[http] Allow for domain names within NTLM user names

Allow a NetBIOS domain name to be specified within a URL using a
syntax such as:

  http://domain%5Cusername:password@server/path

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/netbios.c

+/*
+ * Copyright (C) 2018 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * NetBIOS user names
+ *
+ */
+
+#include <stddef.h>
+#include <string.h>
+#include <ipxe/netbios.h>
+
+/**
+ * Split NetBIOS [domain\]username into separate domain and username fields
+ *
+ * @v username		NetBIOS [domain\]username string
+ * @ret domain		Domain portion of string, or NULL if no domain present
+ *
+ * This function modifies the original string by removing the
+ * separator.  The caller may restore the string using
+ * netbios_domain_undo().
+ */
+const char * netbios_domain ( char **username ) {
+	char *domain_username = *username;
+	char *sep;
+
+	/* Find separator, if present */
+	sep = strchr ( domain_username, '\\' );
+	if ( ! sep )
+		return NULL;
+
+	/* Overwrite separator with NUL terminator and update username string */
+	*sep = '\0';
+	*username = ( sep + 1 );
+
+	return domain_username;
+}

src/include/ipxe/netbios.h

+#ifndef _IPXE_NETBIOS_H
+#define _IPXE_NETBIOS_H
+
+/** @file
+ *
+ * NetBIOS user names
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+extern const char * netbios_domain ( char **username );
+
+/**
+ * Restore NetBIOS [domain\]username
+ *
+ * @v domain		NetBIOS domain name
+ * @v username		NetBIOS user name
+ *
+ * Restore the separator in a NetBIOS [domain\]username as split by
+ * netbios_domain().
+ */
+static inline void netbios_domain_undo ( const char *domain, char *username ) {
+
+	/* Restore separator, if applicable */
+	if ( domain )
+		username[-1] = '\\';
+}
+
+#endif /* _IPXE_NETBIOS_H */

src/net/tcp/httpntlm.c

 #include <ipxe/uri.h>
 #include <ipxe/base64.h>
 #include <ipxe/ntlm.h>
+#include <ipxe/netbios.h>
 #include <ipxe/http.h>
 
 struct http_authentication http_ntlm_auth __http_authentication;
 	struct http_request_auth_ntlm *req = &http->request.auth.ntlm;
 	struct http_response_auth_ntlm *rsp = &http->response.auth.ntlm;
 	struct ntlm_key key;
+	const char *domain;
+	char *username;
 	const char *password;
 
 	/* If we have no challenge yet, then just send a Negotiate message */
 	req->username = http->uri->user;
 	password = ( http->uri->password ? http->uri->password : "" );
 
+	/* Split NetBIOS [domain\]username */
+	username = ( ( char * ) req->username );
+	domain = netbios_domain ( &username );
+
 	/* Generate key */
-	ntlm_key ( NULL, req->username, password, &key );
+	ntlm_key ( domain, username, password, &key );
 
 	/* Generate responses */
 	ntlm_response ( &rsp->info, &key, NULL, &req->lm, &req->nt );
 
 	/* Calculate Authenticate message length */
-	req->len = ntlm_authenticate_len ( &rsp->info, NULL, req->username,
+	req->len = ntlm_authenticate_len ( &rsp->info, domain, username,
 					   http_ntlm_workstation );
 
+	/* Restore NetBIOS [domain\]username */
+	netbios_domain_undo ( domain, username );
+
 	return 0;
 }
 
 	struct http_request_auth_ntlm *req = &http->request.auth.ntlm;
 	struct http_response_auth_ntlm *rsp = &http->response.auth.ntlm;
 	struct ntlm_authenticate *auth;
+	const char *domain;
+	char *username;
 	size_t check;
 
 	/* If we have no challenge yet, then just send a Negotiate message */
 	if ( ! auth )
 		return -ENOMEM;
 
+	/* Split NetBIOS [domain\]username */
+	username = ( ( char * ) req->username );
+	domain = netbios_domain ( &username );
+
 	/* Construct raw Authenticate message */
-	check = ntlm_authenticate ( &rsp->info, NULL, req->username,
+	check = ntlm_authenticate ( &rsp->info, domain, username,
 				    http_ntlm_workstation, &req->lm,
 				    &req->nt, auth );
 	assert ( check == req->len );
 
+	/* Restore NetBIOS [domain\]username */
+	netbios_domain_undo ( domain, username );
+
 	/* Base64-encode Authenticate message */
 	len = base64_encode ( auth, req->len, buf, len );