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Completed hf iclass unhash pre-image generation

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Finished the pre-image generation algorithm to take in account edge scenarios based on special values of z0..z7 that return the same modulo values even tho they have different original values.
This allows the generation of more than 8 pre-images when reversing hash0, showing the full set of valid pre-images per each diversified key.
This commit is contained in:
Antiklesys 2024-09-30 11:24:32 +08:00
commit 0ae7e2cd68
1 changed files with 91 additions and 33 deletions
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124
client/src/loclass/ikeys.c
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@ -522,12 +522,9 @@ void invert_hash0(uint8_t k[8]) {
uint64_t c = 0;
//Depending on their positions, values 3c, 3d, 3e, 3f can lead to additional pre-images.
//When these values are present we need to generate additional pre-images if they have the same modulo as other values
for (int n=0; n < 4; n++){
uint8_t _zn = getSixBitByte(zP, n); //handles the first 4 six-bit bytes
uint8_t _zn4 = getSixBitByte(zP, n + 4); //handles the second 4 six-bit bytes
uint8_t _zn = getSixBitByte(zP, n);
uint8_t _zn4 = getSixBitByte(zP, n + 4);
uint8_t zn = (_zn + (63 - 2 * n)) % (63 - n);
uint8_t zn4 = (_zn4 + (64 - 2 * n)) % (64 - n);
@ -536,40 +533,101 @@ void invert_hash0(uint8_t k[8]) {
pushbackSixBitByte(&c, zn4, n + 4);
}
//restore the two most significant bytes (x and y)
c |= ((uint64_t)x_array[img] << 56);
c |= ((uint64_t)y << 48);
if (g_debugMode > 0){
PrintAndLogEx(DEBUG, " | x| y|z0|z1|z2|z3|z4|z5|z6|z7|");
printState("origin_r1", c);
}
//reverse the swapZbalues function to get the original six-bit byte order
uint64_t original_z = swapZvalues(c);
//The Hydra: depending on their positions, values 0x00, 0x01, 0x02, 0x03, 0x3c, 0x3d, 0x3e, 0x3f can lead to additional pre-images.
//When these values are present we need to generate additional pre-images if they have the same modulo as other values
if (g_debugMode > 0){
PrintAndLogEx(DEBUG, " | x| y|z0|z1|z2|z3|z4|z5|z6|z7|");
printState("origin_r2", original_z);
PrintAndLogEx(INFO, "--------------------------");
}
//run pre-image through hash0
uint8_t img_div_key[8] = {0};
hash0(original_z, img_div_key); //commented to avoid log spam
// Initialize an array of pointers to uint64_t (start with one value, initialized to 0)
uint64_t* hydra_heads = (uint64_t*)malloc(sizeof(uint64_t)); // Start with one uint64_t
hydra_heads[0] = 0; // Initialize first value to 0
int heads_count = 1; // Track number of forks
//verify result, if it matches add it to the list as a valid pre-image
bool image_match = true;
for(int v=0; v<8; v++){
if(img_div_key[v] != k[v]){ //compare against input key k
image_match = false;
// Iterate 4 times as per the original loop
for (int n=0; n < 8; n++){
uint8_t hydra_head = getSixBitByte(c, n);
if(hydra_head <= (n % 4) || hydra_head >= 63-(n % 4)){
//PrintAndLogEx(INFO, _YELLOW_("Hail Hydra - Hydra Head: %02x"),hydra_head);
// Create new forks by duplicating existing uint64_t values
int new_head = heads_count * 2;
hydra_heads = (uint64_t*)realloc(hydra_heads, new_head * sizeof(uint64_t));
// Duplicate all current values and add the value to both original and new ones
for (int i = 0; i < heads_count; i++) {
// Duplicate current value
hydra_heads[heads_count + i] = hydra_heads[i];
uint8_t small_hydra_head = 0;
uint8_t big_hydra_head = 0;
uint8_t hydra_lil_spawns[4] = {0x00, 0x01, 0x02, 0x03};
uint8_t hydra_big_spawns[4] = {0x3f, 0x3e, 0x3d, 0x3c};
if(hydra_head <= n % 4){ //check if is in the lower range
//replace with big spawn in one hydra and keep small in another
small_hydra_head = hydra_head;
for(int fh = 0; fh < 4; fh++){
if(hydra_lil_spawns[fh] == hydra_head){
big_hydra_head = hydra_big_spawns[fh];
//PrintAndLogEx(INFO, _YELLOW_("Head Replacement B: %02x"),big_hydra_head);
}
}
}else if(hydra_head >= 63-(n % 4)){ //or the higher range
//replace with small in one hydra and keep big in another
big_hydra_head = hydra_head;
for(int fh = 0; fh < 4; fh++){
if(hydra_big_spawns[fh] == hydra_head){
small_hydra_head = hydra_lil_spawns[fh];
//PrintAndLogEx(INFO, _YELLOW_("Head Replacement S: %02x"),small_hydra_head);
}
}
}
// Add to both original and duplicate values
pushbackSixBitByte(&hydra_heads[i], big_hydra_head, n);
pushbackSixBitByte(&hydra_heads[heads_count + i], small_hydra_head, n);
}
// Update the count of total values
heads_count = new_head;
}else{ //no hydra head spawns
for (int i = 0; i < heads_count; i++) {
pushbackSixBitByte(&hydra_heads[i], hydra_head, n);;
}
}
}
uint8_t des_pre_image[8] = {0};
x_num_to_bytes(original_z,sizeof(original_z),des_pre_image);
if(image_match){
PrintAndLogEx(INFO, _GREEN_("Valid pre-image: ")_YELLOW_("%s"), sprint_hex(des_pre_image, sizeof(des_pre_image)));
}else if (!image_match && g_debugMode > 0){
PrintAndLogEx(INFO, _RED_("Invalid pre-image: %s"), sprint_hex(des_pre_image, sizeof(des_pre_image)));
for(int i=0; i<heads_count; i++){
//restore the two most significant bytes (x and y)
hydra_heads[i] |= ((uint64_t)x_array[img] << 56);
hydra_heads[i] |= ((uint64_t)y << 48);
if (g_debugMode > 0){
PrintAndLogEx(DEBUG, " | x| y|z0|z1|z2|z3|z4|z5|z6|z7|");
printState("origin_r1", hydra_heads[i]);
}
//reverse the swapZbalues function to get the original six-bit byte order
uint64_t original_z = swapZvalues(hydra_heads[i]);
if (g_debugMode > 0){
PrintAndLogEx(DEBUG, " | x| y|z0|z1|z2|z3|z4|z5|z6|z7|");
printState("origin_r2", original_z);
PrintAndLogEx(INFO, "--------------------------");
}
//run pre-image through hash0
uint8_t img_div_key[8] = {0};
hash0(original_z, img_div_key); //commented to avoid log spam
//verify result, if it matches add it to the list as a valid pre-image
bool image_match = true;
for(int v=0; v<8; v++){
if(img_div_key[v] != k[v]){ //compare against input key k
image_match = false;
}
}
uint8_t des_pre_image[8] = {0};
x_num_to_bytes(original_z,sizeof(original_z),des_pre_image);
if(image_match){
PrintAndLogEx(INFO, _GREEN_("Valid pre-image: ")_YELLOW_("%s"), sprint_hex(des_pre_image, sizeof(des_pre_image)));
}else if (!image_match && g_debugMode > 0){
//}else if (!image_match){ //debug only
PrintAndLogEx(INFO, _RED_("Invalid pre-image: %s"), sprint_hex(des_pre_image, sizeof(des_pre_image)));
}
// Free allocated memory
}
free(hydra_heads);
}
}