diff -urpN -x arch.h -x '*.o' -x run john-1.8.0/src/Makefile john-1.8.0-mask/src/Makefile
--- john-1.8.0/src/Makefile	2013-05-29 23:21:25 +0000
+++ john-1.8.0-mask/src/Makefile	2013-06-14 23:15:06 +0000
@@ -48,8 +48,9 @@ JOHN_OBJS = \
 	dummy.o \
 	batch.o bench.o charset.o common.o compiler.o config.o cracker.o \
 	crc32.o external.o formats.o getopt.o idle.o inc.o john.o list.o \
-	loader.o logger.o math.o memory.o misc.o options.o params.o path.o \
-	recovery.o rpp.o rules.o signals.o single.o status.o tty.o wordlist.o \
+	loader.o logger.o mask.o math.o memory.o misc.o options.o params.o \
+	path.o recovery.o rpp.o rules.o signals.o single.o status.o tty.o \
+	wordlist.o \
 	unshadow.o \
 	unafs.o \
 	unique.o
diff -urpN -x arch.h -x '*.o' -x run john-1.8.0/src/john.c john-1.8.0-mask/src/john.c
--- john-1.8.0/src/john.c	2013-05-29 23:27:25 +0000
+++ john-1.8.0-mask/src/john.c	2013-06-14 23:14:27 +0000
@@ -57,6 +57,7 @@ static int john_omp_threads_new;
 #include "single.h"
 #include "wordlist.h"
 #include "inc.h"
+#include "mask.h"
 #include "external.h"
 #include "batch.h"
 
@@ -592,6 +593,9 @@ static void john_run(void)
 		if (options.flags & FLG_INC_CHK)
 			do_incremental_crack(&database, options.charset);
 		else
+		if (options.flags & FLG_MASK_CHK)
+			do_mask_crack(&database, options.mask);
+		else
 		if (options.flags & FLG_EXTERNAL_CHK)
 			do_external_crack(&database);
 		else
diff -urpN -x arch.h -x '*.o' -x run john-1.8.0/src/mask.c john-1.8.0-mask/src/mask.c
--- john-1.8.0/src/mask.c	1970-01-01 00:00:00 +0000
+++ john-1.8.0-mask/src/mask.c	2013-06-15 00:01:29 +0000
@@ -0,0 +1,60 @@
+/*
+ * This file is part of John the Ripper password cracker,
+ * Copyright (c) 2013 by Solar Designer
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted.
+ *
+ * There's ABSOLUTELY NO WARRANTY, express or implied.
+ */
+
+#include <stdio.h> /* for fprintf(stderr, ...) */
+
+#include "misc.h" /* for error() */
+#include "logger.h"
+#include "status.h"
+#include "options.h"
+#include "rpp.h"
+#include "external.h"
+#include "cracker.h"
+#include "john.h"
+#include "mask.h"
+
+void do_mask_crack(struct db_main *db, char *mask)
+{
+	struct rpp_context ctx;
+	char *word;
+
+	if (options.node_count) {
+		if (john_main_process)
+			fprintf(stderr, "--mask is not yet compatible with --node and --fork\n");
+		error();
+	}
+
+	log_event("Proceeding with mask mode");
+
+	rpp_init_mask(&ctx, mask);
+
+	status_init(NULL, 0);
+
+#if 0
+	rec_restore_mode(restore_state);
+	rec_init(db, save_state);
+
+	crk_init(db, fix_state, NULL);
+#else
+	crk_init(db, NULL, NULL);
+#endif
+
+	while ((word = rpp_next(&ctx))) {
+		if (ext_filter(word))
+			if (crk_process_key(word))
+				break;
+	}
+
+	crk_done();
+
+#if 0
+	rec_done(event_abort);
+#endif
+}
diff -urpN -x arch.h -x '*.o' -x run john-1.8.0/src/mask.h john-1.8.0-mask/src/mask.h
--- john-1.8.0/src/mask.h	1970-01-01 00:00:00 +0000
+++ john-1.8.0-mask/src/mask.h	2013-06-14 23:52:55 +0000
@@ -0,0 +1,25 @@
+/*
+ * This file is part of John the Ripper password cracker,
+ * Copyright (c) 2013 by Solar Designer
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted.
+ *
+ * There's ABSOLUTELY NO WARRANTY, express or implied.
+ */
+
+/*
+ * Mask mode cracker.
+ */
+
+#ifndef _JOHN_MASK_H
+#define _JOHN_MASK_H
+
+#include "loader.h"
+
+/*
+ * Runs the mask mode cracker.
+ */
+extern void do_mask_crack(struct db_main *db, char *mask);
+
+#endif
diff -urpN -x arch.h -x '*.o' -x run john-1.8.0/src/options.c john-1.8.0-mask/src/options.c
--- john-1.8.0/src/options.c	2013-05-29 23:31:53 +0000
+++ john-1.8.0-mask/src/options.c	2013-06-14 23:11:19 +0000
@@ -40,6 +40,8 @@ static struct opt_entry opt_list[] = {
 	{"rules", FLG_RULES, FLG_RULES, FLG_WORDLIST_CHK, FLG_STDIN_CHK},
 	{"incremental", FLG_INC_SET, FLG_CRACKING_CHK,
 		0, 0, OPT_FMT_STR_ALLOC, &options.charset},
+	{"mask", FLG_MASK_SET, FLG_CRACKING_CHK,
+		0, OPT_REQ_PARAM, OPT_FMT_STR_ALLOC, &options.mask},
 	{"external", FLG_EXTERNAL_SET, FLG_EXTERNAL_CHK,
 		0, OPT_REQ_PARAM, OPT_FMT_STR_ALLOC, &options.external},
 	{"stdout", FLG_STDOUT, FLG_STDOUT,
@@ -104,6 +106,7 @@ static struct opt_entry opt_list[] = {
 "--wordlist=FILE --stdin    wordlist mode, read words from FILE or stdin\n" \
 "--rules                    enable word mangling rules for wordlist mode\n" \
 "--incremental[=MODE]       \"incremental\" mode [using section MODE]\n" \
+"--mask=MASK                mask mode using MASK\n" \
 "--external=MODE            external mode or word filter\n" \
 "--stdout[=LENGTH]          just output candidate passwords [cut at LENGTH]\n" \
 "--restore[=NAME]           restore an interrupted session [called NAME]\n" \
diff -urpN -x arch.h -x '*.o' -x run john-1.8.0/src/options.h john-1.8.0-mask/src/options.h
--- john-1.8.0/src/options.h	2013-05-29 23:31:55 +0000
+++ john-1.8.0-mask/src/options.h	2013-06-14 23:18:49 +0000
@@ -52,8 +52,11 @@
 /* Incremental mode enabled */
 #define FLG_INC_CHK			0x00000800
 #define FLG_INC_SET			(FLG_INC_CHK | FLG_CRACKING_SET)
+/* Mask mode enabled */
+#define FLG_MASK_CHK			0x00001000
+#define FLG_MASK_SET			(FLG_MASK_CHK | FLG_CRACKING_SET)
 /* External mode or word filter enabled */
-#define FLG_EXTERNAL_CHK		0x00001000
+#define FLG_EXTERNAL_CHK		0x00002000
 #define FLG_EXTERNAL_SET \
 	(FLG_EXTERNAL_CHK | FLG_ACTION | FLG_CRACKING_SUP | FLG_PWD_SUP)
 /* Batch cracker */
@@ -116,9 +119,12 @@ struct options_main {
 /* Wordlist file name */
 	char *wordlist;
 
-/* Charset file name */
+/* Incremental mode name or charset file name */
 	char *charset;
 
+/* Mask mode's mask */
+	char *mask;
+
 /* External mode or word filter name */
 	char *external;
 
diff -urpN -x arch.h -x '*.o' -x run john-1.8.0/src/rpp.c john-1.8.0-mask/src/rpp.c
--- john-1.8.0/src/rpp.c	2011-02-27 06:52:52 +0000
+++ john-1.8.0-mask/src/rpp.c	2013-06-15 00:28:53 +0000
@@ -1,6 +1,6 @@
 /*
  * This file is part of John the Ripper password cracker,
- * Copyright (c) 1996-98,2006,2009,2010,2011 by Solar Designer
+ * Copyright (c) 1996-98,2006,2009,2010,2011,2013 by Solar Designer
  */
 
 #include <string.h>
@@ -23,6 +23,14 @@ int rpp_init(struct rpp_context *ctx, ch
 	return 1;
 }
 
+void rpp_init_mask(struct rpp_context *ctx, char *mask)
+{
+	ctx->input = &ctx->dummy_list_entry;
+	ctx->input->data = mask;
+	ctx->input->next = NULL;
+	ctx->count = -1;
+}
+
 static void rpp_add_char(struct rpp_range *range, unsigned char c)
 {
 	if (range->flag_r) {
@@ -43,6 +51,7 @@ static void rpp_process_rule(struct rpp_
 {
 	struct rpp_range *range;
 	unsigned char *input, *output, *end;
+	unsigned char *saved_input;
 	unsigned char c1, c2, c;
 	int flag_p, flag_r;
 
@@ -52,6 +61,8 @@ static void rpp_process_rule(struct rpp_
 	flag_p = flag_r = 0;
 	ctx->count = ctx->refs_count = 0;
 
+	saved_input = NULL;
+
 	while (*input && output < end)
 	switch (*input) {
 	case '\\':
@@ -88,8 +99,34 @@ static void rpp_process_rule(struct rpp_
 		}
 		break;
 
+	case '?':
+		if (ctx->input != &ctx->dummy_list_entry) /* not mask mode */
+			goto not_mask;
+		if (*++input == '?')
+			goto not_mask;
+		saved_input = input + 1;
+		switch (*input) {
+		case 'l':
+			input = (unsigned char *)"[a-z]";
+			break;
+		case 'u':
+			input = (unsigned char *)"[A-Z]";
+			break;
+		case 'd':
+			input = (unsigned char *)"[0-9]";
+			break;
+		default:
+			saved_input = NULL;
+			input--;
+			goto not_mask;
+		}
+
 	case '[':
 		if (ctx->count >= RULE_RANGES_MAX) {
+			if (saved_input) {
+				input = saved_input - 2;
+				saved_input = NULL;
+			}
 			*output++ = *input++;
 			break;
 		}
@@ -130,9 +167,14 @@ static void rpp_process_rule(struct rpp_
 		}
 		if (*input) input++;
 
+		if (saved_input) {
+			input = saved_input;
+			saved_input = NULL;
+		}
 		break;
 
 	default:
+not_mask:
 		*output++ = *input++;
 	}
 
diff -urpN -x arch.h -x '*.o' -x run john-1.8.0/src/rpp.h john-1.8.0-mask/src/rpp.h
--- john-1.8.0/src/rpp.h	2010-02-23 17:06:58 +0000
+++ john-1.8.0-mask/src/rpp.h	2013-06-15 00:03:41 +0000
@@ -1,6 +1,6 @@
 /*
  * This file is part of John the Ripper password cracker,
- * Copyright (c) 1996-98,2009,2010 by Solar Designer
+ * Copyright (c) 1996-98,2009,2010,2013 by Solar Designer
  */
 
 /*
@@ -72,6 +72,9 @@ struct rpp_context {
 
 /* Character ranges */
 	struct rpp_range ranges[RULE_RANGES_MAX];
+
+/* Dummy list entry for use in mask mode */
+	struct cfg_line dummy_list_entry;
 };
 
 /*
@@ -81,6 +84,11 @@ struct rpp_context {
 extern int rpp_init(struct rpp_context *ctx, char *subsection);
 
 /*
+ * Initializes the preprocessor's context for the supplied mask.
+ */
+extern void rpp_init_mask(struct rpp_context *ctx, char *mask);
+
+/*
  * Returns a preprocessed rule and moves to the next one.
  */
 extern char *rpp_next(struct rpp_context *ctx);