#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <inttypes.h>

#include <osmocom/crypt/auth.h>
#include <osmocom/core/utils.h>

int milenage_opc_gen(uint8_t *opc, const uint8_t *k, const uint8_t *op);

static void dump_auth_vec(struct osmo_auth_vector *vec)
{
	printf("RAND:\t%s\n", osmo_hexdump(vec->rand, sizeof(vec->rand)));

	if (vec->auth_types & OSMO_AUTH_TYPE_UMTS) {
		printf("AUTN:\t%s\n", osmo_hexdump(vec->autn, sizeof(vec->autn)));
		printf("IK:\t%s\n", osmo_hexdump(vec->ik, sizeof(vec->ik)));
		printf("CK:\t%s\n", osmo_hexdump(vec->ck, sizeof(vec->ck)));
		printf("RES:\t%s\n", osmo_hexdump(vec->res, vec->res_len));
	}

	if (vec->auth_types & OSMO_AUTH_TYPE_GSM) {
		printf("SRES:\t%s\n", osmo_hexdump(vec->sres, sizeof(vec->sres)));
		printf("Kc:\t%s\n", osmo_hexdump(vec->kc, sizeof(vec->kc)));
	}
}

static struct osmo_sub_auth_data test_aud = {
	.type = OSMO_AUTH_TYPE_UMTS,
	.algo = OSMO_AUTH_ALG_MILENAGE,
	.u.umts = {
		.opc = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
			 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
		.k =   { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
			 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
		.amf = { 0x00, 0x00 },
		.sqn = 0x21,
		.ind_bitlen = 0,
		.ind = 0,
	},
};

static int opc_test(const struct osmo_sub_auth_data *aud)
{
	int rc;
	uint8_t opc[16];
#if 0
	const uint8_t op[16] = { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
				 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f };
#else
	const uint8_t op[16] = { 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0 };
#endif

	printf("MILENAGE supported: %d\n",
	       osmo_auth_supported(osmo_auth_alg_parse("MILENAGE")));

	rc = milenage_opc_gen(opc, aud->u.umts.k, op);

	printf("OP:\t%s\n", osmo_hexdump(op, sizeof(op)));
	printf("OPC:\t%s\n", osmo_hexdump(opc, sizeof(opc)));
	return rc;
}

#define RECALC_AUTS 0
#if RECALC_AUTS
typedef uint8_t u8;
extern int milenage_f2345(const u8 *opc, const u8 *k, const u8 *_rand,
			  u8 *res, u8 *ck, u8 *ik, u8 *ak, u8 *akstar);
extern int milenage_f1(const u8 *opc, const u8 *k, const u8 *_rand,
		       const u8 *sqn, const u8 *amf, u8 *mac_a, u8 *mac_s);
#endif

int main(int argc, char **argv)
{
	struct osmo_auth_vector _vec;
	struct osmo_auth_vector *vec = &_vec;
	uint8_t _rand[16];
	int rc;

#if 0
	srand(time(NULL));
	*(uint32_t *)&_rand[0] = rand();
	*(uint32_t *)(&_rand[4]) = rand();
	*(uint32_t *)(&_rand[8]) = rand();
	*(uint32_t *)(&_rand[12]) = rand();
#else
	memset(_rand, 0, sizeof(_rand));
#endif
	memset(vec, 0, sizeof(*vec));

	/* ind_bitlen == 0 uses the legacy mode of incrementing SQN by 1.
	 * sqn == 0x21 == 33, so the SQN used to generate the vector is
	 * sqn + 1 == 34. */
	rc = osmo_auth_gen_vec(vec, &test_aud, _rand);
	if (rc < 0) {
		fprintf(stderr, "error generating auth vector\n");
		exit(1);
	}

	dump_auth_vec(vec);

	/* The USIM generates an AUTS to tell us it is at SQN == 31:
	 *
	 * SQN_MS = 00000000001f
	 *
	 * AUTS = Conc(SQN_MS) || MAC-S
	 * Conc(SQN_MS) = SQN_MS ⊕ f5*[K](RAND)
	 * MAC-S = f1*[K] (SQN MS || RAND || AMF)
	 *
	 *    K = 000102030405060708090a0b0c0d0e0f
	 * RAND = 00000000000000000000000000000000
	 *
	 * f5*--> Conc(SQN_MS) = SQN_MS ^ f5*(K,RAND)
	 *                     = 00000000001f ^ 8711a0ec9e09
	 *                     = 8711a0ec9e16
	 * AMF = 0000 (TS 33.102 v7.0.0, 6.3.3)
	 * MAC-S = f1*[K] (SQN MS || RAND || AMF)
	 *       = f1*[K] (00000000001f || 00000000000000000000000000000000 || 0000)
	 *       = 37df17f80b384ee4
	 *
	 * AUTS = 8711a0ec9e16 || 37df17f80b384ee4
	 */
#if RECALC_AUTS
	uint8_t ak[6];
	uint8_t akstar[6];
	uint8_t opc[16];
	uint8_t k[16];
	uint8_t rand[16];
	osmo_hexparse("000102030405060708090a0b0c0d0e0f", k, sizeof(k));
	osmo_hexparse("000102030405060708090a0b0c0d0e0f", opc, sizeof(opc));
	osmo_hexparse("00000000000000000000000000000000", rand, sizeof(rand));
	milenage_f2345(opc, k, rand, NULL, NULL, NULL, ak, akstar);
	printf("ak = %s\n", osmo_hexdump_nospc(ak, sizeof(ak)));
	printf("akstar = %s\n", osmo_hexdump_nospc(akstar, sizeof(akstar)));

	uint8_t sqn_ms[6] = { 0, 0, 0, 0, 0, 31 };
	uint8_t amf[2] = {};
	uint8_t mac_s[8];
	milenage_f1(opc, k, rand, sqn_ms, amf, NULL, mac_s);
	printf("mac_s = %s\n", osmo_hexdump_nospc(mac_s, sizeof(mac_s)));
	/* verify valid AUTS resulting in SQN 31 with:
	   osmo-auc-gen -3 -a milenage -k 000102030405060708090a0b0c0d0e0f \
	                -o 000102030405060708090a0b0c0d0e0f \
	                -r 00000000000000000000000000000000 \
	                -A 8711a0ec9e1637df17f80b384ee4
	 */
#endif

	const uint8_t auts[14] = { 0x87, 0x11, 0xa0, 0xec, 0x9e, 0x16, 0x37, 0xdf,
			     0x17, 0xf8, 0x0b, 0x38, 0x4e, 0xe4 };

	/* Invoking with ind_bitlen == 0, the next SQN after 31 is 32. */
	rc = osmo_auth_gen_vec_auts(vec, &test_aud, auts, _rand, _rand);
	if (rc < 0) {
		printf("AUTS failed\n");
	} else {
		printf("AUTS success: tuple generated with SQN = %" PRIu64 "\n",
		       test_aud.u.umts.sqn);
	}

	/* Now test SQN incrementing scheme using SEQ and IND parts:
	 * with ind_bitlen == 5 and ind == 10, the next SQN after 31 is
	 * 32 + 10 == 42. */
	test_aud.u.umts.ind_bitlen = 5;
	test_aud.u.umts.ind = 10;
	rc = osmo_auth_gen_vec_auts(vec, &test_aud, auts, _rand, _rand);
	if (rc < 0)
		printf("AUTS failed\n");
	else
		printf("AUTS success: tuple generated with SQN = %" PRIu64 "\n",
		       test_aud.u.umts.sqn);

	/* And the one after that is 64 + 10 == 74 */
	rc = osmo_auth_gen_vec(vec, &test_aud, _rand);
	if (rc < 0)
		printf("generating vector failed\n");
	else
		printf("tuple generated with SQN = %" PRIu64 "\n",
		       test_aud.u.umts.sqn);

	/* And the one after *that* is 96 + 10 == 106 */
	rc = osmo_auth_gen_vec(vec, &test_aud, _rand);
	if (rc < 0)
		printf("generating vector failed\n");
	else
		printf("tuple generated with SQN = %" PRIu64 "\n",
		       test_aud.u.umts.sqn);

	opc_test(&test_aud);

	exit(0);

}