diff --git a/ext/standard/html.c b/ext/standard/html.c index 0c6231d590d88..fbded4160b55c 100644 --- a/ext/standard/html.c +++ b/ext/standard/html.c @@ -809,112 +809,149 @@ static inline size_t write_octet_sequence(unsigned char *buf, enum entity_charse /* +2 is 1 because of rest (probably unnecessary), 1 because of terminating 0 */ #define TRAVERSE_FOR_ENTITIES_EXPAND_SIZE(oldlen) ((oldlen) + (oldlen) / 5 + 2) static void traverse_for_entities( - const char *old, - size_t oldlen, - zend_string *ret, /* should have allocated TRAVERSE_FOR_ENTITIES_EXPAND_SIZE(olden) */ - int all, - int flags, + const zend_string *input, + zend_string *output, /* should have allocated TRAVERSE_FOR_ENTITIES_EXPAND_SIZE(olden) */ + const int all, + const int flags, const entity_ht *inv_map, - enum entity_charset charset) + const enum entity_charset charset) { - const char *p, - *lim; - char *q; - int doctype = flags & ENT_HTML_DOC_TYPE_MASK; - - lim = old + oldlen; /* terminator address */ - assert(*lim == '\0'); - - for (p = old, q = ZSTR_VAL(ret); p < lim;) { - unsigned code, code2 = 0; - const char *next = NULL; /* when set, next > p, otherwise possible inf loop */ - - /* Shift JIS, Big5 and HKSCS use multi-byte encodings where an - * ASCII range byte can be part of a multi-byte sequence. - * However, they start at 0x40, therefore if we find a 0x26 byte, - * we're sure it represents the '&' character. */ + const char *current_ptr = ZSTR_VAL(input); + const char *input_end = current_ptr + ZSTR_LEN(input); /* terminator address */ + char *output_ptr = ZSTR_VAL(output); + const int doctype = flags & ENT_HTML_DOC_TYPE_MASK; + + while (current_ptr < input_end) { + const char *ampersand_ptr = memchr(current_ptr, '&', input_end - current_ptr); + if (!ampersand_ptr) { + const size_t tail_len = input_end - current_ptr; + if (tail_len > 0) { + memcpy(output_ptr, current_ptr, tail_len); + output_ptr += tail_len; + } + break; + } - /* assumes there are no single-char entities */ - if (p[0] != '&' || (p + 3 >= lim)) { - *(q++) = *(p++); - continue; + /* Copy everything up to the found '&' */ + const size_t chunk_len = ampersand_ptr - current_ptr; + if (chunk_len > 0) { + memcpy(output_ptr, current_ptr, chunk_len); + output_ptr += chunk_len; } - /* now p[3] is surely valid and is no terminator */ - - /* numerical entity */ - if (p[1] == '#') { - next = &p[2]; - if (process_numeric_entity(&next, &code) == FAILURE) - goto invalid_code; - - /* If we're in htmlspecialchars_decode, we're only decoding entities - * that represent &, <, >, " and '. Is this one of them? */ - if (!all && (code > 63U || - stage3_table_be_apos_00000[code].data.ent.entity == NULL)) - goto invalid_code; - - /* are we allowed to decode this entity in this document type? - * HTML 5 is the only that has a character that cannot be used in - * a numeric entity but is allowed literally (U+000D). The - * unoptimized version would be ... || !numeric_entity_is_allowed(code) */ - if (!unicode_cp_is_allowed(code, doctype) || - (doctype == ENT_HTML_DOC_HTML5 && code == 0x0D)) - goto invalid_code; - } else { - const char *start; - size_t ent_len; + /* Now current_ptr points to the '&' character. */ + current_ptr = ampersand_ptr; - next = &p[1]; - start = next; + /* If there are less than 4 bytes remaining, there isn't enough for an entity – copy '&' as a normal character */ + if (input_end - current_ptr < 4){ + const size_t remaining = input_end - current_ptr; + memcpy(output_ptr, current_ptr, remaining); + output_ptr += remaining; + break; + } - if (process_named_entity_html(&next, &start, &ent_len) == FAILURE) - goto invalid_code; + unsigned code = 0, code2 = 0; + const char *entity_end_ptr = NULL; - if (resolve_named_entity_html(start, ent_len, inv_map, &code, &code2) == FAILURE) { - if (doctype == ENT_HTML_DOC_XHTML && ent_len == 4 && start[0] == 'a' - && start[1] == 'p' && start[2] == 'o' && start[3] == 's') { - /* uses html4 inv_map, which doesn't include apos;. This is a - * hack to support it */ - code = (unsigned) '\''; + if (current_ptr[1] == '#') { + /* Processing numeric entity */ + const char *num_start = current_ptr + 2; + entity_end_ptr = num_start; + if (process_numeric_entity(&entity_end_ptr, &code) == FAILURE) { + goto invalid_incomplete_entity; + } + if (!all && (code > 63U || stage3_table_be_apos_00000[code].data.ent.entity == NULL)) { + /* If we're in htmlspecialchars_decode, we're only decoding entities + * that represent &, <, >, " and '. Is this one of them? */ + goto invalid_incomplete_entity; + } else if (!unicode_cp_is_allowed(code, doctype) || + (doctype == ENT_HTML_DOC_HTML5 && code == 0x0D)) { + /* are we allowed to decode this entity in this document type? + * HTML 5 is the only that has a character that cannot be used in + * a numeric entity but is allowed literally (U+000D). The + * unoptimized version would be ... || !numeric_entity_is_allowed(code) */ + goto invalid_incomplete_entity; + } + } else { + /* Processing named entity */ + const char *name_start = current_ptr + 1; + /* Search for ';' */ + const size_t max_search_len = MIN(LONGEST_ENTITY_LENGTH + 1, input_end - name_start); + const char *semi_colon_ptr = memchr(name_start, ';', max_search_len); + if (!semi_colon_ptr) { + goto invalid_incomplete_entity; + } else { + const size_t name_len = semi_colon_ptr - name_start; + if (name_len == 0) { + goto invalid_incomplete_entity; } else { - goto invalid_code; + if (resolve_named_entity_html(name_start, name_len, inv_map, &code, &code2) == FAILURE) { + if (doctype == ENT_HTML_DOC_XHTML && name_len == 4 && + name_start[0] == 'a' && name_start[1] == 'p' && + name_start[2] == 'o' && name_start[3] == 's') + { + /* uses html4 inv_map, which doesn't include apos;. This is a + * hack to support it */ + code = (unsigned)'\''; + } else { + goto invalid_incomplete_entity; + } + } + entity_end_ptr = semi_colon_ptr; } } } - assert(*next == ';'); + /* If entity_end_ptr is not found or does not point to ';', consider the entity invalid */ + if (entity_end_ptr == NULL) { + goto invalid_incomplete_entity; + } - if (((code == '\'' && !(flags & ENT_HTML_QUOTE_SINGLE)) || - (code == '"' && !(flags & ENT_HTML_QUOTE_DOUBLE))) - /* && code2 == '\0' always true for current maps */) - goto invalid_code; + /* Check if quotes are allowed for entities representing ' or " */ + if ((code == '\'' && !(flags & ENT_HTML_QUOTE_SINGLE)) || + (code == '"' && !(flags & ENT_HTML_QUOTE_DOUBLE))) + { + goto invalid_complete_entity; + } /* UTF-8 doesn't need mapping (ISO-8859-1 doesn't either, but * the call is needed to ensure the codepoint <= U+00FF) */ if (charset != cs_utf_8) { /* replace unicode code point */ - if (map_from_unicode(code, charset, &code) == FAILURE || code2 != 0) - goto invalid_code; /* not representable in target charset */ + if (map_from_unicode(code, charset, &code) == FAILURE || code2 != 0) { + goto invalid_complete_entity; + } } - q += write_octet_sequence((unsigned char*)q, charset, code); + /* Write the parsed entity into the output buffer */ + output_ptr += write_octet_sequence((unsigned char*)output_ptr, charset, code); if (code2) { - q += write_octet_sequence((unsigned char*)q, charset, code2); + output_ptr += write_octet_sequence((unsigned char*)output_ptr, charset, code2); } + /* Move current_ptr past the semicolon */ + current_ptr = entity_end_ptr + 1; + continue; - /* jump over the valid entity; may go beyond size of buffer; np */ - p = next + 1; +invalid_incomplete_entity: + /* If the entity is invalid at parse stage or entity_end_ptr was never found, copy '&' as normal */ + *output_ptr++ = *current_ptr++; continue; -invalid_code: - for (; p < next; p++) { - *(q++) = *p; +invalid_complete_entity: + /* If the entity became invalid after we found entity_end_ptr */ + if (entity_end_ptr) { + const size_t len = entity_end_ptr - current_ptr; + memcpy(output_ptr, current_ptr, len); + output_ptr += len; + current_ptr = entity_end_ptr; + } else { + *output_ptr++ = *current_ptr++; } + continue; } - *q = '\0'; - ZSTR_LEN(ret) = (size_t)(q - ZSTR_VAL(ret)); + *output_ptr = '\0'; + ZSTR_LEN(output) = (size_t)(output_ptr - ZSTR_VAL(output)); } /* }}} */ @@ -999,7 +1036,7 @@ PHPAPI zend_string *php_unescape_html_entities(zend_string *str, int all, int fl inverse_map = unescape_inverse_map(all, flags); /* replace numeric entities */ - traverse_for_entities(ZSTR_VAL(str), ZSTR_LEN(str), ret, all, flags, inverse_map, charset); + traverse_for_entities(str, ret, all, flags, inverse_map, charset); return ret; }