php - What is the difference between CURLOPT_SSLKEY and CURLOPT_SSH_PRIVATE_KEYFILE? -

i looking @ this question and, try find mistake, went php manual seen 2 options :

curlopt_ssh_private_keyfile file name private key. if not used, libcurl defaults $home/.ssh/id_dsa if home environment variable set, , "id_dsa" in current directory if home not set. if file password-protected, set password curlopt_keypasswd.

curlopt_sslkey name of file containing private ssl key.

op of question uses curlopt_ssh_public_keyfile guess should uses curlopt_ssh_private_keyfile instead of curlopt_sslkey, don't know difference between options.

so here comes question :

what difference between curlopt_sslkey , curlopt_ssh_private_keyfile ?

well, found difference between ssh , ssl in it security question.

thomas pornin answered :

ssl , ssh both provide cryptographic elements build tunnel confidential data transport checked integrity. part, use similar techniques, , may suffer same kind of attacks, should provide similar security (i.e. security) assuming both implemented. both exist kind of nih syndrome: ssh developers should have reused ssl tunnel part (the ssl protocol flexible enough accommodate many variations, including not using certificates).

they differ on things around tunnel. ssl traditionally uses x.509 certificates announcing server , client public keys; ssh has own format. also, ssh comes set of protocols goes inside tunnel (multiplexing several transfers, performing password-based authentication within tunnel, terminal management...) while there no such thing in ssl, or, more accurately, when such things used in ssl not considered part of ssl (for instance, when doing password-based http authentication in ssl tunnel, part of "https", works in way similar happens ssh).

conceptually, take ssh , replace tunnel part 1 ssl. take https , replace ssl thing ssh-with-data-transport , hook extract server public key certificate. there no scientific impossibility and, if done properly, security remain same. however, there no widespread set of conventions or existing tools that.

so not use ssl , ssh same things, that's because of tools historically came implementations of protocols, not due security related difference. , whoever implements ssl or ssh advised @ kind of attacks tried on both protocols.

i able answer question without guessing :-)