129 lines
4.0 KiB
C
129 lines
4.0 KiB
C
#include "crypto1.h"
|
|
#include "nfc_util.h"
|
|
#include <furi.h>
|
|
|
|
// Algorithm from https://github.com/RfidResearchGroup/proxmark3.git
|
|
|
|
#define SWAPENDIAN(x) \
|
|
((x) = ((x) >> 8 & 0xff00ff) | ((x)&0xff00ff) << 8, (x) = (x) >> 16 | (x) << 16)
|
|
#define LF_POLY_ODD (0x29CE5C)
|
|
#define LF_POLY_EVEN (0x870804)
|
|
|
|
#define BEBIT(x, n) FURI_BIT(x, (n) ^ 24)
|
|
|
|
void crypto1_reset(Crypto1* crypto1) {
|
|
furi_assert(crypto1);
|
|
crypto1->even = 0;
|
|
crypto1->odd = 0;
|
|
}
|
|
|
|
void crypto1_init(Crypto1* crypto1, uint64_t key) {
|
|
furi_assert(crypto1);
|
|
crypto1->even = 0;
|
|
crypto1->odd = 0;
|
|
for(int8_t i = 47; i > 0; i -= 2) {
|
|
crypto1->odd = crypto1->odd << 1 | FURI_BIT(key, (i - 1) ^ 7);
|
|
crypto1->even = crypto1->even << 1 | FURI_BIT(key, i ^ 7);
|
|
}
|
|
}
|
|
|
|
uint32_t crypto1_filter(uint32_t in) {
|
|
uint32_t out = 0;
|
|
out = 0xf22c0 >> (in & 0xf) & 16;
|
|
out |= 0x6c9c0 >> (in >> 4 & 0xf) & 8;
|
|
out |= 0x3c8b0 >> (in >> 8 & 0xf) & 4;
|
|
out |= 0x1e458 >> (in >> 12 & 0xf) & 2;
|
|
out |= 0x0d938 >> (in >> 16 & 0xf) & 1;
|
|
return FURI_BIT(0xEC57E80A, out);
|
|
}
|
|
|
|
uint8_t crypto1_bit(Crypto1* crypto1, uint8_t in, int is_encrypted) {
|
|
furi_assert(crypto1);
|
|
uint8_t out = crypto1_filter(crypto1->odd);
|
|
uint32_t feed = out & (!!is_encrypted);
|
|
feed ^= !!in;
|
|
feed ^= LF_POLY_ODD & crypto1->odd;
|
|
feed ^= LF_POLY_EVEN & crypto1->even;
|
|
crypto1->even = crypto1->even << 1 | (nfc_util_even_parity32(feed));
|
|
|
|
FURI_SWAP(crypto1->odd, crypto1->even);
|
|
return out;
|
|
}
|
|
|
|
uint8_t crypto1_byte(Crypto1* crypto1, uint8_t in, int is_encrypted) {
|
|
furi_assert(crypto1);
|
|
uint8_t out = 0;
|
|
for(uint8_t i = 0; i < 8; i++) {
|
|
out |= crypto1_bit(crypto1, FURI_BIT(in, i), is_encrypted) << i;
|
|
}
|
|
return out;
|
|
}
|
|
|
|
uint32_t crypto1_word(Crypto1* crypto1, uint32_t in, int is_encrypted) {
|
|
furi_assert(crypto1);
|
|
uint32_t out = 0;
|
|
for(uint8_t i = 0; i < 32; i++) {
|
|
out |= crypto1_bit(crypto1, BEBIT(in, i), is_encrypted) << (24 ^ i);
|
|
}
|
|
return out;
|
|
}
|
|
|
|
uint32_t prng_successor(uint32_t x, uint32_t n) {
|
|
SWAPENDIAN(x);
|
|
while(n--) x = x >> 1 | (x >> 16 ^ x >> 18 ^ x >> 19 ^ x >> 21) << 31;
|
|
|
|
return SWAPENDIAN(x);
|
|
}
|
|
|
|
void crypto1_decrypt(
|
|
Crypto1* crypto,
|
|
uint8_t* encrypted_data,
|
|
uint16_t encrypted_data_bits,
|
|
uint8_t* decrypted_data) {
|
|
furi_assert(crypto);
|
|
furi_assert(encrypted_data);
|
|
furi_assert(decrypted_data);
|
|
|
|
if(encrypted_data_bits < 8) {
|
|
uint8_t decrypted_byte = 0;
|
|
decrypted_byte |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(encrypted_data[0], 0)) << 0;
|
|
decrypted_byte |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(encrypted_data[0], 1)) << 1;
|
|
decrypted_byte |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(encrypted_data[0], 2)) << 2;
|
|
decrypted_byte |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(encrypted_data[0], 3)) << 3;
|
|
decrypted_data[0] = decrypted_byte;
|
|
} else {
|
|
for(size_t i = 0; i < encrypted_data_bits / 8; i++) {
|
|
decrypted_data[i] = crypto1_byte(crypto, 0, 0) ^ encrypted_data[i];
|
|
}
|
|
}
|
|
}
|
|
|
|
void crypto1_encrypt(
|
|
Crypto1* crypto,
|
|
uint8_t* keystream,
|
|
uint8_t* plain_data,
|
|
uint16_t plain_data_bits,
|
|
uint8_t* encrypted_data,
|
|
uint8_t* encrypted_parity) {
|
|
furi_assert(crypto);
|
|
furi_assert(plain_data);
|
|
furi_assert(encrypted_data);
|
|
furi_assert(encrypted_parity);
|
|
|
|
if(plain_data_bits < 8) {
|
|
encrypted_data[0] = 0;
|
|
for(size_t i = 0; i < plain_data_bits; i++) {
|
|
encrypted_data[0] |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(plain_data[0], i)) << i;
|
|
}
|
|
} else {
|
|
memset(encrypted_parity, 0, plain_data_bits / 8 + 1);
|
|
for(uint8_t i = 0; i < plain_data_bits / 8; i++) {
|
|
encrypted_data[i] = crypto1_byte(crypto, keystream ? keystream[i] : 0, 0) ^
|
|
plain_data[i];
|
|
encrypted_parity[i / 8] |=
|
|
(((crypto1_filter(crypto->odd) ^ nfc_util_odd_parity8(plain_data[i])) & 0x01)
|
|
<< (7 - (i & 0x0007)));
|
|
}
|
|
}
|
|
}
|