1 files changed, 100 insertions, 0 deletions
diff --git a/src/util/printable.c b/src/util/printable.c
new file mode 100644
index 0000000..6c148fd
--- /dev/null
+++ b/src/util/printable.c
@@ -0,0 +1,100 @@
+/*++
+/* NAME
+/*	printable 3
+/* SUMMARY
+/*	mask non-printable characters
+/* SYNOPSIS
+/*	#include <stringops.h>
+/*
+/*	int	util_utf8_enable;
+/*
+/*	char	*printable(buffer, replacement)
+/*	char	*buffer;
+/*	int	replacement;
+/*
+/*	char	*printable_except(buffer, replacement, except)
+/*	char	*buffer;
+/*	int	replacement;
+/*	const char *except;
+/* DESCRIPTION
+/*	printable() replaces non-printable characters
+/*	in its input with the given replacement.
+/*
+/*	util_utf8_enable controls whether UTF8 is considered printable.
+/*	With util_utf8_enable equal to zero, non-ASCII text is replaced.
+/*
+/*	Arguments:
+/* .IP buffer
+/*	The null-terminated input string.
+/* .IP replacement
+/*	Replacement value for characters in \fIbuffer\fR that do not
+/*	pass the ASCII isprint(3) test or that are not valid UTF8.
+/* .IP except
+/*	Null-terminated sequence of non-replaced ASCII characters.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include "sys_defs.h"
+#include <ctype.h>
+#include <string.h>
+
+/* Utility library. */
+
+#include "stringops.h"
+
+int util_utf8_enable = 0;
+
+/* printable -  binary compatibility */
+
+#undef printable
+
+char   *printable(char *, int);
+
+char   *printable(char *string, int replacement)
+{
+    return (printable_except(string, replacement, (char *) 0));
+}
+
+/* printable_except -  pass through printable or other preserved characters */
+
+char   *printable_except(char *string, int replacement, const char *except)
+{
+    unsigned char *cp;
+    int     ch;
+
+    /*
+     * XXX Replace invalid UTF8 sequences (too short, over-long encodings,
+     * out-of-range code points, etc). See valid_utf8_string.c.
+     */
+    cp = (unsigned char *) string;
+    while ((ch = *cp) != 0) {
+	if (ISASCII(ch) && (ISPRINT(ch) || (except && strchr(except, ch)))) {
+	    /* ok */
+	} else if (util_utf8_enable && ch >= 194 && ch <= 254
+		   && cp[1] >= 128 && cp[1] < 192) {
+	    /* UTF8; skip the rest of the bytes in the character. */
+	    while (cp[1] >= 128 && cp[1] < 192)
+		cp++;
+	} else {
+	    /* Not ASCII and not UTF8. */
+	    *cp = replacement;
+	}
+	cp++;
+    }
+    return (string);
+}