From 1581d454a0d5b7c2dcc850f22051a1ecf3be3246 Mon Sep 17 00:00:00 2001
From: Andy Caldwell <andrew.caldwell@metaswitch.com>
Date: Mon, 18 Oct 2021 16:43:23 +0100
Subject: [PATCH] Support OpenSSL configured with `no-chacha`

---
 openssl-sys/build/expando.c | 4 ++++
 openssl-sys/build/main.rs   | 1 +
 openssl-sys/src/evp.rs      | 4 ++--
 openssl/src/symm.rs         | 4 ++--
 4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/openssl-sys/build/expando.c b/openssl-sys/build/expando.c
index edf7431ea8..300c50bb05 100644
--- a/openssl-sys/build/expando.c
+++ b/openssl-sys/build/expando.c
@@ -23,6 +23,10 @@ RUST_CONF_OPENSSL_NO_BF
 RUST_CONF_OPENSSL_NO_BUF_FREELISTS
 #endif
 
+#ifdef OPENSSL_NO_CHACHA
+RUST_CONF_OPENSSL_NO_CHACHA
+#endif
+
 #ifdef OPENSSL_NO_CMS
 RUST_CONF_OPENSSL_NO_CMS
 #endif
diff --git a/openssl-sys/build/main.rs b/openssl-sys/build/main.rs
index 156056288d..e8dd5451ac 100644
--- a/openssl-sys/build/main.rs
+++ b/openssl-sys/build/main.rs
@@ -137,6 +137,7 @@ fn validate_headers(include_dirs: &[PathBuf]) -> Version {
     // file of OpenSSL, `opensslconf.h`, and then dump out everything it defines
     // as our own #[cfg] directives. That way the `ossl10x.rs` bindings can
     // account for compile differences and such.
+    println!("cargo:rerun-if-changed=build/expando.c");
     let mut gcc = cc::Build::new();
     for include_dir in include_dirs {
         gcc.include(include_dir);
diff --git a/openssl-sys/src/evp.rs b/openssl-sys/src/evp.rs
index 7616bafbc5..e5c2595d26 100644
--- a/openssl-sys/src/evp.rs
+++ b/openssl-sys/src/evp.rs
@@ -359,9 +359,9 @@ extern "C" {
     pub fn EVP_aes_256_ofb() -> *const EVP_CIPHER;
     #[cfg(ossl110)]
     pub fn EVP_aes_256_ocb() -> *const EVP_CIPHER;
-    #[cfg(ossl110)]
+    #[cfg(all(ossl110, not(osslconf = "OPENSSL_NO_CHACHA")))]
     pub fn EVP_chacha20() -> *const ::EVP_CIPHER;
-    #[cfg(ossl110)]
+    #[cfg(all(ossl110, not(osslconf = "OPENSSL_NO_CHACHA")))]
     pub fn EVP_chacha20_poly1305() -> *const ::EVP_CIPHER;
     #[cfg(not(osslconf = "OPENSSL_NO_SEED"))]
     pub fn EVP_seed_cbc() -> *const EVP_CIPHER;
diff --git a/openssl/src/symm.rs b/openssl/src/symm.rs
index f18c6f70c6..0f9b0d4860 100644
--- a/openssl/src/symm.rs
+++ b/openssl/src/symm.rs
@@ -279,13 +279,13 @@ impl Cipher {
     }
 
     /// Requires OpenSSL 1.1.0 or newer.
-    #[cfg(any(ossl110))]
+    #[cfg(all(ossl110, not(osslconf = "OPENSSL_NO_CHACHA")))]
     pub fn chacha20() -> Cipher {
         unsafe { Cipher(ffi::EVP_chacha20()) }
     }
 
     /// Requires OpenSSL 1.1.0 or newer.
-    #[cfg(any(ossl110))]
+    #[cfg(all(ossl110, not(osslconf = "OPENSSL_NO_CHACHA")))]
     pub fn chacha20_poly1305() -> Cipher {
         unsafe { Cipher(ffi::EVP_chacha20_poly1305()) }
     }