Stub out SSL_CTX_set_tmp_dh_callback

This is needed by ubuntu-22 haproxy.

Author: ctz

MATRIX.md

@@ -195,7 +195,7 @@
 | `SSL_CTX_set_tlsext_max_fragment_length`  |  |  |  |  |
 | `SSL_CTX_set_tlsext_ticket_key_evp_cb`  |  |  | :white_check_mark: | :exclamation: [^stub] |
 | `SSL_CTX_set_tlsext_use_srtp` [^srtp] |  |  |  |  |
-| `SSL_CTX_set_tmp_dh_callback` [^deprecatedin_3_0] [^dh] |  |  |  |  |
+| `SSL_CTX_set_tmp_dh_callback` [^deprecatedin_3_0] [^dh] |  |  |  | :exclamation: [^stub] |
 | `SSL_CTX_set_trust`  |  |  |  |  |
 | `SSL_CTX_set_verify`  | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | `SSL_CTX_set_verify_depth`  |  | :white_check_mark: |  | :white_check_mark: |

build.rs

@@ -139,6 +139,7 @@ const ENTRYPOINTS: &[&str] = &[
     "SSL_CTX_set_srp_username_callback",
     "SSL_CTX_set_timeout",
     "SSL_CTX_set_tlsext_ticket_key_evp_cb",
+    "SSL_CTX_set_tmp_dh_callback",
     "SSL_CTX_set_verify",
     "SSL_CTX_set_verify_depth",
     "SSL_CTX_up_ref",

src/entry.rs

@@ -2462,12 +2462,19 @@ entry_stub! {
     pub fn _SSL_get_srp_userinfo(_ssl: *mut SSL) -> *mut c_char;
 }
 
-// no DH ciphersuites
+// no DH ciphersuites or DH KX reuse
 
 entry_stub! {
     pub fn _SSL_CTX_set0_tmp_dh_pkey(_ctx: *mut SSL_CTX, _dhpkey: *mut EVP_PKEY) -> c_int;
 }
 
+entry_stub! {
+    pub fn _SSL_CTX_set_tmp_dh_callback(_ctx: *mut SSL_CTX, _dh: SSL_CTX_tmp_dh_callback);
+}
+
+type SSL_CTX_tmp_dh_callback =
+    Option<unsafe extern "C" fn(ssl: *mut SSL, is_export: c_int, keylength: c_int) -> *mut c_void>;
+
 // no post-handshake auth
 
 entry_stub! {