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extract sm_c1_t3 in preparation to use AES128 engine

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matthias.ringwald@gmail.com 2013-11-11 21:45:29 +00:00
parent eb71d41a8d
commit 9168dfeb6e
1 changed files with 34 additions and 27 deletions
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61
example/libusb/ble_server.c
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@ -319,32 +319,9 @@ static void sm_c1_t1(key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uin
printf("t1' "); hexdump(t1, 16);
}
// Endianess:
// - preq, pres as found in SM PDUs (little endian), we flip it here
// - everything else in big endian incl. result
static void sm_c1(key_t k, key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, bd_addr_t ia, bd_addr_t ra, key_t c1){
printf("iat %u: ia ", iat);
print_bd_addr(ia);
printf("rat %u: ra ", rat);
print_bd_addr(ra);
key_t t1;
sm_c1_t1(r, preq, pres, iat, rat, t1);
printf("k "); hexdump(k, 16);
// setup aes decryption
unsigned long rk[RKLENGTH(KEYBITS)];
int nrounds = rijndaelSetupEncrypt(rk, &k[0], KEYBITS);
// t2 = e(k, r_xor_p1)
key_t t2;
rijndaelEncrypt(rk, nrounds, t1, t2);
printf("t2' "); hexdump(t2, 16);
// p2 = padding || ia || ra
// calculate arguments for second AES128 operation in C1 function
static void sm_c1_t3(key_t t2, bd_addr_t ia, bd_addr_t ra, key_t t3){
// p2 = padding || ia || ra
// "The least significant octet of ra becomes the least significant octet of p2 and
// the most significant octet of padding becomes the most significant octet of p2.
// For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is
@ -357,12 +334,42 @@ static void sm_c1(key_t k, key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t ia
printf("p2 "); hexdump(p2, 16);
// c1 = e(k, t2_xor_p2)
key_t t3;
int i;
for (i=0;i<16;i++){
t3[i] = t2[i] ^ p2[i];
}
printf("t3' "); hexdump(t3, 16);
}
//
// Endianess:
// - preq, pres as found in SM PDUs (little endian), we flip it here
// - everything else in big endian incl. result
static void sm_c1(key_t k, key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, bd_addr_t ia, bd_addr_t ra, key_t c1){
printf("iat %u: ia ", iat);
print_bd_addr(ia);
printf("rat %u: ra ", rat);
print_bd_addr(ra);
printf("k "); hexdump(k, 16);
// first operation
key_t t1;
sm_c1_t1(r, preq, pres, iat, rat, t1);
unsigned long rk[RKLENGTH(KEYBITS)];
int nrounds = rijndaelSetupEncrypt(rk, &k[0], KEYBITS);
// t2 = e(k, r_xor_p1)
key_t t2;
rijndaelEncrypt(rk, nrounds, t1, t2);
printf("t2' "); hexdump(t2, 16);
// second operation
key_t t3;
sm_c1_t3(t2, ia, ra, t3);
rijndaelEncrypt(rk, nrounds, t3, c1);