diff options
Diffstat (limited to 'plugins/cryptopan/cryptopan.c')
| -rw-r--r-- | plugins/cryptopan/cryptopan.c | 100 |
1 files changed, 79 insertions, 21 deletions
diff --git a/plugins/cryptopan/cryptopan.c b/plugins/cryptopan/cryptopan.c index 5eb54c7..6274c3d 100644 --- a/plugins/cryptopan/cryptopan.c +++ b/plugins/cryptopan/cryptopan.c @@ -47,6 +47,10 @@ #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> +#include <netinet/in.h> +#ifndef s6_addr32 +#define s6_addr32 __u6_addr.__u6_addr32 +#endif #include "dnscap_common.h" @@ -55,12 +59,13 @@ #include <openssl/evp.h> #include <openssl/err.h> #define USE_OPENSSL 1 +#include "edns0_ecs.c" #endif static set_iaddr_t cryptopan_set_iaddr = 0; static logerr_t* logerr; -static int only_clients = 0, only_servers = 0, dns_port = 53, encrypt_v6 = 0, decrypt = 0; +static int only_clients = 0, only_servers = 0, dns_port = 53, encrypt_v6 = 0, decrypt = 0, edns = 0; static unsigned char key[16]; static unsigned char iv[16]; static unsigned char pad[16]; @@ -94,7 +99,9 @@ void cryptopan_usage() "\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-6 En/de-crypt IPv6 addresses, not default or recommended\n"); + "\t-6 En/de-crypt IPv6 addresses, not default or recommended\n" + "\t-e Also en/de-crypt EDNS(0) Client Subnet\n" + "\t-E ONLY en/de-crypt EDNS(0) Client Subnet, not IP addresses\n"); } void cryptopan_extension(int ext, void* arg) @@ -112,7 +119,7 @@ void cryptopan_getopt(int* argc, char** argv[]) unsigned long ul; char* p; - while ((c = getopt(*argc, *argv, "?k:K:i:I:a:A:Dcsp:6")) != EOF) { + while ((c = getopt(*argc, *argv, "?k:K:i:I:a:A:Dcsp:6eE")) != EOF) { switch (c) { case 'k': if (strlen(optarg) != 16) { @@ -207,6 +214,13 @@ void cryptopan_getopt(int* argc, char** argv[]) case '6': encrypt_v6 = 1; break; + case 'e': + if (!edns) + edns = 1; + break; + case 'E': + edns = -1; + break; case '?': cryptopan_usage(); if (!optopt || optopt == '?') { @@ -396,12 +410,56 @@ static inline void _decrypt(uint32_t* in) } #endif +#ifdef USE_OPENSSL +void ecs_callback(int family, u_char* buf, size_t len) +{ + struct in6_addr in6 = IN6ADDR_ANY_INIT; + + switch (family) { + case 1: // IPv4 + if (len > sizeof(struct in_addr)) + break; + memcpy(&in6, buf, len); + decrypt ? _decrypt((uint32_t*)&in6) : _encrypt((uint32_t*)&in6); + memcpy(buf, &in6, len); + break; + case 2: // IPv6 + if (len > sizeof(struct in6_addr)) + break; + if (encrypt_v6) { + memcpy(&in6, buf, len); + if (decrypt) { + _decrypt(&in6.s6_addr32[0]); + _decrypt(&in6.s6_addr32[1]); + _decrypt(&in6.s6_addr32[2]); + _decrypt(&in6.s6_addr32[3]); + } else { + _encrypt(&in6.s6_addr32[0]); + _encrypt(&in6.s6_addr32[1]); + _encrypt(&in6.s6_addr32[2]); + _encrypt(&in6.s6_addr32[3]); + } + memcpy(buf, &in6, len); + } + break; + default: + break; + } +} +#endif + int cryptopan_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) + u_char* pkt_copy, const unsigned olen, + u_char* payload, const unsigned payloadlen) { #ifdef USE_OPENSSL + if (edns && flags & DNSCAP_OUTPUT_ISDNS && payload && payloadlen > DNS_MSG_HDR_SZ) { + parse_for_edns0_ecs(payload, payloadlen, ecs_callback); + if (edns < 0) + return 0; + } + for (;;) { if (only_clients && sport == dns_port) { if (sport != dport) { @@ -421,15 +479,15 @@ int cryptopan_filter(const char* descr, iaddr* from, iaddr* to, uint8_t proto, u case AF_INET6: if (encrypt_v6) { if (decrypt) { - _decrypt((uint32_t*)&from->u.a6); - _decrypt(((uint32_t*)&from->u.a6) + 1); // lgtm [cpp/suspicious-pointer-scaling] - _decrypt(((uint32_t*)&from->u.a6) + 2); // lgtm [cpp/suspicious-pointer-scaling] - _decrypt(((uint32_t*)&from->u.a6) + 3); // lgtm [cpp/suspicious-pointer-scaling] + _decrypt(&from->u.a6.s6_addr32[0]); + _decrypt(&from->u.a6.s6_addr32[1]); + _decrypt(&from->u.a6.s6_addr32[2]); + _decrypt(&from->u.a6.s6_addr32[3]); } else { - _encrypt((uint32_t*)&from->u.a6); - _encrypt(((uint32_t*)&from->u.a6) + 1); // lgtm [cpp/suspicious-pointer-scaling] - _encrypt(((uint32_t*)&from->u.a6) + 2); // lgtm [cpp/suspicious-pointer-scaling] - _encrypt(((uint32_t*)&from->u.a6) + 3); // lgtm [cpp/suspicious-pointer-scaling] + _encrypt(&from->u.a6.s6_addr32[0]); + _encrypt(&from->u.a6.s6_addr32[1]); + _encrypt(&from->u.a6.s6_addr32[2]); + _encrypt(&from->u.a6.s6_addr32[3]); } break; } @@ -459,15 +517,15 @@ int cryptopan_filter(const char* descr, iaddr* from, iaddr* to, uint8_t proto, u case AF_INET6: if (encrypt_v6) { if (decrypt) { - _decrypt((uint32_t*)&to->u.a6); - _decrypt(((uint32_t*)&to->u.a6) + 1); // lgtm [cpp/suspicious-pointer-scaling] - _decrypt(((uint32_t*)&to->u.a6) + 2); // lgtm [cpp/suspicious-pointer-scaling] - _decrypt(((uint32_t*)&to->u.a6) + 3); // lgtm [cpp/suspicious-pointer-scaling] + _decrypt(&to->u.a6.s6_addr32[0]); + _decrypt(&to->u.a6.s6_addr32[1]); + _decrypt(&to->u.a6.s6_addr32[2]); + _decrypt(&to->u.a6.s6_addr32[3]); } else { - _encrypt((uint32_t*)&to->u.a6); - _encrypt(((uint32_t*)&to->u.a6) + 1); // lgtm [cpp/suspicious-pointer-scaling] - _encrypt(((uint32_t*)&to->u.a6) + 2); // lgtm [cpp/suspicious-pointer-scaling] - _encrypt(((uint32_t*)&to->u.a6) + 3); // lgtm [cpp/suspicious-pointer-scaling] + _encrypt(&to->u.a6.s6_addr32[0]); + _encrypt(&to->u.a6.s6_addr32[1]); + _encrypt(&to->u.a6.s6_addr32[2]); + _encrypt(&to->u.a6.s6_addr32[3]); } break; } |