From fad5b3a7171d0d127ad6535b8954dfc1ad10fbc6 Mon Sep 17 00:00:00 2001
From: Joseph Birr-Pixton <jpixton@gmail.com>
Date: Fri, 23 Feb 2024 15:29:57 +0000
Subject: [PATCH] Implement `BIO_f_ssl` stub

---
 rustls-libssl/build.rs     |  1 +
 rustls-libssl/src/bio.rs   | 20 +++++++++++++++++++-
 rustls-libssl/src/entry.rs |  8 +++++++-
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/rustls-libssl/build.rs b/rustls-libssl/build.rs
index fdf5a6b..4d0051d 100644
--- a/rustls-libssl/build.rs
+++ b/rustls-libssl/build.rs
@@ -42,6 +42,7 @@ fn write_version_file() -> String {
 }
 
 const ENTRYPOINTS: &[&str] = &[
+    "BIO_f_ssl",
     "OPENSSL_init_ssl",
     "SSL_alert_desc_string",
     "SSL_alert_desc_string_long",
diff --git a/rustls-libssl/src/bio.rs b/rustls-libssl/src/bio.rs
index 1f4eccf..b7236c6 100644
--- a/rustls-libssl/src/bio.rs
+++ b/rustls-libssl/src/bio.rs
@@ -1,4 +1,4 @@
-use core::ffi::{c_char, c_int, c_long, c_void};
+use core::ffi::{c_char, c_int, c_long, c_void, CStr};
 use std::io;
 
 // nb. cannot use any BIO types from openssl_sys: it doesn't
@@ -226,6 +226,24 @@ impl Drop for Bio {
     }
 }
 
+static NAME: &CStr = c"ssl";
+const BIO_TYPE_SSL: i32 = 0x0200 | 7;
+
+pub static SSL_BIO_METHOD: bio_method_st = bio_method_st {
+    type_: BIO_TYPE_SSL,
+    name: NAME.as_ptr(),
+    bwrite: None,
+    bwrite_old: None,
+    bread: None,
+    bread_old: None,
+    bputs: None,
+    bgets: None,
+    ctrl: None,
+    create: None,
+    destroy: None,
+    callback_ctrl: None,
+};
+
 // This is a public interface between libcrypto and libssl, but is
 // defined in `internal/bio.h`.  Hmm.
 #[repr(C)]
diff --git a/rustls-libssl/src/entry.rs b/rustls-libssl/src/entry.rs
index b7a103a..2981f71 100644
--- a/rustls-libssl/src/entry.rs
+++ b/rustls-libssl/src/entry.rs
@@ -12,7 +12,7 @@ use openssl_sys::{
     stack_st_X509, OPENSSL_malloc, X509, X509_STORE, X509_STORE_CTX, X509_V_ERR_UNSPECIFIED,
 };
 
-use crate::bio::{Bio, BIO};
+use crate::bio::{Bio, BIO, BIO_METHOD};
 use crate::error::{ffi_panic_boundary, Error, MysteriouslyOppositeReturnValue};
 use crate::ffi::{
     free_arc, str_from_cstring, to_arc_mut_ptr, try_clone_arc, try_from, try_mut_slice_int,
@@ -69,6 +69,12 @@ entry! {
     }
 }
 
+entry! {
+    pub fn _BIO_f_ssl() -> *const BIO_METHOD {
+        &crate::bio::SSL_BIO_METHOD
+    }
+}
+
 type SSL_METHOD = crate::SslMethod;
 
 entry! {