username@someurl.com
OpenSSH_6.2p2, OpenSSL 1.0.1k-fips 8 Jan 2015
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 50: Applying options for *
debug1: Connecting to someurl.com [199.187.***.***] port 22.
debug1: Connection established.
debug1: identity file /home/ec2-user/.ssh/id_rsa type -1
debug1: identity file /home/ec2-user/.ssh/id_rsa-cert type -1
debug1: identity file /home/ec2-user/.ssh/id_dsa type -1
debug1: identity file /home/ec2-user/.ssh/id_dsa-cert type -1
debug1: identity file /home/ec2-user/.ssh/id_ecdsa type -1
debug1: identity file /home/ec2-user/.ssh/id_ecdsa-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.2
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH_5*
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<3072<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Server host key: RSA 68:31:ea:e6:3f:23:09:52:a1:77:5e:0f:67:f8:0e:7b
debug1: Host 'someurl.com' is known and matches the RSA host key.
debug1: Found key in /home/ec2-user/.ssh/known_hosts:6
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available
debug1: Unspecified GSS failure. Minor code may provide more information
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available
debug1: Next authentication method: publickey
debug1: Trying private key: /home/ec2-user/.ssh/id_rsa
debug1: Trying private key: /home/ec2-user/.ssh/id_dsa
debug1: Trying private key: /home/ec2-user/.ssh/id_ecdsa
debug1: Next authentication method: password
username@someurl.com's password:
debug1: Authentication succeeded (password).
Authenticated to someurl.com ([199.187.***.***]:22).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: Sending environment.
debug1: Sending env LANG = en_US.UTF-8
debug1: Sending subsystem: sftp
Connected to someurl.com.
sftp> ls
incoming
sftp>
Any help from those smarter-than-me people would be greatly appreciated.
Got it working, turned out to be pretty simple but would only work with the username and password in the url.
curl -v --insecure sftp://username:urlencodedPassword@somedomain.com
This would not work.
curl -v --insecure --user username:urlencodedPassword sftp://somedomain.com
Someone who knows more than me could probably elaborate as to why they 2nd one wouldn't work.
thanks and for publickey authentication :
curl -v -k --pubkey ~/.ssh/id_rsa.pub sftp://username@host/
来源：https://stackoverflow.com/questions/31730476/curl-fails-on-sftp-password-authentication