How to use the features of the old version in the new version？

[yylime]

When I used ssh2 = "0.9.4" to connect to my switch, which only supports the diffie-hellman-group1-sha1 key exchange algorithm and ssh-rsa cipher, I encountered an error.

Finisheddevprofile [unoptimized + debuginfo] target(s) in 0.06s Runningtarget/debug/switch_sshthread 'main' panicked at src/main.rs:13:22: calledResult::unwrap()on anErrvalue: Error { code: Session(-41), msg: "out of bounds" } stack backtrace: 0: rust_begin_unwind at /rustc/90b35a6239c3d8bdabc530a6a0816f7ff89a0aaf/library/std/src/panicking.rs:665:5 1: core::panicking::panic_fmt at /rustc/90b35a6239c3d8bdabc530a6a0816f7ff89a0aaf/library/core/src/panicking.rs:74:14 2: core::result::unwrap_failed at /rustc/90b35a6239c3d8bdabc530a6a0816f7ff89a0aaf/library/core/src/result.rs:1700:5 3: core::result::Result<T,E>::unwrap at /rustc/90b35a6239c3d8bdabc530a6a0816f7ff89a0aaf/library/core/src/result.rs:1104:23 4: switch_ssh::main at ./src/main.rs:13:5 5: core::ops::function::FnOnce::call_once at /rustc/90b35a6239c3d8bdabc530a6a0816f7ff89a0aaf/library/core/src/ops/function.rs:250:5 note: Some details are omitted, run withRUST_BACKTRACE=full for a verbose backtrace.

However, when I changed the ssh2 version to 0.8, it worked for this switch, but I then faced the following error when connecting to a newer switch:SSH handshake failed: Error { code: Session(-5), msg: "Unable to exchange encryption keys" }
What should I do to resolve this issue?

[yodaldevoid]

I believe your issue is with the underlying libssh2. You can choose to use a version of libssh2 that is not the vendored version, but we can't guarantee it will work. You may want to look into the (relatively) recent changes around ssh-rsa support in libssh2.