Don't send an ACK message after the first key exchange in the SPTPS protocol.

diff --git a/src/sptps.c b/src/sptps.c
index fa1594d..2449e7b 100644 (file)
--- a/src/sptps.c
+++ b/src/sptps.c
@@ -301,7 +301,7 @@ static bool receive_sig(sptps_t *s, const char *data, uint16_t len) {
        s->hiskex = NULL;
 
        // Send cipher change record
-       if(!send_ack(s))
+       if(s->outstate && !send_ack(s))
                return false;
 
        // TODO: only set new keys after ACK has been set/received
@@ -319,8 +319,6 @@ static bool receive_sig(sptps_t *s, const char *data, uint16_t len) {
                        return false;
        }
 
-       s->outstate = true;
-
        return true;
 }
 
@@ -352,7 +350,16 @@ static bool receive_handshake(sptps_t *s, const char *data, uint16_t len) {
                        // If we already sent our secondary public ECDH key, we expect the peer to send his.
                        if(!receive_sig(s, data, len))
                                return false;
-                       s->state = SPTPS_ACK;
+                       if(s->outstate)
+                               s->state = SPTPS_ACK;
+                       else {
+                               s->outstate = true;
+                               if(!receive_ack(s, NULL, 0))
+                                       return false;
+                               s->receive_record(s->handle, SPTPS_HANDSHAKE, NULL, 0);
+                               s->state = SPTPS_SECONDARY_KEX;
+                       }
+
                        return true;
                case SPTPS_ACK:
                        // We expect a handshake message to indicate transition to the new keys.