55 lines
1.2 KiB
C
55 lines
1.2 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <string.h>
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#include "auc.h"
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uint8_t *sqn_ms_derive(uint8_t *key, uint8_t *auts, uint8_t *rand_p)
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{
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/* AUTS = Conc(SQN MS ) || MAC-S
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* Conc(SQN MS ) = SQN MS ^ f5* (RAND)
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* MAC-S = f1* (SQN MS || RAND || AMF)
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*/
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uint8_t ak[6];
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uint8_t *conc_sqn_ms;
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uint8_t *mac_s;
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uint8_t mac_s_computed[MAC_S_LENGTH];
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uint8_t *sqn_ms;
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uint8_t amf[2] = { 0, 0 };
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int i;
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conc_sqn_ms = auts;
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mac_s = &auts[6];
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sqn_ms = malloc(SQN_LENGTH_OCTEST);
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SetOPc(opc);
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/* Derive AK from key and rand */
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f5star(key, rand_p, ak);
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for (i = 0; i < 6; i++) {
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sqn_ms[i] = ak[i] ^ conc_sqn_ms[i];
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}
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print_buffer("KEY : ", key, 16);
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print_buffer("RAND : ", rand_p, 16);
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print_buffer("AUTS : ", auts, 14);
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print_buffer("AK : ", ak, 6);
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print_buffer("SQN_MS : ", sqn_ms, 6);
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print_buffer("MAC_S : ", mac_s, 8);
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f1star(key, rand_p, sqn_ms, amf, mac_s_computed);
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print_buffer("MAC_S +: ", mac_s_computed, 8);
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if (memcmp(mac_s_computed, mac_s, 8) != 0) {
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fprintf(stderr, "Failed to verify computed SQN_MS\n");
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free(sqn_ms);
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return NULL;
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}
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return sqn_ms;
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}
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