From: Stefan Metzmacher <metze@samba.org>
Date: Tue, 9 Sep 2008 16:02:07 +0000 (+0200)
Subject: libcli/smb_composite: for spnego session setups check the smb signature manually
X-Git-Url: http://git.samba.org/?p=metze%2Fsamba%2Fwip.git;a=commitdiff_plain;h=79ca1a29fd329df1de4f9b22d34aaab1806c5307

libcli/smb_composite: for spnego session setups check the smb signature manually

This is needed as the response might be signed with the krb5 acceptor subkey,
which comes within the response.

metze
---

diff --git a/source/libcli/smb_composite/sesssetup.c b/source/libcli/smb_composite/sesssetup.c
index 11ac37e257ab..b39ff69b91ab 100644
--- a/source/libcli/smb_composite/sesssetup.c
+++ b/source/libcli/smb_composite/sesssetup.c
@@ -85,6 +85,12 @@ static void request_handler(struct smbcli_request *req)
 	DATA_BLOB session_key = data_blob(NULL, 0);
 	DATA_BLOB null_data_blob = data_blob(NULL, 0);
 	NTSTATUS session_key_err, nt_status;
+	struct smbcli_request *check_req = NULL;
+
+	if (req->sign_caller_checks) {
+		req->do_not_free = true;
+		check_req = req;
+	}
 
 	c->status = smb_raw_sesssetup_recv(req, state, &state->setup);
 	state->req = NULL;
@@ -102,6 +108,7 @@ static void request_handler(struct smbcli_request *req)
 							      state->io, 
 							      &state->req);
 				if (NT_STATUS_IS_OK(nt_status)) {
+					talloc_free(check_req);
 					c->status = nt_status;
 					composite_continue_smb(c, state->req, request_handler, c);
 					return;
@@ -120,6 +127,7 @@ static void request_handler(struct smbcli_request *req)
 							      state->io, 
 							      &state->req);
 				if (NT_STATUS_IS_OK(nt_status)) {
+					talloc_free(check_req);
 					c->status = nt_status;
 					composite_continue_smb(c, state->req, request_handler, c);
 					return;
@@ -138,6 +146,7 @@ static void request_handler(struct smbcli_request *req)
 								      state->io, 
 								      &state->req);
 				if (NT_STATUS_IS_OK(nt_status)) {
+					talloc_free(check_req);
 					c->status = nt_status;
 					composite_continue_smb(c, state->req, request_handler, c);
 					return;
@@ -146,6 +155,7 @@ static void request_handler(struct smbcli_request *req)
 		}
 		if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED) && 
 		    !NT_STATUS_IS_OK(c->status)) {
+			talloc_free(check_req);
 			break;
 		}
 		if (NT_STATUS_EQUAL(state->gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
@@ -163,6 +173,7 @@ static void request_handler(struct smbcli_request *req)
 			c->status = state->gensec_status;
 			if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED) && 
 			    !NT_STATUS_IS_OK(c->status)) {
+				talloc_free(check_req);
 				break;
 			}
 		} else {
@@ -178,6 +189,16 @@ static void request_handler(struct smbcli_request *req)
 		}
 
 		if (state->setup.spnego.in.secblob.length) {
+			if (check_req) {
+				check_req->sign_caller_checks = false;
+				if (!smbcli_request_check_sign_mac(check_req)) {
+					talloc_free(check_req);
+					c->status = NT_STATUS_ACCESS_DENIED;
+					break;
+				}
+				talloc_free(check_req);
+			}
+
 			/* 
 			 * set the session->vuid value only for calling
 			 * smb_raw_sesssetup_send()
@@ -196,6 +217,14 @@ static void request_handler(struct smbcli_request *req)
 		break;
 	}
 
+	if (check_req) {
+		check_req->sign_caller_checks = false;
+		if (!smbcli_request_check_sign_mac(check_req)) {
+			c->status = NT_STATUS_ACCESS_DENIED;
+		}
+		talloc_free(check_req);
+	}
+
 	/* enforce the local signing required flag */
 	if (NT_STATUS_IS_OK(c->status) && !cli_credentials_is_anonymous(state->io->in.credentials)) {
 		if (!session->transport->negotiate.sign_info.doing_signing 
@@ -449,6 +478,15 @@ static NTSTATUS session_setup_spnego(struct composite_context *c,
 	if (!*req) {
 		return NT_STATUS_NO_MEMORY;
 	}
+
+	if (NT_STATUS_IS_OK(session_key_err)) {
+		/*
+		 * as the response might be signed with a session key from within the response
+		 * we need to check the signiture of the response ourself.
+		 */
+		(*req)->sign_caller_checks = true;
+	}
+
 	return (*req)->status;
 }