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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2021-03-04 19:22:03 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2021-03-04 20:43:22 +0000 |
commit | 22c74419e2c258319bc723351876604b3304604b (patch) | |
tree | 8c799a78d53f67388fdf42900657eda617c1306a /plugins/ipcrypt/ipcrypt.c | |
parent | Initial commit. (diff) | |
download | dnscap-upstream/2.0.0+debian.tar.xz dnscap-upstream/2.0.0+debian.zip |
Adding upstream version 2.0.0+debian.upstream/2.0.0+debian
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | plugins/ipcrypt/ipcrypt.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/plugins/ipcrypt/ipcrypt.c b/plugins/ipcrypt/ipcrypt.c new file mode 100644 index 0000000..2fadcf4 --- /dev/null +++ b/plugins/ipcrypt/ipcrypt.c @@ -0,0 +1,351 @@ +/* + * Copyright (c) 2018-2021, OARC, Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. Neither the name of the copyright holder nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include "config.h" + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> + +#include "dnscap_common.h" + +static set_iaddr_t ipcrypt_set_iaddr = 0; + +static logerr_t* logerr; +static int only_clients = 0, only_servers = 0, dns_port = 53, iterations = 1, encrypt_v6 = 0, decrypt = 0; +static uint8_t key[16]; + +/* + * ipcrypt based on Python and Go code at https://github.com/veorq/ipcrypt + * by Jean-Philippe Aumasson jeanphilippe.aumasson@gmail.com + */ + +static inline uint8_t rotl(uint8_t b, int r) +{ + return (b << r) | (b >> (8 - r)); +} + +static inline void permute_fwd(uint8_t* state) +{ + state[0] += state[1]; + state[2] += state[3]; + state[1] = rotl(state[1], 2) ^ state[0]; + state[3] = rotl(state[3], 5) ^ state[2]; + // state[1] ^= state[0]; + // state[3] ^= state[2]; + state[0] = rotl(state[0], 4) + state[3]; + // state[0] += state[3]; + state[2] += state[1]; + state[1] = rotl(state[1], 3) ^ state[2]; + state[3] = rotl(state[3], 7) ^ state[0]; + // state[1] ^= state[2]; + // state[3] ^= state[0]; + state[2] = rotl(state[2], 4); +} + +static inline void permute_bwd(uint8_t* state) +{ + state[2] = rotl(state[2], 4); + state[1] ^= state[2]; + state[3] ^= state[0]; + state[1] = rotl(state[1], 5); + state[3] = rotl(state[3], 1); + state[0] -= state[3]; + state[2] -= state[1]; + state[0] = rotl(state[0], 4); + state[1] ^= state[0]; + state[3] ^= state[2]; + state[1] = rotl(state[1], 6); + state[3] = rotl(state[3], 3); + state[0] -= state[1]; + state[2] -= state[3]; +} + +static inline void xor4(uint8_t* x, uint8_t* y) +{ + *(uint32_t*)x ^= *(uint32_t*)y; + // x[0] ^= y[0]; + // x[1] ^= y[1]; + // x[2] ^= y[2]; + // x[3] ^= y[3]; +} + +static inline void _encrypt(uint8_t* ip) +{ + int i = iterations; + for (; i; i--) { + xor4(ip, key); + permute_fwd(ip); + xor4(ip, &key[4]); + permute_fwd(ip); + xor4(ip, &key[8]); + permute_fwd(ip); + xor4(ip, &key[12]); + } +} + +static inline void _decrypt(uint8_t* ip) +{ + int i = iterations; + for (; i; i--) { + xor4(ip, &key[12]); + permute_bwd(ip); + xor4(ip, &key[8]); + permute_bwd(ip); + xor4(ip, &key[4]); + permute_bwd(ip); + xor4(ip, key); + } +} + +enum plugin_type ipcrypt_type() +{ + return plugin_filter; +} + +void usage(const char* msg) +{ + fprintf(stderr, "ipcrypt.so usage error: %s\n", msg); + exit(1); +} + +void ipcrypt_usage() +{ + fprintf(stderr, + "\nipcrypt.so options:\n" + "\t-? print these instructions and exit\n" + "\t-k <key> A 16 character long key\n" + "\t-f <file> Read the 16 first bytes from file and use as key\n" + "\t-D Decrypt IP addresses\n" + "\t-c Only en/de-crypt clients (port != 53)\n" + "\t-s Only en/de-crypt servers (port == 53)\n" + "\t-p <port> Set port for -c/-s, default 53\n" + "\t-i <num> Number of en/de-cryption iterations, default 1\n" + "\t-6 En/de-crypt IPv6 addresses, not default or recommended\n"); +} + +void ipcrypt_extension(int ext, void* arg) +{ + switch (ext) { + case DNSCAP_EXT_SET_IADDR: + ipcrypt_set_iaddr = (set_iaddr_t)arg; + break; + } +} + +void ipcrypt_getopt(int* argc, char** argv[]) +{ + int c, got_key = 0; + unsigned long ul; + char* p; + + while ((c = getopt(*argc, *argv, "?k:f:Dcsp:i:6")) != EOF) { + switch (c) { + case 'k': + if (strlen(optarg) != 16) { + usage("key must be 16 characters long"); + } + memcpy(key, optarg, 16); + got_key = 1; + break; + case 'f': { + int fd; + ssize_t r; + if ((fd = open(optarg, O_RDONLY)) < 0) { + perror("open()"); + usage("unable to open key file"); + } + if ((r = read(fd, key, 16)) < 0) { + perror("read()"); + usage("unable to read from key file"); + } + if (r != 16) { + usage("unable to read 16 bytes from key file"); + } + close(fd); + got_key = 1; + break; + } + case 'D': + decrypt = 1; + break; + case 'c': + only_clients = 1; + break; + case 's': + only_servers = 1; + break; + case 'p': + ul = strtoul(optarg, &p, 0); + if (*p != '\0' || ul < 1U || ul > 65535U) + usage("port must be an integer 1..65535"); + dns_port = (unsigned)ul; + break; + case 'i': + ul = strtoul(optarg, &p, 0); + if (*p != '\0' || ul < 1U || ul > 65535U) + usage("iterations must be an integer 1..65535"); + iterations = (unsigned)ul; + break; + case '6': + encrypt_v6 = 1; + break; + case '?': + ipcrypt_usage(); + if (!optopt || optopt == '?') { + exit(0); + } + // fallthrough + default: + exit(1); + } + } + + if (!got_key) { + usage("must have -k <key> or -f <file>"); + } + + if (only_clients && only_servers) { + usage("-c and -s options are mutually exclusive"); + } +} + +int ipcrypt_start(logerr_t* a_logerr) +{ + logerr = a_logerr; + return 0; +} + +void ipcrypt_stop() +{ +} + +int ipcrypt_open(my_bpftimeval ts) +{ + return 0; +} + +int ipcrypt_close(my_bpftimeval ts) +{ + return 0; +} + +int ipcrypt_filter(const char* descr, iaddr* from, iaddr* to, uint8_t proto, unsigned flags, + unsigned sport, unsigned dport, my_bpftimeval ts, + const u_char* pkt_copy, const unsigned olen, + const u_char* payload, const unsigned payloadlen) +{ + for (;;) { + if (only_clients && sport == dns_port) { + from = 0; + break; + } + if (only_servers && sport != dns_port) { + from = 0; + break; + } + + switch (from->af) { + case AF_INET: + decrypt ? _decrypt((uint8_t*)&from->u.a4) : _encrypt((uint8_t*)&from->u.a4); + break; + case AF_INET6: + if (encrypt_v6) { + if (decrypt) { + _decrypt((uint8_t*)&from->u.a6); + _decrypt(((uint8_t*)&from->u.a6) + 4); + _decrypt(((uint8_t*)&from->u.a6) + 8); + _decrypt(((uint8_t*)&from->u.a6) + 12); + } else { + _encrypt((uint8_t*)&from->u.a6); + _encrypt(((uint8_t*)&from->u.a6) + 4); + _encrypt(((uint8_t*)&from->u.a6) + 8); + _encrypt(((uint8_t*)&from->u.a6) + 12); + } + break; + } + default: + from = 0; + break; + } + break; + } + + for (;;) { + if (only_clients && dport == dns_port) { + to = 0; + break; + } + if (only_servers && dport != dns_port) { + to = 0; + break; + } + + switch (to->af) { + case AF_INET: + decrypt ? _decrypt((uint8_t*)&to->u.a4) : _encrypt((uint8_t*)&to->u.a4); + break; + case AF_INET6: + if (encrypt_v6) { + if (decrypt) { + _decrypt((uint8_t*)&to->u.a6); + _decrypt(((uint8_t*)&to->u.a6) + 4); + _decrypt(((uint8_t*)&to->u.a6) + 8); + _decrypt(((uint8_t*)&to->u.a6) + 12); + } else { + _encrypt((uint8_t*)&to->u.a6); + _encrypt(((uint8_t*)&to->u.a6) + 4); + _encrypt(((uint8_t*)&to->u.a6) + 8); + _encrypt(((uint8_t*)&to->u.a6) + 12); + } + break; + } + default: + to = 0; + break; + } + break; + } + + if (ipcrypt_set_iaddr && (from || to)) { + ipcrypt_set_iaddr(from, to); + } + + return 0; +} |