Can anyone recommend a decent SFTP library for use with Windows C++ apps? If a cross-platform one is available then all the better, but it's not essential. It's for use with a commercial application, so paying for something isn't an issue.
I am using the superb Ultimate TCP/IP library which supports FTP-S but not SFTP (yeh, I know, confusing isn't it!).
I've come across the Chilkat library, which looks very good, but wondered if there are any others that people have used.
Check out libcurl.
libcurl is a free and easy-to-use client-side URL transfer library, supporting FTP, FTPS, HTTP, HTTPS, SCP, SFTP, TFTP, TELNET, DICT, LDAP, LDAPS and FILE. libcurl supports SSL certificates, HTTP POST, HTTP PUT, FTP uploading, HTTP form based upload, proxies, cookies, user+password authentication (Basic, Digest, NTLM, Negotiate, Kerberos4), file transfer resume, http proxy tunneling and more!
libcurl is highly portable, it builds and works identically on numerous platforms, including Solaris, NetBSD, FreeBSD, OpenBSD, Darwin, HPUX, IRIX, AIX, Tru64, Linux, UnixWare, HURD, Windows, Amiga, OS/2, BeOs, Mac OS X, Ultrix, QNX, OpenVMS, RISC OS, Novell NetWare, DOS and more...
OpenSSH would be a good option. It's cross-platform and comes with a BSD license, so you can use it in your commercial application without having to disclose your source code.