SSL: RSA_generate_key() is deprecated in OpenSSL 1.1.0.
OpenSSL removed support for all 40 and 56 bit ciphers.
diff --git a/src/mail/ngx_mail_ssl_module.c b/src/mail/ngx_mail_ssl_module.c
index 971085c..ff5c141 100644
--- a/src/mail/ngx_mail_ssl_module.c
+++ b/src/mail/ngx_mail_ssl_module.c
@@ -421,7 +421,7 @@
SSL_CTX_set_options(conf->ssl.ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
}
-#ifndef LIBRESSL_VERSION_NUMBER
+#if (OPENSSL_VERSION_NUMBER < 0x10100001L && !defined LIBRESSL_VERSION_NUMBER)
SSL_CTX_set_tmp_rsa_callback(conf->ssl.ctx, ngx_ssl_rsa512_key_callback);
#endif