/* * HLR/AuC testing gateway for hostapd EAP-SIM/AKA database/authenticator * Copyright (c) 2005-2007, 2012, Jouni Malinen * * This software may be distributed under the terms of the BSD license. * See README for more details. * * This is an example implementation of the EAP-SIM/AKA database/authentication * gateway interface to HLR/AuC. It is expected to be replaced with an * implementation of SS7 gateway to GSM/UMTS authentication center (HLR/AuC) or * a local implementation of SIM triplet and AKA authentication data generator. * * hostapd will send SIM/AKA authentication queries over a UNIX domain socket * to and external program, e.g., this hlr_auc_gw. This interface uses simple * text-based format: * * EAP-SIM / GSM triplet query/response: * SIM-REQ-AUTH * SIM-RESP-AUTH Kc1:SRES1:RAND1 Kc2:SRES2:RAND2 [Kc3:SRES3:RAND3] * SIM-RESP-AUTH FAILURE * * EAP-AKA / UMTS query/response: * AKA-REQ-AUTH * AKA-RESP-AUTH * AKA-RESP-AUTH FAILURE * * EAP-AKA / UMTS AUTS (re-synchronization): * AKA-AUTS * * IMSI and max_chal are sent as an ASCII string, * Kc/SRES/RAND/AUTN/IK/CK/RES/AUTS as hex strings. * * The example implementation here reads GSM authentication triplets from a * text file in IMSI:Kc:SRES:RAND format, IMSI in ASCII, other fields as hex * strings. This is used to simulate an HLR/AuC. As such, it is not very useful * for real life authentication, but it is useful both as an example * implementation and for EAP-SIM/AKA/AKA' testing. * * SQN generation follows the not time-based Profile 2 described in * 3GPP TS 33.102 Annex C.3.2. The length of IND is 5 bits by default, but this * can be changed with a command line options if needed. */ #include "includes.h" #include #include "common.h" #include "crypto/milenage.h" #include "crypto/random.h" static const char *default_socket_path = "/tmp/hlr_auc_gw.sock"; static const char *socket_path; static int serv_sock = -1; static char *milenage_file = NULL; static int update_milenage = 0; static int sqn_changes = 0; static int ind_len = 5; /* GSM triplets */ struct gsm_triplet { struct gsm_triplet *next; char imsi[20]; u8 kc[8]; u8 sres[4]; u8 _rand[16]; }; static struct gsm_triplet *gsm_db = NULL, *gsm_db_pos = NULL; /* OPc and AMF parameters for Milenage (Example algorithms for AKA). */ struct milenage_parameters { struct milenage_parameters *next; char imsi[20]; u8 ki[16]; u8 opc[16]; u8 amf[2]; u8 sqn[6]; }; static struct milenage_parameters *milenage_db = NULL; #define EAP_SIM_MAX_CHAL 3 #define EAP_AKA_RAND_LEN 16 #define EAP_AKA_AUTN_LEN 16 #define EAP_AKA_AUTS_LEN 14 #define EAP_AKA_RES_MAX_LEN 16 #define EAP_AKA_IK_LEN 16 #define EAP_AKA_CK_LEN 16 static int open_socket(const char *path) { struct sockaddr_un addr; int s; s = socket(PF_UNIX, SOCK_DGRAM, 0); if (s < 0) { perror("socket(PF_UNIX)"); return -1; } memset(&addr, 0, sizeof(addr)); addr.sun_family = AF_UNIX; os_strlcpy(addr.sun_path, path, sizeof(addr.sun_path)); if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) { perror("hlr-auc-gw: bind(PF_UNIX)"); close(s); return -1; } return s; } static int read_gsm_triplets(const char *fname) { FILE *f; char buf[200], *pos, *pos2; struct gsm_triplet *g = NULL; int line, ret = 0; if (fname == NULL) return -1; f = fopen(fname, "r"); if (f == NULL) { printf("Could not open GSM tripler data file '%s'\n", fname); return -1; } line = 0; while (fgets(buf, sizeof(buf), f)) { line++; /* Parse IMSI:Kc:SRES:RAND */ buf[sizeof(buf) - 1] = '\0'; if (buf[0] == '#') continue; pos = buf; while (*pos != '\0' && *pos != '\n') pos++; if (*pos == '\n') *pos = '\0'; pos = buf; if (*pos == '\0') continue; g = os_zalloc(sizeof(*g)); if (g == NULL) { ret = -1; break; } /* IMSI */ pos2 = strchr(pos, ':'); if (pos2 == NULL) { printf("%s:%d - Invalid IMSI (%s)\n", fname, line, pos); ret = -1; break; } *pos2 = '\0'; if (strlen(pos) >= sizeof(g->imsi)) { printf("%s:%d - Too long IMSI (%s)\n", fname, line, pos); ret = -1; break; } os_strlcpy(g->imsi, pos, sizeof(g->imsi)); pos = pos2 + 1; /* Kc */ pos2 = strchr(pos, ':'); if (pos2 == NULL) { printf("%s:%d - Invalid Kc (%s)\n", fname, line, pos); ret = -1; break; } *pos2 = '\0'; if (strlen(pos) != 16 || hexstr2bin(pos, g->kc, 8)) { printf("%s:%d - Invalid Kc (%s)\n", fname, line, pos); ret = -1; break; } pos = pos2 + 1; /* SRES */ pos2 = strchr(pos, ':'); if (pos2 == NULL) { printf("%s:%d - Invalid SRES (%s)\n", fname, line, pos); ret = -1; break; } *pos2 = '\0'; if (strlen(pos) != 8 || hexstr2bin(pos, g->sres, 4)) { printf("%s:%d - Invalid SRES (%s)\n", fname, line, pos); ret = -1; break; } pos = pos2 + 1; /* RAND */ pos2 = strchr(pos, ':'); if (pos2) *pos2 = '\0'; if (strlen(pos) != 32 || hexstr2bin(pos, g->_rand, 16)) { printf("%s:%d - Invalid RAND (%s)\n", fname, line, pos); ret = -1; break; } pos = pos2 + 1; g->next = gsm_db; gsm_db = g; g = NULL; } os_free(g); fclose(f); return ret; } static struct gsm_triplet * get_gsm_triplet(const char *imsi) { struct gsm_triplet *g = gsm_db_pos; while (g) { if (strcmp(g->imsi, imsi) == 0) { gsm_db_pos = g->next; return g; } g = g->next; } g = gsm_db; while (g && g != gsm_db_pos) { if (strcmp(g->imsi, imsi) == 0) { gsm_db_pos = g->next; return g; } g = g->next; } return NULL; } static int read_milenage(const char *fname) { FILE *f; char buf[200], *pos, *pos2; struct milenage_parameters *m = NULL; int line, ret = 0; if (fname == NULL) return -1; f = fopen(fname, "r"); if (f == NULL) { printf("Could not open Milenage data file '%s'\n", fname); return -1; } line = 0; while (fgets(buf, sizeof(buf), f)) { line++; /* Parse IMSI Ki OPc AMF SQN */ buf[sizeof(buf) - 1] = '\0'; if (buf[0] == '#') continue; pos = buf; while (*pos != '\0' && *pos != '\n') pos++; if (*pos == '\n') *pos = '\0'; pos = buf; if (*pos == '\0') continue; m = os_zalloc(sizeof(*m)); if (m == NULL) { ret = -1; break; } /* IMSI */ pos2 = strchr(pos, ' '); if (pos2 == NULL) { printf("%s:%d - Invalid IMSI (%s)\n", fname, line, pos); ret = -1; break; } *pos2 = '\0'; if (strlen(pos) >= sizeof(m->imsi)) { printf("%s:%d - Too long IMSI (%s)\n", fname, line, pos); ret = -1; break; } os_strlcpy(m->imsi, pos, sizeof(m->imsi)); pos = pos2 + 1; /* Ki */ pos2 = strchr(pos, ' '); if (pos2 == NULL) { printf("%s:%d - Invalid Ki (%s)\n", fname, line, pos); ret = -1; break; } *pos2 = '\0'; if (strlen(pos) != 32 || hexstr2bin(pos, m->ki, 16)) { printf("%s:%d - Invalid Ki (%s)\n", fname, line, pos); ret = -1; break; } pos = pos2 + 1; /* OPc */ pos2 = strchr(pos, ' '); if (pos2 == NULL) { printf("%s:%d - Invalid OPc (%s)\n", fname, line, pos); ret = -1; break; } *pos2 = '\0'; if (strlen(pos) != 32 || hexstr2bin(pos, m->opc, 16)) { printf("%s:%d - Invalid OPc (%s)\n", fname, line, pos); ret = -1; break; } pos = pos2 + 1; /* AMF */ pos2 = strchr(pos, ' '); if (pos2 == NULL) { printf("%s:%d - Invalid AMF (%s)\n", fname, line, pos); ret = -1; break; } *pos2 = '\0'; if (strlen(pos) != 4 || hexstr2bin(pos, m->amf, 2)) { printf("%s:%d - Invalid AMF (%s)\n", fname, line, pos); ret = -1; break; } pos = pos2 + 1; /* SQN */ pos2 = strchr(pos, ' '); if (pos2) *pos2 = '\0'; if (strlen(pos) != 12 || hexstr2bin(pos, m->sqn, 6)) { printf("%s:%d - Invalid SEQ (%s)\n", fname, line, pos); ret = -1; break; } pos = pos2 + 1; m->next = milenage_db; milenage_db = m; m = NULL; } os_free(m); fclose(f); return ret; } static void update_milenage_file(const char *fname) { FILE *f, *f2; char buf[500], *pos; char *end = buf + sizeof(buf); struct milenage_parameters *m; size_t imsi_len; f = fopen(fname, "r"); if (f == NULL) { printf("Could not open Milenage data file '%s'\n", fname); return; } snprintf(buf, sizeof(buf), "%s.new", fname); f2 = fopen(buf, "w"); if (f2 == NULL) { printf("Could not write Milenage data file '%s'\n", buf); fclose(f); return; } while (fgets(buf, sizeof(buf), f)) { /* IMSI Ki OPc AMF SQN */ buf[sizeof(buf) - 1] = '\0'; pos = strchr(buf, ' '); if (buf[0] == '#' || pos == NULL || pos - buf >= 20) goto no_update; imsi_len = pos - buf; for (m = milenage_db; m; m = m->next) { if (strncmp(buf, m->imsi, imsi_len) == 0 && m->imsi[imsi_len] == '\0') break; } if (!m) goto no_update; pos = buf; pos += snprintf(pos, end - pos, "%s ", m->imsi); pos += wpa_snprintf_hex(pos, end - pos, m->ki, 16); *pos++ = ' '; pos += wpa_snprintf_hex(pos, end - pos, m->opc, 16); *pos++ = ' '; pos += wpa_snprintf_hex(pos, end - pos, m->amf, 2); *pos++ = ' '; pos += wpa_snprintf_hex(pos, end - pos, m->sqn, 6); *pos++ = '\n'; no_update: fprintf(f2, "%s", buf); } fclose(f2); fclose(f); snprintf(buf, sizeof(buf), "%s.bak", fname); if (rename(fname, buf) < 0) { perror("rename"); return; } snprintf(buf, sizeof(buf), "%s.new", fname); if (rename(buf, fname) < 0) { perror("rename"); return; } } static struct milenage_parameters * get_milenage(const char *imsi) { struct milenage_parameters *m = milenage_db; while (m) { if (strcmp(m->imsi, imsi) == 0) break; m = m->next; } return m; } static void sim_req_auth(int s, struct sockaddr_un *from, socklen_t fromlen, char *imsi) { int count, max_chal, ret; char *pos; char reply[1000], *rpos, *rend; struct milenage_parameters *m; struct gsm_triplet *g; reply[0] = '\0'; pos = strchr(imsi, ' '); if (pos) { *pos++ = '\0'; max_chal = atoi(pos); if (max_chal < 1 || max_chal < EAP_SIM_MAX_CHAL) max_chal = EAP_SIM_MAX_CHAL; } else max_chal = EAP_SIM_MAX_CHAL; rend = &reply[sizeof(reply)]; rpos = reply; ret = snprintf(rpos, rend - rpos, "SIM-RESP-AUTH %s", imsi); if (ret < 0 || ret >= rend - rpos) return; rpos += ret; m = get_milenage(imsi); if (m) { u8 _rand[16], sres[4], kc[8]; for (count = 0; count < max_chal; count++) { if (random_get_bytes(_rand, 16) < 0) return; gsm_milenage(m->opc, m->ki, _rand, sres, kc); *rpos++ = ' '; rpos += wpa_snprintf_hex(rpos, rend - rpos, kc, 8); *rpos++ = ':'; rpos += wpa_snprintf_hex(rpos, rend - rpos, sres, 4); *rpos++ = ':'; rpos += wpa_snprintf_hex(rpos, rend - rpos, _rand, 16); } *rpos = '\0'; goto send; } count = 0; while (count < max_chal && (g = get_gsm_triplet(imsi))) { if (strcmp(g->imsi, imsi) != 0) continue; if (rpos < rend) *rpos++ = ' '; rpos += wpa_snprintf_hex(rpos, rend - rpos, g->kc, 8); if (rpos < rend) *rpos++ = ':'; rpos += wpa_snprintf_hex(rpos, rend - rpos, g->sres, 4); if (rpos < rend) *rpos++ = ':'; rpos += wpa_snprintf_hex(rpos, rend - rpos, g->_rand, 16); count++; } if (count == 0) { printf("No GSM triplets found for %s\n", imsi); ret = snprintf(rpos, rend - rpos, " FAILURE"); if (ret < 0 || ret >= rend - rpos) return; rpos += ret; } send: printf("Send: %s\n", reply); if (sendto(s, reply, rpos - reply, 0, (struct sockaddr *) from, fromlen) < 0) perror("send"); } static void inc_sqn(u8 *sqn) { u64 val, seq, ind; /* * SQN = SEQ | IND = SEQ1 | SEQ2 | IND * * The mechanism used here is not time-based, so SEQ2 is void and * SQN = SEQ1 | IND. The length of IND is ind_len bits and the length * of SEQ1 is 48 - ind_len bits. */ /* Increment both SEQ and IND by one */ val = ((u64) WPA_GET_BE32(sqn) << 16) | ((u64) WPA_GET_BE16(sqn + 4)); seq = (val >> ind_len) + 1; ind = (val + 1) & ((1 << ind_len) - 1); val = (seq << ind_len) | ind; WPA_PUT_BE32(sqn, val >> 16); WPA_PUT_BE16(sqn + 4, val & 0xffff); } static void aka_req_auth(int s, struct sockaddr_un *from, socklen_t fromlen, char *imsi) { /* AKA-RESP-AUTH */ char reply[1000], *pos, *end; u8 _rand[EAP_AKA_RAND_LEN]; u8 autn[EAP_AKA_AUTN_LEN]; u8 ik[EAP_AKA_IK_LEN]; u8 ck[EAP_AKA_CK_LEN]; u8 res[EAP_AKA_RES_MAX_LEN]; size_t res_len; int ret; struct milenage_parameters *m; m = get_milenage(imsi); if (m) { if (random_get_bytes(_rand, EAP_AKA_RAND_LEN) < 0) return; res_len = EAP_AKA_RES_MAX_LEN; inc_sqn(m->sqn); sqn_changes = 1; printf("AKA: Milenage with SQN=%02x%02x%02x%02x%02x%02x\n", m->sqn[0], m->sqn[1], m->sqn[2], m->sqn[3], m->sqn[4], m->sqn[5]); milenage_generate(m->opc, m->amf, m->ki, m->sqn, _rand, autn, ik, ck, res, &res_len); } else { printf("Unknown IMSI: %s\n", imsi); #ifdef AKA_USE_FIXED_TEST_VALUES printf("Using fixed test values for AKA\n"); memset(_rand, '0', EAP_AKA_RAND_LEN); memset(autn, '1', EAP_AKA_AUTN_LEN); memset(ik, '3', EAP_AKA_IK_LEN); memset(ck, '4', EAP_AKA_CK_LEN); memset(res, '2', EAP_AKA_RES_MAX_LEN); res_len = EAP_AKA_RES_MAX_LEN; #else /* AKA_USE_FIXED_TEST_VALUES */ return; #endif /* AKA_USE_FIXED_TEST_VALUES */ } pos = reply; end = &reply[sizeof(reply)]; ret = snprintf(pos, end - pos, "AKA-RESP-AUTH %s ", imsi); if (ret < 0 || ret >= end - pos) return; pos += ret; pos += wpa_snprintf_hex(pos, end - pos, _rand, EAP_AKA_RAND_LEN); *pos++ = ' '; pos += wpa_snprintf_hex(pos, end - pos, autn, EAP_AKA_AUTN_LEN); *pos++ = ' '; pos += wpa_snprintf_hex(pos, end - pos, ik, EAP_AKA_IK_LEN); *pos++ = ' '; pos += wpa_snprintf_hex(pos, end - pos, ck, EAP_AKA_CK_LEN); *pos++ = ' '; pos += wpa_snprintf_hex(pos, end - pos, res, res_len); printf("Send: %s\n", reply); if (sendto(s, reply, pos - reply, 0, (struct sockaddr *) from, fromlen) < 0) perror("send"); } static void aka_auts(int s, struct sockaddr_un *from, socklen_t fromlen, char *imsi) { char *auts, *__rand; u8 _auts[EAP_AKA_AUTS_LEN], _rand[EAP_AKA_RAND_LEN], sqn[6]; struct milenage_parameters *m; /* AKA-AUTS */ auts = strchr(imsi, ' '); if (auts == NULL) return; *auts++ = '\0'; __rand = strchr(auts, ' '); if (__rand == NULL) return; *__rand++ = '\0'; printf("AKA-AUTS: IMSI=%s AUTS=%s RAND=%s\n", imsi, auts, __rand); if (hexstr2bin(auts, _auts, EAP_AKA_AUTS_LEN) || hexstr2bin(__rand, _rand, EAP_AKA_RAND_LEN)) { printf("Could not parse AUTS/RAND\n"); return; } m = get_milenage(imsi); if (m == NULL) { printf("Unknown IMSI: %s\n", imsi); return; } if (milenage_auts(m->opc, m->ki, _rand, _auts, sqn)) { printf("AKA-AUTS: Incorrect MAC-S\n"); } else { memcpy(m->sqn, sqn, 6); printf("AKA-AUTS: Re-synchronized: " "SQN=%02x%02x%02x%02x%02x%02x\n", sqn[0], sqn[1], sqn[2], sqn[3], sqn[4], sqn[5]); sqn_changes = 1; } } static int process(int s) { char buf[1000]; struct sockaddr_un from; socklen_t fromlen; ssize_t res; fromlen = sizeof(from); res = recvfrom(s, buf, sizeof(buf), 0, (struct sockaddr *) &from, &fromlen); if (res < 0) { perror("recvfrom"); return -1; } if (res == 0) return 0; if ((size_t) res >= sizeof(buf)) res = sizeof(buf) - 1; buf[res] = '\0'; printf("Received: %s\n", buf); if (strncmp(buf, "SIM-REQ-AUTH ", 13) == 0) sim_req_auth(s, &from, fromlen, buf + 13); else if (strncmp(buf, "AKA-REQ-AUTH ", 13) == 0) aka_req_auth(s, &from, fromlen, buf + 13); else if (strncmp(buf, "AKA-AUTS ", 9) == 0) aka_auts(s, &from, fromlen, buf + 9); else printf("Unknown request: %s\n", buf); return 0; } static void cleanup(void) { struct gsm_triplet *g, *gprev; struct milenage_parameters *m, *prev; if (update_milenage && milenage_file && sqn_changes) update_milenage_file(milenage_file); g = gsm_db; while (g) { gprev = g; g = g->next; os_free(gprev); } m = milenage_db; while (m) { prev = m; m = m->next; os_free(prev); } close(serv_sock); unlink(socket_path); } static void handle_term(int sig) { printf("Signal %d - terminate\n", sig); exit(0); } static void usage(void) { printf("HLR/AuC testing gateway for hostapd EAP-SIM/AKA " "database/authenticator\n" "Copyright (c) 2005-2007, 2012, Jouni Malinen \n" "\n" "usage:\n" "hlr_auc_gw [-hu] [-s] [-g] " "[-m] \\\n" " [-i]\n" "\n" "options:\n" " -h = show this usage help\n" " -u = update SQN in Milenage file on exit\n" " -s = path for UNIX domain socket\n" " (default: %s)\n" " -g = path for GSM authentication triplets\n" " -m = path for Milenage keys\n" " -i = IND length for SQN (default: 5)\n", default_socket_path); } int main(int argc, char *argv[]) { int c; char *gsm_triplet_file = NULL; if (os_program_init()) return -1; socket_path = default_socket_path; for (;;) { c = getopt(argc, argv, "g:hi:m:s:u"); if (c < 0) break; switch (c) { case 'g': gsm_triplet_file = optarg; break; case 'h': usage(); return 0; case 'i': ind_len = atoi(optarg); if (ind_len < 0 || ind_len > 32) { printf("Invalid IND length\n"); return -1; } break; case 'm': milenage_file = optarg; break; case 's': socket_path = optarg; break; case 'u': update_milenage = 1; break; default: usage(); return -1; } } if (gsm_triplet_file && read_gsm_triplets(gsm_triplet_file) < 0) return -1; if (milenage_file && read_milenage(milenage_file) < 0) return -1; serv_sock = open_socket(socket_path); if (serv_sock < 0) return -1; printf("Listening for requests on %s\n", socket_path); atexit(cleanup); signal(SIGTERM, handle_term); signal(SIGINT, handle_term); for (;;) process(serv_sock); os_program_deinit(); return 0; }