unit: Add test for SAE Hash to Curve derivation

unit/test-sae.c

@@ -34,6 +34,7 @@
 #include "src/mpdu.h"
 #include "src/sae.h"
 #include "src/auth-proto.h"
+#include "src/crypto.h"
 
 struct test_handshake_state {
 	struct handshake_state super;
@@ -627,6 +628,244 @@ static void test_end_to_end(const void *arg)
 	l_free(td2);
 }
 
+static enum l_checksum_type ecc_hash_from_prime_len(size_t prime_len)
+{
+	if (prime_len <= 256 / 8)
+		return L_CHECKSUM_SHA256;
+
+	if (prime_len <= 384 / 8)
+		return L_CHECKSUM_SHA384;
+
+	return L_CHECKSUM_SHA512;
+}
+
+static void test_pt_pwe(const void *data)
+{
+	static const char *ssid = "byteme";
+	static const char *identifier = "psk4internet";
+	static const char *password = "mekmitasdigoat";
+	static const uint8_t mac1[] = { 0x00, 0x09, 0x5b, 0x66, 0xec, 0x1e };
+	static const uint8_t mac2[] = { 0x00, 0x0b, 0x6b, 0xd9, 0x02, 0x46 };
+	static const uint8_t prk[] = {
+		0x3b, 0xd5, 0x3f, 0xe9, 0x22, 0x3d, 0xc0, 0x28,
+		0x0f, 0xbf, 0xce, 0x17, 0xd7, 0xa3, 0x56, 0x40,
+		0x64, 0xe2, 0x0f, 0x48, 0xc6, 0xec, 0x72, 0x24,
+		0x6c, 0xe3, 0x67, 0xb5, 0x56, 0x9a, 0x22, 0xaf,
+	};
+	static const uint8_t okm1[] = {
+		0xa5, 0x04, 0x44, 0x69, 0xab, 0x16, 0xf2, 0x5b,
+		0x6a, 0xbf, 0x1e, 0x0e, 0x37, 0xa3, 0x6b, 0x56,
+		0xf5, 0x0b, 0xe7, 0x33, 0x69, 0x05, 0x3d, 0xf8,
+		0xdb, 0x87, 0x98, 0x9a, 0x6b, 0x66, 0xfd, 0x1a,
+		0x49, 0x1f, 0x1c, 0xda, 0xcb, 0xd0, 0x79, 0x31,
+		0x62, 0x0f, 0x83, 0x00, 0x8f, 0xfc, 0x0e, 0xcc,
+	};
+	static const uint8_t u1_data[] = {
+		0xdc, 0x94, 0x1b, 0xc3, 0xc6, 0xa2, 0xb4, 0x94,
+		0x8b, 0x6c, 0x61, 0xd5, 0x55, 0x90, 0xec, 0xb1,
+		0xf0, 0xc5, 0x1c, 0x4b, 0x1b, 0xeb, 0xaf, 0xf6,
+		0x77, 0xe5, 0x93, 0x69, 0x8d, 0x5a, 0x53, 0xc6,
+	};
+	static const uint8_t okm2[] = {
+		0x9b, 0x4e, 0x0d, 0x5b, 0x18, 0x79, 0xf2, 0x53,
+		0xc5, 0x31, 0x96, 0x15, 0x09, 0x9b, 0x05, 0xae,
+		0xc5, 0xb0, 0x6f, 0xa5, 0xe7, 0x88, 0xbc, 0xfd,
+		0x1e, 0x9e, 0xa6, 0x0d, 0x33, 0x43, 0x69, 0x27,
+		0x19, 0x08, 0x14, 0xc3, 0x22, 0xa6, 0x25, 0x85,
+		0xc9, 0x3c, 0x57, 0x7b, 0xba, 0xa3, 0xd3, 0x07,
+	};
+	static const uint8_t u2_data[] = {
+		0x1b, 0x83, 0x75, 0xa5, 0x18, 0xbc, 0x21, 0x39,
+		0x6a, 0xd6, 0xa6, 0x5e, 0x55, 0x97, 0xe0, 0xbf,
+		0x80, 0xd7, 0x93, 0xb6, 0xd6, 0x6e, 0x25, 0x34,
+		0xa6, 0xe7, 0xdf, 0xe3, 0xee, 0x22, 0x61, 0x6f,
+	};
+	static const uint8_t p1x_data[] = {
+		0xa0, 0x7c, 0x26, 0x07, 0x64, 0xa1, 0x34, 0x45,
+		0xff, 0x8c, 0xd9, 0x7c, 0x5a, 0xcc, 0x64, 0x4e,
+		0x71, 0x19, 0xbd, 0xe5, 0x1b, 0xad, 0x42, 0x58,
+		0x3e, 0xed, 0x6f, 0x41, 0x09, 0x63, 0x9e, 0x6b,
+	};
+	static const uint8_t p1y_data[] = {
+		0x3b, 0xdc, 0x8d, 0xf0, 0xd3, 0x23, 0x37, 0x93,
+		0x6c, 0x74, 0xdf, 0x60, 0x49, 0x33, 0xa4, 0x54,
+		0x14, 0x22, 0x51, 0xc5, 0x3c, 0x57, 0x6c, 0x03,
+		0x51, 0xb2, 0x8d, 0xea, 0xf9, 0x42, 0x8d, 0x7e,
+	};
+	static const uint8_t p2x_data[] = {
+		0x72, 0xcd, 0x2a, 0x96, 0x7a, 0x83, 0x7f, 0xea,
+		0x50, 0x51, 0xf0, 0x13, 0x3d, 0xb4, 0x62, 0x27,
+		0x77, 0x5b, 0xa0, 0x9f, 0x7b, 0x6d, 0xfb, 0x99,
+		0xae, 0x7a, 0x8e, 0xf2, 0x2c, 0x7d, 0x34, 0xa0,
+	};
+	static const uint8_t p2y_data[] = {
+		0x86, 0x43, 0x90, 0xd7, 0x97, 0xd3, 0x52, 0xb3,
+		0x68, 0xd3, 0x11, 0xaf, 0x51, 0x5b, 0xde, 0x11,
+		0x6f, 0xe5, 0x44, 0x59, 0xfe, 0xc8, 0x67, 0xee,
+		0x18, 0xa8, 0xa1, 0x61, 0x9c, 0xa3, 0xff, 0x59,
+	};
+	static const uint8_t ptx_data[] = {
+		0xb6, 0xe3, 0x8c, 0x98, 0x75, 0x0c, 0x68, 0x4b,
+		0x5d, 0x17, 0xc3, 0xd8, 0xc9, 0xa4, 0x10, 0x0b,
+		0x39, 0x93, 0x12, 0x79, 0x18, 0x7c, 0xa6, 0xcc,
+		0xed, 0x5f, 0x37, 0xef, 0x46, 0xdd, 0xfa, 0x97,
+	};
+	static const uint8_t pty_data[] = {
+		0x56, 0x87, 0xe9, 0x72, 0xe5, 0x0f, 0x73, 0xe3,
+		0x89, 0x88, 0x61, 0xe7, 0xed, 0xad, 0x21, 0xbe,
+		0xa7, 0xd5, 0xf6, 0x22, 0xdf, 0x88, 0x24, 0x3b,
+		0xb8, 0x04, 0x92, 0x0a, 0xe8, 0xe6, 0x47, 0xfa,
+	};
+	static const uint8_t val_data[] = {
+		0xbb, 0x7f, 0x9c, 0xac, 0x5a, 0xa8, 0xb7, 0x2c,
+		0x02, 0xb5, 0xda, 0xac, 0xc2, 0x77, 0x1a, 0xbe,
+		0x74, 0xe7, 0x26, 0x04, 0x61, 0x22, 0x95, 0xec,
+		0xa2, 0xce, 0x18, 0x36, 0x3a, 0xe9, 0xa9, 0x27,
+	};
+	static const uint8_t pwex_data[] = {
+		0xc9, 0x30, 0x49, 0xb9, 0xe6, 0x40, 0x00, 0xf8,
+		0x48, 0x20, 0x16, 0x49, 0xe9, 0x99, 0xf2, 0xb5,
+		0xc2, 0x2d, 0xea, 0x69, 0xb5, 0x63, 0x2c, 0x9d,
+		0xf4, 0xd6, 0x33, 0xb8, 0xaa, 0x1f, 0x6c, 0x1e,
+	};
+	static const uint8_t pwey_data[] = {
+		0x73, 0x63, 0x4e, 0x94, 0xb5, 0x3d, 0x82, 0xe7,
+		0x38, 0x3a, 0x8d, 0x25, 0x81, 0x99, 0xd9, 0xdc,
+		0x1a, 0x5e, 0xe8, 0x26, 0x9d, 0x06, 0x03, 0x82,
+		0xcc, 0xbf, 0x33, 0xe6, 0x14, 0xff, 0x59, 0xa0,
+	};
+
+	const struct l_ecc_curve *curve;
+	struct l_ecc_scalar *u1;
+	struct l_ecc_scalar *u2;
+	struct l_ecc_scalar *val;
+	struct l_ecc_point *p1;
+	struct l_ecc_point *p2;
+	struct l_ecc_point *pt;
+	struct l_ecc_point *pwe;
+	enum l_checksum_type hash;
+	size_t hash_len;
+	uint8_t pwd_seed[64]; /* SHA512 is the biggest possible right now */
+	uint8_t pwd_value[128];
+	size_t pwd_value_len;
+	uint8_t ubuf[64];
+	uint64_t num[L_ECC_MAX_DIGITS];
+	uint8_t zero[64] = { 0 };
+	uint8_t val_buf[32];
+	uint8_t sorted_macs[12];
+
+	curve = l_ecc_curve_get_ike_group(19);
+	assert(curve);
+
+	hash = ecc_hash_from_prime_len(l_ecc_curve_get_scalar_bytes(curve));
+	hash_len = l_checksum_digest_length(hash);
+
+	assert(hash_len == 32);
+
+	/* pwd-seed = HKDF-Extract(ssid, password [|| identifier]) */
+	assert(hkdf_extract(hash, ssid, strlen(ssid), 2, pwd_seed,
+				password, strlen(password),
+				identifier, strlen(identifier)));
+	assert(!memcmp(pwd_seed, prk, sizeof(prk)));
+
+	/* len = olen(p) + floor(olen(p)/2) */
+	pwd_value_len = l_ecc_curve_get_scalar_bytes(curve);
+	pwd_value_len += pwd_value_len / 2;
+
+	/*
+	 * pwd-value = HKDF-Expand(pwd-seed, "SAE Hash to Element u1 P1", len)
+	 */
+	assert(hkdf_expand(hash, pwd_seed, hash_len,
+				"SAE Hash to Element u1 P1",
+				pwd_value, pwd_value_len));
+	assert(!memcmp(pwd_value, okm1, sizeof(okm1)));
+
+	u1 = l_ecc_scalar_new_modp(curve, pwd_value, pwd_value_len);
+	assert(u1);
+
+	assert(l_ecc_scalar_get_data(u1, ubuf, sizeof(ubuf)) ==
+			(ssize_t) sizeof(u1_data));
+	assert(!memcmp(ubuf, u1_data, sizeof(u1_data)));
+
+	/*
+	 * pwd-value = HKDF-Expand(pwd-seed, "SAE Hash to Element u2 P2", len)
+	 */
+	assert(hkdf_expand(hash, pwd_seed, hash_len,
+				"SAE Hash to Element u2 P2",
+				pwd_value, pwd_value_len));
+	assert(!memcmp(pwd_value, okm2, sizeof(okm2)));
+
+	u2 = l_ecc_scalar_new_modp(curve, pwd_value, pwd_value_len);
+	assert(u2);
+
+	assert(l_ecc_scalar_get_data(u2, ubuf, sizeof(ubuf)) ==
+			(ssize_t) sizeof(u2_data));
+	assert(!memcmp(ubuf, u2_data, sizeof(u2_data)));
+
+	p1 = l_ecc_point_from_sswu(u1);
+	assert(p1);
+
+	assert(l_ecc_point_get_x(p1, num, sizeof(num)) > 0);
+	assert(!memcmp(num, p1x_data, sizeof(p1x_data)));
+
+	assert(l_ecc_point_get_y(p1, num, sizeof(num)) > 0);
+	assert(!memcmp(num, p1y_data, sizeof(p1y_data)));
+
+	p2 = l_ecc_point_from_sswu(u2);
+	assert(p2);
+
+	assert(l_ecc_point_get_x(p2, num, sizeof(num)) > 0);
+	assert(!memcmp(num, p2x_data, sizeof(p2x_data)));
+
+	assert(l_ecc_point_get_y(p2, num, sizeof(num)) > 0);
+	assert(!memcmp(num, p2y_data, sizeof(p2y_data)));
+
+	pt = l_ecc_point_new(curve);
+	assert(pt);
+	assert(l_ecc_point_add(pt, p1, p2));
+
+	assert(l_ecc_point_get_x(pt, num, sizeof(num)) > 0);
+	assert(!memcmp(num, ptx_data, sizeof(ptx_data)));
+
+	assert(l_ecc_point_get_y(pt, num, sizeof(num)) > 0);
+	assert(!memcmp(num, pty_data, sizeof(pty_data)));
+
+	l_ecc_point_free(p1);
+	l_ecc_point_free(p2);
+	l_ecc_scalar_free(u1);
+	l_ecc_scalar_free(u2);
+
+	if (memcmp(mac1, mac2, 6) > 0) {
+		memcpy(sorted_macs, mac1, 6);
+		memcpy(sorted_macs + 6, mac2, 6);
+	} else {
+		memcpy(sorted_macs, mac2, 6);
+		memcpy(sorted_macs + 6, mac1, 6);
+	}
+
+	assert(hkdf_extract(hash, zero, hash_len, 1, val_buf,
+				sorted_macs, sizeof(sorted_macs)));
+	val = l_ecc_scalar_new_reduced_1_to_n(curve, val_buf, sizeof(val_buf));
+	assert(val);
+	assert(l_ecc_scalar_get_data(val, ubuf, sizeof(ubuf)) ==
+			(ssize_t) sizeof(val_data));
+	assert(!memcmp(ubuf, val_data, sizeof(val_data)));
+
+	pwe = l_ecc_point_new(curve);
+	assert(pwe);
+	assert(l_ecc_point_multiply(pwe, val, pt));
+
+	assert(l_ecc_point_get_x(pwe, num, sizeof(num)) > 0);
+	assert(!memcmp(num, pwex_data, sizeof(pwex_data)));
+
+	assert(l_ecc_point_get_y(pwe, num, sizeof(num)) > 0);
+	assert(!memcmp(num, pwey_data, sizeof(pwey_data)));
+
+	l_ecc_point_free(pt);
+	l_ecc_scalar_free(val);
+	l_ecc_point_free(pwe);
+}
+
 int main(int argc, char *argv[])
 {
 	l_test_init(&argc, &argv);
@@ -651,6 +890,8 @@ int main(int argc, char *argv[])
 	l_test_add("SAE confirm after accept", test_confirm_after_accept, NULL);
 	l_test_add("SAE end-to-end", test_end_to_end, NULL);
 
+	l_test_add("SAE pt-pwe", test_pt_pwe, NULL);
+
 done:
 	return l_test_run();
 }