diff options
Diffstat (limited to 'src/lib/protocols/rsh.c')
| -rw-r--r-- | src/lib/protocols/rsh.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/src/lib/protocols/rsh.c b/src/lib/protocols/rsh.c new file mode 100644 index 000000000..3344c8660 --- /dev/null +++ b/src/lib/protocols/rsh.c @@ -0,0 +1,163 @@ +/* + * rsh.c + * + * Copyright (C) 2022 - ntop.org + * + * This file is part of nDPI, an open source deep packet inspection + * library based on the OpenDPI and PACE technology by ipoque GmbH + * + * nDPI is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * nDPI 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 + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with nDPI. If not, see <http://www.gnu.org/licenses/>. + * + */ + +#include "ndpi_protocol_ids.h" + +#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_RSH + +#include "ndpi_api.h" + +#define RSH_DEFAULT_PORT 514 + +static void ndpi_int_rsh_add_connection(struct ndpi_detection_module_struct * ndpi_struct, + struct ndpi_flow_struct * flow) +{ + ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_UNKNOWN, NDPI_PROTOCOL_RSH, + NDPI_CONFIDENCE_DPI); +} + +void ndpi_search_rsh(struct ndpi_detection_module_struct * ndpi_struct, + struct ndpi_flow_struct *flow) +{ + struct ndpi_packet_struct *packet = &ndpi_struct->packet; + + /* Use a port based approach for midstream detection. */ + if (packet->tcp->dest == RSH_DEFAULT_PORT || + packet->tcp->source == RSH_DEFAULT_PORT) + { + if (packet->payload[packet->payload_packet_len - 1] == '\n') + { + if (flow->packet_counter > 5) + { + ndpi_int_rsh_add_connection(ndpi_struct, flow); + flow->protos.rsh.client_username[0] = '\0'; + flow->protos.rsh.server_username[0] = '\0'; + flow->protos.rsh.command[0] = '\0'; + } + return; + } + } + + switch (flow->packet_counter) + { + case 1: + if (packet->payload_packet_len >= 2 && + packet->payload_packet_len <= 6) + { + int i; + + for (i = 0; i < packet->payload_packet_len - 1; ++i) + { + if (ndpi_isdigit(packet->payload[i]) == 0) + { + NDPI_EXCLUDE_PROTO(ndpi_struct, flow); + return; + } + } + } else { + NDPI_EXCLUDE_PROTO(ndpi_struct, flow); + } + return; + + case 2: + if (packet->payload_packet_len < 3 || + packet->payload[packet->payload_packet_len - 1] != '\0') + { + NDPI_EXCLUDE_PROTO(ndpi_struct, flow); + return; + } + + { + char const * dissected_info[] = { (char const *)packet->payload, + NULL, NULL }; + size_t i; + + for (i = 1; i < NDPI_ARRAY_LENGTH(dissected_info); ++i) + { + dissected_info[i] = memchr(dissected_info[i - 1], '\0', + packet->payload_packet_len - + (dissected_info[i - 1] - dissected_info[0])); + + if (dissected_info[i] == NULL || + ndpi_is_printable_buffer((uint8_t const *)dissected_info[i - 1], + (dissected_info[i] - dissected_info[i - 1])) == 0) + { + NDPI_EXCLUDE_PROTO(ndpi_struct, flow); + return; + } + + if (dissected_info[i] - dissected_info[0] >= packet->payload_packet_len - 1) + { + if (dissected_info[NDPI_ARRAY_LENGTH(dissected_info) - 1] == NULL) + { + NDPI_EXCLUDE_PROTO(ndpi_struct, flow); + return; + } + break; + } + + dissected_info[i]++; + } + + ndpi_int_rsh_add_connection(ndpi_struct, flow); + + strncpy(flow->protos.rsh.client_username, dissected_info[0], + ndpi_min(NDPI_ARRAY_LENGTH(flow->protos.rsh.client_username), + (unsigned long)(dissected_info[1] - dissected_info[0]))); + strncpy(flow->protos.rsh.server_username, dissected_info[1], + ndpi_min(NDPI_ARRAY_LENGTH(flow->protos.rsh.server_username), + (unsigned long)(dissected_info[2] - dissected_info[1]))); + strncpy(flow->protos.rsh.command, dissected_info[2], + ndpi_min(NDPI_ARRAY_LENGTH(flow->protos.rsh.command), + (unsigned long)packet->payload_packet_len - + (unsigned long)(dissected_info[2] - dissected_info[0]))); + + char str[64]; + if (snprintf(str, NDPI_ARRAY_LENGTH(str), "User '%s' executing '%s'", + flow->protos.rsh.server_username, + flow->protos.rsh.command) < 0) + { + str[0] = '\0'; + } + ndpi_set_risk(ndpi_struct, flow, NDPI_CLEAR_TEXT_CREDENTIALS, str); + } + return; + + default: + NDPI_EXCLUDE_PROTO(ndpi_struct, flow); + return; + } +} + + +void init_rsh_dissector(struct ndpi_detection_module_struct * ndpi_struct, + u_int32_t * id, NDPI_PROTOCOL_BITMASK * detection_bitmask) +{ + ndpi_set_bitmask_protocol_detection("RSH", ndpi_struct, detection_bitmask, *id, + NDPI_PROTOCOL_RSH, ndpi_search_rsh, + NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION, + SAVE_DETECTION_BITMASK_AS_UNKNOWN, + ADD_TO_DETECTION_BITMASK); + + *id += 1; +} |