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;
}
virtual void SetUp() {
home = getenv("srcdir");
if (home == NULL) {
fprintf(stderr, "This program needs environment variable 'srcdir' set.");
exit(EXIT_FAILURE);
}
cfg = htp_config_create();
htp_config_set_server_personality(cfg, HTP_SERVER_APACHE_2);
connp = htp_connp_create(cfg);
tx = htp_connp_tx_create(connp);
htp_tx_set_user_data(tx, &output);
decompressor = htp_gzip_decompressor_create(connp, HTP_COMPRESSION_GZIP);
decompressor->callback = GUnzip_decompressor_callback;
o_boxing_wizards = bstr_dup_c("The five boxing wizards jump quickly.");
output = NULL;
}
/**
* Determines presence (and encoding) of a response body.
*
* @param connp
* @returns HTP_OK on state change, HTTP_ERROR on error, or HTP_DATA when more data is needed.
*/
int htp_connp_RES_BODY_DETERMINE(htp_connp_t *connp) {
// If the request uses the CONNECT method, then not only are we
// to assume there's no body, but we need to ignore all
// subsequent data in the stream.
if (connp->out_tx->request_method_number == M_CONNECT) {
if ((connp->out_tx->response_status_number >= 200)
&& (connp->out_tx->response_status_number <= 299))
{
// This is a successful CONNECT stream, which means
// we need to switch into tunnelling mode.
connp->in_status = STREAM_STATE_TUNNEL;
connp->out_status = STREAM_STATE_TUNNEL;
connp->out_state = htp_connp_RES_IDLE;
connp->out_tx->progress = TX_PROGRESS_DONE;
return HTP_OK;
} else {
// This is a failed CONNECT stream, which means that
// we can unblock request parsing
connp->in_status = STREAM_STATE_DATA;
// We are going to continue processing this transaction,
// adding a note for ourselves to stop at the end (because
// we don't want to see the beginning of a new transaction).
connp->out_data_other_at_tx_end = 1;
}
}
// Check for an interim "100 Continue"
// response. Ignore it if found, and revert back to RES_FIRST_LINE.
if (connp->out_tx->response_status_number == 100) {
if (connp->out_tx->seen_100continue != 0) {
htp_log(connp, HTP_LOG_MARK, HTP_LOG_ERROR, 0, "Already seen 100-Continue");
return HTP_ERROR;
}
// Ignore any response headers set
table_clear(connp->out_tx->response_headers);
connp->out_state = htp_connp_RES_LINE;
connp->out_tx->progress = TX_PROGRESS_RES_LINE;
connp->out_tx->seen_100continue++;
return HTP_OK;
}
// Check for compression
if (connp->cfg->response_decompression_enabled) {
htp_header_t *ce = table_get_c(connp->out_tx->response_headers, "content-encoding");
if (ce != NULL) {
if ((bstr_cmp_c(ce->value, "gzip") == 0) || (bstr_cmp_c(ce->value, "x-gzip") == 0)) {
connp->out_tx->response_content_encoding = COMPRESSION_GZIP;
} else if ((bstr_cmp_c(ce->value, "deflate") == 0) || (bstr_cmp_c(ce->value, "x-deflate") == 0)) {
connp->out_tx->response_content_encoding = COMPRESSION_DEFLATE;
}
if (connp->out_tx->response_content_encoding != COMPRESSION_NONE) {
connp->out_decompressor = (htp_decompressor_t *) htp_gzip_decompressor_create(connp,
connp->out_tx->response_content_encoding);
if (connp->out_decompressor != NULL) {
connp->out_decompressor->callback = htp_connp_RES_BODY_DECOMPRESSOR_CALLBACK;
} else {
// No need to do anything; the error will have already
// been reported by the failed decompressor.
}
}
}
}
// 1. Any response message which MUST NOT include a message-body
// (such as the 1xx, 204, and 304 responses and any response to a HEAD
// request) is always terminated by the first empty line after the
// header fields, regardless of the entity-header fields present in the
// message.
if (((connp->out_tx->response_status_number >= 100) && (connp->out_tx->response_status_number <= 199))
|| (connp->out_tx->response_status_number == 204) || (connp->out_tx->response_status_number == 304)
|| (connp->out_tx->request_method_number == M_HEAD)) {
// There's no response body
connp->out_state = htp_connp_RES_IDLE;
} else {
// We have a response body
htp_header_t *cl = table_get_c(connp->out_tx->response_headers, "content-length");
htp_header_t *te = table_get_c(connp->out_tx->response_headers, "transfer-encoding");
// 2. If a Transfer-Encoding header field (section 14.40) is present and
// indicates that the "chunked" transfer coding has been applied, then
// the length is defined by the chunked encoding (section 3.6).
if ((te != NULL) && (bstr_cmp_c(te->value, "chunked") == 0)) {
// If the T-E header is present we are going to use it.
connp->out_tx->response_transfer_coding = CHUNKED;
// We are still going to check for the presence of C-L
if (cl != NULL) {
// This is a violation of the RFC
connp->out_tx->flags |= HTP_REQUEST_SMUGGLING;
// TODO
}
connp->out_state = htp_connp_RES_BODY_CHUNKED_LENGTH;
connp->out_tx->progress = TX_PROGRESS_RES_BODY;
}// 3. If a Content-Length header field (section 14.14) is present, its
// value in bytes represents the length of the message-body.
else if (cl != NULL) {
// We know the exact length
connp->out_tx->response_transfer_coding = IDENTITY;
// Check for multiple C-L headers
if (cl->flags & HTP_FIELD_REPEATED) {
connp->out_tx->flags |= HTP_REQUEST_SMUGGLING;
// TODO Log
}
// Get body length
int i = htp_parse_content_length(cl->value);
if (i < 0) {
htp_log(connp, HTP_LOG_MARK, HTP_LOG_ERROR, 0, "Invalid C-L field in response: %d", i);
return HTP_ERROR;
} else {
connp->out_content_length = i;
connp->out_body_data_left = connp->out_content_length;
if (connp->out_content_length != 0) {
connp->out_state = htp_connp_RES_BODY_IDENTITY;
connp->out_tx->progress = TX_PROGRESS_RES_BODY;
} else {
connp->out_state = htp_connp_RES_IDLE;
connp->out_tx->progress = TX_PROGRESS_DONE;
}
}
} else {
// 4. If the message uses the media type "multipart/byteranges", which is
// self-delimiting, then that defines the length. This media type MUST
// NOT be used unless the sender knows that the recipient can parse it;
// the presence in a request of a Range header with multiple byte-range
// specifiers implies that the client can parse multipart/byteranges
// responses.
htp_header_t *ct = table_get_c(connp->out_tx->response_headers, "content-type");
if (ct != NULL) {
// TODO Handle multipart/byteranges
if (bstr_index_of_c_nocase(ct->value, "multipart/byteranges") != -1) {
htp_log(connp, HTP_LOG_MARK, HTP_LOG_ERROR, 0,
"C-T multipart/byteranges in responses not supported");
return HTP_ERROR;
}
}
// 5. By the server closing the connection. (Closing the connection
// cannot be used to indicate the end of a request body, since that
// would leave no possibility for the server to send back a response.)
connp->out_state = htp_connp_RES_BODY_IDENTITY;
connp->out_tx->progress = TX_PROGRESS_RES_BODY;
}
}
// NOTE We do not need to check for short-style HTTP/0.9 requests here because
// that is done earlier, before response line parsing begins
// Run hook RESPONSE_HEADERS_COMPLETE
int rc = hook_run_all(connp->cfg->hook_response_headers, connp);
if (rc != HOOK_OK) {
htp_log(connp, HTP_LOG_MARK, HTP_LOG_ERROR, 0,
"Response headers callback returned error (%d)", rc);
return HTP_ERROR;
}
return HTP_OK;
}
