security: tighten enum protection_level usage.

While changing Curl_sec_read_msg to accept an enum protection_level
instead of an int, I went ahead and fixed the usage of the associated
fields.

Some code was assuming that prot_clear == 0. Fixed those to use the
proper value. Added assertions prior to any code that would set the
protection level.

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/ftp.c b/lib/ftp.c
index 416e5ecfa..22589355f 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -3784,11 +3784,13 @@ CURLcode Curl_ftpsendf(struct connectdata *conn,
 
   for(;;) {
 #if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
+    DEBUGASSERT(prot_cmd > prot_none && prot_cmd < prot_last);
     conn->data_prot = prot_cmd;
 #endif
     res = Curl_write(conn, conn->sock[FIRSTSOCKET], sptr, write_len,
                      &bytes_written);
 #if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
+    DEBUGASSERT(data_sec > prot_none && data_sec < prot_last);
     conn->data_prot = data_sec;
 #endif