| /* |
| * 3GPP AKA - Milenage algorithm (3GPP TS 35.205, .206, .207, .208) |
| * Copyright (c) 2006-2007 <j@w1.fi> |
| * |
| * This software may be distributed under the terms of the BSD license. |
| * See README for more details. |
| * |
| * This file implements an example authentication algorithm defined for 3GPP |
| * AKA. This can be used to implement a simple HLR/AuC into hlr_auc_gw to allow |
| * EAP-AKA to be tested properly with real USIM cards. |
| * |
| * This implementations assumes that the r1..r5 and c1..c5 constants defined in |
| * TS 35.206 are used, i.e., r1=64, r2=0, r3=32, r4=64, r5=96, c1=00..00, |
| * c2=00..01, c3=00..02, c4=00..04, c5=00..08. The block cipher is assumed to |
| * be AES (Rijndael). |
| */ |
| |
| #include "includes.h" |
| |
| #include "common.h" |
| #include "crypto/aes_wrap.h" |
| #include "milenage.h" |
| |
| |
| /** |
| * milenage_f1 - Milenage f1 and f1* algorithms |
| * @opc: OPc = 128-bit value derived from OP and K |
| * @k: K = 128-bit subscriber key |
| * @_rand: RAND = 128-bit random challenge |
| * @sqn: SQN = 48-bit sequence number |
| * @amf: AMF = 16-bit authentication management field |
| * @mac_a: Buffer for MAC-A = 64-bit network authentication code, or %NULL |
| * @mac_s: Buffer for MAC-S = 64-bit resync authentication code, or %NULL |
| * Returns: 0 on success, -1 on failure |
| */ |
| int milenage_f1(const u8 *opc, const u8 *k, const u8 *_rand, |
| const u8 *sqn, const u8 *amf, u8 *mac_a, u8 *mac_s) |
| { |
| u8 tmp1[16], tmp2[16], tmp3[16]; |
| int i; |
| |
| /* tmp1 = TEMP = E_K(RAND XOR OP_C) */ |
| for (i = 0; i < 16; i++) |
| tmp1[i] = _rand[i] ^ opc[i]; |
| if (aes_128_encrypt_block(k, tmp1, tmp1)) |
| return -1; |
| |
| /* tmp2 = IN1 = SQN || AMF || SQN || AMF */ |
| os_memcpy(tmp2, sqn, 6); |
| os_memcpy(tmp2 + 6, amf, 2); |
| os_memcpy(tmp2 + 8, tmp2, 8); |
| |
| /* OUT1 = E_K(TEMP XOR rot(IN1 XOR OP_C, r1) XOR c1) XOR OP_C */ |
| |
| /* rotate (tmp2 XOR OP_C) by r1 (= 0x40 = 8 bytes) */ |
| for (i = 0; i < 16; i++) |
| tmp3[(i + 8) % 16] = tmp2[i] ^ opc[i]; |
| /* XOR with TEMP = E_K(RAND XOR OP_C) */ |
| for (i = 0; i < 16; i++) |
| tmp3[i] ^= tmp1[i]; |
| /* XOR with c1 (= ..00, i.e., NOP) */ |
| |
| /* f1 || f1* = E_K(tmp3) XOR OP_c */ |
| if (aes_128_encrypt_block(k, tmp3, tmp1)) |
| return -1; |
| for (i = 0; i < 16; i++) |
| tmp1[i] ^= opc[i]; |
| if (mac_a) |
| os_memcpy(mac_a, tmp1, 8); /* f1 */ |
| if (mac_s) |
| os_memcpy(mac_s, tmp1 + 8, 8); /* f1* */ |
| return 0; |
| } |
| |
| |
| /** |
| * milenage_f2345 - Milenage f2, f3, f4, f5, f5* algorithms |
| * @opc: OPc = 128-bit value derived from OP and K |
| * @k: K = 128-bit subscriber key |
| * @_rand: RAND = 128-bit random challenge |
| * @res: Buffer for RES = 64-bit signed response (f2), or %NULL |
| * @ck: Buffer for CK = 128-bit confidentiality key (f3), or %NULL |
| * @ik: Buffer for IK = 128-bit integrity key (f4), or %NULL |
| * @ak: Buffer for AK = 48-bit anonymity key (f5), or %NULL |
| * @akstar: Buffer for AK = 48-bit anonymity key (f5*), or %NULL |
| * Returns: 0 on success, -1 on failure |
| */ |
| int milenage_f2345(const u8 *opc, const u8 *k, const u8 *_rand, |
| u8 *res, u8 *ck, u8 *ik, u8 *ak, u8 *akstar) |
| { |
| u8 tmp1[16], tmp2[16], tmp3[16]; |
| int i; |
| |
| /* tmp2 = TEMP = E_K(RAND XOR OP_C) */ |
| for (i = 0; i < 16; i++) |
| tmp1[i] = _rand[i] ^ opc[i]; |
| if (aes_128_encrypt_block(k, tmp1, tmp2)) |
| return -1; |
| |
| /* OUT2 = E_K(rot(TEMP XOR OP_C, r2) XOR c2) XOR OP_C */ |
| /* OUT3 = E_K(rot(TEMP XOR OP_C, r3) XOR c3) XOR OP_C */ |
| /* OUT4 = E_K(rot(TEMP XOR OP_C, r4) XOR c4) XOR OP_C */ |
| /* OUT5 = E_K(rot(TEMP XOR OP_C, r5) XOR c5) XOR OP_C */ |
| |
| /* f2 and f5 */ |
| /* rotate by r2 (= 0, i.e., NOP) */ |
| for (i = 0; i < 16; i++) |
| tmp1[i] = tmp2[i] ^ opc[i]; |
| tmp1[15] ^= 1; /* XOR c2 (= ..01) */ |
| /* f5 || f2 = E_K(tmp1) XOR OP_c */ |
| if (aes_128_encrypt_block(k, tmp1, tmp3)) |
| return -1; |
| for (i = 0; i < 16; i++) |
| tmp3[i] ^= opc[i]; |
| if (res) |
| os_memcpy(res, tmp3 + 8, 8); /* f2 */ |
| if (ak) |
| os_memcpy(ak, tmp3, 6); /* f5 */ |
| |
| /* f3 */ |
| if (ck) { |
| /* rotate by r3 = 0x20 = 4 bytes */ |
| for (i = 0; i < 16; i++) |
| tmp1[(i + 12) % 16] = tmp2[i] ^ opc[i]; |
| tmp1[15] ^= 2; /* XOR c3 (= ..02) */ |
| if (aes_128_encrypt_block(k, tmp1, ck)) |
| return -1; |
| for (i = 0; i < 16; i++) |
| ck[i] ^= opc[i]; |
| } |
| |
| /* f4 */ |
| if (ik) { |
| /* rotate by r4 = 0x40 = 8 bytes */ |
| for (i = 0; i < 16; i++) |
| tmp1[(i + 8) % 16] = tmp2[i] ^ opc[i]; |
| tmp1[15] ^= 4; /* XOR c4 (= ..04) */ |
| if (aes_128_encrypt_block(k, tmp1, ik)) |
| return -1; |
| for (i = 0; i < 16; i++) |
| ik[i] ^= opc[i]; |
| } |
| |
| /* f5* */ |
| if (akstar) { |
| /* rotate by r5 = 0x60 = 12 bytes */ |
| for (i = 0; i < 16; i++) |
| tmp1[(i + 4) % 16] = tmp2[i] ^ opc[i]; |
| tmp1[15] ^= 8; /* XOR c5 (= ..08) */ |
| if (aes_128_encrypt_block(k, tmp1, tmp1)) |
| return -1; |
| for (i = 0; i < 6; i++) |
| akstar[i] = tmp1[i] ^ opc[i]; |
| } |
| |
| return 0; |
| } |
| |
| |
| /** |
| * milenage_generate - Generate AKA AUTN,IK,CK,RES |
| * @opc: OPc = 128-bit operator variant algorithm configuration field (encr.) |
| * @amf: AMF = 16-bit authentication management field |
| * @k: K = 128-bit subscriber key |
| * @sqn: SQN = 48-bit sequence number |
| * @_rand: RAND = 128-bit random challenge |
| * @autn: Buffer for AUTN = 128-bit authentication token |
| * @ik: Buffer for IK = 128-bit integrity key (f4), or %NULL |
| * @ck: Buffer for CK = 128-bit confidentiality key (f3), or %NULL |
| * @res: Buffer for RES = 64-bit signed response (f2), or %NULL |
| * @res_len: Max length for res; set to used length or 0 on failure |
| */ |
| void milenage_generate(const u8 *opc, const u8 *amf, const u8 *k, |
| const u8 *sqn, const u8 *_rand, u8 *autn, u8 *ik, |
| u8 *ck, u8 *res, size_t *res_len) |
| { |
| int i; |
| u8 mac_a[8], ak[6]; |
| |
| if (*res_len < 8) { |
| *res_len = 0; |
| return; |
| } |
| if (milenage_f1(opc, k, _rand, sqn, amf, mac_a, NULL) || |
| milenage_f2345(opc, k, _rand, res, ck, ik, ak, NULL)) { |
| *res_len = 0; |
| return; |
| } |
| *res_len = 8; |
| |
| /* AUTN = (SQN ^ AK) || AMF || MAC */ |
| for (i = 0; i < 6; i++) |
| autn[i] = sqn[i] ^ ak[i]; |
| os_memcpy(autn + 6, amf, 2); |
| os_memcpy(autn + 8, mac_a, 8); |
| } |
| |
| |
| /** |
| * milenage_auts - Milenage AUTS validation |
| * @opc: OPc = 128-bit operator variant algorithm configuration field (encr.) |
| * @k: K = 128-bit subscriber key |
| * @_rand: RAND = 128-bit random challenge |
| * @auts: AUTS = 112-bit authentication token from client |
| * @sqn: Buffer for SQN = 48-bit sequence number |
| * Returns: 0 = success (sqn filled), -1 on failure |
| */ |
| int milenage_auts(const u8 *opc, const u8 *k, const u8 *_rand, const u8 *auts, |
| u8 *sqn) |
| { |
| u8 amf[2] = { 0x00, 0x00 }; /* TS 33.102 v7.0.0, 6.3.3 */ |
| u8 ak[6], mac_s[8]; |
| int i; |
| |
| if (milenage_f2345(opc, k, _rand, NULL, NULL, NULL, NULL, ak)) |
| return -1; |
| for (i = 0; i < 6; i++) |
| sqn[i] = auts[i] ^ ak[i]; |
| if (milenage_f1(opc, k, _rand, sqn, amf, NULL, mac_s) || |
| memcmp(mac_s, auts + 6, 8) != 0) |
| return -1; |
| return 0; |
| } |
| |
| |
| /** |
| * gsm_milenage - Generate GSM-Milenage (3GPP TS 55.205) authentication triplet |
| * @opc: OPc = 128-bit operator variant algorithm configuration field (encr.) |
| * @k: K = 128-bit subscriber key |
| * @_rand: RAND = 128-bit random challenge |
| * @sres: Buffer for SRES = 32-bit SRES |
| * @kc: Buffer for Kc = 64-bit Kc |
| * Returns: 0 on success, -1 on failure |
| */ |
| int gsm_milenage(const u8 *opc, const u8 *k, const u8 *_rand, u8 *sres, u8 *kc) |
| { |
| u8 res[8], ck[16], ik[16]; |
| int i; |
| |
| if (milenage_f2345(opc, k, _rand, res, ck, ik, NULL, NULL)) |
| return -1; |
| |
| for (i = 0; i < 8; i++) |
| kc[i] = ck[i] ^ ck[i + 8] ^ ik[i] ^ ik[i + 8]; |
| |
| #ifdef GSM_MILENAGE_ALT_SRES |
| os_memcpy(sres, res, 4); |
| #else /* GSM_MILENAGE_ALT_SRES */ |
| for (i = 0; i < 4; i++) |
| sres[i] = res[i] ^ res[i + 4]; |
| #endif /* GSM_MILENAGE_ALT_SRES */ |
| return 0; |
| } |
| |
| |
| /** |
| * milenage_generate - Generate AKA AUTN,IK,CK,RES |
| * @opc: OPc = 128-bit operator variant algorithm configuration field (encr.) |
| * @k: K = 128-bit subscriber key |
| * @sqn: SQN = 48-bit sequence number |
| * @_rand: RAND = 128-bit random challenge |
| * @autn: AUTN = 128-bit authentication token |
| * @ik: Buffer for IK = 128-bit integrity key (f4), or %NULL |
| * @ck: Buffer for CK = 128-bit confidentiality key (f3), or %NULL |
| * @res: Buffer for RES = 64-bit signed response (f2), or %NULL |
| * @res_len: Variable that will be set to RES length |
| * @auts: 112-bit buffer for AUTS |
| * Returns: 0 on success, -1 on failure, or -2 on synchronization failure |
| */ |
| int milenage_check(const u8 *opc, const u8 *k, const u8 *sqn, const u8 *_rand, |
| const u8 *autn, u8 *ik, u8 *ck, u8 *res, size_t *res_len, |
| u8 *auts) |
| { |
| int i; |
| u8 mac_a[8], ak[6], rx_sqn[6]; |
| const u8 *amf; |
| |
| wpa_hexdump(MSG_DEBUG, "Milenage: AUTN", autn, 16); |
| wpa_hexdump(MSG_DEBUG, "Milenage: RAND", _rand, 16); |
| |
| if (milenage_f2345(opc, k, _rand, res, ck, ik, ak, NULL)) |
| return -1; |
| |
| *res_len = 8; |
| wpa_hexdump_key(MSG_DEBUG, "Milenage: RES", res, *res_len); |
| wpa_hexdump_key(MSG_DEBUG, "Milenage: CK", ck, 16); |
| wpa_hexdump_key(MSG_DEBUG, "Milenage: IK", ik, 16); |
| wpa_hexdump_key(MSG_DEBUG, "Milenage: AK", ak, 6); |
| |
| /* AUTN = (SQN ^ AK) || AMF || MAC */ |
| for (i = 0; i < 6; i++) |
| rx_sqn[i] = autn[i] ^ ak[i]; |
| wpa_hexdump(MSG_DEBUG, "Milenage: SQN", rx_sqn, 6); |
| |
| if (os_memcmp(rx_sqn, sqn, 6) <= 0) { |
| u8 auts_amf[2] = { 0x00, 0x00 }; /* TS 33.102 v7.0.0, 6.3.3 */ |
| if (milenage_f2345(opc, k, _rand, NULL, NULL, NULL, NULL, ak)) |
| return -1; |
| wpa_hexdump_key(MSG_DEBUG, "Milenage: AK*", ak, 6); |
| for (i = 0; i < 6; i++) |
| auts[i] = sqn[i] ^ ak[i]; |
| if (milenage_f1(opc, k, _rand, sqn, auts_amf, NULL, auts + 6)) |
| return -1; |
| wpa_hexdump(MSG_DEBUG, "Milenage: AUTS", auts, 14); |
| return -2; |
| } |
| |
| amf = autn + 6; |
| wpa_hexdump(MSG_DEBUG, "Milenage: AMF", amf, 2); |
| if (milenage_f1(opc, k, _rand, rx_sqn, amf, mac_a, NULL)) |
| return -1; |
| |
| wpa_hexdump(MSG_DEBUG, "Milenage: MAC_A", mac_a, 8); |
| |
| if (os_memcmp(mac_a, autn + 8, 8) != 0) { |
| wpa_printf(MSG_DEBUG, "Milenage: MAC mismatch"); |
| wpa_hexdump(MSG_DEBUG, "Milenage: Received MAC_A", |
| autn + 8, 8); |
| return -1; |
| } |
| |
| return 0; |
| } |
