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extract sm_c1_t1 in preparation to use AES128 engine

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matthias.ringwald@gmail.com 2013-11-11 21:38:07 +00:00
parent 552dcccdf8
commit eb71d41a8d
1 changed files with 32 additions and 25 deletions
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53
example/libusb/ble_server.c
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@ -292,16 +292,8 @@ static void sm_dhk(key_t ir, key_t dhk){
sm_d1(ir, 3, 0, dhk);
}
// 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);
// calculate arguments for first AES128 operation in C1 function
static void sm_c1_t1(key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, key_t t1){
// p1 = pres || preq || rat’ || iat’
// "The octet of iat’ becomes the least significant octet of p1 and the most signifi-
@ -317,27 +309,28 @@ static void sm_c1(key_t k, key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t ia
p1[15] = iat;
printf("p1 "); hexdump(p1, 16);
// 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
// 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6.
key_t p2;
memset(p2, 0, 16);
memcpy(&p2[4], ia, 6);
memcpy(&p2[10], ra, 6);
printf("p2 "); hexdump(p2, 16);
printf("r "); hexdump(r, 16);
// t1 = r xor p1
int i;
key_t t1;
for (i=0;i<16;i++){
t1[i] = r[i] ^ p1[i];
}
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);
@ -351,7 +344,21 @@ static void sm_c1(key_t k, key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t ia
printf("t2' "); hexdump(t2, 16);
// 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
// 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6.
key_t p2;
memset(p2, 0, 16);
memcpy(&p2[4], ia, 6);
memcpy(&p2[10], ra, 6);
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];
}