libcli/smb: make sure the session->{smb2->,smb2_channel.}signing_key is never NULL!

Before commit 17e22e020fcb84fb9ddda350915369dc9ea28ef1 they we not a
pointer and always be present.

We used the local pointer variable 'signing_key = NULL' and logic like
this:

    if (state->smb2.should_sign) {
        signing_key = state->session->smb2_channel.signing_key;
    }

    if (signing_key != NULL ...

In order to keep this we need to nake sure
state->session->smb2_channel.signing_key is never NULL!

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

diff --git a/libcli/smb/smbXcli_base.c b/libcli/smb/smbXcli_base.c
index a82146a60f4f839778fff9a91d4a80f75f5999a8..0296d5b8752759444b1633c8be6db60856c7e9b9 100644 (file)
--- a/libcli/smb/smbXcli_base.c
+++ b/libcli/smb/smbXcli_base.c
@@ -5526,9 +5526,27 @@ struct smbXcli_session *smbXcli_session_create(TALLOC_CTX *mem_ctx,
        }
        talloc_set_destructor(session, smbXcli_session_destructor);
 
+       session->smb2->signing_key = talloc_zero(session,
+                                                struct smb2_signing_key);
+       if (session->smb2->signing_key == NULL) {
+               talloc_free(session);
+               return NULL;
+       }
+       talloc_set_destructor(session->smb2->signing_key,
+                             smb2_signing_key_destructor);
+
        DLIST_ADD_END(conn->sessions, session);
        session->conn = conn;
 
+       session->smb2_channel.signing_key =
+               talloc_zero(session, struct smb2_signing_key);
+       if (session->smb2_channel.signing_key == NULL) {
+               talloc_free(session);
+               return NULL;
+       }
+       talloc_set_destructor(session->smb2_channel.signing_key,
+                             smb2_signing_key_destructor);
+
        memcpy(session->smb2_channel.preauth_sha512,
               conn->smb2.preauth_sha512,
               sizeof(session->smb2_channel.preauth_sha512));
@@ -6038,15 +6056,6 @@ NTSTATUS smb2cli_session_set_session_key(struct smbXcli_session *session,
        memcpy(session_key, _session_key.data,
               MIN(_session_key.length, sizeof(session_key)));
 
-       session->smb2->signing_key = talloc_zero(session,
-                                                struct smb2_signing_key);
-       if (session->smb2->signing_key == NULL) {
-               ZERO_STRUCT(session_key);
-               return NT_STATUS_NO_MEMORY;
-       }
-       talloc_set_destructor(session->smb2->signing_key,
-                             smb2_signing_key_destructor);
-
        session->smb2->signing_key->blob =
                data_blob_talloc(session->smb2->signing_key,
                                 session_key,
@@ -6117,14 +6126,6 @@ NTSTATUS smb2cli_session_set_session_key(struct smbXcli_session *session,
        }
        ZERO_STRUCT(session_key);
 
-       session->smb2_channel.signing_key =
-               talloc_zero(session, struct smb2_signing_key);
-       if (session->smb2_channel.signing_key == NULL) {
-               return NT_STATUS_NO_MEMORY;
-       }
-       talloc_set_destructor(session->smb2_channel.signing_key,
-                             smb2_signing_key_destructor);
-
        session->smb2_channel.signing_key->blob =
                data_blob_dup_talloc(session->smb2_channel.signing_key,
                                     session->smb2->signing_key->blob);
@@ -6243,6 +6244,15 @@ NTSTATUS smb2cli_session_create_channel(TALLOC_CTX *mem_ctx,
        DLIST_ADD_END(conn->sessions, session2);
        session2->conn = conn;
 
+       session2->smb2_channel.signing_key =
+               talloc_zero(session2, struct smb2_signing_key);
+       if (session2->smb2_channel.signing_key == NULL) {
+               talloc_free(session2);
+               return NT_STATUS_NO_MEMORY;
+       }
+       talloc_set_destructor(session2->smb2_channel.signing_key,
+                             smb2_signing_key_destructor);
+
        memcpy(session2->smb2_channel.preauth_sha512,
               conn->smb2.preauth_sha512,
               sizeof(session2->smb2_channel.preauth_sha512));