maride/guacamole-spice-protocol
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Validate filenames.

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This commit is contained in:
Michael Jumper 2013-10-18 22:30:09 -07:00
parent f133cb4caa
commit 4381485051
1 changed files with 43 additions and 6 deletions
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49
src/protocols/ssh/guac_handlers.c
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@ -456,26 +456,63 @@ int ssh_guac_client_free_handler(guac_client* client) {
return 0;
}
static bool __ssh_guac_valid_filename(char* filename) {
/* Disallow "." as a filename */
if (strcmp(filename, ".") == 0)
return false;
/* Disallow ".." as a filename */
if (strcmp(filename, "..") == 0)
return false;
/* Search for path separator characters */
for (;;) {
char c = *(filename++);
if (c == '\0')
break;
/* Replace slashes with underscores */
if (c == '\\' || c == '/')
return false;
}
/* If filename does not contain a path, it's ok */
return true;
}
int ssh_guac_client_file_handler(guac_client* client, guac_stream* stream,
char* mimetype, char* filename) {
ssh_guac_client_data* client_data = (ssh_guac_client_data*) client->data;
sftp_file file;
/* Ensure filename is a valid filename and not a path */
if (!__ssh_guac_valid_filename(filename)) {
guac_protocol_send_ack(client->socket, stream,
"SFTP: Illegal filename",
GUAC_PROTOCOL_STATUS_INVALID_PARAMETER);
guac_socket_flush(client->socket);
return 0;
}
/* Open file via SFTP */
file = sftp_open(client_data->sftp_session, filename,
O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
/* Inform of status */
if (file != NULL) {
guac_protocol_send_ack(client->socket, stream, "SFTP - File opened",
guac_protocol_send_ack(client->socket, stream, "SFTP: File opened",
GUAC_PROTOCOL_STATUS_SUCCESS);
guac_socket_flush(client->socket);
}
else {
guac_client_log_error(client, "Unable to open file: %s",
ssh_get_error(client_data->session));
guac_protocol_send_ack(client->socket, stream, "SFTP - Open failed",
guac_protocol_send_ack(client->socket, stream, "SFTP: Open failed",
GUAC_PROTOCOL_STATUS_INTERNAL_ERROR);
guac_socket_flush(client->socket);
}
@ -495,7 +532,7 @@ int ssh_guac_client_blob_handler(guac_client* client, guac_stream* stream,
/* Attempt write */
if (sftp_write(file, data, length) == length) {
guac_protocol_send_ack(client->socket, stream, "SFTP - OK",
guac_protocol_send_ack(client->socket, stream, "SFTP: OK",
GUAC_PROTOCOL_STATUS_SUCCESS);
guac_socket_flush(client->socket);
}
@ -504,7 +541,7 @@ int ssh_guac_client_blob_handler(guac_client* client, guac_stream* stream,
else {
guac_client_log_error(client, "Unable to write to file: %s",
ssh_get_error(client_data->session));
guac_protocol_send_ack(client->socket, stream, "SFTP - Write failed",
guac_protocol_send_ack(client->socket, stream, "SFTP: Write failed",
GUAC_PROTOCOL_STATUS_INTERNAL_ERROR);
guac_socket_flush(client->socket);
}
@ -520,13 +557,13 @@ int ssh_guac_client_end_handler(guac_client* client, guac_stream* stream) {
/* Attempt to close file */
if (sftp_close(file) == SSH_OK) {
guac_protocol_send_ack(client->socket, stream, "SFTP - OK",
guac_protocol_send_ack(client->socket, stream, "SFTP: OK",
GUAC_PROTOCOL_STATUS_SUCCESS);
guac_socket_flush(client->socket);
}
else {
guac_client_log_error(client, "Unable to close file");
guac_protocol_send_ack(client->socket, stream, "SFTP - Close failed",
guac_protocol_send_ack(client->socket, stream, "SFTP: Close failed",
GUAC_PROTOCOL_STATUS_INTERNAL_ERROR);
guac_socket_flush(client->socket);
}