lib-storage: mail-storage - Make mailbox_name_check_forbidden_chars() check a broader...

Before, it only checked for ASCII control characters.

diff --git a/src/lib-storage/mail-storage.c b/src/lib-storage/mail-storage.c
index 3127fe3140115588973d6ddc6d5eb0ae05e8e6ee..4afbbbd0a2cbd7c3ec2769999c70505d7a2f1b68 100644 (file)
--- a/src/lib-storage/mail-storage.c
+++ b/src/lib-storage/mail-storage.c
@@ -8,6 +8,7 @@
 #include "str.h"
 #include "str-parse.h"
 #include "sha1.h"
+#include "unicode-data.h"
 #include "unichar.h"
 #include "hex-binary.h"
 #include "fs-api.h"
@@ -1629,11 +1630,46 @@ static int mailbox_verify_existing_name(struct mailbox *box)
 static int
 mailbox_name_check_forbidden_chars(const char *name, const char **error_r)
 {
-       const char *p;
+       const unsigned char *input = (const unsigned char *)name;
+       size_t size = strlen(name);
 
-       for (p = name; *p != '\0'; p++) {
-               if ((unsigned char)*p < ' ') {
-                       *error_r = "Control characters not allowed in new mailbox names";
+       /* RFC 9755, Section 3:
+
+          Mailbox names MUST comply with the Net-Unicode Definition ([RFC5198],
+          Section 2) with the specific exception that they MUST NOT contain
+          control characters (U+0000 - U+001F and U+0080 - U+009F), a delete
+          character (U+007F), a line separator (U+2028), or a paragraph
+          separator (U+2029).
+
+          RFC 5198, Section 2:
+
+          5.  As suggested in Section 6 of RFC 3629, the Byte Order Mark
+              ("BOM") signature MUST NOT appear at the beginning of these text
+              strings.
+
+          6.  Systems conforming to this specification MUST NOT transmit any
+              string containing any code point that is unassigned in the
+              version of Unicode on which they are dependent.  The version of
+              NFC and the version of Unicode used by that system MUST be
+              consistent.
+        */
+
+       while (size > 0) {
+               unichar_t chr;
+               int bytes;
+
+               bytes = uni_utf8_get_char_n(input, size, &chr);
+               i_assert(bytes > 0); /* UTF8 already checked */
+               input += bytes;
+               size -= bytes;
+
+               if (chr <= 0x1f || chr == 0x7f ||
+                   (chr >= 0x0080 && chr <= 0x009f) ||
+                   chr == 0x2028 || chr == 0x2029 || chr == 0xFEFF ||
+                   !unicode_code_point_is_assigned(chr)) {
+                       *error_r = t_strdup_printf(
+                               "New mailbox name contains forbidden character "
+                               "(U+%04X)", chr);
                        return -1;
                }
        }