#pragma once /*! \defgroup auth GSM/GPRS/3G Authentication * @{ * \file auth.h */ #include <stdint.h> #include <osmocom/core/linuxlist.h> #include <osmocom/core/utils.h> #define OSMO_A5_MAX_KEY_LEN_BYTES (128/8) #define OSMO_MILENAGE_IND_BITLEN_MAX 28 /*! Authentication Type (GSM/UMTS) */ enum osmo_sub_auth_type { OSMO_AUTH_TYPE_NONE = 0x00, OSMO_AUTH_TYPE_GSM = 0x01, OSMO_AUTH_TYPE_UMTS = 0x02, }; extern const struct value_string osmo_sub_auth_type_names[]; static inline const char *osmo_sub_auth_type_name(enum osmo_sub_auth_type val) { return get_value_string(osmo_sub_auth_type_names, val); } /*! Authentication Algorithm. * See also osmo_auth_alg_name() and osmo_auth_alg_parse(). */ enum osmo_auth_algo { OSMO_AUTH_ALG_NONE, OSMO_AUTH_ALG_COMP128v1, OSMO_AUTH_ALG_COMP128v2, OSMO_AUTH_ALG_COMP128v3, OSMO_AUTH_ALG_XOR_3G, OSMO_AUTH_ALG_MILENAGE, OSMO_AUTH_ALG_XOR_2G, OSMO_AUTH_ALG_TUAK, _OSMO_AUTH_ALG_NUM, }; /* Backwards-compatibility. We used to call XOR-3G just "XOR" which became ambiguous when * we started to add XOR-2G support. */ #define OSMO_AUTH_ALG_XOR OSMO_AUTH_ALG_XOR_3G /*! permanent (secret) subscriber auth data */ struct osmo_sub_auth_data2 { enum osmo_sub_auth_type type; enum osmo_auth_algo algo; union { struct { /* See 3GPP TS 33.102 Section 9.3.7 Length of authentication parameters */ uint8_t opc[32]; /*!< operator invariant value */ uint8_t opc_len; /*!< OPc length (in bytes): 16 or 32 */ uint8_t k[32]; /*!< secret key of the subscriber */ uint8_t k_len; /*!< K length (in bytes): 16 or 32 */ uint8_t amf[2]; uint64_t sqn; /*!< sequence number (in: prev sqn; out: used sqn) */ int opc_is_op; /*!< is the OPC field OPC (0) or OP (1) ? */ unsigned int ind_bitlen; /*!< nr of bits not in SEQ, only SQN */ unsigned int ind; /*!< which IND slot to use an SQN from */ uint64_t sqn_ms; /*!< sqn from AUTS (output value only) */ } umts; struct { uint8_t ki[OSMO_A5_MAX_KEY_LEN_BYTES]; /*!< secret key */ } gsm; } u; }; /* deprecated older structure without support for 32-byte K/OP[c] */ struct osmo_sub_auth_data { enum osmo_sub_auth_type type; enum osmo_auth_algo algo; union { struct { uint8_t opc[16]; /*!< operator invariant value */ uint8_t k[OSMO_A5_MAX_KEY_LEN_BYTES]; /*!< secret key of the subscriber */ uint8_t amf[2]; uint64_t sqn; /*!< sequence number (in: prev sqn; out: used sqn) */ int opc_is_op; /*!< is the OPC field OPC (0) or OP (1) ? */ unsigned int ind_bitlen; /*!< nr of bits not in SEQ, only SQN */ unsigned int ind; /*!< which IND slot to use an SQN from */ uint64_t sqn_ms; /*!< sqn from AUTS (output value only) */ } umts; struct { uint8_t ki[OSMO_A5_MAX_KEY_LEN_BYTES]; /*!< secret key */ } gsm; } u; }; /* data structure describing a computed auth vector, generated by AuC */ struct osmo_auth_vector { uint8_t rand[16]; /*!< random challenge */ uint8_t autn[16]; /*!< authentication nonce */ uint8_t ck[OSMO_A5_MAX_KEY_LEN_BYTES]; /*!< ciphering key */ uint8_t ik[OSMO_A5_MAX_KEY_LEN_BYTES]; /*!< integrity key */ uint8_t res[16]; /*!< authentication result */ uint8_t res_len; /*!< length (in bytes) of res: 4..16 bytes */ uint8_t kc[8]; /*!< Kc for GSM encryption (A5) */ uint8_t sres[4]; /*!< authentication result for GSM */ uint32_t auth_types; /*!< bitmask of OSMO_AUTH_TYPE_* */ }; /* An implementation of an authentication algorithm */ struct osmo_auth_impl { struct llist_head list; enum osmo_auth_algo algo; /*!< algorithm we implement */ const char *name; /*!< name of the implementation */ unsigned int priority; /*!< priority value (resp. othe implementations */ /*! callback for generate authentication vectors */ int (*gen_vec)(struct osmo_auth_vector *vec, struct osmo_sub_auth_data2 *aud, const uint8_t *_rand); /*! callback for generating auth vectors + re-sync */ int (*gen_vec_auts)(struct osmo_auth_vector *vec, struct osmo_sub_auth_data2 *aud, const uint8_t *auts, const uint8_t *rand_auts, const uint8_t *_rand); }; int osmo_auth_gen_vec(struct osmo_auth_vector *vec, struct osmo_sub_auth_data *aud, const uint8_t *_rand) OSMO_DEPRECATED_OUTSIDE("Use osmo_auth_gen_vec2 instead"); int osmo_auth_gen_vec2(struct osmo_auth_vector *vec, struct osmo_sub_auth_data2 *aud, const uint8_t *_rand); int osmo_auth_gen_vec_auts(struct osmo_auth_vector *vec, struct osmo_sub_auth_data *aud, const uint8_t *auts, const uint8_t *rand_auts, const uint8_t *_rand) OSMO_DEPRECATED_OUTSIDE("Use osmo_auth_gen_vec_auts2 instead"); int osmo_auth_gen_vec_auts2(struct osmo_auth_vector *vec, struct osmo_sub_auth_data2 *aud, const uint8_t *auts, const uint8_t *rand_auts, const uint8_t *_rand); int osmo_auth_register(struct osmo_auth_impl *impl); int osmo_auth_load(const char *path); int osmo_auth_supported(enum osmo_auth_algo algo); void osmo_c4(uint8_t *ck, const uint8_t *kc); const char *osmo_auth_alg_name(enum osmo_auth_algo alg); enum osmo_auth_algo osmo_auth_alg_parse(const char *name); void osmo_auth_c3(uint8_t kc[], const uint8_t ck[], const uint8_t ik[]); void osmo_auth_c2(uint8_t sres[4], const uint8_t *res, size_t res_len, uint8_t sres_deriv_func); /* @} */