buck: build libssh2

Signed-off-by: Austin Seipp <aseipp@pobox.com>

buck/third-party/libssh2/BUILD

@@ -0,0 +1,122 @@
+
+load("@root//buck/shims/jj.bzl", "jj")
+
+VERSION = 'ef292424bb5d136f888a2d2e92460de12c143ab4'
+
+http_archive(
+    name = 'src',
+    sha256 = 'de10623f0ab08ca0ccedc95d50f5e827b5f4680935024e6c5ebd7b2ef2129e5f',
+    urls = [
+        f'https://github.com/libssh2/libssh2/archive/{VERSION}.tar.gz',
+    ],
+    type = 'tar.gz',
+    strip_prefix = f'libssh2-{VERSION}',
+    sub_targets = [
+        "include/libssh2.h",
+        "src/agent.c",
+        "src/bcrypt_pbkdf.c",
+        "src/blowfish.c",
+        "src/channel.c",
+        "src/comp.c",
+        "src/crypt.c",
+        "src/global.c",
+        "src/hostkey.c",
+        "src/keepalive.c",
+        "src/kex.c",
+        "src/knownhost.c",
+        "src/mac.c",
+        "src/misc.c",
+        "src/openssl.c",
+        "src/packet.c",
+        "src/pem.c",
+        "src/publickey.c",
+        "src/scp.c",
+        "src/session.c",
+        "src/sftp.c",
+        "src/transport.c",
+        "src/userauth.c",
+        "src/userauth_kbd_packet.c",
+        "src/agent_win.c",
+    ],
+)
+
+jj.cxx_library(
+    name = 'libssh2',
+    srcs = [
+        ":src[src/agent.c]",
+        ":src[src/bcrypt_pbkdf.c]",
+        ":src[src/blowfish.c]",
+        ":src[src/channel.c]",
+        ":src[src/comp.c]",
+        ":src[src/crypt.c]",
+        ":src[src/global.c]",
+        ":src[src/hostkey.c]",
+        ":src[src/keepalive.c]",
+        ":src[src/kex.c]",
+        ":src[src/knownhost.c]",
+        ":src[src/mac.c]",
+        ":src[src/misc.c]",
+        ":src[src/openssl.c]",
+        ":src[src/packet.c]",
+        ":src[src/pem.c]",
+        ":src[src/publickey.c]",
+        ":src[src/scp.c]",
+        ":src[src/session.c]",
+        ":src[src/sftp.c]",
+        ":src[src/transport.c]",
+        ":src[src/userauth.c]",
+        ":src[src/userauth_kbd_packet.c]",
+    ] + select({
+        'config//os:windows': [
+            ':src[src/agent_win.c]',
+        ],
+        'DEFAULT': [],
+    }),
+    headers = ["include/libssh2_config.h"],
+    header_namespace = "",
+    exported_headers = {
+        'libssh2.h': ':src[include/libssh2.h]',
+    },
+    include_directories = ["include"],
+    compiler_flags = select({
+        'config//os:windows': [],
+        'DEFAULT': ["-fvisibility=hidden"],
+    }),
+    preferred_linkage = "static",
+    preprocessor_flags = [
+        "-I$(location :src)/src",
+        "-I$(location :src)/include",
+        "-DLIBSSH2_OPENSSL",
+        "-DHAVE_EVP_AES_128_CTR",
+        "-DLIBSSH2_DH_GEX_NEW",
+        "-DLIBSSH2_HAVE_ZLIB",
+    ] + select({
+        'config//os:windows': [
+            "-I$(location :src)/win32",
+            "-DLIBSSH2_WIN32",
+            "-DWIN32_LEAN_AND_MEAN",
+            "-DNOMINMAX",
+        ],
+        'DEFAULT': [
+            "-DHAVE_SNPRINTF",
+            "-DHAVE_UNISTD_H",
+            "-DHAVE_INTTYPES_H",
+            "-DHAVE_SYS_SELECT_H",
+            "-DHAVE_SYS_UIO",
+            "-DHAVE_SYS_SOCKET_H",
+            "-DHAVE_SYS_IOCTL_H",
+            "-DHAVE_SYS_TIME_H",
+            "-DHAVE_SYS_UN_H",
+            "-DHAVE_O_NONBLOCK",
+            "-DHAVE_LIBCRYPT32",
+            "-DHAVE_POLL",
+            "-DHAVE_GETTIMEOFDAY",
+        ],
+    }),
+
+    deps = [
+        "third-party//bssl:crypto",
+        "third-party//bssl:ssl",
+        "third-party//libz:libz",
+    ],
+)

buck/third-party/libssh2/PACKAGE

@@ -0,0 +1,5 @@
+
+package(
+    inherit = True,
+    visibility = [ 'PUBLIC' ],
+)

buck/third-party/libssh2/include/libssh2_config.h

@@ -0,0 +1,5 @@
+// NOTE (aseipp): this file is supposed to contain CMake-generated #define's in
+// the upstream build system. we don't use CMake to build, and we pass those
+// flags directly using -D, just like the libssh2-rs build.rs script does it. so
+// this file only needs to exist so that the C source files can include it as a
+// no-op