Introduce pk_sign() and use it in ssl
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 4e5b3e6..d4723d7 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3169,6 +3169,7 @@
                                rsa_key_len_func rsa_key_len )
 {
     ssl->own_cert    = own_cert;
+    ssl->rsa_use_alt = 1;
     ssl->rsa_key     = rsa_key;
     ssl->rsa_decrypt = rsa_decrypt;
     ssl->rsa_sign    = rsa_sign;