Piotr Krysik | 9e2e835 | 2018-02-27 12:16:25 +0100 | [diff] [blame] | 1 | #pragma once |
| 2 | |
| 3 | /*! \defgroup auth GSM/GPRS/3G Authentication |
| 4 | * @{ |
| 5 | * \file auth.h */ |
| 6 | |
| 7 | #include <stdint.h> |
| 8 | |
| 9 | #include <osmocom/core/linuxlist.h> |
| 10 | #include <osmocom/core/utils.h> |
| 11 | |
| 12 | #define OSMO_A5_MAX_KEY_LEN_BYTES (128/8) |
| 13 | #define OSMO_MILENAGE_IND_BITLEN_MAX 28 |
| 14 | |
| 15 | /*! Authentication Type (GSM/UMTS) */ |
| 16 | enum osmo_sub_auth_type { |
| 17 | OSMO_AUTH_TYPE_NONE = 0x00, |
| 18 | OSMO_AUTH_TYPE_GSM = 0x01, |
| 19 | OSMO_AUTH_TYPE_UMTS = 0x02, |
| 20 | }; |
| 21 | |
| 22 | extern const struct value_string osmo_sub_auth_type_names[]; |
| 23 | /*static inline const char *osmo_sub_auth_type_name(enum osmo_sub_auth_type val) |
| 24 | { return get_value_string(osmo_sub_auth_type_names, val); } |
| 25 | */ |
| 26 | |
| 27 | /*! Authentication Algorithm. |
| 28 | * See also osmo_auth_alg_name() and osmo_auth_alg_parse(). */ |
| 29 | enum osmo_auth_algo { |
| 30 | OSMO_AUTH_ALG_NONE, |
| 31 | OSMO_AUTH_ALG_COMP128v1, |
| 32 | OSMO_AUTH_ALG_COMP128v2, |
| 33 | OSMO_AUTH_ALG_COMP128v3, |
| 34 | OSMO_AUTH_ALG_XOR, |
| 35 | OSMO_AUTH_ALG_MILENAGE, |
| 36 | _OSMO_AUTH_ALG_NUM, |
| 37 | }; |
| 38 | |
| 39 | /*! permanent (secret) subscriber auth data */ |
| 40 | struct osmo_sub_auth_data { |
| 41 | enum osmo_sub_auth_type type; |
| 42 | enum osmo_auth_algo algo; |
| 43 | union { |
| 44 | struct { |
| 45 | uint8_t opc[16]; /*!< operator invariant value */ |
| 46 | uint8_t k[16]; /*!< secret key of the subscriber */ |
| 47 | uint8_t amf[2]; |
| 48 | uint64_t sqn; /*!< sequence number (in: prev sqn; out: used sqn) */ |
| 49 | int opc_is_op; /*!< is the OPC field OPC (0) or OP (1) ? */ |
| 50 | unsigned int ind_bitlen; /*!< nr of bits not in SEQ, only SQN */ |
| 51 | unsigned int ind; /*!< which IND slot to use an SQN from */ |
| 52 | uint64_t sqn_ms; /*!< sqn from AUTS (output value only) */ |
| 53 | } umts; |
| 54 | struct { |
| 55 | uint8_t ki[OSMO_A5_MAX_KEY_LEN_BYTES]; /*!< secret key */ |
| 56 | } gsm; |
| 57 | } u; |
| 58 | }; |
| 59 | |
| 60 | /* data structure describing a computed auth vector, generated by AuC */ |
| 61 | struct osmo_auth_vector { |
| 62 | uint8_t rand[16]; /*!< random challenge */ |
| 63 | uint8_t autn[16]; /*!< authentication nonce */ |
| 64 | uint8_t ck[16]; /*!< ciphering key */ |
| 65 | uint8_t ik[16]; /*!< integrity key */ |
| 66 | uint8_t res[16]; /*!< authentication result */ |
| 67 | uint8_t res_len; /*!< length (in bytes) of res */ |
| 68 | uint8_t kc[8]; /*!< Kc for GSM encryption (A5) */ |
| 69 | uint8_t sres[4]; /*!< authentication result for GSM */ |
| 70 | uint32_t auth_types; /*!< bitmask of OSMO_AUTH_TYPE_* */ |
| 71 | }; |
| 72 | |
| 73 | /* An implementation of an authentication algorithm */ |
| 74 | struct osmo_auth_impl { |
| 75 | struct llist_head list; |
| 76 | enum osmo_auth_algo algo; /*!< algorithm we implement */ |
| 77 | const char *name; /*!< name of the implementation */ |
| 78 | unsigned int priority; /*!< priority value (resp. othe implementations */ |
| 79 | |
| 80 | /*! callback for generate authentication vectors */ |
| 81 | int (*gen_vec)(struct osmo_auth_vector *vec, |
| 82 | struct osmo_sub_auth_data *aud, |
| 83 | const uint8_t *_rand); |
| 84 | |
| 85 | /* callback for generationg auth vectors + re-sync */ |
| 86 | int (*gen_vec_auts)(struct osmo_auth_vector *vec, |
| 87 | struct osmo_sub_auth_data *aud, |
| 88 | const uint8_t *auts, const uint8_t *rand_auts, |
| 89 | const uint8_t *_rand); |
| 90 | }; |
| 91 | |
| 92 | int osmo_auth_gen_vec(struct osmo_auth_vector *vec, |
| 93 | struct osmo_sub_auth_data *aud, const uint8_t *_rand); |
| 94 | |
| 95 | int osmo_auth_gen_vec_auts(struct osmo_auth_vector *vec, |
| 96 | struct osmo_sub_auth_data *aud, |
| 97 | const uint8_t *auts, const uint8_t *rand_auts, |
| 98 | const uint8_t *_rand); |
| 99 | |
| 100 | int osmo_auth_register(struct osmo_auth_impl *impl); |
| 101 | |
| 102 | int osmo_auth_load(const char *path); |
| 103 | |
| 104 | int osmo_auth_supported(enum osmo_auth_algo algo); |
| 105 | void osmo_c4(uint8_t *ck, const uint8_t *kc); |
| 106 | const char *osmo_auth_alg_name(enum osmo_auth_algo alg); |
| 107 | //enum osmo_auth_algo osmo_auth_alg_parse(const char *name); |
| 108 | |
| 109 | void osmo_auth_c3(uint8_t kc[], const uint8_t ck[], const uint8_t ik[]); |
| 110 | |
| 111 | /* @} */ |