/**
* Configures the data receiver hook. If there is a previous hook, it will be finalized and cleared.
*
* @param[in] connp
* @param[in] data_receiver_hook
* @return HTP_OK, or a value returned from a callback.
*/
static htp_status_t htp_connp_res_receiver_set(htp_connp_t *connp, htp_hook_t *data_receiver_hook) {
htp_connp_res_receiver_finalize_clear(connp);
connp->out_data_receiver_hook = data_receiver_hook;
connp->out_current_receiver_offset = connp->out_current_read_offset;
return HTP_OK;
}
htp_status_t htp_tx_state_response_headers(htp_tx_t *tx) {
if (tx == NULL) return HTP_ERROR;
// Check for compression.
// Determine content encoding.
tx->response_content_encoding = HTP_COMPRESSION_NONE;
htp_header_t *ce = htp_table_get_c(tx->response_headers, "content-encoding");
if (ce != NULL) {
if ((bstr_cmp_c(ce->value, "gzip") == 0) || (bstr_cmp_c(ce->value, "x-gzip") == 0)) {
tx->response_content_encoding = HTP_COMPRESSION_GZIP;
} else if ((bstr_cmp_c(ce->value, "deflate") == 0) || (bstr_cmp_c(ce->value, "x-deflate") == 0)) {
tx->response_content_encoding = HTP_COMPRESSION_DEFLATE;
}
}
// Configure decompression, if enabled in the configuration.
if (tx->connp->cfg->response_decompression_enabled) {
tx->response_content_encoding_processing = tx->response_content_encoding;
} else {
tx->response_content_encoding_processing = HTP_COMPRESSION_NONE;
}
// Finalize sending raw header data.
htp_status_t rc = htp_connp_res_receiver_finalize_clear(tx->connp);
if (rc != HTP_OK) return rc;
// Run hook RESPONSE_HEADERS.
rc = htp_hook_run_all(tx->connp->cfg->hook_response_headers, tx);
if (rc != HTP_OK) return rc;
// Initialize the decompression engine as necessary. We can deal with three
// scenarios:
//
// 1. Decompression is enabled, compression indicated in headers, and we decompress.
//
// 2. As above, but the user disables decompression by setting response_content_encoding
// to COMPRESSION_NONE.
//
// 3. Decompression is disabled and we do not attempt to enable it, but the user
// forces decompression by setting response_content_encoding to one of the
// supported algorithms.
if ((tx->response_content_encoding_processing == HTP_COMPRESSION_GZIP) || (tx->response_content_encoding_processing == HTP_COMPRESSION_DEFLATE)) {
if (tx->connp->out_decompressor != NULL) {
tx->connp->out_decompressor->destroy(tx->connp->out_decompressor);
tx->connp->out_decompressor = NULL;
}
tx->connp->out_decompressor = (htp_decompressor_t *) htp_gzip_decompressor_create(tx->connp,
tx->response_content_encoding_processing);
if (tx->connp->out_decompressor == NULL) return HTP_ERROR;
tx->connp->out_decompressor->callback = htp_tx_res_process_body_data_decompressor_callback;
} else if (tx->response_content_encoding_processing != HTP_COMPRESSION_NONE) {
return HTP_ERROR;
}
return HTP_OK;
}
/**
* Parses response headers.
*
* @param[in] connp
* @returns HTP_OK on state change, HTP_ERROR on error, or HTP_DATA when more data is needed.
*/
htp_status_t htp_connp_RES_HEADERS(htp_connp_t *connp) {
for (;;) {
OUT_COPY_BYTE_OR_RETURN(connp);
// Have we reached the end of the line?
if (connp->out_next_byte == LF) {
unsigned char *data;
size_t len;
htp_connp_res_consolidate_data(connp, &data, &len);
#ifdef HTP_DEBUG
fprint_raw_data(stderr, __FUNCTION__, data, len);
#endif
// Should we terminate headers?
if (htp_connp_is_line_terminator(connp, data, len)) {
// Parse previous header, if any.
if (connp->out_header != NULL) {
if (connp->cfg->process_response_header(connp, bstr_ptr(connp->out_header),
bstr_len(connp->out_header)) != HTP_OK) return HTP_ERROR;
bstr_free(connp->out_header);
connp->out_header = NULL;
}
htp_connp_res_clear_buffer(connp);
// We've seen all response headers.
if (connp->out_tx->progress == HTP_RESPONSE_HEADERS) {
// Response headers.
// The next step is to determine if this response has a body.
connp->out_state = htp_connp_RES_BODY_DETERMINE;
} else {
// Response trailer.
// Finalize sending raw trailer data.
htp_status_t rc = htp_connp_res_receiver_finalize_clear(connp);
if (rc != HTP_OK) return rc;
// Run hook response_TRAILER.
rc = htp_hook_run_all(connp->cfg->hook_response_trailer, connp);
if (rc != HTP_OK) return rc;
// The next step is to finalize this response.
connp->out_state = htp_connp_RES_FINALIZE;
}
return HTP_OK;
}
htp_chomp(data, &len);
// Check for header folding.
if (htp_connp_is_line_folded(data, len) == 0) {
// New header line.
// Parse previous header, if any.
if (connp->out_header != NULL) {
if (connp->cfg->process_response_header(connp, bstr_ptr(connp->out_header),
bstr_len(connp->out_header)) != HTP_OK) return HTP_ERROR;
bstr_free(connp->out_header);
connp->out_header = NULL;
}
OUT_PEEK_NEXT(connp);
if (htp_is_folding_char(connp->out_next_byte) == 0) {
// Because we know this header is not folded, we can process the buffer straight away.
if (connp->cfg->process_response_header(connp, data, len) != HTP_OK) return HTP_ERROR;
} else {
// Keep the partial header data for parsing later.
connp->out_header = bstr_dup_mem(data, len);
if (connp->out_header == NULL) return HTP_ERROR;
}
} else {
// Folding; check that there's a previous header line to add to.
if (connp->out_header == NULL) {
// Invalid folding.
// Warn only once per transaction.
if (!(connp->out_tx->flags & HTP_INVALID_FOLDING)) {
connp->out_tx->flags |= HTP_INVALID_FOLDING;
htp_log(connp, HTP_LOG_MARK, HTP_LOG_WARNING, 0, "Invalid response field folding");
}
// Keep the header data for parsing later.
connp->out_header = bstr_dup_mem(data, len);
if (connp->out_header == NULL) return HTP_ERROR;
} else {
// Add to the existing header.
bstr *new_out_header = bstr_add_mem(connp->out_header, data, len);
if (new_out_header == NULL) return HTP_ERROR;
connp->out_header = new_out_header;
}
}
htp_connp_res_clear_buffer(connp);
}
}
return HTP_ERROR;
}
