librpc/rpc: don't send auth trailers in level connect
authorStefan Metzmacher <metze@samba.org>
Fri, 12 Sep 2008 12:39:57 +0000 (14:39 +0200)
committerStefan Metzmacher <metze@samba.org>
Sat, 13 Sep 2008 18:37:12 +0000 (20:37 +0200)
Also ignore auth trailers in level connect on receive.

This fixes [krb5,connect] against windows.

TODO: maybe the gensec mech need to decide if signatures
      are needed in level connect.

metze

source/librpc/rpc/dcerpc.c

index 28b5cd65a9143a3f398bfc2146103a7739973308..5bbcc5e91c81bb4c45acedc9f4a8fede62a489f8 100644 (file)
@@ -210,32 +210,6 @@ static NTSTATUS ncacn_pull(struct dcerpc_connection *c, DATA_BLOB *blob, TALLOC_
        return NT_STATUS_OK;
 }
 
-/*
-  generate a CONNECT level verifier
-*/
-static NTSTATUS dcerpc_connect_verifier(TALLOC_CTX *mem_ctx, DATA_BLOB *blob)
-{
-       *blob = data_blob_talloc(mem_ctx, NULL, 16);
-       if (blob->data == NULL) {
-               return NT_STATUS_NO_MEMORY;
-       }
-       SIVAL(blob->data, 0, 1);
-       memset(blob->data+4, 0, 12);
-       return NT_STATUS_OK;
-}
-
-/*
-  check a CONNECT level verifier
-*/
-static NTSTATUS dcerpc_check_connect_verifier(DATA_BLOB *blob)
-{
-       if (blob->length != 16 ||
-           IVAL(blob->data, 0) != 1) {
-               return NT_STATUS_ACCESS_DENIED;
-       }
-       return NT_STATUS_OK;
-}
-
 /* 
    parse the authentication information on a dcerpc response packet
 */
@@ -249,9 +223,29 @@ static NTSTATUS ncacn_pull_request_auth(struct dcerpc_connection *c, TALLOC_CTX
        DATA_BLOB auth_blob;
        enum ndr_err_code ndr_err;
 
-       if (pkt->auth_length == 0 &&
-           c->security_state.auth_info->auth_level == DCERPC_AUTH_LEVEL_CONNECT) {
+       if (!c->security_state.auth_info ||
+           !c->security_state.generic_state) {
+               return NT_STATUS_OK;
+       }
+
+       switch (c->security_state.auth_info->auth_level) {
+       case DCERPC_AUTH_LEVEL_PRIVACY:
+       case DCERPC_AUTH_LEVEL_INTEGRITY:
+               break;
+
+       case DCERPC_AUTH_LEVEL_CONNECT:
+               if (pkt->auth_length != 0) {
+                       break;
+               }
                return NT_STATUS_OK;
+       case DCERPC_AUTH_LEVEL_NONE:
+               if (pkt->auth_length != 0) {
+                       return NT_STATUS_INVALID_NETWORK_RESPONSE;
+               }
+               return NT_STATUS_OK;
+
+       default:
+               return NT_STATUS_INVALID_LEVEL;
        }
 
        auth_blob.length = 8 + pkt->auth_length;
@@ -308,10 +302,8 @@ static NTSTATUS ncacn_pull_request_auth(struct dcerpc_connection *c, TALLOC_CTX
                break;
 
        case DCERPC_AUTH_LEVEL_CONNECT:
-               status = dcerpc_check_connect_verifier(&auth.credentials);
-               break;
-
-       case DCERPC_AUTH_LEVEL_NONE:
+               /* for now we ignore possible signatures here */
+               status = NT_STATUS_OK;
                break;
 
        default:
@@ -344,9 +336,24 @@ static NTSTATUS ncacn_push_request_sign(struct dcerpc_connection *c,
        enum ndr_err_code ndr_err;
 
        /* non-signed packets are simpler */
-       if (!c->security_state.auth_info || 
-           !c->security_state.generic_state) {
-               return ncacn_push_auth(blob, mem_ctx, c->iconv_convenience, pkt, c->security_state.auth_info);
+       if (sig_size == 0) {
+               return ncacn_push_auth(blob, mem_ctx, c->iconv_convenience, pkt, NULL);
+       }
+
+       switch (c->security_state.auth_info->auth_level) {
+       case DCERPC_AUTH_LEVEL_PRIVACY:
+       case DCERPC_AUTH_LEVEL_INTEGRITY:
+               break;
+
+       case DCERPC_AUTH_LEVEL_CONNECT:
+               /* TODO: let the gensec mech decide if it wants to generate a signature */
+               return ncacn_push_auth(blob, mem_ctx, c->iconv_convenience, pkt, NULL);
+
+       case DCERPC_AUTH_LEVEL_NONE:
+               return ncacn_push_auth(blob, mem_ctx, c->iconv_convenience, pkt, NULL);
+
+       default:
+               return NT_STATUS_INVALID_LEVEL;
        }
 
        ndr = ndr_push_init_ctx(mem_ctx, c->iconv_convenience);
@@ -372,39 +379,17 @@ static NTSTATUS ncacn_push_request_sign(struct dcerpc_connection *c,
           packet. This matches what w2k3 does */
        c->security_state.auth_info->auth_pad_length = 
                (16 - (pkt->u.request.stub_and_verifier.length & 15)) & 15;
-       ndr_push_zero(ndr, c->security_state.auth_info->auth_pad_length);
+       ndr_err = ndr_push_zero(ndr, c->security_state.auth_info->auth_pad_length);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               return ndr_map_error2ntstatus(ndr_err);
+       }
+       status = NT_STATUS_OK;
 
        payload_length = pkt->u.request.stub_and_verifier.length + 
                c->security_state.auth_info->auth_pad_length;
 
-       /* sign or seal the packet */
-       switch (c->security_state.auth_info->auth_level) {
-       case DCERPC_AUTH_LEVEL_PRIVACY:
-       case DCERPC_AUTH_LEVEL_INTEGRITY:
-               /* We hope this length is accruate.  If must be if the
-                * GENSEC mech does AEAD signing of the packet
-                * headers */
-               c->security_state.auth_info->credentials
-                       = data_blob_talloc(mem_ctx, NULL, sig_size);
-               data_blob_clear(&c->security_state.auth_info->credentials);
-               break;
-
-       case DCERPC_AUTH_LEVEL_CONNECT:
-               status = dcerpc_connect_verifier(mem_ctx, &c->security_state.auth_info->credentials);
-               break;
-               
-       case DCERPC_AUTH_LEVEL_NONE:
-               c->security_state.auth_info->credentials = data_blob(NULL, 0);
-               break;
-               
-       default:
-               status = NT_STATUS_INVALID_LEVEL;
-               break;
-       }
-       
-       if (!NT_STATUS_IS_OK(status)) {
-               return status;
-       }       
+       /* we start without signature, it will appended later */
+       c->security_state.auth_info->credentials = data_blob(NULL,0);
 
        /* add the auth verifier */
        ndr_err = ndr_push_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, c->security_state.auth_info);
@@ -416,13 +401,14 @@ static NTSTATUS ncacn_push_request_sign(struct dcerpc_connection *c,
        /* extract the whole packet as a blob */
        *blob = ndr_push_blob(ndr);
 
-       /* fill in the fragment length and auth_length, we can't fill
-          in these earlier as we don't know the signature length (it
-          could be variable length) */
-       dcerpc_set_frag_length(blob, blob->length);
-       /* We hope this value is accruate.  If must be if the GENSEC
-        * mech does AEAD signing of the packet headers */
-       dcerpc_set_auth_length(blob, c->security_state.auth_info->credentials.length);
+       /*
+        * 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 + sig_size);
+       dcerpc_set_auth_length(blob, sig_size);
 
        /* sign or seal the packet */
        switch (c->security_state.auth_info->auth_level) {
@@ -432,25 +418,11 @@ static NTSTATUS ncacn_push_request_sign(struct dcerpc_connection *c,
                                            blob->data + DCERPC_REQUEST_LENGTH, 
                                            payload_length,
                                            blob->data,
-                                           blob->length - 
-                                           c->security_state.auth_info->credentials.length,
+                                           blob->length,
                                            &creds2);
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }
-               blob->length -= c->security_state.auth_info->credentials.length;
-               if (!data_blob_append(mem_ctx, blob,
-                                         creds2.data, creds2.length)) {
-                       return NT_STATUS_NO_MEMORY;
-               }
-               dcerpc_set_auth_length(blob, creds2.length);
-               if (c->security_state.auth_info->credentials.length == 0) {
-                       /* this is needed for krb5 only, to correct the total packet
-                          length */
-                       dcerpc_set_frag_length(blob, 
-                                              dcerpc_get_frag_length(blob)
-                                              +creds2.length);
-               }
                break;
 
        case DCERPC_AUTH_LEVEL_INTEGRITY:
@@ -459,32 +431,11 @@ static NTSTATUS ncacn_push_request_sign(struct dcerpc_connection *c,
                                            blob->data + DCERPC_REQUEST_LENGTH, 
                                            payload_length, 
                                            blob->data,
-                                           blob->length - 
-                                           c->security_state.auth_info->credentials.length,
+                                           blob->length,
                                            &creds2);
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }
-               blob->length -= c->security_state.auth_info->credentials.length;
-               if (!data_blob_append(mem_ctx, blob,
-                                         creds2.data, creds2.length)) {
-                       return NT_STATUS_NO_MEMORY;
-               }
-               dcerpc_set_auth_length(blob, creds2.length);
-               if (c->security_state.auth_info->credentials.length == 0) {
-                       /* this is needed for krb5 only, to correct the total packet
-                          length */
-                       dcerpc_set_frag_length(blob, 
-                                              dcerpc_get_frag_length(blob)
-                                              +creds2.length);
-               }
-               break;
-
-       case DCERPC_AUTH_LEVEL_CONNECT:
-               break;
-
-       case DCERPC_AUTH_LEVEL_NONE:
-               c->security_state.auth_info->credentials = data_blob(NULL, 0);
                break;
 
        default:
@@ -492,7 +443,17 @@ static NTSTATUS ncacn_push_request_sign(struct dcerpc_connection *c,
                break;
        }
 
-       data_blob_free(&c->security_state.auth_info->credentials);
+       if (creds2.length != sig_size) {
+               DEBUG(0,("dcesrv_auth_response: creds2.length[%u] != sig_size[%u] pad[%u] stub[%u]\n",
+                       creds2.length, (uint32_t)sig_size,
+                       c->security_state.auth_info->auth_pad_length,
+                       pkt->u.request.stub_and_verifier.length));
+               return NT_STATUS_INTERNAL_ERROR;
+       }
+
+       if (!data_blob_append(mem_ctx, blob, creds2.data, creds2.length)) {
+               return NT_STATUS_NO_MEMORY;
+       }
 
        return NT_STATUS_OK;
 }
@@ -1068,13 +1029,16 @@ static void dcerpc_ship_next_request(struct dcerpc_connection *c)
           request header size */
        chunk_size = p->conn->srv_max_recv_frag;
        chunk_size -= DCERPC_REQUEST_LENGTH;
-       if (c->security_state.generic_state) {
-               chunk_size -= DCERPC_AUTH_TRAILER_LENGTH;
+       if (c->security_state.auth_info &&
+           c->security_state.generic_state) {
                sig_size = gensec_sig_size(c->security_state.generic_state,
                                           p->conn->srv_max_recv_frag);
-               chunk_size -= sig_size;
-               chunk_size -= (chunk_size % 16);
+               if (sig_size) {
+                       chunk_size -= DCERPC_AUTH_TRAILER_LENGTH;
+                       chunk_size -= sig_size;
+               }
        }
+       chunk_size -= (chunk_size % 16);
 
        pkt.ptype = DCERPC_PKT_REQUEST;
        pkt.call_id = req->call_id;