libssh2 1.10

This release includes the following enhancements and bugfixes:

 o adds agent forwarding support
 o adds OpenSSH Agent support on Windows
 o adds ECDSA key support using the Mbed TLS backend
 o adds ECDSA cert authentication
 o adds diffie-hellman-group14-sha256, diffie-hellman-group16-sha512,
   diffie-hellman-group18-sha512 key exchanges
 o adds support for PKIX key reading when using ed25519 with OpenSSL
 o adds support for EWOULDBLOCK on VMS systems
 o adds support for building with OpenSSL 3
 o adds support for using FIPS mode in OpenSSL
 o adds debug symbols when building with MSVC
 o adds support for building on the 3DS
 o adds unicode build support on Windows
 o restores os400 building
 o increases min, max and opt Diffie Hellman group values
 o improves portiablity of the make file
 o improves timeout behavior with 2FA keyboard auth
 o various improvements to the Wincng backend
 o fixes reading parital packet replies when using an agent
 o fixes Diffie Hellman key exchange on Windows 1903+ builds
 o fixes building tests with older versions of OpenSSL
 o fixes possible multiple definition warnings
 o fixes potential cast issues _libssh2_ecdsa_key_get_curve_type()
 o fixes potential use after free if libssh2_init() is called twice
 o improved linking when using Mbed TLS
 o fixes call to libssh2_crypto_exit() if crypto hasn't been initialized
 o fixes crash when loading public keys with no id
 o fixes possible out of bounds read when exchanging keys
 o fixes possible out of bounds read when reading packets
 o fixes possible out of bounds read when opening an X11 connection
 o fixes possible out of bounds read when ecdh host keys
 o fixes possible hang when trying to read a disconnected socket
 o fixes a crash when using the delayed compression option
 o fixes read error with large known host entries
 o fixes various warnings
 o fixes various small memory leaks
 o improved error handling, various detailed errors will now be reported
 o builds are now using OSS-Fuzz
 o builds now use autoreconf instead of a custom build script
 o cmake now respects install directory
 o improved CI backend
 o updated HACKING-CRYPTO documentation
 o use markdown file extensions
 o improved unit tests

This release would not have looked like this without help, code, reports and
advice from friends like these:

  katzer, Orgad Shaneh, mark-i-m, Zenju, axjowa, Thilo Schulz,
  Etienne Samson, hlefebvre, seba30, Panos, jethrogb, Fabrice Fontaine,
  Will Cosgrove, Daniel Stenberg, Michael Buckley, Wallace Souza Silva,
  Romain-Geissler-1A, meierha, Tseng Jun, Thomas Klausner, Brendan Shanks,
  Harry Sintonen, monnerat, Koutheir Attouchi, Marc Hörsken, yann-morin-1998,
  Wez Furlong, TDi-jonesds, David Benjamin, Max Dymond, Igor Klevanets,
  Viktor Szakats, Laurent Stacul, Mstrodl, Gabriel Smith, MarcT512,
  Paul Capron, teottin, Tor Erik Ottinsen, Brian Inglis

  (40 contributors)