Update secret object upon splitting

When splitting, update the threshold field of the secret object,
and the length field of each share.

src/secret.c

@@ -544,6 +544,8 @@ gfsec_secret_split(gfsec_secret_t *secret, unsigned char threshold)
     if ( threshold >= n )
         return GFSEC_ERR_NOT_ENOUGH_SHARES;
 
+    secret->threshold = threshold;
+
     if ( gfshare_fill_rand == NULL )
         gfshare_fill_rand = gfsec_fill_rand;
 
@@ -557,6 +559,8 @@ gfsec_secret_split(gfsec_secret_t *secret, unsigned char threshold)
             rc = GFSEC_ERR_SYSTEM_ERROR;
         if ( ! (share->hash = malloc(32)) )
             rc = GFSEC_ERR_SYSTEM_ERROR;
+
+        share->len = secret->len;
     }
 
     if ( rc == 0 && ! (ctx = gfshare_ctx_init_enc(sharenrs, n, threshold,

src/secretcfg.h

@@ -31,6 +31,9 @@ gfsec_parse_uri(const char *, gfsec_secret_t *, int);
 int
 gfsec_read_config(gfsec_secret_t **, const char *, unsigned int *);
 
+int
+gfsec_write_config(gfsec_secret_t *, const char *);
+
 #ifdef __cplusplus
 }
 #endif