Tcl

SFTP Authenticate with Password and Private Key

Demonstrates the Chilkat SFtp.AuthenticatePwPk method, which authenticates with a server that requires both a password and a private key. The arguments are the username, the password, and an SshKey private key.

Note: The private-key path is relative to the application's current working directory. Supply the path to your own key file.

Background: Most servers require either a password or a public key, not both — but some high-security deployments mandate two-factor SSH, combining something you know (the password) with something you have (the key). This method satisfies that policy in one call. As always, the password should come from a secure source rather than a literal in code.

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Tcl


load ./chilkat.dll

set success 0

#  Demonstrates the SFtp.AuthenticatePwPk method, which authenticates with a server that requires
#  BOTH a password and a private key.  The 1st argument is the username, the 2nd is the password,
#  and the 3rd is an SshKey private key.

set sftp [new_CkSFtp]

#  Step 1: Connect the SSH transport.  Port 22 is the usual port.
set port 22
set success [CkSFtp_Connect $sftp "sftp.example.com" $port]
if {$success == 0} then {
    puts [CkSFtp_lastErrorText $sftp]
    delete_CkSFtp $sftp
    exit
}

#  Normally you would not hard-code the password in source.  You should instead obtain it
#  from an interactive prompt, environment variable, or a secrets vault.
set password "mySshPassword"

#  Load the SSH private key.  LoadText reads the file's text, which is then imported.
set privKey [new_CkSshKey]

set keyText [CkSshKey_loadText $privKey "qa_data/id_rsa"]
if {[CkSshKey_get_LastMethodSuccess $privKey] == 0} then {
    puts [CkSshKey_lastErrorText $privKey]
    delete_CkSFtp $sftp
    delete_CkSshKey $privKey
    exit
}

set success [CkSshKey_FromOpenSshPrivateKey $privKey $keyText]
if {$success == 0} then {
    puts [CkSshKey_lastErrorText $privKey]
    delete_CkSFtp $sftp
    delete_CkSshKey $privKey
    exit
}

set success [CkSFtp_AuthenticatePwPk $sftp "mySshLogin" $password $privKey]
if {$success == 0} then {
    puts [CkSFtp_lastErrorText $sftp]
    delete_CkSFtp $sftp
    delete_CkSshKey $privKey
    exit
}

#  Step 3: Open the SFTP subsystem.  This must be done after authentication and before any
#  file or directory operations.
set success [CkSFtp_InitializeSftp $sftp]
if {$success == 0} then {
    puts [CkSFtp_lastErrorText $sftp]
    delete_CkSFtp $sftp
    delete_CkSshKey $privKey
    exit
}

puts "Authenticated with a password and a private key."

CkSFtp_Disconnect $sftp

delete_CkSFtp $sftp
delete_CkSshKey $privKey