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记一次刨根问底的HTTP包WAF绕过
记一次刨根问底的HTTP包WAF绕过
![1](https://shs3.b.qianxin.com/butian_public/f7d28ccc9e8e997f37c6302e45e841637.jpg) ```php POST /sql/post.php HTTP/1.1 Host: 192.168.1.72 Cache-Control: max-age=0 Upgrade-Insecure-Requests: 1 Origin: http://192.168.1.76 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.190 Safari/537.36 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9 Referer: http://192.168.1.76/sql.html Accept-Encoding: gzip, deflate Accept-Language: zh-CN,zh;q=0.9 Connection: close Content-Type: multipart/form-data; boundary=--------1721837650 Content-Length: 156 ----------1721837650 Content-Disposition: form-data; name="name\"; filename=";name='username'" Content-Type: image/jpeg admin ----------1721837650-- ``` 首先他是一个from-data的参数传递。并不上文件上传。因为\\ 把双引号给注释起来了。然后name=”name; filename=”; 然后另外一个是name=’username’ 猜测。两个只会选择最后一个进行参数传递。 一、Fastcgi 了解 <https://segmentfault.com/a/1190000016901718> 然后两台机器 WEB 192.168.1.72 PHP 192.168.1.70 PHP 服务器开启php-fpm 端口 ![](https://shs3.b.qianxin.com/butian_public/fc7a65159079a62a01c55fa0f7ecee65a.jpg) WEB服务器通过192.168.1.70:9000 去连接PHP ![](https://shs3.b.qianxin.com/butian_public/f8cb495b2745b7ad186b5ebcf8ba741a5.jpg) 然后进行抓包。 PHP 服务器抓WEB服务器发过来的包 `tcpdump src host 192.168.1.72 -w qq.cap` 看看FastCgi 具体的一个from-data 的内容 ![](https://shs3.b.qianxin.com/butian_public/f74d70bd227bb5ce1fa28d16de8484a06.jpg) ```php .........................&SCRIPT_FILENAME/www/wwwroot/192.168.1.72/sql/post.php..QUERY_STRING..REQUEST_METHODPOST.0CONTENT_TYPEmultipart/form-data; boundary=--------1721837650..CONTENT_LENGTH156. SCRIPT_NAME/sql/post.php. REQUEST_URI/sql/post.php. DOCUMENT_URI/sql/post.php .DOCUMENT_ROOT/www/wwwroot/192.168.1.72..SERVER_PROTOCOLHTTP/1.1..REQUEST_SCHEMEhttp..GATEWAY_INTERFACECGI/1.1..SERVER_SOFTWAREnginx/1.18.0..REMOTE_ADDR192.168.1.75..REMOTE_PORT59676..SERVER_ADDR192.168.1.72..SERVER_PORT80..SERVER_NAME192.168.1.72..REDIRECT_STATUS200.&SCRIPT_FILENAME/www/wwwroot/192.168.1.72/sql/post.php. SCRIPT_NAME/sql/post.php .PATH_INFO .HTTP_HOST192.168.1.72. HTTP_CACHE_CONTROLmax-age=0..HTTP_UPGRADE_INSECURE_REQUESTS1..HTTP_ORIGINhttp://192.168.1.76.sHTTP_USER_AGENTMozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.190 Safari/537.36.....HTTP_ACCEPTtext/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9..HTTP_REFERERhttp://192.168.1.76/sql.html. HTTP_ACCEPT_ENCODINGgzip, deflate..HTTP_ACCEPT_LANGUAGEzh-CN,zh;q=0.9..HTTP_CONNECTIONclose.0HTTP_CONTENT_TYPEmultipart/form-data; boundary=--------1721837650..HTTP_CONTENT_LENGTH156..................... ----------1721837650 Content-Disposition: form-data; name="name\"; filename=";name='username'" Content-Type: image/jpeg admin ----------1721837650--............ ``` 看到流量包的时候,感觉之前的东西是错了。前期和Yukion 师傅一直感觉是Nginx 做了处理,现在才明白其实最终是PHP进行了处理 Params 数据包参数整理: | key len | val len | key | val | | |---|---|---|---|---| | 10 | 4 | PRODUCTION | true | | | 15 | 38 | SCRIPT\_FILENAME | /home/xiaoju/webroot/default/index.php | | | 12 | 0 | QUERY\_STRING | | | | 14 | 3 | REQUEST\_METHOD | GET | | | 12 | 0 | CONTENT\_TYPE | | | | 14 | 0 | CONTENT\_LENGTH | | | | 11 | 10 | SCRIPT\_NAME | /index.php | | | 11 | 1 | REQUEST\_URI | / | | | 12 | 10 | DOCUMENT\_URI | /index.php | | | 13 | 28 | DOCUMENT\_ROOT | /home/xiaoju/webroot/default | | | 15 | 8 | SERVER\_PROTOCOL | HTTP/1.1 | | | 17 | 7 | GATEWAY\_INTERFACE | CGI/1.1 | | | 15 | 11 | SERVER\_SOFTWARE | nginx/1.6.2 | | | 11 | 9 | REMOTE\_ADDR | 127.0.0.1 | | | 11 | 5 | REMOTE\_PORT | 42282 | | | 11 | 9 | SERVER\_ADDR | 127.0.0.1 | | | 11 | 4 | SERVER\_PORT | 8100 | | | 11 | 0 | SERVER\_NAME | | | | 15 | 3 | REDIRECT\_STATUS | 200 | | | 15 | 11 | HTTP\_USER\_AGENT | curl/7.29.0 | | | 9 | 14 | HTTP\_HOST | localhost:8100 | | | 11 | 3 | HTTP\_ACCEPT | */* | | 对于Fastcgi 协议。前面的文章介绍的很全了。 那么fastcgi 传递到PHP中PHP 是怎么处理的 参考文章:<https://segmentfault.com/a/1190000016868502> 从该文件中得到了具体的答案: ```php 对于multipart/form-data,post_handler是rfc1867_post_handler。 由于它的代码过长,这里不再贴代码了。由于在body信息读取阶段, 钩子的post_reader是空, 所以rfc1867_post_handler会一边做FCGI_STDIN数据包的读取, 一边做解析存储工作, 最终将数据包中的key-value对存储到PG(http_globals)[0]中。 另外,该函数还会对上传的文件进行处理,有兴趣的同学可以读下这个函数。 ``` 打开github [https://github.com/php/php-src/search?q=ALLOC\_HASHTABLE](https://github.com/php/php-src/search?q=ALLOC_HASHTABLE) 搜索rfc1867\_post\_handler ![](https://shs3.b.qianxin.com/butian_public/f507f86ad8368b63fd78ef2f15820c126.jpg) 找到具体的函数实现方法 ```php SAPI_API SAPI_POST_HANDLER_FUNC(rfc1867_post_handler) /* {{{ */ { char *boundary, *s = NULL, *boundary_end = NULL, *start_arr = NULL, *array_index = NULL; char *lbuf = NULL, *abuf = NULL; zend_string *temp_filename = NULL; int boundary_len = 0, cancel_upload = 0, is_arr_upload = 0; size_t array_len = 0; int64_t total_bytes = 0, max_file_size = 0; int skip_upload = 0, anonindex = 0, is_anonymous; HashTable *uploaded_files = NULL; multipart_buffer *mbuff; zval *array_ptr = (zval *) arg; int fd = -1; zend_llist header; void *event_extra_data = NULL; unsigned int llen = 0; int upload_cnt = INI_INT("max_file_uploads"); const zend_encoding *internal_encoding = zend_multibyte_get_internal_encoding(); php_rfc1867_getword_t getword; php_rfc1867_getword_conf_t getword_conf; php_rfc1867_basename_t _basename; zend_long count = 0; if (php_rfc1867_encoding_translation() && internal_encoding) { getword = php_rfc1867_getword; getword_conf = php_rfc1867_getword_conf; _basename = php_rfc1867_basename; } else { getword = php_ap_getword; getword_conf = php_ap_getword_conf; _basename = php_ap_basename; } if (SG(post_max_size) > 0 && SG(request_info).content_length > SG(post_max_size)) { sapi_module.sapi_error(E_WARNING, "POST Content-Length of " ZEND_LONG_FMT " bytes exceeds the limit of " ZEND_LONG_FMT " bytes", SG(request_info).content_length, SG(post_max_size)); return; } /* Get the boundary */ boundary = strstr(content_type_dup, "boundary"); if (!boundary) { int content_type_len = (int)strlen(content_type_dup); char *content_type_lcase = estrndup(content_type_dup, content_type_len); php_strtolower(content_type_lcase, content_type_len); boundary = strstr(content_type_lcase, "boundary"); if (boundary) { boundary = content_type_dup + (boundary - content_type_lcase); } efree(content_type_lcase); } if (!boundary || !(boundary = strchr(boundary, '='))) { sapi_module.sapi_error(E_WARNING, "Missing boundary in multipart/form-data POST data"); return; } boundary++; boundary_len = (int)strlen(boundary); if (boundary[0] == '"') { boundary++; boundary_end = strchr(boundary, '"'); if (!boundary_end) { sapi_module.sapi_error(E_WARNING, "Invalid boundary in multipart/form-data POST data"); return; } } else { /* search for the end of the boundary */ boundary_end = strpbrk(boundary, ",;"); } if (boundary_end) { boundary_end[0] = '\0'; boundary_len = boundary_end-boundary; } /* Initialize the buffer */ if (!(mbuff = multipart_buffer_new(boundary, boundary_len))) { sapi_module.sapi_error(E_WARNING, "Unable to initialize the input buffer"); return; } /* Initialize $_FILES[] */ zend_hash_init(&PG(rfc1867_protected_variables), 8, NULL, NULL, 0); ALLOC_HASHTABLE(uploaded_files); zend_hash_init(uploaded_files, 8, NULL, free_filename, 0); SG(rfc1867_uploaded_files) = uploaded_files; if (Z_TYPE(PG(http_globals)[TRACK_VARS_FILES]) != IS_ARRAY) { /* php_auto_globals_create_files() might have already done that */ array_init(&PG(http_globals)[TRACK_VARS_FILES]); } zend_llist_init(&header, sizeof(mime_header_entry), (llist_dtor_func_t) php_free_hdr_entry, 0); if (php_rfc1867_callback != NULL) { multipart_event_start event_start; event_start.content_length = SG(request_info).content_length; if (php_rfc1867_callback(MULTIPART_EVENT_START, &event_start, &event_extra_data) == FAILURE) { goto fileupload_done; } } while (!multipart_buffer_eof(mbuff)) { char buff[FILLUNIT]; char *cd = NULL, *param = NULL, *filename = NULL, *tmp = NULL; size_t blen = 0, wlen = 0; zend_off_t offset; zend_llist_clean(&header); if (!multipart_buffer_headers(mbuff, &header)) { goto fileupload_done; } if ((cd = php_mime_get_hdr_value(header, "Content-Disposition"))) { char *pair = NULL; int end = 0; while (isspace(*cd)) { ++cd; } while (*cd && (pair = getword(mbuff->input_encoding, &cd, ';'))) { char *key = NULL, *word = pair; while (isspace(*cd)) { ++cd; } if (strchr(pair, '=')) { key = getword(mbuff->input_encoding, &pair, '='); if (!strcasecmp(key, "name")) { if (param) { efree(param); } param = getword_conf(mbuff->input_encoding, pair); if (mbuff->input_encoding && internal_encoding) { unsigned char *new_param; size_t new_param_len; if ((size_t)-1 != zend_multibyte_encoding_converter(&new_param, &new_param_len, (unsigned char *)param, strlen(param), internal_encoding, mbuff->input_encoding)) { efree(param); param = (char *)new_param; } } } else if (!strcasecmp(key, "filename")) { if (filename) { efree(filename); } filename = getword_conf(mbuff->input_encoding, pair); if (mbuff->input_encoding && internal_encoding) { unsigned char *new_filename; size_t new_filename_len; if ((size_t)-1 != zend_multibyte_encoding_converter(&new_filename, &new_filename_len, (unsigned char *)filename, strlen(filename), internal_encoding, mbuff->input_encoding)) { efree(filename); filename = (char *)new_filename; } } } } if (key) { efree(key); } efree(word); } /* Normal form variable, safe to read all data into memory */ if (!filename && param) { size_t value_len; char *value = multipart_buffer_read_body(mbuff, &value_len); size_t new_val_len; /* Dummy variable */ if (!value) { value = estrdup(""); value_len = 0; } if (mbuff->input_encoding && internal_encoding) { unsigned char *new_value; size_t new_value_len; if ((size_t)-1 != zend_multibyte_encoding_converter(&new_value, &new_value_len, (unsigned char *)value, value_len, internal_encoding, mbuff->input_encoding)) { efree(value); value = (char *)new_value; value_len = new_value_len; } } if (++count <= PG(max_input_vars) && sapi_module.input_filter(PARSE_POST, param, &value, value_len, &new_val_len)) { if (php_rfc1867_callback != NULL) { multipart_event_formdata event_formdata; size_t newlength = new_val_len; event_formdata.post_bytes_processed = SG(read_post_bytes); event_formdata.name = param; event_formdata.value = &value; event_formdata.length = new_val_len; event_formdata.newlength = &newlength; if (php_rfc1867_callback(MULTIPART_EVENT_FORMDATA, &event_formdata, &event_extra_data) == FAILURE) { efree(param); efree(value); continue; } new_val_len = newlength; } safe_php_register_variable(param, value, new_val_len, array_ptr, 0); } else { if (count == PG(max_input_vars) + 1) { php_error_docref(NULL, E_WARNING, "Input variables exceeded " ZEND_LONG_FMT ". To increase the limit change max_input_vars in php.ini.", PG(max_input_vars)); } if (php_rfc1867_callback != NULL) { multipart_event_formdata event_formdata; event_formdata.post_bytes_processed = SG(read_post_bytes); event_formdata.name = param; event_formdata.value = &value; event_formdata.length = value_len; event_formdata.newlength = NULL; php_rfc1867_callback(MULTIPART_EVENT_FORMDATA, &event_formdata, &event_extra_data); } } if (!strcasecmp(param, "MAX_FILE_SIZE")) { max_file_size = strtoll(value, NULL, 10); } efree(param); efree(value); continue; } /* If file_uploads=off, skip the file part */ if (!PG(file_uploads)) { skip_upload = 1; } else if (upload_cnt <= 0) { skip_upload = 1; sapi_module.sapi_error(E_WARNING, "Maximum number of allowable file uploads has been exceeded"); } /* Return with an error if the posted data is garbled */ if (!param && !filename) { sapi_module.sapi_error(E_WARNING, "File Upload Mime headers garbled"); goto fileupload_done; } if (!param) { is_anonymous = 1; param = emalloc(MAX_SIZE_ANONNAME); snprintf(param, MAX_SIZE_ANONNAME, "%u", anonindex++); } else { is_anonymous = 0; } /* New Rule: never repair potential malicious user input */ if (!skip_upload) { long c = 0; tmp = param; while (*tmp) { if (*tmp == '[') { c++; } else if (*tmp == ']') { c--; if (tmp[1] && tmp[1] != '[') { skip_upload = 1; break; } } if (c < 0) { skip_upload = 1; break; } tmp++; } /* Brackets should always be closed */ if(c != 0) { skip_upload = 1; } } total_bytes = cancel_upload = 0; temp_filename = NULL; fd = -1; if (!skip_upload && php_rfc1867_callback != NULL) { multipart_event_file_start event_file_start; event_file_start.post_bytes_processed = SG(read_post_bytes); event_file_start.name = param; event_file_start.filename = &filename; if (php_rfc1867_callback(MULTIPART_EVENT_FILE_START, &event_file_start, &event_extra_data) == FAILURE) { temp_filename = NULL; efree(param); efree(filename); continue; } } if (skip_upload) { efree(param); efree(filename); continue; } if (filename[0] == '\0') { #if DEBUG_FILE_UPLOAD sapi_module.sapi_error(E_NOTICE, "No file uploaded"); #endif cancel_upload = UPLOAD_ERROR_D; } offset = 0; end = 0; if (!cancel_upload) { /* only bother to open temp file if we have data */ blen = multipart_buffer_read(mbuff, buff, sizeof(buff), &end); #if DEBUG_FILE_UPLOAD if (blen > 0) { #else /* in non-debug mode we have no problem with 0-length files */ { #endif fd = php_open_temporary_fd_ex(PG(upload_tmp_dir), "php", &temp_filename, PHP_TMP_FILE_OPEN_BASEDIR_CHECK_ON_FALLBACK); upload_cnt--; if (fd == -1) { sapi_module.sapi_error(E_WARNING, "File upload error - unable to create a temporary file"); cancel_upload = UPLOAD_ERROR_E; } } } while (!cancel_upload && (blen > 0)) { if (php_rfc1867_callback != NULL) { multipart_event_file_data event_file_data; event_file_data.post_bytes_processed = SG(read_post_bytes); event_file_data.offset = offset; event_file_data.data = buff; event_file_data.length = blen; event_file_data.newlength = &blen; if (php_rfc1867_callback(MULTIPART_EVENT_FILE_DATA, &event_file_data, &event_extra_data) == FAILURE) { cancel_upload = UPLOAD_ERROR_X; continue; } } if (PG(upload_max_filesize) > 0 && (zend_long)(total_bytes+blen) > PG(upload_max_filesize)) { #if DEBUG_FILE_UPLOAD sapi_module.sapi_error(E_NOTICE, "upload_max_filesize of " ZEND_LONG_FMT " bytes exceeded - file [%s=%s] not saved", PG(upload_max_filesize), param, filename); #endif cancel_upload = UPLOAD_ERROR_A; } else if (max_file_size && ((zend_long)(total_bytes+blen) > max_file_size)) { #if DEBUG_FILE_UPLOAD sapi_module.sapi_error(E_NOTICE, "MAX_FILE_SIZE of %" PRId64 " bytes exceeded - file [%s=%s] not saved", max_file_size, param, filename); #endif cancel_upload = UPLOAD_ERROR_B; } else if (blen > 0) { #ifdef PHP_WIN32 wlen = write(fd, buff, (unsigned int)blen); #else wlen = write(fd, buff, blen); #endif if (wlen == (size_t)-1) { /* write failed */ #if DEBUG_FILE_UPLOAD sapi_module.sapi_error(E_NOTICE, "write() failed - %s", strerror(errno)); #endif cancel_upload = UPLOAD_ERROR_F; } else if (wlen < blen) { #if DEBUG_FILE_UPLOAD sapi_module.sapi_error(E_NOTICE, "Only %zd bytes were written, expected to write %zd", wlen, blen); #endif cancel_upload = UPLOAD_ERROR_F; } else { total_bytes += wlen; } offset += wlen; } /* read data for next iteration */ blen = multipart_buffer_read(mbuff, buff, sizeof(buff), &end); } if (fd != -1) { /* may not be initialized if file could not be created */ close(fd); } if (!cancel_upload && !end) { #if DEBUG_FILE_UPLOAD sapi_module.sapi_error(E_NOTICE, "Missing mime boundary at the end of the data for file %s", filename[0] != '\0' ? filename : ""); #endif cancel_upload = UPLOAD_ERROR_C; } #if DEBUG_FILE_UPLOAD if (filename[0] != '\0' && total_bytes == 0 && !cancel_upload) { sapi_module.sapi_error(E_WARNING, "Uploaded file size 0 - file [%s=%s] not saved", param, filename); cancel_upload = 5; } #endif if (php_rfc1867_callback != NULL) { multipart_event_file_end event_file_end; event_file_end.post_bytes_processed = SG(read_post_bytes); event_file_end.temp_filename = temp_filename ? ZSTR_VAL(temp_filename) : NULL; event_file_end.cancel_upload = cancel_upload; if (php_rfc1867_callback(MULTIPART_EVENT_FILE_END, &event_file_end, &event_extra_data) == FAILURE) { cancel_upload = UPLOAD_ERROR_X; } } if (cancel_upload) { if (temp_filename) { if (cancel_upload != UPLOAD_ERROR_E) { /* file creation failed */ unlink(ZSTR_VAL(temp_filename)); } zend_string_release_ex(temp_filename, 0); } temp_filename = NULL; } else { zend_hash_add_ptr(SG(rfc1867_uploaded_files), temp_filename, temp_filename); } /* is_arr_upload is true when name of file upload field * ends in [.*] * start_arr is set to point to 1st [ */ is_arr_upload = (start_arr = strchr(param,'[')) && (param[strlen(param)-1] == ']'); if (is_arr_upload) { array_len = strlen(start_arr); if (array_index) { efree(array_index); } array_index = estrndup(start_arr + 1, array_len - 2); } /* Add $foo_name */ if (llen < strlen(param) + MAX_SIZE_OF_INDEX + 1) { llen = (int)strlen(param); lbuf = (char *) safe_erealloc(lbuf, llen, 1, MAX_SIZE_OF_INDEX + 1); llen += MAX_SIZE_OF_INDEX + 1; } if (is_arr_upload) { if (abuf) efree(abuf); abuf = estrndup(param, strlen(param)-array_len); snprintf(lbuf, llen, "%s_name[%s]", abuf, array_index); } else { snprintf(lbuf, llen, "%s_name", param); } /* Pursuant to RFC 7578, strip any path components in the * user-supplied file name: * > If a "filename" parameter is supplied ... do not use * > directory path information that may be present." */ s = _basename(internal_encoding, filename); if (!s) { s = filename; } if (!is_anonymous) { safe_php_register_variable(lbuf, s, strlen(s), NULL, 0); } /* Add $foo[name] */ if (is_arr_upload) { snprintf(lbuf, llen, "%s[name][%s]", abuf, array_index); } else { snprintf(lbuf, llen, "%s[name]", param); } register_http_post_files_variable(lbuf, s, &PG(http_globals)[TRACK_VARS_FILES], 0); efree(filename); s = NULL; /* Possible Content-Type: */ if (cancel_upload || !(cd = php_mime_get_hdr_value(header, "Content-Type"))) { cd = ""; } else { /* fix for Opera 6.01 */ s = strchr(cd, ';'); if (s != NULL) { *s = '\0'; } } /* Add $foo_type */ if (is_arr_upload) { snprintf(lbuf, llen, "%s_type[%s]", abuf, array_index); } else { snprintf(lbuf, llen, "%s_type", param); } if (!is_anonymous) { safe_php_register_variable(lbuf, cd, strlen(cd), NULL, 0); } /* Add $foo[type] */ if (is_arr_upload) { snprintf(lbuf, llen, "%s[type][%s]", abuf, array_index); } else { snprintf(lbuf, llen, "%s[type]", param); } register_http_post_files_variable(lbuf, cd, &PG(http_globals)[TRACK_VARS_FILES], 0); /* Restore Content-Type Header */ if (s != NULL) { *s = ';'; } s = ""; { /* store temp_filename as-is (in case upload_tmp_dir * contains escapable characters. escape only the variable name.) */ zval zfilename; /* Initialize variables */ add_protected_variable(param); /* if param is of form xxx[.*] this will cut it to xxx */ if (!is_anonymous) { if (temp_filename) { ZVAL_STR_COPY(&zfilename, temp_filename); } else { ZVAL_EMPTY_STRING(&zfilename); } safe_php_register_variable_ex(param, &zfilename, NULL, 1); } /* Add $foo[tmp_name] */ if (is_arr_upload) { snprintf(lbuf, llen, "%s[tmp_name][%s]", abuf, array_index); } else { snprintf(lbuf, llen, "%s[tmp_name]", param); } add_protected_variable(lbuf); if (temp_filename) { ZVAL_STR_COPY(&zfilename, temp_filename); } else { ZVAL_EMPTY_STRING(&zfilename); } register_http_post_files_variable_ex(lbuf, &zfilename, &PG(http_globals)[TRACK_VARS_FILES], 1); } { zval file_size, error_type; int size_overflow = 0; char file_size_buf[65]; ZVAL_LONG(&error_type, cancel_upload); /* Add $foo[error] */ if (cancel_upload) { ZVAL_LONG(&file_size, 0); } else { if (total_bytes > ZEND_LONG_MAX) { #ifdef PHP_WIN32 if (_i64toa_s(total_bytes, file_size_buf, 65, 10)) { file_size_buf[0] = '0'; file_size_buf[1] = '\0'; } #else { int __len = snprintf(file_size_buf, 65, "%" PRId64, total_bytes); file_size_buf[__len] = '\0'; } #endif size_overflow = 1; } else { ZVAL_LONG(&file_size, total_bytes); } } if (is_arr_upload) { snprintf(lbuf, llen, "%s[error][%s]", abuf, array_index); } else { snprintf(lbuf, llen, "%s[error]", param); } register_http_post_files_variable_ex(lbuf, &error_type, &PG(http_globals)[TRACK_VARS_FILES], 0); /* Add $foo_size */ if (is_arr_upload) { snprintf(lbuf, llen, "%s_size[%s]", abuf, array_index); } else { snprintf(lbuf, llen, "%s_size", param); } if (!is_anonymous) { if (size_overflow) { ZVAL_STRING(&file_size, file_size_buf); } safe_php_register_variable_ex(lbuf, &file_size, NULL, size_overflow); } /* Add $foo[size] */ if (is_arr_upload) { snprintf(lbuf, llen, "%s[size][%s]", abuf, array_index); } else { snprintf(lbuf, llen, "%s[size]", param); } if (size_overflow) { ZVAL_STRING(&file_size, file_size_buf); } register_http_post_files_variable_ex(lbuf, &file_size, &PG(http_globals)[TRACK_VARS_FILES], size_overflow); } efree(param); } } fileupload_done: if (php_rfc1867_callback != NULL) { multipart_event_end event_end; event_end.post_bytes_processed = SG(read_post_bytes); php_rfc1867_callback(MULTIPART_EVENT_END, &event_end, &event_extra_data); } if (lbuf) efree(lbuf); if (abuf) efree(abuf); if (array_index) efree(array_index); zend_hash_destroy(&PG(rfc1867_protected_variables)); zend_llist_destroy(&header); if (mbuff->boundary_next) efree(mbuff->boundary_next); if (mbuff->boundary) efree(mbuff->boundary); if (mbuff->buffer) efree(mbuff->buffer); if (mbuff) efree(mbuff); } /* }}} */ ``` 代码的逻辑首先是获取boundary 然后进入!multipart\_buffer\_eof(mbuff) 循环 解析头multipart\_buffer\_headers ```c++ if ((cd = php_mime_get_hdr_value(header, "Content-Disposition"))) { char *pair = NULL; int end = 0; while (isspace(*cd)) { ++cd; } // 最终调用的是php_ap_getword 函数 while (*cd && (pair = getword(mbuff->input_encoding, &cd, ';'))) { // pair = char *key = NULL, *word = pair; while (isspace(*cd)) { ++cd; } if (strchr(pair, '=')) { key = getword(mbuff->input_encoding, &pair, '='); if (!strcasecmp(key, "name")) { if (param) { efree(param); } param = getword_conf(mbuff->input_encoding, pair); if (mbuff->input_encoding && internal_encoding) { unsigned char *new_param; size_t new_param_len; if ((size_t)-1 != zend_multibyte_encoding_converter(&new_param, &new_param_len, (unsigned char *)param, strlen(param), internal_encoding, mbuff->input_encoding)) { efree(param); param = (char *)new_param; } } } else if (!strcasecmp(key, "filename")) { if (filename) { efree(filename); } filename = getword_conf(mbuff->input_encoding, pair); if (mbuff->input_encoding && internal_encoding) { unsigned char *new_filename; size_t new_filename_len; if ((size_t)-1 != zend_multibyte_encoding_converter(&new_filename, &new_filename_len, (unsigned char *)filename, strlen(filename), internal_encoding, mbuff->input_encoding)) { efree(filename); filename = (char *)new_filename; } } } } if (key) { efree(key); } efree(word); } ``` 关键点在于getword。追踪一下getword 函数 ```php php_rfc1867_getword_t getword; php_rfc1867_getword_conf_t getword_conf; php_rfc1867_basename_t _basename; zend_long count = 0; if (php_rfc1867_encoding_translation() && internal_encoding) { getword = php_rfc1867_getword; getword_conf = php_rfc1867_getword_conf; _basename = php_rfc1867_basename; } else { getword = php_ap_getword; getword_conf = php_ap_getword_conf; _basename = php_ap_basename; } ``` 最终最终到php\_ap\_getword ```php static char *php_ap_getword(const zend_encoding *encoding, char **line, char stop) { char *pos = *line, quote; char *res; while (*pos && *pos != stop) { if ((quote = *pos) == '"' || quote == '\'') { ++pos; while (*pos && *pos != quote) { if (*pos == '\\' && pos[1] && pos[1] == quote) { pos += 2; } else { ++pos; } } if (*pos) { ++pos; } } else ++pos; } if (*pos == '\0') { res = estrdup(*line); *line += strlen(*line); return res; } res = estrndup(*line, pos - *line); while (*pos == stop) { ++pos; } *line = pos; return res; } ``` 发现这里是跳过了。\\ 那么就从最开始的如下 `Content-Disposition: form-data; name="name\"; filename=";name='username'"` 获取到了Content-Disposition 之后的数据。然后以; 结尾的数据取出来。然后再通过name filename 这样的key进行存入到结构体中。 当\\ 出现之后。 那么name 获取的value 的值为 name=”name\\”; filename=”; name=’username’ 最终PHP 获取得到的为$\_POST 中的数据值 username=>admin 如果哪里写的不对。请斧正 文章首发在自己博客,原文地址为:<https://www.o2oxy.cn/3239.html>
发表于 2021-04-16 11:36:35
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努力学习c++的落魄程序员
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