more tsig_verify stuff

diff --git a/source4/dns_server/dns_crypto.c b/source4/dns_server/dns_crypto.c
index 7a049c04ef780d80df3f9bbec47a078e5a7f566a..14dc4ca69b5c95d8db108237b2114f03eda05661 100644 (file)
--- a/source4/dns_server/dns_crypto.c
+++ b/source4/dns_server/dns_crypto.c
@@ -91,16 +91,17 @@ struct dns_server_tkey *dns_find_tkey(struct dns_server_tkey_store *store,
 WERROR dns_verify_tsig(struct dns_server *dns,
                       TALLOC_CTX *mem_ctx,
                       struct dns_request_state *state,
-                      struct dns_name_packet *packet)
+                      struct dns_name_packet *packet,
+                      DATA_BLOB *in)
 {
        WERROR werror;
        NTSTATUS status;
        enum ndr_err_code ndr_err;
        bool found_tsig = false;
-       uint16_t i;
-       DATA_BLOB packet_blob, tsig_blob, sig;
+       uint16_t i, arcount = 0;
+       DATA_BLOB tsig_blob, fake_tsig_blob, sig;
        uint8_t *buffer = NULL;
-       size_t buffer_len = 0;
+       size_t buffer_len = 0, packet_len = 0;
        struct dns_server_tkey *tkey = NULL;
        struct dns_fake_tsig_rec *check_rec = talloc_zero(mem_ctx,
                        struct dns_fake_tsig_rec);
@@ -169,15 +170,15 @@ WERROR dns_verify_tsig(struct dns_server *dns,
        check_rec->other_size = 0;
        check_rec->other_data = NULL;
 
-       ndr_err = ndr_push_struct_blob(&packet_blob, mem_ctx, packet,
-               (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
+       ndr_err = ndr_push_struct_blob(&tsig_blob, mem_ctx, state->tsig,
+               (ndr_push_flags_fn_t)ndr_push_dns_res_rec);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DEBUG(1, ("Failed to push packet: %s!\n",
                          ndr_errstr(ndr_err)));
                return DNS_ERR(SERVER_FAILURE);
        }
 
-       ndr_err = ndr_push_struct_blob(&tsig_blob, mem_ctx, check_rec,
+       ndr_err = ndr_push_struct_blob(&fake_tsig_blob, mem_ctx, check_rec,
                (ndr_push_flags_fn_t)ndr_push_dns_fake_tsig_rec);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DEBUG(1, ("Failed to push packet: %s!\n",
@@ -185,14 +186,17 @@ WERROR dns_verify_tsig(struct dns_server *dns,
                return DNS_ERR(SERVER_FAILURE);
        }
 
-       buffer_len = packet_blob.length + tsig_blob.length;
+       /* we need to work some magic here. we need to keep the input packet
+        * exactly like we got it, but we need to cut off the tsig record */
+       packet_len = in->length - tsig_blob.length;
+       buffer_len = packet_len + fake_tsig_blob.length;
        buffer = talloc_zero_array(mem_ctx, uint8_t, buffer_len);
        if (buffer == NULL) {
                return WERR_NOMEM;
        }
 
-       memcpy(buffer, packet_blob.data, packet_blob.length);
-       memcpy(buffer, tsig_blob.data, tsig_blob.length);
+       memcpy(buffer, in->data, packet_len);
+       memcpy(buffer + packet_len, fake_tsig_blob.data, fake_tsig_blob.length);
 
        sig.length = state->tsig->rdata.tsig_record.mac_size;
        sig.data = talloc_memdup(mem_ctx, state->tsig->rdata.tsig_record.mac, sig.length);
@@ -200,6 +204,12 @@ WERROR dns_verify_tsig(struct dns_server *dns,
                return WERR_NOMEM;
        }
 
+       /*FIXME: Why is there too much padding? */
+       buffer_len -= 2;
+
+       /* Now we also need to count down the additional record counter */
+       arcount = RSVAL(buffer, 10);
+       RSSVAL(buffer, 10, arcount-1);
 
        status = gensec_check_packet(tkey->gensec, buffer, buffer_len,
                                    buffer, buffer_len, &sig);

diff --git a/source4/dns_server/dns_server.c b/source4/dns_server/dns_server.c
index 57c3b0134fc3d55efca37655bfbb67b8164e38a8..c5f516dd2018dd1bb1c4972a02a8568d465ecba5 100644 (file)
--- a/source4/dns_server/dns_server.c
+++ b/source4/dns_server/dns_server.c
@@ -145,7 +145,7 @@ static struct tevent_req *dns_process_send(TALLOC_CTX *mem_ctx,
                NDR_PRINT_DEBUG(dns_name_packet, &state->in_packet);
        }
 
-       ret = dns_verify_tsig(dns, state, &state->state, &state->in_packet);
+       ret = dns_verify_tsig(dns, state, &state->state, &state->in_packet, in);
        if (!W_ERROR_IS_OK(ret)) {
                DEBUG(0, ("Bailing out early!\n"));
                state->dns_err = werr_to_dns_err(ret);

diff --git a/source4/dns_server/dns_server.h b/source4/dns_server/dns_server.h
index f807cd1536a9626e75c66e14b30d695d69ce16ff..ef85730ff833af41d292abdb0afea85e9e18746e 100644 (file)
--- a/source4/dns_server/dns_server.h
+++ b/source4/dns_server/dns_server.h
@@ -112,7 +112,8 @@ struct dns_server_tkey *dns_find_tkey(struct dns_server_tkey_store *store,
 WERROR dns_verify_tsig(struct dns_server *dns,
                       TALLOC_CTX *mem_ctx,
                       struct dns_request_state *state,
-                      struct dns_name_packet *packet);
+                      struct dns_name_packet *packet,
+                      DATA_BLOB *in);
 WERROR dns_sign_tsig(struct dns_server *dns,
                     TALLOC_CTX *mem_ctx,
                     struct dns_request_state *state,