workaround openssl shutdown race condition

refs: openssl/openssl#6214
refs: sfackler/rust-openssl#1324

Author: wez

libssh-rs/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libssh-rs"
-version = "0.1.6"
+version = "0.1.7"
 edition = "2018"
 repository = "https://github.com/wez/libssh-rs"
 description = "Bindings to the libssh library"
@@ -12,6 +12,10 @@ license = "MIT"
 bitflags = "1.3"
 libssh-rs-sys = { version = "0.1.3", path = "../libssh-rs-sys" }
 thiserror = "1.0"
+# Pinned on this last version with openssl-src-300 until a newer release
+# is made that unblocks it.
+# <https://github.com/sfackler/rust-openssl/pull/1578>
+openssl-sys = "=0.9.71"
 
 [features]
 vendored = ["libssh-rs-sys/vendored"]

libssh-rs/src/lib.rs

@@ -31,6 +31,17 @@ pub use crate::sftp::*;
 struct LibraryState {}
 impl LibraryState {
     pub fn new() -> Option<Self> {
+        // Force openssl to initialize.
+        // In theory, we don't need this, but in practice we do because of
+        // this bug:
+        // <https://github.com/openssl/openssl/issues/6214>
+        // which weirdly requires that *all* openssl threads be joined before
+        // the process exits, which is an unrealistic expectation on behalf
+        // of that library.
+        // That was worked around in openssl_sys:
+        // <https://github.com/sfackler/rust-openssl/pull/1324>
+        // which tells openssl to skip the process-wide shutdown.
+        openssl_sys::init();
         let res = unsafe { sys::ssh_init() };
         if res != sys::SSH_OK as i32 {
             None