memcmp: Introduce and use consttime_memeq

[secnet.git] / transform.c

diff --git a/transform.c b/transform.c
index f55aa447dfd41c1c64c3dfc6b658010057b77d55..012f6186a5072516b3069a70f40c658a4c2adfd7 100644 (file)
--- a/transform.c
+++ b/transform.c
@@ -68,6 +68,13 @@ static bool_t transform_setkey(void *sst, uint8_t *key, int32_t keylen)
     return True;
 }
 
+static bool_t transform_valid(void *sst)
+{
+    struct transform_inst *ti=sst;
+
+    return ti->keyed;
+}
+
 static void transform_delkey(void *sst)
 {
     struct transform_inst *ti=sst;
@@ -213,7 +220,7 @@ static uint32_t transform_reverse(void *sst, struct buffer_if *buf,
        serpent_encrypt(&ti->mackey,macplain,macacc);
     }
     serpent_encrypt(&ti->mackey,macacc,macacc);
-    if (memcmp(macexpected,macacc,16)!=0) {
+    if (!consttime_memeq(macexpected,macacc,16)!=0) {
        *errmsg="invalid MAC";
        return 1;
     }
@@ -247,7 +254,7 @@ static uint32_t transform_reverse(void *sst, struct buffer_if *buf,
     } else {
        /* Too much skew */
        *errmsg="seqnum: too much skew";
-       return 1;
+       return 2;
     }
     
     return 0;
@@ -271,6 +278,7 @@ static struct transform_inst_if *transform_create(void *sst)
 
     ti->ops.st=ti;
     ti->ops.setkey=transform_setkey;
+    ti->ops.valid=transform_valid;
     ti->ops.delkey=transform_delkey;
     ti->ops.forwards=transform_forward;
     ti->ops.reverse=transform_reverse;