Fix GH-10648: add check function pointer into mbfl_encoding

Previously, mbstring used the same logic for encoding validation as for encoding conversion. However, there are cases where we want to use different logic for validation and conversion. For example, if a string ends up with missing input required by the encoding, or if a character is input that is invalid as an encoding but can be converted, the conversion should succeed and the validation should fail. To achieve this, a function pointer mb_check_fn has been added to struct mbfl_encoding to implement the logic used for validation. Also, added implementation of validation logic for UTF-7, UTF7-IMAP, and JIS.

Author: pakutoma

ext/mbstring/libmbfl/filters/mbfilter_7bit.c

@@ -64,7 +64,8 @@ const mbfl_encoding mbfl_encoding_7bit = {
 	&vtbl_7bit_wchar,
 	&vtbl_wchar_7bit,
 	mb_7bit_to_wchar,
-	mb_wchar_to_7bit
+	mb_wchar_to_7bit,
+	NULL
 };
 
 #define CK(statement)	do { if ((statement) < 0) return (-1); } while (0)

ext/mbstring/libmbfl/filters/mbfilter_base64.c

@@ -44,7 +44,8 @@ const mbfl_encoding mbfl_encoding_base64 = {
 	NULL,
 	NULL,
 	mb_base64_to_wchar,
-	mb_wchar_to_base64
+	mb_wchar_to_base64,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_8bit_b64 = {

ext/mbstring/libmbfl/filters/mbfilter_big5.c

@@ -69,7 +69,8 @@ const mbfl_encoding mbfl_encoding_big5 = {
 	&vtbl_big5_wchar,
 	&vtbl_wchar_big5,
 	mb_big5_to_wchar,
-	mb_wchar_to_big5
+	mb_wchar_to_big5,
+	NULL
 };
 
 const mbfl_encoding mbfl_encoding_cp950 = {
@@ -82,7 +83,8 @@ const mbfl_encoding mbfl_encoding_cp950 = {
 	&vtbl_cp950_wchar,
 	&vtbl_wchar_cp950,
 	mb_cp950_to_wchar,
-	mb_wchar_to_cp950
+	mb_wchar_to_cp950,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_big5_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_cp5022x.c

@@ -61,7 +61,8 @@ const mbfl_encoding mbfl_encoding_cp50220 = {
 	&vtbl_cp50220_wchar,
 	&vtbl_wchar_cp50220,
 	mb_cp5022x_to_wchar,
-	mb_wchar_to_cp50220
+	mb_wchar_to_cp50220,
+	NULL
 };
 
 const mbfl_encoding mbfl_encoding_cp50221 = {
@@ -74,7 +75,8 @@ const mbfl_encoding mbfl_encoding_cp50221 = {
 	&vtbl_cp50221_wchar,
 	&vtbl_wchar_cp50221,
 	mb_cp5022x_to_wchar,
-	mb_wchar_to_cp50221
+	mb_wchar_to_cp50221,
+	NULL
 };
 
 const mbfl_encoding mbfl_encoding_cp50222 = {
@@ -87,7 +89,8 @@ const mbfl_encoding mbfl_encoding_cp50222 = {
 	&vtbl_cp50222_wchar,
 	&vtbl_wchar_cp50222,
 	mb_cp5022x_to_wchar,
-	mb_wchar_to_cp50222
+	mb_wchar_to_cp50222,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_cp50220_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_cp51932.c

@@ -69,7 +69,8 @@ const mbfl_encoding mbfl_encoding_cp51932 = {
 	&vtbl_cp51932_wchar,
 	&vtbl_wchar_cp51932,
 	mb_cp51932_to_wchar,
-	mb_wchar_to_cp51932
+	mb_wchar_to_cp51932,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_cp51932_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_cp932.c

@@ -100,7 +100,8 @@ const mbfl_encoding mbfl_encoding_cp932 = {
 	&vtbl_cp932_wchar,
 	&vtbl_wchar_cp932,
 	mb_cp932_to_wchar,
-	mb_wchar_to_cp932
+	mb_wchar_to_cp932,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_cp932_wchar = {
@@ -133,7 +134,8 @@ const mbfl_encoding mbfl_encoding_sjiswin = {
 	&vtbl_sjiswin_wchar,
 	&vtbl_wchar_sjiswin,
 	mb_cp932_to_wchar,
-	mb_wchar_to_sjiswin
+	mb_wchar_to_sjiswin,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_sjiswin_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_cp936.c

@@ -68,7 +68,8 @@ const mbfl_encoding mbfl_encoding_cp936 = {
 	&vtbl_cp936_wchar,
 	&vtbl_wchar_cp936,
 	mb_cp936_to_wchar,
-	mb_wchar_to_cp936
+	mb_wchar_to_cp936,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_cp936_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_euc_cn.c

@@ -67,7 +67,8 @@ const mbfl_encoding mbfl_encoding_euc_cn = {
 	&vtbl_euccn_wchar,
 	&vtbl_wchar_euccn,
 	mb_euccn_to_wchar,
-	mb_wchar_to_euccn
+	mb_wchar_to_euccn,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_euccn_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_euc_jp.c

@@ -68,7 +68,8 @@ const mbfl_encoding mbfl_encoding_euc_jp = {
 	&vtbl_eucjp_wchar,
 	&vtbl_wchar_eucjp,
 	mb_eucjp_to_wchar,
-	mb_wchar_to_eucjp
+	mb_wchar_to_eucjp,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_eucjp_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_euc_jp_win.c

@@ -69,7 +69,8 @@ const mbfl_encoding mbfl_encoding_eucjp_win = {
 	&vtbl_eucjpwin_wchar,
 	&vtbl_wchar_eucjpwin,
 	mb_eucjpwin_to_wchar,
-	mb_wchar_to_eucjpwin
+	mb_wchar_to_eucjpwin,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_eucjpwin_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_euc_kr.c

@@ -66,7 +66,8 @@ const mbfl_encoding mbfl_encoding_euc_kr = {
 	&vtbl_euckr_wchar,
 	&vtbl_wchar_euckr,
 	mb_euckr_to_wchar,
-	mb_wchar_to_euckr
+	mb_wchar_to_euckr,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_euckr_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_euc_tw.c

@@ -68,7 +68,8 @@ const mbfl_encoding mbfl_encoding_euc_tw = {
 	&vtbl_euctw_wchar,
 	&vtbl_wchar_euctw,
 	mb_euctw_to_wchar,
-	mb_wchar_to_euctw
+	mb_wchar_to_euctw,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_euctw_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_gb18030.c

@@ -49,7 +49,8 @@ const mbfl_encoding mbfl_encoding_gb18030 = {
 	&vtbl_gb18030_wchar,
 	&vtbl_wchar_gb18030,
 	mb_gb18030_to_wchar,
-	mb_wchar_to_gb18030
+	mb_wchar_to_gb18030,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_gb18030_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_htmlent.c

@@ -66,7 +66,8 @@ const mbfl_encoding mbfl_encoding_html_ent = {
 	&vtbl_html_wchar,
 	&vtbl_wchar_html,
 	mb_htmlent_to_wchar,
-	mb_wchar_to_htmlent
+	mb_wchar_to_htmlent,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_wchar_html = {

ext/mbstring/libmbfl/filters/mbfilter_hz.c

@@ -47,7 +47,8 @@ const mbfl_encoding mbfl_encoding_hz = {
 	&vtbl_hz_wchar,
 	&vtbl_wchar_hz,
 	mb_hz_to_wchar,
-	mb_wchar_to_hz
+	mb_wchar_to_hz,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_hz_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_iso2022_jp_ms.c

@@ -51,7 +51,8 @@ const mbfl_encoding mbfl_encoding_2022jpms = {
 	&vtbl_2022jpms_wchar,
 	&vtbl_wchar_2022jpms,
 	mb_iso2022jpms_to_wchar,
-	mb_wchar_to_iso2022jpms
+	mb_wchar_to_iso2022jpms,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_2022jpms_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_iso2022_kr.c

@@ -54,7 +54,8 @@ const mbfl_encoding mbfl_encoding_2022kr = {
 	&vtbl_2022kr_wchar,
 	&vtbl_wchar_2022kr,
 	mb_iso2022kr_to_wchar,
-	mb_wchar_to_iso2022kr
+	mb_wchar_to_iso2022kr,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_wchar_2022kr = {

ext/mbstring/libmbfl/filters/mbfilter_iso2022jp_mobile.c

@@ -71,7 +71,8 @@ const mbfl_encoding mbfl_encoding_2022jp_kddi = {
 	&vtbl_2022jp_kddi_wchar,
 	&vtbl_wchar_2022jp_kddi,
 	mb_iso2022jp_kddi_to_wchar,
-	mb_wchar_to_iso2022jp_kddi
+	mb_wchar_to_iso2022jp_kddi,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_2022jp_kddi_wchar = {

ext/mbstring/libmbfl/filters/mbfilter_jis.c

@@ -37,6 +37,7 @@ static int mbfl_filt_conv_jis_wchar_flush(mbfl_convert_filter *filter);
 static size_t mb_iso2022jp_to_wchar(unsigned char **in, size_t *in_len, uint32_t *buf, size_t bufsize, unsigned int *state);
 static void mb_wchar_to_iso2022jp(uint32_t *in, size_t len, mb_convert_buf *buf, bool end);
 static void mb_wchar_to_jis(uint32_t *in, size_t len, mb_convert_buf *buf, bool end);
+static bool mb_check_iso2022jp(unsigned char *in, size_t in_len);
 
 const mbfl_encoding mbfl_encoding_jis = {
 	mbfl_no_encoding_jis,
@@ -49,6 +50,7 @@ const mbfl_encoding mbfl_encoding_jis = {
 	&vtbl_wchar_jis,
 	mb_iso2022jp_to_wchar,
 	mb_wchar_to_jis,
+	mb_check_iso2022jp
 };
 
 const mbfl_encoding mbfl_encoding_2022jp = {
@@ -61,7 +63,8 @@ const mbfl_encoding mbfl_encoding_2022jp = {
 	&vtbl_2022jp_wchar,
 	&vtbl_wchar_2022jp,
 	mb_iso2022jp_to_wchar,
-	mb_wchar_to_iso2022jp
+	mb_wchar_to_iso2022jp,
+	mb_check_iso2022jp
 };
 
 const struct mbfl_convert_vtbl vtbl_jis_wchar = {
@@ -780,3 +783,95 @@ static void mb_wchar_to_jis(uint32_t *in, size_t len, mb_convert_buf *buf, bool
 
 	MB_CONVERT_BUF_STORE(buf, out, limit);
 }
+
+static bool mb_check_iso2022jp(unsigned char *in, size_t in_len)
+{
+	unsigned char *p = in, *e = p + in_len;
+	unsigned int state = ASCII;
+
+	while (p < e) {
+		unsigned char c = *p++;
+		if (c == 0x1B) {
+			/* ESC seen; this is an escape sequence */
+			if ((e - p) < 2) {
+				return false;
+			}
+			unsigned char c2 = *p++;
+			if (c2 == '$') {
+				unsigned char c3 = *p++;
+				if (c3 == '@' || c3 == 'B') {
+					state = JISX_0208;
+				} else if (c3 == '(') {
+					if (p == e) {
+						return false;
+					}
+					unsigned char c4 = *p++;
+					if (c4 == '@' || c4 == 'B') {
+						state = JISX_0208;
+					} else if (c4 == 'D') {
+						state = JISX_0212;
+					} else {
+						return false;
+					}
+				} else {
+					return false;
+				}
+			} else if (c2 == '(') {
+				unsigned char c3 = *p++;
+				if (c3 == 'B' || c3 == 'H') {
+					state = ASCII;
+				} else if (c3 == 'J') {
+					state = JISX_0201_LATIN;
+				} else if (c3 == 'I') {
+					state = JISX_0201_KANA;
+				} else {
+					return false;
+				}
+			} else {
+				return false;
+			}
+		} else if (c == 0xE) {
+			/* "Kana In" marker; this is just for JIS-7/8, but we also accept it for ISO-2022-JP */
+			state = JISX_0201_KANA;
+		} else if (c == 0xF) {
+			/* "Kana Out" marker */
+			state = ASCII;
+		} else if (state >= JISX_0208 && (c > 0x20 && c < 0x7F)) {
+			if (p == e) {
+				return false;
+			}
+			unsigned char c2 = *p++;
+			if (c2 > 0x20 && c2 < 0x7F) {
+				unsigned int s = (c - 0x21)*94 + c2 - 0x21;
+				uint32_t w = 0;
+				if (state == JISX_0208) {
+					if (s < jisx0208_ucs_table_size) {
+						w = jisx0208_ucs_table[s];
+					}
+					if (w > 0) {
+						continue;
+					}
+				} else {
+					if (s < jisx0212_ucs_table_size) {
+						w = jisx0212_ucs_table[s];
+					}
+					if (w > 0) {
+						continue;
+					}
+				}
+				return false;
+			} else {
+				return false;
+			}
+		} else if (c < 0x80) {
+			continue;
+		} else if (c >= 0xA1 && c <= 0xDF) {
+			/* GR-invoked Kana; Conversion is accepted, check is not. */
+			return false;
+		} else {
+			return false;
+		}
+	}
+
+	return state == ASCII;
+}

ext/mbstring/libmbfl/filters/mbfilter_qprint.c

@@ -46,7 +46,8 @@ const mbfl_encoding mbfl_encoding_qprint = {
 	NULL,
 	NULL,
 	mb_qprint_to_wchar,
-	mb_wchar_to_qprint
+	mb_wchar_to_qprint,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_8bit_qprint = {

ext/mbstring/libmbfl/filters/mbfilter_singlebyte.c

@@ -86,7 +86,8 @@ static int mbfl_conv_reverselookup_table(int c, mbfl_convert_filter *filter, int
 		&vtbl_##id##_wchar, \
 		&vtbl_wchar_##id, \
 		mb_##id##_to_wchar, \
-		mb_wchar_to_##id \
+		mb_wchar_to_##id, \
+		NULL \
 	}
 
 /* For single-byte encodings which use a conversion table */

ext/mbstring/libmbfl/filters/mbfilter_sjis.c

@@ -71,7 +71,8 @@ const mbfl_encoding mbfl_encoding_sjis = {
 	&vtbl_sjis_wchar,
 	&vtbl_wchar_sjis,
 	mb_sjis_to_wchar,
-	mb_wchar_to_sjis
+	mb_wchar_to_sjis,
+	NULL
 };
 
 const struct mbfl_convert_vtbl vtbl_sjis_wchar = {