diff options
Diffstat (limited to 'src/dhcpv6.c')
| -rw-r--r-- | src/dhcpv6.c | 54 |
1 files changed, 50 insertions, 4 deletions
diff --git a/src/dhcpv6.c b/src/dhcpv6.c index a368987..86f24e0 100644 --- a/src/dhcpv6.c +++ b/src/dhcpv6.c @@ -32,6 +32,7 @@ #include <net/ethernet.h> #include "odhcp6c.h" +#include "md5.h" #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\ @@ -84,6 +85,9 @@ static int request_prefix = -1; static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE; static bool accept_reconfig = false; +// Reconfigure key +static uint8_t reconf_key[16]; + int init_dhcpv6(const char *ifname, int request_pd) @@ -470,19 +474,55 @@ static bool dhcpv6_response_is_valid(const void *buf, ssize_t len, uint8_t *end = ((uint8_t*)buf) + len, *odata; uint16_t otype, olen; - bool clientid_ok = false, serverid_ok = false; + bool clientid_ok = false, serverid_ok = false, rcauth_ok = false; size_t client_id_len, server_id_len; void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len); void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len); - dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) - if (otype == DHCPV6_OPT_CLIENTID) + dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) { + if (otype == DHCPV6_OPT_CLIENTID) { clientid_ok = (olen + 4U == client_id_len) && !memcmp( &odata[-4], client_id, client_id_len); - else if (otype == DHCPV6_OPT_SERVERID) + } else if (otype == DHCPV6_OPT_SERVERID) { serverid_ok = (olen + 4U == server_id_len) && !memcmp( &odata[-4], server_id, server_id_len); + } else if (otype == DHCPV6_OPT_AUTH && olen == -4 + + sizeof(struct dhcpv6_auth_reconfigure)) { + struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4]; + if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2) + continue; + + md5_state_t md5; + uint8_t serverhash[16], secretbytes[16], hash[16]; + memcpy(serverhash, r->key, sizeof(serverhash)); + memset(r->key, 0, sizeof(r->key)); + memcpy(secretbytes, reconf_key, sizeof(secretbytes)); + + for (size_t i = 0; i < sizeof(secretbytes); ++i) + secretbytes[i] ^= 0x36; + + md5_init(&md5); + md5_append(&md5, secretbytes, sizeof(secretbytes)); + md5_append(&md5, buf, len); + md5_finish(&md5, hash); + + for (size_t i = 0; i < sizeof(secretbytes); ++i) { + secretbytes[i] ^= 0x36; + secretbytes[i] ^= 0x5c; + } + + md5_init(&md5); + md5_append(&md5, secretbytes, sizeof(secretbytes)); + md5_append(&md5, hash, 16); + md5_finish(&md5, hash); + + rcauth_ok = !memcmp(hash, serverhash, sizeof(hash)); + } + } + + if (rep->msg_type == DHCPV6_MSG_RECONF && !rcauth_ok) + return false; return clientid_ok && (serverid_ok || server_id_len == 0); } @@ -732,6 +772,12 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig, uint32_t refresh = ntohl(*((uint32_t*)odata)); if (refresh < (uint32_t)t1) t1 = refresh; + } else if (otype == DHCPV6_OPT_AUTH && olen == -4 + + sizeof(struct dhcpv6_auth_reconfigure)) { + struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4]; + if (r->protocol == 3 && r->algorithm == 1 && + r->reconf_type == 1) + memcpy(reconf_key, r->key, sizeof(r->key)); } else if (otype != DHCPV6_OPT_CLIENTID && otype != DHCPV6_OPT_SERVERID) { odhcp6c_add_state(STATE_CUSTOM_OPTS, |