s3-winbindd: let winbind try to use samlogon validation level 6. (bug #7945)

The benefit of this that it makes us more robust to secure channel resets
triggered from tools outside the winbind process. Long term we need to have a
shared tdb secure channel store though as well.

Guenther

Signed-off-by: Stefan Metzmacher <metze@samba.org>

Autobuild-User: Stefan Metzmacher <metze@samba.org>
Autobuild-Date: Fri Feb  4 18:11:04 CET 2011 on sn-devel-104

7 files changed, 121 insertions, 6 deletions

diff --git a/source3/auth/auth_domain.c b/source3/auth/auth_domain.c
index 0f541cd1e7..05421debbb 100644
--- a/source3/auth/auth_domain.c
+++ b/source3/auth/auth_domain.c
@@ -309,6 +309,7 @@ static NTSTATUS domain_client_validate(TALLOC_CTX *mem_ctx,
 						      user_info->client.domain_name,       /* domain name */
 						      user_info->workstation_name,         /* workstation name */
 						      chal,                                /* 8 byte challenge. */
+						      3,				   /* validation level */
 						      user_info->password.response.lanman, /* lanman 24 byte response */
 						      user_info->password.response.nt,     /* nt 24 byte response */
 						      &info3);                             /* info3 out */
diff --git a/source3/auth/auth_netlogond.c b/source3/auth/auth_netlogond.c
index 889371c722..1e3ccb1189 100644
--- a/source3/auth/auth_netlogond.c
+++ b/source3/auth/auth_netlogond.c
@@ -88,6 +88,7 @@ static NTSTATUS netlogond_validate(TALLOC_CTX *mem_ctx,
 		user_info->client.domain_name,         /* domain name */
 		user_info->workstation_name,           /* workstation name */
 		(uchar *)auth_context->challenge.data, /* 8 byte challenge. */
+		3,				       /* validation level */
 		user_info->password.response.lanman,   /* lanman 24 byte response */
 		user_info->password.response.nt,       /* nt 24 byte response */
 		&info3);                               /* info3 out */
diff --git a/source3/rpc_client/cli_netlogon.c b/source3/rpc_client/cli_netlogon.c
index 914bfd3df6..f34d794ea4 100644
--- a/source3/rpc_client/cli_netlogon.c
+++ b/source3/rpc_client/cli_netlogon.c
@@ -25,6 +25,8 @@
 #include "../librpc/gen_ndr/ndr_netlogon_c.h"
 #include "rpc_client/cli_netlogon.h"
 #include "rpc_client/init_netlogon.h"
+#include "rpc_client/util_netlogon.h"
+#include "../libcli/security/security.h"
 
 /****************************************************************************
  Wrapper function that uses the auth and auth2 calls to set up a NETLOGON
@@ -298,6 +300,52 @@ NTSTATUS rpccli_netlogon_sam_logon(struct rpc_pipe_client *cli,
 	return result;
 }
 
+static NTSTATUS map_validation_to_info3(TALLOC_CTX *mem_ctx,
+					uint16_t validation_level,
+					union netr_Validation *validation,
+					struct netr_SamInfo3 **info3_p)
+{
+	struct netr_SamInfo3 *info3;
+	NTSTATUS status;
+
+	if (validation == NULL) {
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
+	switch (validation_level) {
+	case 3:
+		if (validation->sam3 == NULL) {
+			return NT_STATUS_INVALID_PARAMETER;
+		}
+
+		info3 = talloc_move(mem_ctx, &validation->sam3);
+		break;
+	case 6:
+		if (validation->sam6 == NULL) {
+			return NT_STATUS_INVALID_PARAMETER;
+		}
+
+		info3 = talloc_zero(mem_ctx, struct netr_SamInfo3);
+		if (info3 == NULL) {
+			return NT_STATUS_NO_MEMORY;
+		}
+		status = copy_netr_SamBaseInfo(info3, &validation->sam6->base, &info3->base);
+		if (!NT_STATUS_IS_OK(status)) {
+			TALLOC_FREE(info3);
+			return status;
+		}
+
+		info3->sidcount = validation->sam6->sidcount;
+		info3->sids = talloc_move(info3, &validation->sam6->sids);
+		break;
+	default:
+		return NT_STATUS_BAD_VALIDATION_CLASS;
+	}
+
+	*info3_p = info3;
+
+	return NT_STATUS_OK;
+}
 
 /**
  * Logon domain user with an 'network' SAM logon
@@ -313,13 +361,13 @@ NTSTATUS rpccli_netlogon_sam_network_logon(struct rpc_pipe_client *cli,
 					   const char *domain,
 					   const char *workstation,
 					   const uint8 chal[8],
+					   uint16_t validation_level,
 					   DATA_BLOB lm_response,
 					   DATA_BLOB nt_response,
 					   struct netr_SamInfo3 **info3)
 {
 	NTSTATUS result = NT_STATUS_UNSUCCESSFUL;
 	NTSTATUS status;
-	int validation_level = 3;
 	const char *workstation_name_slash;
 	const char *server_name_slash;
 	struct netr_Authenticator clnt_creds;
@@ -417,7 +465,10 @@ NTSTATUS rpccli_netlogon_sam_network_logon(struct rpc_pipe_client *cli,
 
 	netlogon_creds_decrypt_samlogon(cli->dc, validation_level, &validation);
 
-	*info3 = validation.sam3;
+	result = map_validation_to_info3(mem_ctx, validation_level, &validation, info3);
+	if (!NT_STATUS_IS_OK(result)) {
+		return result;
+	}
 
 	return result;
 }
@@ -430,13 +481,13 @@ NTSTATUS rpccli_netlogon_sam_network_logon_ex(struct rpc_pipe_client *cli,
 					      const char *domain,
 					      const char *workstation,
 					      const uint8 chal[8],
+					      uint16_t validation_level,
 					      DATA_BLOB lm_response,
 					      DATA_BLOB nt_response,
 					      struct netr_SamInfo3 **info3)
 {
 	NTSTATUS result = NT_STATUS_UNSUCCESSFUL;
 	NTSTATUS status;
-	int validation_level = 3;
 	const char *workstation_name_slash;
 	const char *server_name_slash;
 	union netr_LogonLevel *logon = NULL;
@@ -522,7 +573,10 @@ NTSTATUS rpccli_netlogon_sam_network_logon_ex(struct rpc_pipe_client *cli,
 
 	netlogon_creds_decrypt_samlogon(cli->dc, validation_level, &validation);
 
-	*info3 = validation.sam3;
+	result = map_validation_to_info3(mem_ctx, validation_level, &validation, info3);
+	if (!NT_STATUS_IS_OK(result)) {
+		return result;
+	}
 
 	return result;
 }
diff --git a/source3/rpc_client/cli_netlogon.h b/source3/rpc_client/cli_netlogon.h
index bb38b75b95..808a4283ce 100644
--- a/source3/rpc_client/cli_netlogon.h
+++ b/source3/rpc_client/cli_netlogon.h
@@ -25,6 +25,7 @@ NTSTATUS rpccli_netlogon_sam_network_logon(struct rpc_pipe_client *cli,
 					   const char *domain,
 					   const char *workstation,
 					   const uint8 chal[8],
+					   uint16_t validation_level,
 					   DATA_BLOB lm_response,
 					   DATA_BLOB nt_response,
 					   struct netr_SamInfo3 **info3);
@@ -36,6 +37,7 @@ NTSTATUS rpccli_netlogon_sam_network_logon_ex(struct rpc_pipe_client *cli,
 					      const char *domain,
 					      const char *workstation,
 					      const uint8 chal[8],
+					      uint16_t validation_level,
 					      DATA_BLOB lm_response,
 					      DATA_BLOB nt_response,
 					      struct netr_SamInfo3 **info3);
diff --git a/source3/winbindd/winbindd.h b/source3/winbindd/winbindd.h
index 3217acc8ea..a32c78f4e4 100644
--- a/source3/winbindd/winbindd.h
+++ b/source3/winbindd/winbindd.h
@@ -169,6 +169,7 @@ struct winbindd_domain {
 				  * we don't have to try _ex every time. */
 
 	bool can_do_ncacn_ip_tcp;
+	bool can_do_validation6;
 
 	/* Lookup methods for this domain (LDAP or RPC) */
 	struct winbindd_methods *methods;
diff --git a/source3/winbindd/winbindd_cm.c b/source3/winbindd/winbindd_cm.c
index c692ffe75c..c53a553af8 100644
--- a/source3/winbindd/winbindd_cm.c
+++ b/source3/winbindd/winbindd_cm.c
@@ -2086,6 +2086,7 @@ done:
 		  domain->name, domain->active_directory ? "" : "NOT "));
 
 	domain->can_do_ncacn_ip_tcp = domain->active_directory;
+	domain->can_do_validation6 = domain->active_directory;
 
 	TALLOC_FREE(cli);
 
diff --git a/source3/winbindd/winbindd_pam.c b/source3/winbindd/winbindd_pam.c
index 760fa3bc60..68fa01f6d7 100644
--- a/source3/winbindd/winbindd_pam.c
+++ b/source3/winbindd/winbindd_pam.c
@@ -1148,6 +1148,8 @@ static NTSTATUS winbind_samlogon_retry_loop(struct winbindd_domain *domain,
 
 	do {
 		struct rpc_pipe_client *netlogon_pipe;
+		const struct pipe_auth_data *auth;
+		uint32_t neg_flags = 0;
 
 		ZERO_STRUCTP(info3);
 		retry = false;
@@ -1159,6 +1161,10 @@ static NTSTATUS winbind_samlogon_retry_loop(struct winbindd_domain *domain,
 				  nt_errstr(result)));
 			return result;
 		}
+		auth = netlogon_pipe->auth;
+		if (netlogon_pipe->dc) {
+			neg_flags = netlogon_pipe->dc->negotiate_flags;
+		}
 
 		/* It is really important to try SamLogonEx here,
 		 * because in a clustered environment, we want to use
@@ -1179,8 +1185,35 @@ static NTSTATUS winbind_samlogon_retry_loop(struct winbindd_domain *domain,
 		 * wrapping SamLogon context.
 		 *
 		 *  -- abartlet 21 April 2008
+		 *
+		 * It's also important to use NetlogonValidationSamInfo4 (6),
+		 * because it relies on the rpc transport encryption
+		 * and avoids using the global netlogon schannel
+		 * session key to en/decrypt secret information
+		 * like the user_session_key for network logons.
+		 *
+		 * [MS-APDS] 3.1.5.2 NTLM Network Logon
+		 * says NETLOGON_NEG_CROSS_FOREST_TRUSTS and
+		 * NETLOGON_NEG_AUTHENTICATED_RPC set together
+		 * are the indication that the server supports
+		 * NetlogonValidationSamInfo4 (6). And it must only
+		 * be used if "SealSecureChannel" is used.
+		 *
+		 * -- metze 4 February 2011
 		 */
 
+		if (auth == NULL) {
+			domain->can_do_validation6 = false;
+		} else if (auth->auth_type != DCERPC_AUTH_TYPE_SCHANNEL) {
+			domain->can_do_validation6 = false;
+		} else if (auth->auth_level != DCERPC_AUTH_LEVEL_PRIVACY) {
+			domain->can_do_validation6 = false;
+		} else if (!(neg_flags & NETLOGON_NEG_CROSS_FOREST_TRUSTS)) {
+			domain->can_do_validation6 = false;
+		} else if (!(neg_flags & NETLOGON_NEG_AUTHENTICATED_RPC)) {
+			domain->can_do_validation6 = false;
+		}
+
 		if (domain->can_do_samlogon_ex) {
 			result = rpccli_netlogon_sam_network_logon_ex(
 					netlogon_pipe,
@@ -1191,6 +1224,7 @@ static NTSTATUS winbind_samlogon_retry_loop(struct winbindd_domain *domain,
 					domainname,	/* target domain */
 					workstation,	/* workstation */
 					chal,
+					domain->can_do_validation6 ? 6 : 3,
 					lm_response,
 					nt_response,
 					info3);
@@ -1204,22 +1238,43 @@ static NTSTATUS winbind_samlogon_retry_loop(struct winbindd_domain *domain,
 					domainname,	/* target domain */
 					workstation,	/* workstation */
 					chal,
+					domain->can_do_validation6 ? 6 : 3,
 					lm_response,
 					nt_response,
 					info3);
 		}
 
-		attempts += 1;
-
 		if ((NT_STATUS_V(result) == DCERPC_FAULT_OP_RNG_ERROR)
 		    && domain->can_do_samlogon_ex) {
 			DEBUG(3, ("Got a DC that can not do NetSamLogonEx, "
 				  "retrying with NetSamLogon\n"));
 			domain->can_do_samlogon_ex = false;
+			/*
+			 * It's likely that the server also does not support
+			 * validation level 6
+			 */
+			domain->can_do_validation6 = false;
 			retry = true;
 			continue;
 		}
 
+		if (domain->can_do_validation6 &&
+		    (NT_STATUS_EQUAL(result, NT_STATUS_INVALID_INFO_CLASS) ||
+		     NT_STATUS_EQUAL(result, NT_STATUS_INVALID_PARAMETER) ||
+		     NT_STATUS_EQUAL(result, NT_STATUS_BUFFER_TOO_SMALL))) {
+			DEBUG(3,("Got a DC that can not do validation level 6, "
+				  "retrying with level 3\n"));
+			domain->can_do_validation6 = false;
+			retry = true;
+			continue;
+		}
+
+		/*
+		 * we increment this after the "feature negotiation"
+		 * for can_do_samlogon_ex and can_do_validation6
+		 */
+		attempts += 1;
+
 		/* We have to try a second time as cm_connect_netlogon
 		   might not yet have noticed that the DC has killed
 		   our connection. */