fix: compilation on RedHat 7

src/src/lib/shared/openssl_utils.h

@@ -118,7 +118,11 @@ namespace seismicdrive
         static std::string SignStringWithPem(std::string const &str, std::string const &pem_contents, JwtSigningAlgorithms alg)
         {
             std::string msg = "Permanent error in SignStringWithPem (failed to sign string with PEM key): Unable to ";
+#if (OPENSSL_VERSION_NUMBER < 0x10100000L) // Older than version 1.1.0
+            std::unique_ptr<EVP_MD_CTX, decltype(&EVP_MD_CTX_destroy)> digest_ctx(EVP_MD_CTX_create(), &EVP_MD_CTX_destroy);
+#else
             std::unique_ptr<EVP_MD_CTX, decltype(&EVP_MD_CTX_free)> digest_ctx(EVP_MD_CTX_new(), &EVP_MD_CTX_free);
+#endif
             if (!digest_ctx)
             {
                 throw error::authprovider::Error(msg + "create context for OpenSSL digest.");