rsa: Fix LibreSSL before v2.7.0

Fix LibreSSL compilation for versions before v2.7.0.

Signed-off-by: Caliph Nomble <nomble@palism.com>
Reviewed-by: Jonathan Gray <jsg@jsg.id.au>
diff --git a/lib/rsa/rsa-sign.c b/lib/rsa/rsa-sign.c
index cfe09cc..05ac67b 100644
--- a/lib/rsa/rsa-sign.c
+++ b/lib/rsa/rsa-sign.c
@@ -20,7 +20,8 @@
 #define HAVE_ERR_REMOVE_THREAD_STATE
 #endif
 
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || \
+	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)
 static void RSA_get0_key(const RSA *r,
                  const BIGNUM **n, const BIGNUM **e, const BIGNUM **d)
 {
@@ -299,7 +300,8 @@
 {
 	int ret;
 
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || \
+	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)
 	ret = SSL_library_init();
 #else
 	ret = OPENSSL_init_ssl(0, NULL);
@@ -308,7 +310,8 @@
 		fprintf(stderr, "Failure to init SSL library\n");
 		return -1;
 	}
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || \
+	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)
 	SSL_load_error_strings();
 
 	OpenSSL_add_all_algorithms();
@@ -354,7 +357,8 @@
 err_engine_init:
 	ENGINE_free(e);
 err_engine_by_id:
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || \
+	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)
 	ENGINE_cleanup();
 #endif
 	return ret;
@@ -362,7 +366,8 @@
 
 static void rsa_remove(void)
 {
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || \
+	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)
 	CRYPTO_cleanup_all_ex_data();
 	ERR_free_strings();
 #ifdef HAVE_ERR_REMOVE_THREAD_STATE
@@ -432,7 +437,8 @@
 		ret = rsa_err("Could not obtain signature");
 		goto err_sign;
 	}
-	#if OPENSSL_VERSION_NUMBER < 0x10100000L
+	#if OPENSSL_VERSION_NUMBER < 0x10100000L || \
+		(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x02070000fL)
 		EVP_MD_CTX_cleanup(context);
 	#else
 		EVP_MD_CTX_reset(context);