Hi all, Balsa has a bug in encoding IMAP mailbox names to modified UTF-7 as defined in RFC 3501, sect. 5.1.3 [1], as the '\' (0x5c) is encoded as '\\' which is explicitly prohibited. To reproduce: activate main() in libbalsa/imap/util.c, compile it, and run e.g. (yes, the mailbox name is weird, but it includes all special cases from the RFC…)
./util 'ϴä ab c&d+e/f\~ßx' orig='ϴä ab c&d+e/f\~ßx' mbx='&A,QA5A- ab c&-d+e/f\\~&AN8-x' back='ϴä ab c&d+e/f\\~ßx' WRONG CONVERSION: --------------------------------^^ The attached patch replaces the hand-coded conversion by utilising g_convert(), and also fixes the bug. For testing: ./util 'ϴä ab c&d+e/f\~ßx' orig='ϴä ab c&d+e/f\~ßx' mbx='&A,QA5A- ab c&-d+e/f\~&AN8-x' back='ϴä ab c&d+e/f\~ßx' PROPER CONVERSION: -----------------------------^ Opinions? Cheers, Albrecht. [1] <https://tools.ietf.org/html/rfc3501#section-5.1.3>
diff --git a/libbalsa/imap/util.c b/libbalsa/imap/util.c
index 6860ab3da..bb29575f9 100644
--- a/libbalsa/imap/util.c
+++ b/libbalsa/imap/util.c
@@ -94,220 +94,102 @@ imap_next_word(char *s)
/* ===================================================================
* UTF-7 conversion routines as in RFC 2192
* =================================================================== */
-/* UTF7 modified base64 alphabet */
-static char base64chars[] =
- "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
-#define UNDEFINED 64
-/* UTF16 definitions */
-#define UTF16MASK 0x03FFUL
-#define UTF16SHIFT 10
-#define UTF16BASE 0x10000UL
-#define UTF16HIGHSTART 0xD800UL
-#define UTF16HIGHEND 0xDBFFUL
-#define UTF16LOSTART 0xDC00UL
-#define UTF16LOEND 0xDFFFUL
+/* see RFC 3501, Section 5.1.3. Mailbox International Naming Convention:
+ * In modified UTF-7, printable US-ASCII characters, except for "&", represent themselves; that is, characters with octet values
+ * 0x20-0x25 and 0x27-0x7e. */
+#define IS_VALID_ASCII(c) ((((c) >= '\x20') && ((c) <= '\x25')) || (((c) >= '\x27') && ((c) <= '\x7e')))
-
-/* Convert an IMAP mailbox to a UTF-8 string.
- * dst needs to have roughly 4 times the storage space of src
- * Hex encoding can triple the size of the input
- * UTF-7 can be slightly denser than UTF-8
- * (worst case: 8 octets UTF-7 becomes 9 octets UTF-8)
- */
-char*
-imap_mailbox_to_utf8(const char *mbox)
+gchar *
+imap_utf8_to_mailbox(const gchar *mbox)
{
- unsigned c, i, bitcount;
- unsigned long ucs4, utf16, bitbuf;
- unsigned char base64[256];
- const char *src;
- char *dst, *res = malloc(2*strlen(mbox)+1);
-
- bitbuf = 0;
- dst = res;
- src = mbox;
- if(!dst) return NULL;
- /* initialize modified base64 decoding table */
- memset(base64, UNDEFINED, sizeof (base64));
- for (i = 0; i < sizeof (base64chars); ++i) {
- base64[(unsigned)base64chars[i]] = i;
- }
-
- /* loop until end of string */
- while (*src != '\0') {
- c = *src++;
- /* deal with literal characters and &- */
- if (c != '&' || *src == '-') {
- /* encode literally */
- *dst++ = c;
- /* skip over the '-' if this is an &- sequence */
- if (c == '&') ++src;
- } else {
- /* convert modified UTF-7 -> UTF-16 -> UCS-4 -> UTF-8 -> HEX */
- bitbuf = 0;
- bitcount = 0;
- ucs4 = 0;
- while ((c = base64[(unsigned char) *src]) != UNDEFINED) {
- ++src;
- bitbuf = (bitbuf << 6) | c;
- bitcount += 6;
- /* enough bits for a UTF-16 character? */
- if (bitcount >= 16) {
- bitcount -= 16;
- utf16 = (bitcount ? bitbuf >> bitcount
- : bitbuf) & 0xffff;
- /* convert UTF16 to UCS4 */
- if
- (utf16 >= UTF16HIGHSTART && utf16 <= UTF16HIGHEND) {
- ucs4 = (utf16 - UTF16HIGHSTART) << UTF16SHIFT;
- continue;
- } else if
- (utf16 >= UTF16LOSTART && utf16 <= UTF16LOEND) {
- ucs4 += utf16 - UTF16LOSTART + UTF16BASE;
- } else {
- ucs4 = utf16;
- }
-
- /* convert UTF-16 range of UCS4 to UTF-8 */
- if (ucs4 <= 0x7fUL) {
- dst[0] = ucs4;
- dst += 1;
- } else if (ucs4 <= 0x7ffUL) {
- dst[0] = 0xc0 | (ucs4 >> 6);
- dst[1] = 0x80 | (ucs4 & 0x3f);
- dst += 2;
- } else if (ucs4 <= 0xffffUL) {
- dst[0] = 0xe0 | (ucs4 >> 12);
- dst[1] = 0x80 | ((ucs4 >> 6) & 0x3f);
- dst[2] = 0x80 | (ucs4 & 0x3f);
- dst += 3;
- } else {
- dst[0] = 0xf0 | (ucs4 >> 18);
- dst[1] = 0x80 | ((ucs4 >> 12) & 0x3f);
- dst[2] = 0x80 | ((ucs4 >> 6) & 0x3f);
- dst[3] = 0x80 | (ucs4 & 0x3f);
- dst += 4;
- }
- }
- }
- /* skip over trailing '-' in modified UTF-7 encoding */
- if (*src == '-') ++src;
- }
- }
- /* terminate destination string */
- *dst = '\0';
- return res;
+ GString *buffer;
+ const gchar *next_in;
+
+ buffer = g_string_sized_new(strlen(mbox)); /* sufficient size for ASCII only */
+ next_in = mbox;
+ while (*next_in != '\0') {
+ if (IS_VALID_ASCII(*next_in)) {
+ g_string_append_c(buffer, *next_in++);
+ } else if (*next_in == '&') {
+ g_string_append(buffer, "&-"); /* see RFC 3501, Section 5.1.3 */
+ next_in++;
+ } else {
+ const gchar *next_ascii;
+ gchar *utf7;
+ gsize utf7len;
+
+ next_ascii = g_utf8_next_char(next_in);
+ while ((*next_ascii != '\0') && !IS_VALID_ASCII(*next_ascii)) {
+ next_ascii = g_utf8_next_char(next_ascii);
+ }
+ utf7 = g_convert(next_in, next_ascii - next_in, "utf7", "utf8", NULL, &utf7len, NULL);
+ if (utf7 != NULL) {
+ gsize n;
+ utf7[0] = '&'; /* see RFC 3501, Section 5.1.3 */
+
+ for (n = 1U; n < utf7len; n++) {
+ if (utf7[n] == '/') { /* see RFC 3501, Section 5.1.3 */
+ utf7[n] = ',';
+ }
+ }
+ g_string_append_len(buffer, utf7, utf7len);
+ g_free(utf7);
+ }
+ next_in = next_ascii;
+ }
+ }
+
+ return g_string_free(buffer, FALSE);
}
-/* Convert hex coded UTF-8 string to modified UTF-7 IMAP mailbox
- * dst should be about twice the length of src to deal with non-hex
- * coded URLs
- */
-char*
-imap_utf8_to_mailbox(const char *src)
+gchar *
+imap_mailbox_to_utf8(const gchar *mbox)
{
- unsigned int utf8pos, utf8total, c, utf7mode, bitstogo, utf16flag;
- unsigned long ucs4 = 0, bitbuf = 0;
-
- /* initialize hex lookup table */
- char *dst, *res = malloc(2*strlen(src)+1);
- dst = res;
- if(!dst) return NULL;
+ GString *buffer;
+ const gchar *next_in;
+
+ buffer = g_string_sized_new(strlen(mbox)); /* always sufficiently long */
+ next_in = mbox;
+ while (*next_in != '\0') {
+ if (*next_in == '&') {
+ if (next_in[1] == '-') { /* see RFC 3501, Section 5.1.3 */
+ g_string_append_c(buffer, '&');
+ next_in = &next_in[2];
+ } else {
+ gchar *utf7buf;
+ gchar *next_utf7;
+ gchar *utf8;
+ gsize utf8len;
+
+ utf7buf = g_malloc0(strlen(next_in) + 1U);
+ utf7buf[0] = '+'; /* RFC 2152 shift character */
+ next_in++;
+ next_utf7 = &utf7buf[1];
+ for (next_utf7 = &utf7buf[1]; (*next_in != '\0') && (*next_in != '-'); next_in++) {
+ if (*next_in == ',') { /* see RFC 3501, Section 5.1.3 */
+ *next_utf7++ = '/';
+ } else {
+ *next_utf7++ = *next_in;
+ }
+ }
+ *next_utf7 = *next_in;
+ if (*next_in == '-') {
+ next_in++;
+ }
+ utf8 = g_convert(utf7buf, -1, "utf8", "utf7", NULL, &utf8len, NULL);
+ if (utf8 != NULL) {
+ g_string_append_len(buffer, utf8, utf8len);
+ g_free(utf8);
+ }
+ g_free(utf7buf);
+ }
+ } else {
+ g_string_append_c(buffer, *next_in++);
+ }
+ }
- utf7mode = 0;
- utf8total = 0;
- bitstogo = 0;
- utf8pos = 0;
- while ((c = (unsigned char)*src) != '\0') {
- ++src;
- /* normal character? */
- if (c >= ' ' && c <= '~') {
- /* switch out of UTF-7 mode */
- if (utf7mode) {
- if (bitstogo) {
- *dst++ = base64chars[(bitbuf << (6 - bitstogo)) & 0x3F];
- }
- *dst++ = '-';
- utf7mode = 0;
- utf8pos = 0;
- bitstogo = 0;
- utf8total= 0;
- }
- /* encode '\' as '\\', and '"' as '\"' */
- if (c == '\\' || c == '"') {
- *dst++ = '\\';
- }
- *dst++ = c;
- /* encode '&' as '&-' */
- if (c == '&') {
- *dst++ = '-';
- }
- continue;
- }
- /* switch to UTF-7 mode */
- if (!utf7mode) {
- *dst++ = '&';
- utf7mode = 1;
- }
- /* Encode US-ASCII characters as themselves */
- if (c < 0x80) {
- ucs4 = c;
- utf8total = 1;
- } else if (utf8total) {
- /* save UTF8 bits into UCS4 */
- ucs4 = (ucs4 << 6) | (c & 0x3FUL);
- if (++utf8pos < utf8total) {
- continue;
- }
- } else {
- utf8pos = 1;
- if (c < 0xE0) {
- utf8total = 2;
- ucs4 = c & 0x1F;
- } else if (c < 0xF0) {
- utf8total = 3;
- ucs4 = c & 0x0F;
- } else {
- /* NOTE: can't convert UTF8 sequences longer than 4 */
- utf8total = 4;
- ucs4 = c & 0x03;
- }
- continue;
- }
- /* loop to split ucs4 into two utf16 chars if necessary */
- utf8total = 0;
- do {
- if (ucs4 >= UTF16BASE) {
- ucs4 -= UTF16BASE;
- bitbuf = (bitbuf << 16) | ((ucs4 >> UTF16SHIFT)
- + UTF16HIGHSTART);
- ucs4 = (ucs4 & UTF16MASK) + UTF16LOSTART;
- utf16flag = 1;
- } else {
- bitbuf = (bitbuf << 16) | ucs4;
- utf16flag = 0;
- }
- bitstogo += 16;
- /* spew out base64 */
- while (bitstogo >= 6) {
- bitstogo -= 6;
- *dst++ = base64chars[(bitstogo ? (bitbuf >> bitstogo)
- : bitbuf)
- & 0x3F];
- }
- } while (utf16flag);
- }
- /* if in UTF-7 mode, finish in ASCII */
- if (utf7mode) {
- if (bitstogo) {
- *dst++ = base64chars[(bitbuf << (6 - bitstogo)) & 0x3F];
- }
- *dst++ = '-';
- }
- /* tie off string */
- *dst = '\0';
- return res;
+ return g_string_free(buffer, FALSE);
}
#if 0
diff --git a/libbalsa/imap/util.h b/libbalsa/imap/util.h
index a01477f1d..1557e1a99 100644
--- a/libbalsa/imap/util.h
+++ b/libbalsa/imap/util.h
@@ -24,7 +24,9 @@ gchar *imap_quote_string(const gchar *src)
char* imap_next_word(char *s);
char* imap_skip_atom(char *s);
-char* imap_mailbox_to_utf8(const char *src);
-char* imap_utf8_to_mailbox(const char *src);
+gchar* imap_mailbox_to_utf8(const char *src)
+ G_GNUC_WARN_UNUSED_RESULT;
+gchar* imap_utf8_to_mailbox(const char *src)
+ G_GNUC_WARN_UNUSED_RESULT;
#endif
pgpNJ6Nk6REj3.pgp
Description: PGP signature
_______________________________________________ balsa-list mailing list [email protected] https://mail.gnome.org/mailman/listinfo/balsa-list
