Question about using NULL for public key and determining whether my distro built libssh2 against openssl

Will Cosgrove will at
Wed Sep 28 00:52:03 CEST 2022

There isn't currently a runtime check to get what backend libssh2 was built against. 

This has come up from time to time but never been implemented.


> On Sep 27, 2022, at 2:20 PM, Reid Thompson via libssh2-devel <libssh2-devel at> wrote:
> Hi,
> If I use the following, the authentication succeeds.
>        if (libssh2_userauth_publickey_fromfile(session, "rthompso",                                                                 
>                            "/home/rthompso/.ssh/",                                                                        
>                            "/home/rthompso/.ssh/id_rsa",                                                                            
>                            NULL)) {                                                                                                 
>            fprintf(stderr, "\tAuthentication by public key failed\n");
> It fails if I set the public key to NULL.
> The documentation states that if libssh2 is built against openssl that
> the public key can be NULL.  Is there a way to determine if my distro built
> libssh2 against openssl?  
> Thanks,
> reid
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