记一次刨根问底的HTTP包WAF绕过
一：具体的包
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。
二、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
WEB服务器通过192.168.1.70:9000 去连接PHP
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
.........................&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
三、Params 数据包参数整理
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：
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。
四、函数跟踪
打开github
https://github.com/php/php-src/search?q=ALLOC_HASHTABLE
搜索rfc1867_post_handler
找到具体的函数实现方法
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
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_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
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;
}
五、归纳总结
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
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