r10066: This is the second in my patches to work on Samba4's kerberos support,

with an aim to make the code simpiler and more correct.

Gone is the old (since the very early Samba 3.0 krb5 days) 'iterate over
all keytypes)' code in gensec_krb5, we now follow the approach used in
gensec_gssapi, and use a keytab.

I have also done a lot of work in the GSSAPI code, to try and reduce
the diff between us and upstream heimdal.  It was becoming hard to
track patches in this code, and I also want this patch (the DCE_STYLE
support) to be in a 'manageable' state for when lha considers it for
merging.  (metze assures me it still has memory leak problems, but
I've started to address some of that).

This patch also includes a simple update of other code to current
heimdal, as well as changes we need for better PAC verification.

On the PAC side of things we now match windows member servers by
checking the name and authtime on an incoming PAC.  Not generating these
right was the cause of the PAC pain, and so now both the main code and
torture test validate this behaviour.

One thing doesn't work with this patch:
 - the sealing of RPC pipes with kerberos, Samba -> Samba seems
broken.  I'm pretty sure this is related to AES, and the need to break
apart the gss_wrap interface.

Andrew Bartlett
(This used to be commit a3aba57c00a9c5318f4706db55d03f64e8bea60c)

1 files changed, 49 insertions, 167 deletions

diff --git a/source4/auth/kerberos/kerberos_verify.c b/source4/auth/kerberos/kerberos_verify.c
index b140eb6ae9..dec084299b 100644
--- a/source4/auth/kerberos/kerberos_verify.c
+++ b/source4/auth/kerberos/kerberos_verify.c
@@ -71,9 +71,10 @@ DATA_BLOB unwrap_pac(TALLOC_CTX *mem_ctx, DATA_BLOB *auth_data)
 ***********************************************************************************/
 
 static krb5_error_code ads_keytab_verify_ticket(TALLOC_CTX *mem_ctx, krb5_context context, 
-						krb5_auth_context auth_context,
+						krb5_auth_context *auth_context,
 						const char *service,
-						const DATA_BLOB *ticket, krb5_data *p_packet, 
+						const krb5_data *p_packet, 
+						krb5_flags *ap_req_options,
 						krb5_ticket **pp_tkt,
 						krb5_keyblock **keyblock)
 {
@@ -146,12 +147,10 @@ static krb5_error_code ads_keytab_verify_ticket(TALLOC_CTX *mem_ctx, krb5_contex
 				}
 
 				number_matched_principals++;
-				p_packet->length = ticket->length;
-				p_packet->data = (krb5_pointer)ticket->data;
 				*pp_tkt = NULL;
-				ret = krb5_rd_req_return_keyblock(context, &auth_context, p_packet, 
+				ret = krb5_rd_req_return_keyblock(context, auth_context, p_packet, 
 								  kt_entry.principal, keytab, 
-								  NULL, pp_tkt, keyblock);
+								  ap_req_options, pp_tkt, keyblock);
 				if (ret) {
 					last_error_message = smb_get_krb5_error_message(context, ret, mem_ctx);
 					DEBUG(10, ("ads_keytab_verify_ticket: krb5_rd_req(%s) failed: %s\n",
@@ -216,121 +215,28 @@ static krb5_error_code ads_keytab_verify_ticket(TALLOC_CTX *mem_ctx, krb5_contex
 }
 
 /**********************************************************************************
- Try to verify a ticket using the secrets.tdb.
-***********************************************************************************/
-
-static krb5_error_code ads_secrets_verify_ticket(TALLOC_CTX *mem_ctx,	
-						 struct cli_credentials *machine_account,
-						 krb5_context context, 
-						 krb5_auth_context auth_context,
-						 krb5_principal salt_princ,
-						 const DATA_BLOB *ticket, krb5_data *p_packet, 
-						 krb5_ticket **pp_tkt,
-						 krb5_keyblock **keyblock)
-{
-	krb5_error_code ret = 0;
-	krb5_error_code our_ret;
-	krb5_data password;
-	krb5_enctype *enctypes = NULL;
-	int i;
-	char *password_s = talloc_strdup(mem_ctx, cli_credentials_get_password(machine_account));
-	if (!password_s) {
-		DEBUG(1, ("ads_secrets_verify_ticket: Could not obtain password for our local machine account!\n"));
-		return ENOENT;
-	}
-	
-	ZERO_STRUCTP(keyblock);
-
-	password.data = password_s;
-	password.length = strlen(password_s);
-
-	/* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
-
-	if ((ret = get_kerberos_allowed_etypes(context, &enctypes))) {
-		DEBUG(1,("ads_secrets_verify_ticket: krb5_get_permitted_enctypes failed (%s)\n", 
-			 error_message(ret)));
-
-		krb5_free_principal(context, salt_princ);
-		return ret;
-	}
-
-	p_packet->length = ticket->length;
-	p_packet->data = (krb5_pointer)ticket->data;
-
-	/* We need to setup a auth context with each possible encoding type in turn. */
-
-	ret =  KRB5_BAD_ENCTYPE;
-	for (i=0;enctypes[i];i++) {
-		krb5_keyblock *key = NULL;
-
-		if (!(key = malloc_p(krb5_keyblock))) {
-			break;
-		}
-	
-		if (create_kerberos_key_from_string(context, salt_princ, &password, key, enctypes[i])) {
-			SAFE_FREE(key);
-			continue;
-		}
-
-		krb5_auth_con_setuseruserkey(context, auth_context, key);
-
-		krb5_free_keyblock(context, key);
-
-		our_ret = krb5_rd_req_return_keyblock(context, &auth_context, p_packet, 
-						      NULL,
-						      NULL, NULL, pp_tkt,
-						      keyblock);
-		if (!our_ret) {
-	
-			DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
-				  (unsigned int)enctypes[i] ));
-			ret = our_ret;
-			break;
-		}
-	
-		DEBUG((our_ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
-				("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
-				 (unsigned int)enctypes[i], smb_get_krb5_error_message(context, our_ret, mem_ctx)));
-
-		if (our_ret !=  KRB5_BAD_ENCTYPE) {
-			ret = our_ret;
-		}
-	}
-
-	free_kerberos_etypes(context, enctypes);
-
-	return ret;
-}
-
-/**********************************************************************************
  Verify an incoming ticket and parse out the principal name and 
  authorization_data if available.
 ***********************************************************************************/
 
  NTSTATUS ads_verify_ticket(TALLOC_CTX *mem_ctx, 
 			    struct smb_krb5_context *smb_krb5_context,
-			    krb5_auth_context auth_context,
+			    krb5_auth_context *auth_context,
 			    const char *realm, const char *service, 
-			    const DATA_BLOB *ticket, 
-			    char **principal, DATA_BLOB *auth_data,
+			    const DATA_BLOB *enc_ticket, 
+			    krb5_ticket **tkt,
 			    DATA_BLOB *ap_rep,
 			    krb5_keyblock **keyblock)
 {
-	NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
+	krb5_keyblock *local_keyblock;
 	krb5_data packet;
-	krb5_ticket *tkt = NULL;
 	krb5_principal salt_princ;
 	int ret;
+	krb5_flags ap_req_options = 0;
 
-	char *malloc_principal;
-
-	NTSTATUS creds_nt_status;
+	NTSTATUS creds_nt_status, status;
 	struct cli_credentials *machine_account;
 
-	ZERO_STRUCT(packet);
-	ZERO_STRUCTP(auth_data);
-	ZERO_STRUCTP(ap_rep);
-
 	machine_account = cli_credentials_init(mem_ctx);
 	cli_credentials_set_conf(machine_account);
 	creds_nt_status = cli_credentials_set_machine_account(machine_account);
@@ -360,78 +266,54 @@ static krb5_error_code ads_secrets_verify_ticket(TALLOC_CTX *mem_ctx,
 	 * directory.  This will eventually prevent replay attacks
 	 */
 
+	packet.length = enc_ticket->length;
+	packet.data = (krb5_pointer)enc_ticket->data;
+
 	ret = ads_keytab_verify_ticket(mem_ctx, smb_krb5_context->krb5_context, auth_context, 
-				       service, ticket, &packet, &tkt, keyblock);
+				       service, &packet, &ap_req_options, tkt, &local_keyblock);
 	if (ret && machine_account) {
-		ret = ads_secrets_verify_ticket(mem_ctx, machine_account, smb_krb5_context->krb5_context, auth_context,
-						salt_princ, ticket, 
-						&packet, &tkt, keyblock);
-	}
-
-	if (ret) {
-		goto out;
+		krb5_keytab keytab;
+		krb5_principal server;
+		status = create_memory_keytab(mem_ctx, machine_account, smb_krb5_context, 
+					      &keytab);
+		if (!NT_STATUS_IS_OK(status)) {
+			return status;
+		}
+		ret = principal_from_credentials(mem_ctx, machine_account, smb_krb5_context, 
+						 &server);
+		if (ret == 0) {
+			ret = krb5_rd_req_return_keyblock(smb_krb5_context->krb5_context, auth_context, &packet,
+							  server,
+							  keytab, &ap_req_options, tkt,
+							  &local_keyblock);
+		}
 	}
 
-	ret = krb5_mk_rep(smb_krb5_context->krb5_context, auth_context, &packet);
 	if (ret) {
-		DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
+		DEBUG(3,("ads_secrets_verify_ticket: failed to decrypt with error %s\n",
 			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, mem_ctx)));
-		goto out;
-	}
-
-	*ap_rep = data_blob_talloc(mem_ctx, packet.data, packet.length);
-	SAFE_FREE(packet.data);
-	packet.length = 0;
-
-#if 0
-	file_save("/tmp/ticket.dat", ticket->data, ticket->length);
-#endif
-
-	*auth_data = get_auth_data_from_tkt(mem_ctx, tkt);
-
-	*auth_data = unwrap_pac(mem_ctx, auth_data);
-
-#if 0
-	if (tkt->enc_part2) {
-		file_save("/tmp/authdata.dat",
-			  tkt->enc_part2->authorization_data[0]->contents,
-			  tkt->enc_part2->authorization_data[0]->length);
+		return NT_STATUS_LOGON_FAILURE;
 	}
-#endif
+	*keyblock = local_keyblock;
 
-	if ((ret = krb5_unparse_name(smb_krb5_context->krb5_context, get_principal_from_tkt(tkt),
-				     &malloc_principal))) {
-		DEBUG(3,("ads_verify_ticket: krb5_unparse_name failed (%s)\n", 
-			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, mem_ctx)));
-		sret = NT_STATUS_LOGON_FAILURE;
-		goto out;
-	}
-
-	*principal = talloc_strdup(mem_ctx, malloc_principal);
-	SAFE_FREE(malloc_principal);
-	if (!principal) {
-		DEBUG(3,("ads_verify_ticket: talloc_strdup() failed\n"));
-		sret = NT_STATUS_NO_MEMORY;
-		goto out;
-	}
-
-	sret = NT_STATUS_OK;
-
- out:
-
-	if (!NT_STATUS_IS_OK(sret)) {
-		data_blob_free(auth_data);
-	}
-
-	if (!NT_STATUS_IS_OK(sret)) {
-		data_blob_free(ap_rep);
-	}
-
-	if (tkt != NULL) {
-		krb5_free_ticket(smb_krb5_context->krb5_context, tkt);
+	if (ap_req_options & AP_OPTS_MUTUAL_REQUIRED) {
+		krb5_data packet_out;
+		ret = krb5_mk_rep(smb_krb5_context->krb5_context, *auth_context, &packet_out);
+		if (ret) {
+			krb5_free_ticket(smb_krb5_context->krb5_context, *tkt);
+			
+			DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
+				 smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, mem_ctx)));
+			return NT_STATUS_LOGON_FAILURE;
+		}
+		
+		*ap_rep = data_blob_talloc(mem_ctx, packet_out.data, packet_out.length);
+		krb5_free_data_contents(smb_krb5_context->krb5_context, &packet_out);
+	} else {
+		*ap_rep = data_blob(NULL, 0);
 	}
 
-	return sret;
+	return NT_STATUS_OK;
 }
 
 #endif /* HAVE_KRB5 */