libssh2 - SSH2 library
======================
libssh2 is a library implementing the SSH2 protocol, available under
the revised BSD license.
Generic installation instructions are in INSTALL. Some ./configure
options deserve additional comments:
* --enable-crypt-none
The SSH2 Transport allows for unencrypted data
transmission using the "none" cipher. Because this is
such a huge security hole, it is typically disabled on
SSH2 implementations and is disabled in libssh2 by
default as well.
Enabling this option will allow for "none" as a
negotiable method, however it still requires that the
method be advertized by the remote end and that no
more-preferable methods are available.
* --enable-mac-none
The SSH2 Transport also allows implementations to
forego a message authentication code. While this is
less of a security risk than using a "none" cipher, it
is still not recommended as disabling MAC hashes
removes a layer of security.
Enabling this option will allow for "none" as a
negotiable method, however it still requires that the
method be advertized by the remote end and that no
more-preferable methods are available.
* --disable-gex-new
The diffie-hellman-group-exchange-sha1 (dh-gex) key
exchange method originally defined an exchange
negotiation using packet type 30 to request a
generation pair based on a single target value. Later
refinement of dh-gex provided for range and target
values. By default libssh2 will use the newer range
method.
If you experience trouble connecting to an old SSH
server using dh-gex, try this option to fallback on
the older more reliable method.
* --with-libgcrypt
* --without-libgcrypt
* --with-libgcrypt-prefix=DIR
libssh2 can use the Libgcrypt library
(http://www.gnupg.org/) for cryptographic operations.
Either Libgcrypt or OpenSSL is required.
Configure will attempt to locate Libgcrypt
automatically.
If your installation of Libgcrypt is in another
location, specify it using --with-libgcrypt-prefix.
* --with-openssl
* --without-openssl
* --with-libssl-prefix=[DIR]
libssh2 can use the OpenSSL library
(http://www.openssl.org) for cryptographic operations.
Either Libgcrypt or OpenSSL is required.
Configure will attempt to locate OpenSSL in the
default location.
If your installation of OpenSSL is in another
location, specify it using --with-libssl-prefix.
* --with-libz
* --without-libz
* --with-libz-prefix=[DIR]
If present, libssh2 will attempt to use the zlib
(http://www.zlib.org) for payload compression, however
zlib is not required.
If your installation of Libz is in another location,
specify it using --with-libz-prefix.
* --enable-debug
Will make the build use more pedantic and strict compiler
options as well as enable the libssh2_trace() function (for
showing debug traces).
