librpc: add dcerpc_ncacn_push_pkt_auth() helper function

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

diff --git a/librpc/rpc/dcerpc_util.c b/librpc/rpc/dcerpc_util.c
index 8013a610cf4d160dd9a1613b4fc7e3eb10900f53..3319587917f0b84ee4858163a47acedd73e30006 100644 (file)
--- a/librpc/rpc/dcerpc_util.c
+++ b/librpc/rpc/dcerpc_util.c
@@ -501,6 +501,208 @@ NTSTATUS dcerpc_ncacn_pull_pkt_auth(const struct dcerpc_auth *auth_state,
        return NT_STATUS_OK;
 }
 
+NTSTATUS dcerpc_ncacn_push_pkt_auth(const struct dcerpc_auth *auth_state,
+                                   struct gensec_security *gensec,
+                                   TALLOC_CTX *mem_ctx,
+                                   DATA_BLOB *raw_packet,
+                                   size_t sig_size,
+                                   uint8_t payload_offset,
+                                   const DATA_BLOB *payload,
+                                   const struct ncacn_packet *pkt)
+{
+       TALLOC_CTX *frame = talloc_stackframe();
+       NTSTATUS status;
+       enum ndr_err_code ndr_err;
+       struct ndr_push *ndr = NULL;
+       uint32_t payload_length;
+       uint32_t whole_length;
+       DATA_BLOB blob = data_blob_null;
+       DATA_BLOB sig = data_blob_null;
+       struct dcerpc_auth _out_auth_info;
+       struct dcerpc_auth *out_auth_info = NULL;
+
+       *raw_packet = data_blob_null;
+
+       if (auth_state == NULL) {
+               TALLOC_FREE(frame);
+               return NT_STATUS_INTERNAL_ERROR;
+       }
+
+       switch (auth_state->auth_level) {
+       case DCERPC_AUTH_LEVEL_PRIVACY:
+       case DCERPC_AUTH_LEVEL_INTEGRITY:
+       case DCERPC_AUTH_LEVEL_PACKET:
+               if (sig_size == 0) {
+                       TALLOC_FREE(frame);
+                       return NT_STATUS_INTERNAL_ERROR;
+               }
+
+               if (gensec == NULL) {
+                       TALLOC_FREE(frame);
+                       return NT_STATUS_INTERNAL_ERROR;
+               }
+
+               _out_auth_info = (struct dcerpc_auth) {
+                       .auth_type = auth_state->auth_type,
+                       .auth_level = auth_state->auth_level,
+                       .auth_context_id = auth_state->auth_context_id,
+               };
+               out_auth_info = &_out_auth_info;
+               break;
+
+       case DCERPC_AUTH_LEVEL_CONNECT:
+               /*
+                * TODO: let the gensec mech decide if it wants to generate a
+                *       signature that might be needed for schannel...
+                */
+               if (sig_size != 0) {
+                       TALLOC_FREE(frame);
+                       return NT_STATUS_INTERNAL_ERROR;
+               }
+
+               if (gensec == NULL) {
+                       TALLOC_FREE(frame);
+                       return NT_STATUS_INTERNAL_ERROR;
+               }
+               break;
+
+       case DCERPC_AUTH_LEVEL_NONE:
+               if (sig_size != 0) {
+                       TALLOC_FREE(frame);
+                       return NT_STATUS_INTERNAL_ERROR;
+               }
+               break;
+
+       default:
+               TALLOC_FREE(frame);
+               return NT_STATUS_INTERNAL_ERROR;
+       }
+
+       ndr = ndr_push_init_ctx(frame);
+       if (ndr == NULL) {
+               TALLOC_FREE(frame);
+               return NT_STATUS_NO_MEMORY;
+       }
+
+       if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
+               ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
+       }
+
+       if (pkt->pfc_flags & DCERPC_PFC_FLAG_OBJECT_UUID) {
+               ndr->flags |= LIBNDR_FLAG_OBJECT_PRESENT;
+       }
+
+       ndr_err = ndr_push_ncacn_packet(ndr, NDR_SCALARS|NDR_BUFFERS, pkt);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               TALLOC_FREE(frame);
+               return ndr_map_error2ntstatus(ndr_err);
+       }
+
+       if (out_auth_info != NULL) {
+               /*
+                * pad to 16 byte multiple in the payload portion of the
+                * packet. This matches what w2k3 does. Note that we can't use
+                * ndr_push_align() as that is relative to the start of the
+                * whole packet, whereas w2k8 wants it relative to the start
+                * of the stub.
+                */
+               out_auth_info->auth_pad_length =
+                       DCERPC_AUTH_PAD_LENGTH(payload->length);
+               ndr_err = ndr_push_zero(ndr, out_auth_info->auth_pad_length);
+               if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+                       TALLOC_FREE(frame);
+                       return ndr_map_error2ntstatus(ndr_err);
+               }
+
+               payload_length = payload->length +
+                       out_auth_info->auth_pad_length;
+
+               ndr_err = ndr_push_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS,
+                                              out_auth_info);
+               if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+                       TALLOC_FREE(frame);
+                       return ndr_map_error2ntstatus(ndr_err);
+               }
+
+               whole_length = ndr->offset;
+
+               ndr_err = ndr_push_zero(ndr, sig_size);
+               if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+                       TALLOC_FREE(frame);
+                       return ndr_map_error2ntstatus(ndr_err);
+               }
+       } else {
+               payload_length = payload->length;
+               whole_length = ndr->offset;
+       }
+
+       /* extract the whole packet as a blob */
+       blob = ndr_push_blob(ndr);
+
+       /*
+        * Setup the frag and auth length in the packet buffer.
+        * This is needed if the GENSEC mech does AEAD signing
+        * of the packet headers. The signature itself will be
+        * appended later.
+        */
+       dcerpc_set_frag_length(&blob, blob.length);
+       dcerpc_set_auth_length(&blob, sig_size);
+
+       /* sign or seal the packet */
+       switch (auth_state->auth_level) {
+       case DCERPC_AUTH_LEVEL_PRIVACY:
+               status = gensec_seal_packet(gensec,
+                                           frame,
+                                           blob.data + payload_offset,
+                                           payload_length,
+                                           blob.data,
+                                           whole_length,
+                                           &sig);
+               if (!NT_STATUS_IS_OK(status)) {
+                       TALLOC_FREE(frame);
+                       return status;
+               }
+               break;
+
+       case DCERPC_AUTH_LEVEL_INTEGRITY:
+       case DCERPC_AUTH_LEVEL_PACKET:
+               status = gensec_sign_packet(gensec,
+                                           frame,
+                                           blob.data + payload_offset,
+                                           payload_length,
+                                           blob.data,
+                                           whole_length,
+                                           &sig);
+               if (!NT_STATUS_IS_OK(status)) {
+                       TALLOC_FREE(frame);
+                       return status;
+               }
+               break;
+
+       case DCERPC_AUTH_LEVEL_CONNECT:
+       case DCERPC_AUTH_LEVEL_NONE:
+               break;
+
+       default:
+               TALLOC_FREE(frame);
+               return NT_STATUS_INTERNAL_ERROR;
+       }
+
+       if (sig.length != sig_size) {
+               TALLOC_FREE(frame);
+               return NT_STATUS_RPC_SEC_PKG_ERROR;
+       }
+
+       if (sig_size != 0) {
+               memcpy(blob.data + whole_length, sig.data, sig_size);
+       }
+
+       *raw_packet = blob;
+       talloc_steal(mem_ctx, raw_packet->data);
+       TALLOC_FREE(frame);
+       return NT_STATUS_OK;
+}
+
 struct dcerpc_read_ncacn_packet_state {
 #if 0
        struct {

diff --git a/librpc/rpc/rpc_common.h b/librpc/rpc/rpc_common.h
index 2f44ee0ea3f6e74c9dc0f8796bd2a148b155d045..9bc7d86dc722746abdecccf0ed5469e213fb29f8 100644 (file)
--- a/librpc/rpc/rpc_common.h
+++ b/librpc/rpc/rpc_common.h
@@ -213,6 +213,14 @@ NTSTATUS dcerpc_ncacn_pull_pkt_auth(const struct dcerpc_auth *auth_state,
                                    DATA_BLOB *payload_and_verifier,
                                    DATA_BLOB *raw_packet,
                                    const struct ncacn_packet *pkt);
+NTSTATUS dcerpc_ncacn_push_pkt_auth(const struct dcerpc_auth *auth_state,
+                                   struct gensec_security *gensec,
+                                   TALLOC_CTX *mem_ctx,
+                                   DATA_BLOB *raw_packet,
+                                   size_t sig_size,
+                                   uint8_t payload_offset,
+                                   const DATA_BLOB *payload,
+                                   const struct ncacn_packet *pkt);
 struct tevent_req *dcerpc_read_ncacn_packet_send(TALLOC_CTX *mem_ctx,
                                                 struct tevent_context *ev,
                                                 struct tstream_context *stream);