/*************************************************************************** * ncrack_dicom.cc -- ncrack module for the DICOM protocol * * * ***********************IMPORTANT NMAP LICENSE TERMS************************ * * * The Nmap Security Scanner is (C) 1996-2019 Insecure.Com LLC ("The Nmap * * Project"). Nmap is also a registered trademark of the Nmap Project. * * This program is free software; you may redistribute and/or modify it * * under the terms of the GNU General Public License as published by the * * Free Software Foundation; Version 2 ("GPL"), BUT ONLY WITH ALL OF THE * * CLARIFICATIONS AND EXCEPTIONS DESCRIBED HEREIN. This guarantees your * * right to use, modify, and redistribute this software under certain * * conditions. If you wish to embed Nmap technology into proprietary * * software, we sell alternative licenses (contact sales@nmap.com). * * Dozens of software vendors already license Nmap technology such as * * host discovery, port scanning, OS detection, version detection, and * * the Nmap Scripting Engine. * * * * Note that the GPL places important restrictions on "derivative works", * * yet it does not provide a detailed definition of that term. To avoid * * misunderstandings, we interpret that term as broadly as copyright law * * allows. For example, we consider an application to constitute a * * derivative work for the purpose of this license if it does any of the * * following with any software or content covered by this license * * ("Covered Software"): * * * * o Integrates source code from Covered Software. * * * * o Reads or includes copyrighted data files, such as Nmap's nmap-os-db * * or nmap-service-probes. * * * * o Is designed specifically to execute Covered Software and parse the * * results (as opposed to typical shell or execution-menu apps, which will * * execute anything you tell them to). * * * * o Includes Covered Software in a proprietary executable installer. The * * installers produced by InstallShield are an example of this. Including * * Nmap with other software in compressed or archival form does not * * trigger this provision, provided appropriate open source decompression * * or de-archiving software is widely available for no charge. For the * * purposes of this license, an installer is considered to include Covered * * Software even if it actually retrieves a copy of Covered Software from * * another source during runtime (such as by downloading it from the * * Internet). * * * * o Links (statically or dynamically) to a library which does any of the * * above. * * * * o Executes a helper program, module, or script to do any of the above. * * * * This list is not exclusive, but is meant to clarify our interpretation * * of derived works with some common examples. Other people may interpret * * the plain GPL differently, so we consider this a special exception to * * the GPL that we apply to Covered Software. Works which meet any of * * these conditions must conform to all of the terms of this license, * * particularly including the GPL Section 3 requirements of providing * * source code and allowing free redistribution of the work as a whole. * * * * As another special exception to the GPL terms, the Nmap Project grants * * permission to link the code of this program with any version of the * * OpenSSL library which is distributed under a license identical to that * * listed in the included docs/licenses/OpenSSL.txt file, and distribute * * linked combinations including the two. * * * * The Nmap Project has permission to redistribute Npcap, a packet * * capturing driver and library for the Microsoft Windows platform. * * Npcap is a separate work with it's own license rather than this Nmap * * license. Since the Npcap license does not permit redistribution * * without special permission, our Nmap Windows binary packages which * * contain Npcap may not be redistributed without special permission. * * * * Any redistribution of Covered Software, including any derived works, * * must obey and carry forward all of the terms of this license, including * * obeying all GPL rules and restrictions. For example, source code of * * the whole work must be provided and free redistribution must be * * allowed. All GPL references to "this License", are to be treated as * * including the terms and conditions of this license text as well. * * * * Because this license imposes special exceptions to the GPL, Covered * * Work may not be combined (even as part of a larger work) with plain GPL * * software. The terms, conditions, and exceptions of this license must * * be included as well. This license is incompatible with some other open * * source licenses as well. In some cases we can relicense portions of * * Nmap or grant special permissions to use it in other open source * * software. Please contact fyodor@nmap.org with any such requests. * * Similarly, we don't incorporate incompatible open source software into * * Covered Software without special permission from the copyright holders. * * * * If you have any questions about the licensing restrictions on using * * Nmap in other works, we are happy to help. As mentioned above, we also * * offer an alternative license to integrate Nmap into proprietary * * applications and appliances. These contracts have been sold to dozens * * of software vendors, and generally include a perpetual license as well * * as providing support and updates. They also fund the continued * * development of Nmap. Please email sales@nmap.com for further * * information. * * * * If you have received a written license agreement or contract for * * Covered Software stating terms other than these, you may choose to use * * and redistribute Covered Software under those terms instead of these. * * * * Source is provided to this software because we believe users have a * * right to know exactly what a program is going to do before they run it. * * This also allows you to audit the software for security holes. * * * * Source code also allows you to port Nmap to new platforms, fix bugs, * * and add new features. You are highly encouraged to send your changes * * to the dev@nmap.org mailing list for possible incorporation into the * * main distribution. By sending these changes to Fyodor or one of the * * Insecure.Org development mailing lists, or checking them into the Nmap * * source code repository, it is understood (unless you specify * * otherwise) that you are offering the Nmap Project the unlimited, * * non-exclusive right to reuse, modify, and relicense the code. Nmap * * will always be available Open Source, but this is important because * * the inability to relicense code has caused devastating problems for * * other Free Software projects (such as KDE and NASM). We also * * occasionally relicense the code to third parties as discussed above. * * If you wish to specify special license conditions of your * * contributions, just say so when you send them. * * * * This program is distributed in the hope that it will be useful, but * * WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Nmap * * license file for more details (it's in a COPYING file included with * * Nmap, and also available from https://svn.nmap.org/nmap/COPYING) * * * ***************************************************************************/ #include "ncrack.h" #include "nsock.h" #include "NcrackOps.h" #include "Service.h" #include "modules.h" #define DICOM_TIMEOUT 20000 #define DICOM_APP "1.2.840.10008.3.1.1.1" #define DICOM_ABS "1.2.840.10008.5.1.4.1.1.7" #define DICOM_TRX_EXP_L "1.2.840.10008.1.2.1" #define DICOM_TRX_IMP_L "1.2.840.10008.1.2" #define DICOM_TRX_EXP_B "1.2.840.10008.1.2.2" #define DICOM_UID "1.2.826.0.1.3680043.2.1545.1" #define DICOM_IMPL "Ncrack" #define DICOM_ERROR "Received bogus pdu type" typedef struct dicom_assoc { struct assoc_request { struct app_ctx { uint16_t item_type; // 0x10 = app context uint16_t item_length; u_char ctx[21]; app_ctx() { item_type = 0x10; item_length = le_to_be16(21); memcpy(ctx, DICOM_APP, sizeof(ctx)); } } __attribute__((__packed__)); struct pres_context { struct abstract_syntax { uint16_t item_type; // 0x30 = abstract uint16_t item_length; u_char abs_syntax[25]; abstract_syntax() { item_type = 0x30; item_length = le_to_be16(25); memcpy(abs_syntax, DICOM_ABS, sizeof(abs_syntax)); } } __attribute__((__packed__)); #if 0 struct transfer_syntax_explicit_l { uint16_t item_type; // 0x40 = transfer uint16_t item_length; u_char trx_syntax[19]; // explicit vr little endian transfer_syntax_explicit_l() { item_type = 0x40; item_length = le_to_be16(19); memcpy(trx_syntax, DICOM_TRX_EXP_L, sizeof(trx_syntax)); } } __attribute__((__packed__)); struct transfer_syntax_explicit_b { uint16_t item_type; // 0x40 = transfer uint16_t item_length; u_char trx_syntax[19]; // explicit vr big endian transfer_syntax_explicit_b() { item_type = 0x40; item_length = le_to_be16(19); memcpy(trx_syntax, DICOM_TRX_EXP_B, sizeof(trx_syntax)); } } __attribute__((__packed__)); #endif struct transfer_syntax_implicit_l { uint16_t item_type; // 0x40 = transfer uint16_t item_length; u_char trx_syntax[17]; // implicit vr little endian transfer_syntax_implicit_l() { item_type = 0x40; item_length = le_to_be16(17); memcpy(trx_syntax, DICOM_TRX_IMP_L, sizeof(trx_syntax)); } } __attribute__((__packed__)); pres_context() { item_type = 0x20; item_length = le_to_be16(54); context_id = 0x01; } uint16_t item_type; // 0x20 = presentation uint16_t item_length; uint8_t context_id; u_char pad0[3] = { 0x00, 0x00, 0x00 }; abstract_syntax abs; //transfer_syntax_explicit_l trx_el; transfer_syntax_implicit_l trx_il; //transfer_syntax_explicit_b trx_eb; } __attribute__((__packed__)); struct user_info { struct max_length { uint16_t item_type; // 0x51 = max-length uint16_t item_length; uint32_t max_len; max_length() { item_type = 0x51; item_length = le_to_be16(4); max_len = le_to_be32(16384); } } __attribute__((__packed__)); struct implementation_id { uint16_t item_type; // 0x52 = class uid uint16_t item_length; u_char class_uid[28]; implementation_id() { item_type = 0x52; item_length = le_to_be16(28); memcpy(class_uid, DICOM_UID, sizeof(class_uid)); } } __attribute__((__packed__)); struct async_neg { uint16_t item_type; // 0x53 = async op uint16_t item_length; uint16_t max_num_ops_invoked; uint16_t max_num_ops_performed; async_neg() { item_type = 0x53; item_length = le_to_be16(4); max_num_ops_invoked = 0; max_num_ops_performed = 0; } } __attribute__((__packed__)); struct implementation_version { uint16_t item_type; // 0x55 = impl version uint16_t item_length; u_char impl_version[6]; implementation_version() { item_type = 0x55; item_length = le_to_be16(6); memcpy(impl_version, DICOM_IMPL, sizeof(impl_version)); } } __attribute__((__packed__)); user_info() { item_type = 0x50; item_length = le_to_be16(50); // 26 } uint16_t item_type; // 0x50 = user-info uint16_t item_length; max_length max; implementation_id uid; //async_neg async; implementation_version impl; } __attribute__((__packed__)); assoc_request() { version = le_to_be16(1); } uint16_t version; u_char pad[2] = { 0x00, 0x00 }; u_char called_ae[16] = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20 }; u_char calling_ae[16] = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20 }; u_char pad0[32] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; app_ctx app; pres_context pres; user_info user; } __attribute__((__packed__)); dicom_assoc() { pdu_type = le_to_be16(0x100); pdu_length = le_to_be32(205); // 231 } uint16_t pdu_type; uint32_t pdu_length; assoc_request assoc; } __attribute__((__packed__)) dicom_assoc; extern NcrackOps o; extern void ncrack_read_handler(nsock_pool nsp, nsock_event nse, void *mydata); extern void ncrack_write_handler(nsock_pool nsp, nsock_event nse, void *mydata); extern void ncrack_module_end(nsock_pool nsp, void *mydata); static int dicom_loop_read(nsock_pool nsp, Connection *con); enum states { DICOM_INIT, DICOM_FINI }; static int dicom_loop_read(nsock_pool nsp, Connection *con) { uint32_t *pdu_length; /* we need at least 6 bytes to read the whole PDU length */ if (con->inbuf == NULL || con->inbuf->get_len() < 6) { nsock_read(nsp, con->niod, ncrack_read_handler, DICOM_TIMEOUT, con); return -1; } pdu_length = (uint32_t *)((u_char *)con->inbuf->get_dataptr() + 2); *pdu_length = le_to_be32(*pdu_length); if (o.debugging > 9) printf("pdu length: %d\n", *pdu_length); /* now read until we receive all bytes mentioned in length */ if (con->inbuf->get_len() < *pdu_length) { nsock_read(nsp, con->niod, ncrack_read_handler, DICOM_TIMEOUT, con); return -1; } return 0; } void ncrack_dicom(nsock_pool nsp, Connection *con) { nsock_iod nsi = con->niod; Service *serv = con->service; dicom_assoc da; uint8_t *pdu_type; switch (con->state) { case DICOM_INIT: con->state = DICOM_FINI; delete con->inbuf; con->inbuf = NULL; if (con->outbuf) delete con->outbuf; con->outbuf = new Buf(); memcpy(da.assoc.called_ae, con->user, strlen(con->user)); memcpy(da.assoc.calling_ae, con->pass, strlen(con->pass)); con->outbuf->append(&da, sizeof(da)); nsock_write(nsp, nsi, ncrack_write_handler, DICOM_TIMEOUT, con, (const char *)con->outbuf->get_dataptr(), con->outbuf->get_len()); break; case DICOM_FINI: if (dicom_loop_read(nsp, con) < 0) break; pdu_type = (uint8_t *)((u_char *)con->inbuf->get_dataptr()); if (o.debugging > 9) printf("pdu_type: %d \n", *pdu_type); if (*pdu_type == 0x03) { // ASSOC REJECT ; } else if (*pdu_type == 0x02) { // ASSOC ACCEPT con->auth_success = true; con->force_close = true; } else { /* received weird pdu * close connection and stop cracking */ con->force_close = true; con->close_reason = MODULE_ERR; serv->end.orly = true; serv->end.reason = Strndup(DICOM_ERROR, sizeof(DICOM_ERROR)); } con->state = DICOM_INIT; delete con->inbuf; con->inbuf = NULL; return ncrack_module_end(nsp, con); } }