Don't mistakenly assume that a previously used token implies we should

encode the auth option.

diff --git a/auth.c b/auth.c
index cfffe4714e27c8b6a46ec3704f7e503f7e3a1b5c..b1b7024a6fa2f3d3ae1890502b6897e8c31f854b 100644 (file)
--- a/auth.c
+++ b/auth.c
@@ -365,7 +365,7 @@ dhcp_auth_encode(const struct auth *auth, const struct token *t,
        uint64_t rdm;
        uint8_t hmac[HMAC_LENGTH];
        time_t now;
-       uint8_t hops, *p;
+       uint8_t hops, *p, info;
        uint32_t giaddr, secretid;
 
        if (auth->protocol == 0 && t == NULL) {
@@ -415,6 +415,13 @@ dhcp_auth_encode(const struct auth *auth, const struct token *t,
                return -1;
        }
 
+       /* DISCOVER or INFORM messages don't write auth info */
+       if ((mp == 4 && (mt == DHCP_DISCOVER || mt == DHCP_INFORM)) ||
+           (mp == 6 && (mt == DHCP6_SOLICIT || mt == DHCP6_INFORMATION_REQ)))
+               info = 0;
+       else
+               info = 1;
+
        /* Work out the auth area size.
         * We only need to do this for DISCOVER messages */
        if (data == NULL) {
@@ -424,11 +431,11 @@ dhcp_auth_encode(const struct auth *auth, const struct token *t,
                        dlen += t->key_len;
                        break;
                case AUTH_PROTO_DELAYEDREALM:
-                       if (t)
+                       if (info && t)
                                dlen += t->realm_len;
                        /* FALLTHROUGH */
                case AUTH_PROTO_DELAYED:
-                       if (t)
+                       if (info && t)
                                dlen += sizeof(t->secretid) + sizeof(hmac);
                        break;
                }
@@ -480,8 +487,7 @@ dhcp_auth_encode(const struct auth *auth, const struct token *t,
        }
 
        /* DISCOVER or INFORM messages don't write auth info */
-       if ((mp == 4 && (mt == DHCP_DISCOVER || mt == DHCP_INFORM)) ||
-           (mp == 6 && (mt == DHCP6_SOLICIT || mt == DHCP6_INFORMATION_REQ)))
+       if (!info)
                return dlen;
 
        /* Loading a saved lease without an authentication option */