auth.h

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#pragma once
 
#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
 
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); }
 
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
 
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]; 
                        uint8_t opc_len; 
                        uint8_t k[32];  
                        uint8_t k_len;  
                        uint8_t amf[2];
                        uint64_t sqn;   
                        int opc_is_op;  
                        unsigned int ind_bitlen; 
                        unsigned int ind; 
                        uint64_t sqn_ms; 
                } umts;
                struct {
                        uint8_t ki[OSMO_A5_MAX_KEY_LEN_BYTES];  
                } 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]; 
                        uint8_t k[OSMO_A5_MAX_KEY_LEN_BYTES];   
                        uint8_t amf[2];
                        uint64_t sqn;   
                        int opc_is_op;  
                        unsigned int ind_bitlen; 
                        unsigned int ind; 
                        uint64_t sqn_ms; 
                } umts;
                struct {
                        uint8_t ki[OSMO_A5_MAX_KEY_LEN_BYTES];  
                } gsm;
        } u;
};
 
/* data structure describing a computed auth vector, generated by AuC */
struct osmo_auth_vector {
        uint8_t rand[16];       
        uint8_t autn[16];       
        uint8_t ck[OSMO_A5_MAX_KEY_LEN_BYTES];          
        uint8_t ik[OSMO_A5_MAX_KEY_LEN_BYTES];          
        uint8_t res[16];        
        uint8_t res_len;        
        uint8_t kc[8];          
        uint8_t sres[4];        
        uint32_t auth_types;    
};
 
/* An implementation of an authentication algorithm */
struct osmo_auth_impl {
        struct llist_head list;
        enum osmo_auth_algo algo; 
        const char *name;       
        unsigned int priority;  
        int (*gen_vec)(struct osmo_auth_vector *vec,
                        struct osmo_sub_auth_data2 *aud,
                        const uint8_t *_rand);
 
        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);
 
/* @} */