git: Always use OpenSSL on win32

By default, libssh2 uses Windows Cryptography Next Generation when targeting
win32. The wincng backend does not support ED25519, which is a widely-used
algorithm among git hosting services, and in some cases may be the only option
on remotes in certain configurations.

This change adds the feature `openssl-on-win32`, enabling the same one in
`libssh2-sys`, and enables it in the CI release flow, ensuring that release
builds are able to communicate with hosts using ED25519.

Fixes jj-vcs#3322

.github/workflows/release.yml

@@ -46,7 +46,7 @@ jobs:
         toolchain: stable
         target: ${{ matrix.target }}
     - name: Build release binary
-      run: cargo build --target ${{ matrix.target }} --verbose --release --features packaging,vendored-openssl
+      run: cargo build --target ${{ matrix.target }} --verbose --release --features packaging,openssl-on-win32,vendored-openssl
     - name: Build archive
       shell: bash
       run: |

CHANGELOG.md

@@ -31,6 +31,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed bugs
 
+* When built with the `openssl-on-win32` feature, ED25519 host keys are supported
+  when connecting to Git+SSH remotes on Windows.
+
 ## [0.17.1] - 2024-05-07
 
 ### Fixed bugs

Cargo.toml

@@ -60,6 +60,7 @@ indoc = "2.0.4"
 insta = { version = "1.38.0", features = ["filters"] }
 itertools = "0.12.1"
 libc = { version = "0.2.154" }
+libssh2-sys = { version = "0.3.0" }
 maplit = "1.0.2"
 minus = { version = "5.6.1", features = ["dynamic_output", "search"] }
 num_cpus = "1.16.0"

cli/Cargo.toml

@@ -89,6 +89,9 @@ unicode-width = { workspace = true }
 [target.'cfg(unix)'.dependencies]
 libc = { workspace = true }
 
+[target.'cfg(windows)'.dependencies]
+libssh2-sys = { workspace = true }
+
 [dev-dependencies]
 anyhow = { workspace = true }
 assert_cmd = { workspace = true }
@@ -104,6 +107,7 @@ jj-cli = { path = ".", features = ["test-fakes"], default-features = false }
 [features]
 default = ["watchman"]
 bench = ["dep:criterion"]
+openssl-on-win32 = ["libssh2-sys/openssl-on-win32", "jj-lib/openssl-on-win32"]
 packaging = []
 test-fakes = ["jj-lib/testing"]
 vendored-openssl = ["git2/vendored-openssl", "jj-lib/vendored-openssl"]

lib/Cargo.toml

@@ -49,6 +49,7 @@ hex = { workspace = true }
 ignore = { workspace = true }
 itertools = { workspace = true }
 jj-lib-proc-macros = { workspace = true }
+libssh2-sys = { workspace = true }
 maplit = { workspace = true }
 once_cell = { workspace = true }
 pest = { workspace = true }
@@ -92,6 +93,7 @@ tokio = { workspace = true, features = ["full"] }
 
 [features]
 default = []
-vendored-openssl = ["git2/vendored-openssl"]
+openssl-on-win32 = ["libssh2-sys/openssl-on-win32"]
+vendored-openssl = ["git2/vendored-openssl", "libssh2-sys/openssl-on-win32"]
 watchman = ["dep:tokio", "dep:watchman_client"]
 testing = []